DESC:ONBOARD CHARGER FOR ELECTRIC VEHICLE
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202321090113 filed on 30/12/2023, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to an onboard charger for electric vehicles. Particularly, the present disclosure relates to a safety feature of an onboard charger.
BACKGROUND
As a result of advancements in technology, environmental concerns, and changing consumer preferences, in recent years electric vehicles are gaining popularity among consumers for collective or personal mobility. The electric vehicles are equipped with electric motor/motors and other electrical and electronic components that are powered from a power pack in the vehicles. The power pack needs to be electrically recharged once the energy stored in the power pack is depleted. The power pack is charged from a power source that is generally located external to the vehicles.
The onboard charger (OBC) in an electric vehicle (EV) plays a critical role in managing the charging process by converting the alternating current (AC) from the power grid into the direct current (DC) required to charge the vehicle's battery. This device is typically integrated into the vehicle and ensures that the battery is charged safely and efficiently. During the charging of electric vehicle (EV), over-temperature, and over-current are critical issues that can negatively impact the battery and the overall charging process. Over-temperature occurs when the battery heats up excessively, which can lead to thermal runaway or long-term damage. Over-current refers to a situation where the charging current exceeds electrical capacity of the battery or vehicle, which can cause overheating, damage to components, or even short circuits. In severe cases, prolonged exposure to any of these conditions can significantly reduce battery life, and may result in costly repairs, safety hazards, and diminished vehicle performance.
Therefore, there exists a need for an onboard charger capable of ensuring safe, reliable and efficient charging of the battery of an electric vehicle.
SUMMARY
An object of the present disclosure is to provide an onboard charger for uninterrupted, safe and reliable charging of an electric vehicle.
In accordance with the first aspect of the present disclosure, there is provided an onboard charger for an electric vehicle, wherein the onboard charger comprises:
- a voltage sensing module;
- a current sensing module;
- a temperature sensing module; and
- a processing unit communicably coupled with the voltage sensing module, the current sensing module, and the temperature sensing module;
wherein the processing unit is configured to perform current derating based on at least data received from the voltage sensing module, the current sensing module, and the temperature sensing module.
The present disclosure provides an onboard charger for charging an electric vehicle. The onboard charger as disclosed in the present disclosure is advantageous in terms of ensuring uninterrupted charging of an electric vehicle in an event of overcurrent, and/or overtemperature. The uninterrupted charging of battery is achieved by performing current derating in an event of violation of current or temperature thresholds. The current derating prevents damage to the battery or other electrical components, such as switches, wiring, fuses, and the onboard charger itself, by avoiding overheating of electrical components and risk of short circuits. Further, the onboard charger of the present disclosure effectively fulfills charging requirements of the battery by precisely supplying current up to the requirements, within the safety limits.
Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 illustrates a schematic representation of an onboard charger for charging a battery of an electric vehicle, in accordance with various embodiments of the present disclosure.
FIG. 2 illustrates a circuit diagram of an onboard charger for charging a battery of an electric vehicle, in accordance with various embodiments of the present disclosure.
FIG. 3 illustrates a flow chart of a method of charging a battery of an electric vehicle, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of an onboard charger for charging a battery of an electric vehicle and is not intended to represent the only forms that may be developed or utilized. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, or system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings which are shown by way of illustration-specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “electric vehicle”, “EV”, and “EVs” are used interchangeably and refer to any vehicle having stored electrical energy, including the vehicle capable of being charged from a power source that is located outside the vehicle. This may include vehicles having power packs that are exclusively charged from a power source, as well as hybrid vehicles which may include power packs capable of being at least partially recharged via a power source. Additionally, it is to be understood that the ‘electric vehicle’ as used herein includes electric two-wheelers, electric three-wheelers, electric four-wheelers, electric pickup trucks, electric trucks, and so forth.
As used herein, the terms “onboard charger”, “on-board charger”, “OBC” and “charger” are used interchangeably and refer to an electrical and electronic system for converting the input alternating current (AC) power into direct current (DC) power that is suitable for charging of power pack of electric vehicle. The alternating current (AC) power is received from power source including wall sockets of residential outlets.
As used herein, the terms “Battery”, “power pack”, and “battery pack” are used interchangeably and refer to multiple individual battery cells connected to provide a higher combined voltage or capacity than what a single battery can offer. The power pack is designed to store electrical energy in form of chemical energy and supply the electrical energy as needed to various devices or systems. Power pack, as referred herein are used for various purposes such as for powering electric vehicles and other energy storage applications.
