Description:FIELD OF THE INVENTION
The present invention relates to an electric vehicle charging device. More specifically, the present invention relates to a wireless charging system for an electric vehicle with tolerance to misalignment of the charging coil and its adaptive control.
BACKGROUND OF THE INVENTION
The electric vehicles are getting increasingly popular these days. The popularity of electric vehicles is due to the low running cost. Also, electric vehicles have far fewer moving components as compared to IC engine vehicles. Thus, maintenance and repair costs are also lower as compared to the IC engine vehicles. However, the electric vehicles run on batteries, which are expensive and need to be charged frequently, and battery charging process is time consuming. There are few charging stations and they often have only one or two charging cords. Thus, in one station only few vehicles can be charged, unlike a gas station where multiple vehicles can be refuelled at once. The wireless charging is one of the solutions to this problem.
The existing inventions lack inventiveness because they have very low efficiency. The existing invention are costly. Hence there is a need of a present invention.
OBJECTIVE OF THE INVENTION
The main objective of the present invention is to use wireless charging systems for electric vehicles.
Another objective of the present invention is to detect misalignment of coil of the wireless charging systems.
Yet another objective of the present invention is to provide efficient wireless charging systems for the battery of electric vehicles.
Yet another objective of the present invention is to tolerate the misalignment of the charging coil and provide optimize charging current even in case of misalignment.
Yet another objective of the present invention is to develop Internet of Thing based wireless charging system that provides the alert of misalignment and foreign objects.
Yet another objective of the present invention is to use machine learning to identify misalignment and foreign objects.
SUMMARY OF THE INVENTION
The present invention relates to a wireless charging system for an electric vehicle. The present invention includes a ground assembly unit, and a vehicle assembly unit. The ground assembly unit includes a power factor correction unit, a DC-DC converter, a high-frequency inverter, a primary compensation unit, a primary coil, a primary controller unit, a primary communication module, and a GSM module. The vehicle assembly unit includes a secondary coil, a secondary compensation unit, a rectifier, a battery management system a secondary controller unit, and a secondary communication module. The power factor correction unit is connected to the grid supply to draw input voltage and input current. The power factor correction unit maintains input voltage and input current in phase and reduces harmonic distortion. The DC-DC converter is connected to output of the power factor correction unit to receive controlled constant DC voltage. The DC-DC converter regulates the constant DC voltage coming from the power factor correction unit output to control the charging current (Ibat). The high-frequency inverter is connected to the DC-DC converter to receive the amplitude regulated DC-DC converter voltage (VB), the high-frequency inverter converts the DC-DC converter voltage (VB) into high frequency AC output voltage (Vinv). The primary compensation unit is connected to the high-frequency inverter to receive the high frequency AC output voltage (Vinv). and the primary compensation unit compensate the reactive power demanded by the primary coil and enhance electric power transfer efficiency. The primary coil is connected to the primary compensation unit to receive enhance high frequency AC output voltage (Vinv) and the primary coil current (Icoil) and the primary coil transfer electric power wirelessly through Phase Sync Technique based inductive coupling. The primary controller unit is connected to the DC-DC converter, the high-frequency inverter, and the primary coil. The primary controller unit receives DC-DC converter output voltage (VB), high frequency AC output voltage (Vinv) of the high-frequency inverter, and primary coil current (Icoil) from the primary coil. The primary controller unit sends control commands to the DC-DC converter to regulate amplitude of the DC-DC converter voltage to control the primary coil current (Icoil) and battery charging current (Ibat). The primary controller unit sends control commands to the high-frequency inverter to adjust the frequency of the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) based on the phase angle between high frequency AC output voltage (Vinv) and the primary coil current (Icoil) to ensure the optimal charging performance when phase angle between high frequency AC output voltage (Vinv) and the primary coil current change due to air gap and misalignment condition). The primary communication module is connected to the primary controller unit and the primary communication module transmits and receives signals with the vehicle. The GSM module is connected to the primary controller unit. The primary coil transfers the high frequency power wirelessly to the secondary coil through Phase Sync Technique based inductive coupling. The primary coil generates alternating magnetic field that induces the high frequency AC voltage and respective high frequency current in the secondary coil. The secondary compensation unit is connected to the secondary coil to receive the high frequency AC voltage and generate respective secondary coil current. The secondary compensation unit optimizes the power reception by tuning the secondary coil and secondary compensation unit to compensate the reactive power to capture maximum power from the alternating magnetic field. The rectifier is connected to the secondary compensation unit to receive the high frequency AC power output from the secondary coil that are converted to DC charging voltage (Vbat) and charging current (Ibat) by the rectifier. The battery management system is connected to the rectifier to receive stable DC charging voltage (Vbat) and charging current (Ibat) for charging a battery. The battery management system receives the DC voltage from rectifier output and feed to battery. The secondary controller unit is connected to the battery management system to receive data related to state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature. The secondary communication module is connected to the secondary controller unit. The secondary communication module sends data related to the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit through the primary communication module. Herein, the battery charging starts after a successful digital handshake between the ground assembly unit and the vehicle assembly unit with help of the secondary controller unit that starts the digital handshake after receiving green signal from the primary controller unit of detection of vehicle assembly unit that is electric vehicle. The wireless charging system tolerates misalignment up to the range of 30 %. Because of the primary controller unit that adjusts the frequency of the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) based on phase angle between high frequency AC output voltage (Vinv) and the primary coil current (Icoil), by using the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature data of the battery, when phase angle changes based on air gap and misalignment condition.
The main advantage of the present invention is that the present invention provides wireless charging systems for electric vehicles.
Another advantage of the present invention is that the present invention detects misalignment of coil of the wireless charging systems.
Yet another advantage of the present invention is that the present invention provides a low-cost, efficient wireless charging systems for the battery of electric vehicles.
Yet another advantage of the present invention is that the present invention tolerates up to 30 % misalignment of the charging coil and provide optimize charging current even in case of misalignment.
Yet another advantage of the present invention is that the present invention Internet of Thing based wireless charging system that provides the alert of misalignment on the user device through GSM module.
Yet another advantage of the present invention is that the present invention uses machine learning to identify misalignment and foreign objects.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated in and constitute a part of this specification to provide a better understanding of the invention. The drawings illustrate one embodiment of the invention and together with the description, explain the principles of the invention.
Fig. 1 illustrates a block diagram of a wireless charging system.
Fig. 2 illustrates a method of efficient charging of the battery in case of misalignment.
Fig. 3 illustrates block diagram of method of two loops control mechanisms.
DETAILED DESCRIPTION OF THE INVENTION
Definition
The terms “a” or “an” as used herein, are defined as one or as more than one. The term “plurality” as used herein, is defined as two as or more than two. The term “another” as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
The term “comprising” is not intended to limit inventions to only claiming the present invention with such comprising language. Any invention using the term comprising could be separated into one or more claims using “consisting” or “consisting of” claim language and is so intended. The term “comprising” is used interchangeably used by the terms “having” or “containing”.
Reference throughout this document to “one embodiment”, “certain embodiments”, “an embodiment”, “another embodiment”, and “yet another embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics are combined in any suitable manner in one or more embodiments without limitation.
The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
As used herein, the term "one or more" generally refers to, but not limited to, singular as well as the plural form of the term.
The drawings featured in the figures are to illustrate certain convenient embodiments of the present invention and are not to be considered as a limitation to that. Term "means" preceding a present participle of an operation indicates a desired function for which there are one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term "means" is not intended to be limiting.
As used herein, the term “Phase Sync Technique” refers to power transmission between two coils through magnetic field.
Fig 1 illustrates a block diagram of a wireless charging system (100) for an electric vehicle. The wireless charging system (100) includes a ground assembly unit (102), and a vehicle assembly unit (120). The ground assembly unit (102) includes a power factor correction unit(104), a DC-DC converter(106), a high-frequency inverter(108), a primary compensation unit (110), a primary coil (112), a primary controller unit (114), a primary communication module (116), a GSM module (118).The vehicle assembly unit (120) includes a secondary coil (122), a secondary compensation unit (124), a rectifier (126), a battery management system (128), a secondary controller unit (130), and a secondary communication module (132). The power factor correction unit (104) is connected to the grid supply to draw input voltage and input current. The DC-DC converter (106) is connected to output of the power factor correction unit (104). The high-frequency inverter (108) is connected to the DC-DC converter (106). The primary compensation unit (110) is connected to the high-frequency inverter (108). The primary coil (112) is connected to the primary compensation unit (110). The primary controller unit (114) is connected to the DC-DC converter (106), the high-frequency inverter (108), and the primary coil (112). The primary communication module (116) is connected to the primary controller unit (114). The GSM module (118) is connected to the primary controller unit (114). The primary coil (112) transfers the high frequency power wirelessly to the secondary coil (122) through Phase Sync Technique based inductive coupling. The secondary compensation unit (124) is connected to the secondary coil (122). The rectifier (126) is connected to the secondary compensation unit (124). The battery management system (128) is connected to the rectifier (126). The secondary controller unit (130) is connected to the battery management system (128) to receive data related to state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature. The secondary communication module (132) is connected to the secondary controller unit (130). The secondary communication module (132). The secondary communication module (132) communicates with the primary communication module (116) through antenna (134).