As used herein, the term “voltage sensing module” refers to a component that monitors and measures the voltage levels of onboard charger and/or battery. The voltage sensing module comprises components such as a voltage divider circuit, Analog-to-Digital Converters (ADC), and reference voltage sources. The voltage divider reduces the voltage to a safety level for easy interpretation by subsequent microcontroller or processing unit. The ADC converts the analog voltage signal into a digital value for processing by the processing unit. Further, the reference voltage ensures accurate measurements by establishing a standard voltage for comparison with the sensed voltage. Furthermore, the working of the voltage sensing module involves continuously monitoring the input voltage, dividing it to a safe level, converting it into a digital signal, and transmitting it to the microcontroller for further analysis or feedback control, such as triggering an alarm or adjusting system parameters based on the voltage level.
As used herein, the term “current sensing module” refers to a component that monitors the flow of electrical current into and out of the battery pack. Specifically, the current sensing module measures a small voltage drop across a low-resistance element proportional to the current passing through the resistance. Subsequently, the measured voltage is amplified by an amplifier to a level suitable for measurement and converted to a digital value for processing via the processing unit for further analysis. The current sensing module continuously monitors the current flow and provides real-time feedback, such as triggering alerts for overcurrent conditions or controlling systems to adjust power usage.
As used herein, the term “temperature sensing module” refers to a component that monitors the temperature of individual battery cells or the entire battery pack. The temperature sensing module comprises a temperature sensor (such as, but not limited to, a thermistor, thermocouple, or Resistance Temperature Detector (RTD)), an amplifier, and an Analog-to-Digital Converter (ADC). The temperature sensor detects changes in temperature and converts them into a corresponding electrical signal. This signal is then amplified by the amplifier to bring it to an appropriate level for measurement and converted to a digital format that via ADC. The temperature sensing module continuously monitors the temperature, allowing for real-time feedback to adjust system parameters (like triggering cooling or heating mechanisms) or to provide warnings during exceedance of the temperature with respect to a safe threshold.
As used herein, the term “processing unit” refers to a central component of an embedded system or electronic device responsible for managing and executing tasks based on input data, making decisions, and controlling other system components. The processing unit comprises a microcontroller (MCU) or microprocessor (CPU), memory modules (RAM and ROM), and input/output interfaces. The microcontroller or processor executes software instructions to process data from sensors (such as, but not limited to, temperature, current, or voltage), perform calculations, and make control decisions. The memory stores the program code and runtime data, and the input/output interfaces allow communication with other devices or modules. The processing unit performs by receiving sensor inputs, processing them according to predefined algorithms or logic, and then sending control signals to actuators or other parts of the system, enabling the required functions.
As used herein, the term “switching device” refers to a one of more semiconductor switches that regulate the power flow by switching on and off at high frequencies. Possible semiconductor switches may include MOSFET(s) (Metal-Oxide-Semiconductor Field-Effect Transistor(s)), IGBT(s) (Insulated-Gate Bipolar Transistor(s)), SiC MOSFET(s) (Silicon Carbide MOSFET(s)), GaN Transistor(s) (Gallium Nitride Transistor(s)), and Thyristor(s) (SCR - Silicon-Controlled Rectifier(s)) or a combination thereof. The choice of semiconductor switch depends on factors like the voltage, current, switching frequency, and efficiency requirements of the onboard charger.
In accordance with an aspect of the present disclosure, there is provided an onboard charger for an electric vehicle, wherein the onboard charger comprises:
- a voltage sensing module;
- a current sensing module;
- a temperature sensing module; and
- a processing unit communicably coupled with the voltage sensing module, the current sensing module, and the temperature sensing module;
wherein the processing unit is configured to perform current derating based on at least data received from the voltage sensing module, the current sensing module, and the temperature sensing module.
Figure 1, in accordance with an embodiment, describes an onboard charger 100 for charging a battery of an electric vehicle. The onboard charger 100 comprises a voltage sensing module 102, a current sensing module 104, a temperature sensing module 106 and a processing unit 108. The processing unit 108 communicably is coupled with the voltage sensing module 102, the current sensing module 104, and the temperature sensing module 106.