Fig 2 illustrates a flow chart for efficient charging of the battery (138) in case of misalignment. The charging of the battery (138) has been controlled through the DC-DC converter (106) and the high-frequency inverter (108). when an electric vehicle is parked on the primary coil (112), the camera (136) continuously monitors receiver coil and nearby area, and send the data to the primary controller unit (114) that analyses the secondary coil (122) position through machine learning process. If misalignment is within range of 30%, the primary controller unit (114) consider this as detection of the vehicle assembly unit (120) of the electric vehicle. The primary controller unit (114) gives green signal to the secondary controller unit (130) to communicate with battery management system (128). The secondary controller unit (130) starts the process of digital handshake between the ground assembly unit (102) and the vehicle assembly unit (120). During this stage, the secondary controller unit (130) receives state of charge, charging voltage (Vat), charging current (Ibat) and temperature data of the battery (138) from the battery management system (128). The secondary controller unit (130) sends the data related to the state of charge, charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit (114). In the first stage, the ground assembly unit(102) starts the charging process with trickle mode irrespective state of charge of the battery(138) to check the phase angle between the primary coil current(112) and the high frequency inverter output voltage The high frequency AC output voltage(Vinv) of the high-frequency inverter(108) and the primary coil current(Icoil) of the primary coil(112) are continuously monitored in real time. In this stage the primary controller unit (114) evaluates whether the high frequency AC output voltage (Vinv) from the output of the high-frequency inverter (108) and the primary coil current (Icoil) from the primary coil (112) are in phase. If the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are not in phase, adjustments are made in the frequency of the high-frequency inverter (108) by the primary controller unit (114). Once the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are in phase, the charging process transitions to the constant current-constant voltage (CC-CV) mode, depending on the battery management system (128) predefined threshold voltage (VT). If the battery (138) charging voltage (Vbat) is less than predefined threshold voltage (VT) then the battery (138) will charge in the constant current (CC) mode otherwise the battery (138) will charge in constant voltage (CV) mode. In the constant current (CC) mode, the battery charging voltage (Vbat) is monitored and the constant current (CC) reference current set by the battery management system (128). In same loop, the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) continuously monitor for phase check by the primary controller unit (114). If the phase alignment is incorrect, the primary controller unit (114) readjusts frequency of the high-frequency inverter (108) to compensate the reactive power. If the primary coil current (Icoil) leads the high frequency AC output voltage (Vinv), then the primary controller unit (114) increases the switching frequency of the high-frequency inverter (108) until the phase angle difference will be zero. In contrast, the primary coil current (Icoil) lags the high frequency AC output voltage (Vinv), then the primary controller unit (114) decreases the switching frequency of the high-frequency inverter (108) until the phase angle difference will be zero. By adjusting frequency of the high-frequency inverter (108) the primary controller unit (114) keep the phase angle difference zero thus helps in efficient charging of battery (138) even in case of misalignment that causes phase angle difference between the primary coil current (Icoil) and the high frequency AC output voltage (Vinv) which reduces the charging efficiency. Additionally, during misaligned conditions, charging current (Ibat) is reduce. The reduced battery charging current (Ibat) will be compared with reference current set by the battery management system (128) and the primary controller unit (114) will adjust the duty of the DC-DC converter (106) to reduce the error.
Fig. 3 illustrates block diagram of method of two loops control mechanisms. The outer current control loop begins with a reference battery current (Ibat,ref) set by the battery management system (128), which is compared with the actual battery charging current (Ibat_act). The resulting error signal is processed by the primary controller unit (114), which generates a DC-DC converter reference voltage (VB_ref) for the DC-DC converter (106) to regulate DC-DC converter output voltage (VB). This DC-DC converter reference voltage (VB_ref) serves as the input to the inner voltage control loop. In the inner voltage control loop, the reference voltage (VB_ref) is compared with the actual DC-DC converter voltage (VB_act), generating a voltage error signal. This error is then processed by the primary controller unit (114), producing a control signal that influences the duty cycle of the power switch of the DC-DC converter (106).
The present invention relates to a wireless charging system for an electric vehicle. The present invention includes a ground assembly unit, and a vehicle assembly unit. The ground assembly unit includes a power factor correction unit, a DC-DC converter, a high-frequency inverter, a primary compensation unit, a primary coil, a primary controller unit, a primary communication module, a GSM module. The vehicle assembly unit includes a secondary coil, a secondary compensation unit, a rectifier, a battery management system, a secondary controller unit, and a secondary communication module. The power factor correction unit is connected to the grid supply to draw input voltage and input current. The power factor correction unit maintains input voltage and input current in phase and reduces harmonic distortion. The DC-DC converter is connected to output of the power factor correction unit to receive controlled constant DC voltage. The DC-DC converter regulates the constant DC voltage coming from the power factor correction unit output to control the charging current (Ibat). The high-frequency inverter is connected to the DC-DC converter to receive the amplitude regulated DC-DC converter voltage (VB), the high-frequency inverter converts the DC-DC converter voltage (VB) into high frequency AC output voltage (Vinv). The primary compensation unit is connected to the high-frequency inverter to receive the high frequency AC output voltage (Vinv) and the primary compensation unit compensate the reactive power demanded by the primary coil and enhance electric power transfer efficiency. The primary coil is connected to the primary compensation unit to receive enhance high frequency AC output voltage (Vinv) and the primary coil current (Icoil) and the primary coil transfer electric power wirelessly through Phase Sync Technique based inductive coupling. The primary controller unit is connected to the DC-DC converter, the high-frequency inverter, and the primary coil. The primary controller unit receives DC-DC converter output voltage (VB), high frequency AC output voltage (Vinv) of the high-frequency inverter, and primary coil current (Icoil) from the primary coil. The primary controller unit sends control commands to the DC-DC converter to regulate amplitude of the DC-DC converter voltage to control the primary coil current (Icoil) and battery charging current (Ibat). The primary controller unit sends control commands to the high-frequency inverter to adjust the frequency of the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) based on the phase angle between high frequency AC output voltage (Vinv) and the primary coil current (Icoil) to ensure the optimal charging performance when phase angle between high frequency AC output voltage (Vinv) and the primary coil current change due to air gap and misalignment condition. The primary communication module is connected to the primary controller unit and the primary communication module transmits and receives signals with the vehicle. The GSM module is connected to the primary controller unit. The primary coil transfers the high frequency power wirelessly to the secondary coil through Phase Sync Technique based inductive coupling. The primary coil generates alternating magnetic field that induces the high frequency AC voltage and respective high frequency current in the secondary coil. The secondary compensation unit is connected to the secondary coil to receive the high frequency AC voltage and generate respective secondary coil current. The secondary compensation unit optimizes the power reception by tuning the secondary coil and secondary compensation unit to compensate the reactive power to capture maximum power from the alternating magnetic field. The rectifier is connected to the secondary compensation unit to receive the high frequency AC power output from the secondary coil that are converted to DC charging voltage (Vbat) and charging current (Ibat) by the rectifier. The battery management system is connected to the rectifier to receive stable DC charging voltage (Vbat) and charging current (Ibat) for charging a battery. The battery management system receives the DC voltage from rectifier output and feed to battery. The secondary controller unit is connected to the battery management system to receive data related to state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature. The secondary communication module is connected to the secondary controller unit. The secondary communication module sends data related to the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit through the primary communication module. In an embodiment, the secondary communication module communicates with the primary communication module through antenna. Herein, the battery charging starts after a successful digital handshake between the ground assembly unit and the vehicle assembly unit with help of the secondary controller unit that starts the digital handshake after receiving green signal from the primary controller unit of detection of the vehicle assembly unit that is electric vehicle. The wireless charging system tolerates misalignment up to the range of 30 %. Because of the primary controller unit that adjust the frequency of the high frequency AC output voltage(Vinv) and the primary coil current(Icoil) based on phase angle between high frequency AC output voltage(Vinv) and the primary coil current (Icoil), by using the state of charge, DC charging voltage(Vbat), charging current(Ibat) and temperature data of the battery, when phase angle changes based on air gap and misalignment condition. In an embodiment, the GSM module connects the primary controller unit with a cloud sever that is connected to the user device to access real-time charging information and to send commands to the primary controller unit for starting and stopping the charging. In an embodiment, a camera is installed on the primary coil to continuously monitor the foreign object, and upon detection of foreign object the charging is stopped immediately, and alert is sent to the user device. In an embodiment, the secondary controller unit and the primary controller unit include, but not limited to, a jetson computing unit, Raspberry pi, Arduino, Atmel controller unit. In an embodiment, the secondary communication module, the primary communication module are selected from a Wi-Fi module, Zigbee module NRF module.
In an embodiment, the present invention relates to wireless charging system for an electric vehicle. The present invention includes one or more ground assembly units, and one or more vehicle assembly units. The one or more ground assembly units include a power factor correction unit, a DC-DC converter, a high-frequency inverter, a primary compensation unit, a primary coil, a primary controller unit, a primary communication module, and a GSM module. The one or more vehicle assembly units include a secondary coil, a secondary compensation unit, a rectifier, a battery management system, a secondary controller unit, and a secondary communication module. The power factor correction unit is connected to the grid supply to draw input voltage and input current. The power factor correction unit maintains input voltage and input current in phase and reduces harmonic distortion. The DC-DC converter is connected to output of the power factor correction unit to receive controlled constant DC voltage. The DC-DC converter regulates the constant DC voltage coming from the power factor correction unit output to control the charging current (Ibat). The high-frequency inverter is connected to the DC-DC converter to receive the amplitude regulated DC-DC converter voltage (VB), the high-frequency inverter converts the DC-DC converter voltage (VB) into high frequency AC output voltage (Vinv). The primary compensation unit is connected to the high-frequency inverter to receive the high frequency AC output voltage (Vinv) and the primary compensation unit compensate the reactive power demanded by the primary coil and enhance electric power transfer efficiency. The primary coil is connected to the primary compensation unit to receive enhance high frequency AC output voltage (Vinv) and the primary coil current (Icoil) and the primary coil transfer electric power wirelessly through Phase Sync Technique based inductive coupling. The primary controller unit is connected to the DC-DC converter, the high-frequency inverter, and the primary coil. The primary controller unit receives DC-DC converter output voltage (VB), high frequency AC output voltage (Vinv) of the high-frequency inverter, and primary coil current (Icoil) from the primary coil. The primary controller unit sends control commands to the DC-DC converter to regulate amplitude of the DC-DC converter voltage to control the primary coil current (Icoil) and battery charging current (Ibat). The primary controller unit sends control commands to the high-frequency inverter to adjust the frequency of the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) based on the phase angle between high frequency AC output voltage (Vinv) and the primary coil current (Icoil) to ensure the optimal charging performance when phase angle between high frequency AC output voltage (Vinv) and the primary coil current change due to air gap and misalignment condition). The primary communication module is connected to the primary controller unit and the primary communication module transmits and receives signals with the vehicle. The GSM module is connected to the primary controller unit. The primary coil transfers the high frequency power wirelessly to the secondary coil through Phase Sync Technique based inductive coupling. The primary coil generates alternating magnetic field that induces the high frequency AC voltage and respective high frequency current in the secondary coil. The secondary compensation unit is connected to the secondary coil to receive the high frequency AC voltage and generate respective secondary coil current. The secondary compensation unit optimizes the power reception by tuning the secondary coil and secondary compensation unit to compensate the reactive power to capture maximum power from the alternating magnetic field. The rectifier is connected to the secondary compensation unit to receive the high frequency AC power output from the secondary coil that are converted to DC charging voltage (Vbat) and charging current (Ibat) by the rectifier. The battery management system is connected to the rectifier to receive stable DC charging voltage (Vbat) and charging current (Ibat) for charging a battery. The battery management system receives the DC voltage from rectifier output and feed to battery. The secondary controller unit is connected to the battery management system to receive data related to state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature. The secondary communication module is connected to the secondary controller unit. The secondary communication module sends data related to the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit through the primary communication module. In an embodiment, the secondary communication module communicates with the primary communication module through antenna. Herein, the battery charging starts after successful digital handshake between the one or more ground assembly units and the one or more vehicle assembly units with help of the secondary controller unit that start the digital handshake after receiving green signal from the primary controller unit of detection of the one or more vehicle assembly units that are electric vehicles. The wireless charging system tolerates misalignment up to the range of 30%. Because of the primary controller unit that adjusts the frequency of the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) based on phase angle between high frequency AC output voltage (Vinv) and the primary coil current (Icoil), by using the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature data of the battery, when phase angle changes based on air gap and misalignment condition. In an embodiment, the GSM module connects the primary controller unit with the cloud sever that is connected to the user device to access real-time charging information and to send commands to the primary controller unit for starting and stopping the charging. In an embodiment, a camera is installed on the primary coil to continuously monitor the foreign object, and upon detection of foreign object the charging is stopped immediately, and alert is sent to the user device. In an embodiment, the secondary controller unit and the primary controller unit include, but not limited to, a jetson computing unit, Raspberry pi, Arduino, Atmel controller unit. In an embodiment, the secondary communication module, the primary communication module are selected from a Wi-Fi module, Zigbee module NRF module.
In an embodiment, the present invention relates to a method of efficient charging of the battery in case of misalignment, the method comprising:
the charging of the battery has been controlled through the DC-DC converter and the high-frequency inverter;
when an electric vehicle is parked on the primary coil, the camera continuously monitors the receiver coil and surrounded area and sends the data to the primary controller unit that analyses the secondary coil position through machine learning process;
if misalignment is within range of 30%, the primary controller unit consider this as detection of the vehicle assembly unit of the electric vehicle;
the primary controller unit gives green signal to the secondary controller unit to communicate with battery management system;
the secondary controller unit start the process of digital handshake between the ground assembly unit and the vehicle assembly unit;
during this stage, the secondary controller unit receives state of charge, charging voltage (Vbat), charging current (Ibat) and temperature data of the battery from the battery management system;
the secondary controller unit sends the data related to the state of charge, charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit;
In the first stage, the ground assembly unit starts the charging process with trickle mode irrespective state of charge of the battery to check the phase angle between primary coil current and high frequency inverter output voltage;
The high frequency AC output voltage (Vinv) of the high-frequency inverter and the primary coil current (Icoil) of the primary coil are continuously monitored in real time;
In this stage the primary controller unit evaluates whether the high frequency AC output voltage (Vinv) from the output of the high-frequency inverter and the primary coil current (Icoil) from the primary coil are in phase;
If the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are not in phase, adjustments are made in the frequency of the high-frequency inverter by the primary controller unit;
Once the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are in phase, the charging process transitions to the constant current-constant voltage (CC-CV) mode, depending on the battery management system predefined threshold voltage (VT);
If the battery charging voltage (Vbat) is less than predefined threshold voltage (VT) then the battery will charge in the constant current (CC) mode otherwise the battery will charge in constant voltage (CV) mode;
In the constant current (CC) mode, the battery charging voltage (Vbat) is monitored and the constant current (CC) reference current set by the battery management system;
In same loop, the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) continuously monitor for phase check by the primary controller unit;
If the phase alignment is incorrect, the primary controller unit readjusts frequency of the high-frequency inverter to compensate reactive power;
If the primary coil current (Icoil) leads the high frequency AC output voltage (Vinv), then the primary controller unit increases the switching frequency of the high-frequency inverter until the phase angle difference will be zero;
In contrast, the primary coil current (Icoil) lags the high frequency AC output voltage (Vinv), then the primary controller unit decreases the switching frequency of the high-frequency inverter until the phase angle difference will be zero;
Characterized in that, by adjusting frequency of the high-frequency inverter the primary controller unit keep the phase angle difference zero thus helps in efficient charging of battery even in case of misalignment that causes phase angle difference between the primary coil current (Icoil) and the high frequency AC output voltage (Vinv) which reduces the charging efficiency,
Additionally, during misaligned conditions, charging current (Ibat) is reduce;
the reduced battery charging current (Ibat) will be compared with reference current set by the battery management system and the primary controller unit will adjust the duty of the DC-DC converter to reduce the error; and
characterized in that, the method has been developed to compensate for the 30% misalignment in any four directions.
In the preferred embodiment, the wireless charging system operates in two loops: inner loop which maintains constant output of the DC-DC converter and outer loop which controls the charging current (Ibat) by controlling the duty ratio of the DC-DC converter. Two loops control mechanism include
the outer current control loop begins with a reference battery current (Ibat,ref) set by the battery management system, which is compared with the actual battery charging current (Ibat_act);
the resulting error signal is processed by the primary controller unit, which generates a DC-DC converter reference voltage (VB_ref) for the DC-DC converter to regulate DC-DC converter output voltage (VB);
This DC-DC converter reference voltage (VB_ref) serves as the input to the inner voltage control loop;
In the inner voltage control loop, the reference voltage (VB_ref) is compared with the actual DC-DC converter voltage (VB_act), generating a voltage error signal;
this error is then processed by the primary controller unit, producing a control signal that influences the duty cycle of the power switch of the DC-DC converter;
a ramp signal is compared with the control signal, and when the control signal surpasses the ramp waveform, a controlled duty pulse is generated;
this controlled duty pulse signal is used to drive the switching device, ensuring precise current regulation;
thus, ensures that the current remains within the desired limits, thereby improving stability, reducing overshoot, and enhancing dynamic performance.
In an embodiment, the present invention relates to a method of efficient charging of the battery in case of misalignment, the method comprising:
the charging of the battery has been controlled through the DC-DC converter and the high-frequency inverter;
when an electric vehicle is parked on the primary coil, the camera continuously monitors the receiver coil and surrounded area and send the data to the primary controller unit that analyses the secondary coil position through machine learning process;
if misalignment is within range of 30%, the primary controller unit consider this as detection of the one or more vehicle assembly units of the electric vehicle;
the primary controller unit gives green signal to the secondary controller unit to communicate with battery management system;
the secondary controller unit start the process of digital handshake between the one or more ground assembly units and the one or more vehicle assembly units;
during this stage, the secondary controller unit receives state of charge, charging voltage (Vbat), charging current (Ibat) and temperature data of the battery from the battery management system;
the secondary controller unit sends the data related to the state of charge, charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit;
In the first stage, the one or more ground assembly units start the charging process with trickle mode irrespective state of charge of the battery to check the phase angle between primary coil current and high frequency inverter output voltage;
The high frequency AC output voltage (Vinv) of the high-frequency inverter and the primary coil current (Icoil) of the primary coil are continuously monitored in real time;
In this stage the primary controller unit evaluates whether the high frequency AC output voltage (Vinv) from the output of the high-frequency inverter and the primary coil current (Icoil) from the primary coil are in phase;
If the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are not in phase, adjustments are made in the frequency of the high-frequency inverter by the primary controller unit;
Once the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are in phase, the charging process transitions to the constant current-constant voltage (CC-CV) mode, depending on the battery management system predefined threshold voltage (VT);
If the battery charging voltage (Vbat) is less than predefined threshold voltage (VT) then the battery will charge in the constant current (CC) mode otherwise the battery will charge in constant voltage (CV) mode;
In the constant current (CC) mode, the battery charging voltage (Vbat) is monitored and the constant current (CC) reference current set by the battery management system;
In same loop, the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) continuously monitor for phase check by the primary controller unit;
If the phase alignment is incorrect, the primary controller unit readjusts frequency of the high-frequency inverter to compensate the reactive power.;
If the primary coil current (Icoil) leads the high frequency AC output voltage (Vinv), then the primary controller unit increases the switching frequency of the high-frequency inverter until the phase angle difference will be zero;
In contrast, the primary coil current (Icoil) lags the high frequency AC output voltage (Vinv), then the primary controller unit decreases the switching frequency of the high-frequency inverter until the phase angle difference will be zero;
Characterized in that, by adjusting frequency of the high-frequency inverter the primary controller unit keep the phase angle difference zero thus helps in efficient charging of battery even in case of misalignment that causes phase angle difference between the primary coil current (Icoil) and the high frequency AC output voltage (Vinv) which reduces the charging efficiency,
Additionally, during misaligned conditions, charging current (Ibat) is reduce;
the reduced battery charging current (Ibat) will be compared with reference current set by the battery management system and the primary controller unit will adjust the duty of the DC-DC converter to reduce the error; and
characterized in that, the method has been developed to compensate for the 30% misalignment in any four directions.
In the preferred embodiment, the wireless charging system operates in two loops: inner loop which maintains constant output of the DC-DC converter and outer loop which controls the charging current (Ibat) by controlling the duty ratio of the DC-DC converter. Two loops control mechanism include
the outer current control loop begins with a reference battery current (Ibat,ref) set by the battery management system, which is compared with the actual battery charging current (Ibat_act);
the resulting error signal is processed by the primary controller unit, which generates a DC-DC converter reference voltage (VB_ref) for the DC-DC converter to regulate DC-DC converter output voltage (VB);
This DC-DC converter reference voltage (VB_ref) serves as the input to the inner voltage control loop;
In the inner voltage control loop, the reference voltage (VB_ref) is compared with the actual DC-DC converter voltage (VB_act), generating a voltage error signal;
this error is then processed by the primary controller unit, producing a control signal that influences the duty cycle of the power switch of the DC-DC converter;
a ramp signal is compared with the control signal, and when the control signal surpasses the ramp waveform, a controlled duty pulse is generated;
this controlled duty pulse signal is used to drive the switching device, ensuring precise current regulation;
thus, ensures that the current remains within the desired limits, thereby improving stability, reducing overshoot, and enhancing dynamic performance.
, Claims:I/WE CLAIM
1. A wireless charging system (100) for an electric vehicle, the wireless charging system (100) comprising:
an at least one ground assembly unit (102), the at least one ground assembly unit (102) having
a power factor correction unit (104), the power factor correction unit (104) is connected to the grid supply to draw input voltage and input current, the power factor correction unit (104) maintain input voltage and input current in phase and reduces harmonic distortion,
a DC-DC converter (106), the DC-DC converter (106) is connected to output of the power factor correction unit (104) to receive controlled constant DC voltage, the DC-DC converter (106) regulates the constant DC voltage coming from the power factor correction unit (104) output to control the charging current (Ibat),
a high-frequency inverter (108), the high-frequency inverter (108) is connected to the DC-DC converter (106) to receive the amplitude regulated DC-DC converter voltage (VB), the high-frequency inverter (108) converts the DC-DC converter voltage (VB) into high frequency AC output voltage (Vinv),
a primary compensation unit (110), the primary compensation unit (110) is connected to the high-frequency inverter (108) to receive the high frequency AC output voltage (Vinv) and the primary compensation unit (110) compensate the reactive power demand to enhance electric power transfer efficiency,
a primary coil (112), the primary coil (112) is connected to the primary compensation unit (110) to receive enhance high frequency AC output voltage (Vinv) and the primary coil current (Icoil) and the primary coil (112) transfer electric power wirelessly through Phase Sync Technique based inductive coupling,
a primary controller unit(114), the primary controller unit(114) is connected to the DC-DC converter(106), the high-frequency inverter(108), and the primary coil(112), the primary controller unit(114) receives DC-DC converter voltage(VB) of the DC-DC converter(106), high frequency AC output voltage(Vinv) of the high-frequency inverter(108), and primary coil current(Icoil) from the primary coil(112), the primary controller unit(114) sends control commands to the DC-DC converter(106) to regulate amplitude of the DC-DC converter voltage to control the primary coil current(Icoil) and battery charging current (Ibat), the primary controller unit(114) sends control commands to the high-frequency inverter(108) to adjust the frequency of the high frequency AC output voltage(Vinv) and the primary coil current (Icoil) based on the phase angle between high frequency AC output voltage(Vinv) and the primary coil current (Icoil) to ensure the optimal charging performance when phase angle between high frequency AC output voltage(Vinv) and the primary coil current change due to air gap and misalignment condition, and
a primary communication module (116), the primary communication module (116) is connected to the primary controller unit (114) and the primary communication module (116) transmits and receives signal with the vehicle,
a GSM module (118), the GSM module (118) is connected to the primary controller unit (114); and
an at least one vehicle assembly unit (120), the at least one vehicle assembly unit (120) having
a secondary coil (122), the primary coil (112) transfers the high frequency power wirelessly to the secondary coil (122) through Phase Sync Technique based inductive coupling, the primary coil (112) generates alternating magnetic field that induces the high frequency AC voltage and respective high frequency current in the secondary coil (122),
a secondary compensation unit (124), the secondary compensation unit (124) is connected to the secondary coil (122) to receive the high frequency AC voltage and generate respective secondary coil current, the secondary compensation unit (124) optimizes the power reception by tuning the secondary coil (122) and secondary compensation unit (124) to compensate reactive power to capture maximum power from the alternating magnetic field,
a rectifier (126), the rectifier (126) is connected to the secondary compensation unit (124) to receive the high frequency AC power output from the secondary coil (122) that are converted to DC charging voltage (Vbat) and charging current (Ibat) by the rectifier (126)
a battery management system (128), the battery management system (128) is connected to the rectifier (126) to receive stable DC charging voltage (Vbat) and charging current (Ibat) for charging a battery (138), the battery management system (128) receives the DC voltage from the rectifier (126) output and feed to battery (138);
a secondary controller unit (130), the secondary controller unit (130) is connected to the battery management system (128) to receive data related to state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature, and
a secondary communication module (132), the secondary communication module (132) is connected to the secondary controller unit (130), the secondary communication module (132) sends data related to the state of charge, DC charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit (114) through the primary communication module (116),
wherein, the battery (138) charging starts after successful digital handshake between the at least one ground assembly unit (102) and the at least one vehicle assembly unit (120) with help of the secondary controller unit (130) that start the digital handshake after receiving green signal from the primary controller unit (114) upon detection of the at least one vehicle assembly unit (120) that is electric vehicle,
characterized in that, wireless charging system(100) tolerates misalignment up to the range of 30 % , because of the primary controller unit(114) that adjust the frequency of the high frequency AC output voltage(Vinv) and the primary coil current(Icoil) based on phase angle between high frequency AC output voltage(Vinv) and the primary coil current (Icoil), by using the state of charge, DC charging voltage(Vbat), charging current(Ibat) and temperature data of the battery(138), wherein because phase angle changes based on air gap and misalignment condition.
2. The wireless charging system (100) as claimed in claim 1, wherein, the secondary communication module (132) communicates with the primary communication module (116) through antenna (134).
3. The wireless charging system (100) as claimed in claim 1, wherein, the GSM module (118) connects the primary controller unit (114) with a cloud sever that is connected to the user device to access real-time charging information and to send commands to the primary controller unit (114) for starting and stopping the charging.
4.The wireless charging system (100) as claimed in claim 1, wherein, a camera (136) is installed on the primary coil (112) to continuously monitor the foreign object, and upon detection of foreign object the charging is stopped immediately, and alert is sent to the user device.
5. The wireless charging system (100) as claimed in claim 1, wherein, the secondary controller unit (130) and the primary controller unit (114) are selected from a jetson computing unit, Raspberry pi, Arduino, Atmel controller unit.
6. The wireless charging system (100) as claimed in claim 1, wherein, the secondary communication module (132), the primary communication module (116) are selected from a Wi-Fi module, Zigbee module NRF module.
7. A method of efficient charging of the battery (138) in case of misalignment by using the wireless charging system (100) as claimed in claim 1, wherein, the method comprising:
the charging of the battery (138) has been controlled through the DC-DC converter (106) and the high-frequency inverter (108);
when an electric vehicle is parked on the primary coil (112), the camera (136) continuously monitors the receiver coil and surrounding area and sends the data to the primary controller unit (114) that analyses the secondary coil (122) position through machine learning process;
if misalignment is within range of 30%, the primary controller unit (114) consider this as detection of the at least one vehicle assembly unit (120) of the electric vehicle;
the primary controller unit (114) gives green signal to the secondary controller unit (130) to communicate with battery management system (128);
the secondary controller unit (130) start the process of digital handshake between the at least one ground assembly unit (102) and the at least one vehicle assembly unit (120);
during this stage, the secondary controller unit (130) receives state of charge, charging voltage (Vbat), charging current (Ibat) and temperature data of the battery (138) from the battery management system (128);
the secondary controller unit (130) sends the data related to the state of charge, charging voltage (Vbat), charging current (Ibat) and temperature to the primary controller unit (114);
In the first stage, the at least one ground assembly unit (102) starts the charging process with trickle mode irrespective state of charge of the battery (138) to check the phase angle between primary coil current and high frequency inverter output voltage;
The high frequency AC output voltage (Vinv) of the high-frequency inverter (108) and the primary coil current (Icoil) of the primary coil (112) are continuously monitored in real time;
In this stage the primary controller unit (114) evaluates whether the high frequency AC output voltage (Vinv) from the output of the high-frequency inverter (108) and the primary coil current (Icoil) from the primary coil (112) are in phase;
If the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are not in phase, adjustments are made in the frequency of the high-frequency inverter (108) by the primary controller unit (114);
Once the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) are in phase, the charging process transitions to the constant current-constant voltage (CC-CV) mode, depending on the battery management system (128) predefined threshold voltage (VT);
If the battery (138) charging voltage (Vbat) is less than predefined threshold voltage (VT) then the battery (138) will charge in the constant current (CC) mode otherwise the battery (138) will charge in constant voltage (CV) mode;
In the constant current (CC) mode, the battery charging voltage (Vbat) is monitored and the constant current (CC) reference current set by the battery management system (128);
In same loop, the high frequency AC output voltage (Vinv) and the primary coil current (Icoil) continuously monitor for phase check by the primary controller unit (114);
If the phase alignment is incorrect, the primary controller unit (114) readjusts frequency of the high-frequency inverter (108) to compensate the reactive power;
If the primary coil current (Icoil) leads the high frequency AC output voltage (Vinv), then the primary controller unit (114) increases the switching frequency of the high-frequency inverter (108) until the phase angle difference will be zero;
In contrast, the primary coil current (Icoil) lags the high frequency AC output voltage (Vinv), then the primary controller unit (114) decreases the switching frequency of the high-frequency inverter (108) until the phase angle difference will be zero;
Characterized in that, by adjusting frequency of the high-frequency inverter (108) the primary controller unit (114) keeps the phase angle difference zero thus helps in efficient charging of battery (138) even in case of misalignment that causes phase angle difference between the primary coil current (Icoil) and the high frequency AC output voltage (Vinv) which reduces the charging efficiency,
Additionally, during misaligned conditions, charging current (Ibat) is reduce;
the reduced battery charging current (Ibat) will be compared with reference current set by the battery management system (128) and the primary controller unit (114) will adjust the duty of the DC-DC converter (106) to reduce the error;
characterized in that, the method has been developed to compensate for the 30% misalignment in any four directions.
8. The method of efficient charging of the battery (138) as claimed in claim 7, wherein, the wireless charging system (100) operates in two loops: inner loop which maintains constant output of the DC-DC converter (106) and outer loop which control the charging current (Ibat) by controlling the duty ratio of the DC-DC converter (106)
9. The method of two loops control mechanism as claimed in claim 8, wherein two loops control mechanism comprising
the outer current control loop begins with a reference battery current (Ibat,ref) set by the battery management system (128), which is compared with the actual battery charging current (Ibat_act);
the resulting error signal is processed by the primary controller unit (114), which generates a DC-DC converter reference voltage (VB_ref) for the DC-DC converter (106) to regulate DC-DC converter output voltage (VB);
This DC-DC converter reference voltage (VB_ref) serves as the input to the inner voltage control loop;
In the inner voltage control loop, the reference voltage (VB_ref) is compared with the actual DC-DC converter voltage (VB_act), generating a voltage error signal;
this error is then processed by the primary controller unit (114), producing a control signal that influences the duty cycle of the power switch of the DC-DC converter (106);
a ramp signal is compared with the control signal, and when the control signal surpasses the ramp waveform, a controlled duty pulse is generated;
this controlled duty pulse signal is used to drive the switching device, ensuring precise current regulation;
thus, ensures that the current remains within the desired limits, thereby improving stability, reducing overshoot, and enhancing dynamic performance.