The onboard charger 100 as disclosed in the present disclosure is advantageous in terms of facilitating uninterrupted charging of the battery. The uninterrupted and continuous charging of battery is achieved by effectively meeting the power demand of the battery as computed using a processing unit 108 using the voltage sensed by voltage sending module 102 and current sensed by current sensing module 104. Further, the onboard charger 100 ensures the charging of the battery within safety limits by performing current derating in an event of temperature rise beyond an acceptable temperature range.
In an embodiment, the voltage sensing module 102 is configured to sense an output voltage value of the onboard charger 100. The voltage sensing module 102 allows continuous monitoring of voltage level, allowing the onboard charger 100 to effectively meet the battery requirements.
In an embodiment, the current sensing module 104 is configured to sense an output current value of the onboard charger 100. The current sensing module 104 allows continuous monitoring of the current level, allowing the onboard charger 100 to effectively meet the battery requirements. The current sensing module 104 facilitates real-time, accurate measurements of the charging or output current, it enables the system to dynamically adjust the current flow, ensuring safe operation and preventing overcurrent situations that could lead to component damage or inefficient charging of the battery. Further, continuous current monitoring the by current sensing module 104 allows precise derating based on actual load conditions, ensuring optimal performance and protecting sensitive components, from stress caused by excessive current. Furthermore, current sensing module 104 enables faster detection of irregularities, helping to maintain system reliability and extend the lifespan of the system by reducing the risk of thermal overload or other failures.
Figure 2, in accordance with an embodiment, describes an onboard charger 200 for charging a battery. The onboard charger 200 comprises a plurality of switches 202 - 202a, 202b, 202c, 202d, 202e, 202f, 202g, 202h, 202i, 202j, 202k, and 202l. Further, the onboard charger comprises a temperature sensing module 106 for measuring temperature of at least of the switch 202 – 202a, 202b……202l.
In an embodiment, the temperature sensing module 106 is configured to sense a temperature value of at least one switching device 202 of the onboard charger 200. The temperature sensing module 106 allows continuous monitoring of temperature of one or more heat sensitive components such as one or more switching components 202 of the onboard charger 200. The continuous monitoring of temperature allows the onboard charger to prevent overheating by adjusting the current flow accordingly, to avoid thermal damage. Thereby enhancing the safety and reliability of the onboard charger 200 and improving charging efficiency by preventing thermal stress.
In an alternative embodiment, the temperature sensing module 106 is configured to sense a temperature value of at least one switching device 202, by sensing temperature of at least one heatsink associated with one or more switching devices 202. The temperature sensing module 106 detects temperature of at least one heatsink to provide an aggregate indicator of the overall thermal condition of the switching devices and helps in reducing system complexity and cost. Furthermore, heatsink typically reflects the cumulative heat dissipation of at least one switching device 202, hence offering a more stable and averaged temperature reading, and thus minimizing the risk of false alarms or unnecessary adjustments due to localized thermal variations.
In an embodiment, the processing unit 108 is configured to compute an output power value of the onboard charger 100, based on the sensed output voltage value and the sensed output current value. The processing unit 108 allows accurate calculation of the real-time output power, which further allows dynamic adjustments to the charging current to effectively charge the battery.
In an embodiment, the processing unit 108 is configured to derive an input current value corresponding to the computed output power value and/or the sensed temperature value, via a lookup table. The processing unit 108 provides technical advantages by precisely meeting the charging requirements and also keeping a safety check on the charging system. The processing unit 108 by utilizing the lookup table, quickly and accurately correlate output power and temperature data with the appropriate input current values, enabling efficient current derating. Further, the processing unit 108 ensures that the onboard charger 100 adjusts the input current based on both power demands and thermal conditions, preventing overheating or excessive power draw that could strain the system. Further, the use of a lookup table by the processing unit 108 streamlines the computation process, allowing for real-time adjustments without the need for complex calculations, which enhances the overall responsiveness and reliability of the system.
In an embodiment, the processing unit 108 is configured to perform current derating based on the derived input current value. The processing unit 108 thus ensures that the onboard charger 100 operates within safe limits and prevents excessive current draw that could lead to overheating or potential damage to sensitive components. The processing unit 108 dynamic adjustments helps in maintaining system efficiency, as it ensures that the onboard charger 100 is providing the necessary power without overloading the system. Additionally, performing current derating based on the derived input current value allows precise control over the charging process, especially under varying load or temperature conditions, thereby improving the reliability and longevity of both the onboard charger and the connected battery. Ultimately, the processing unit 108 enhances the overall safety, efficiency, and durability of the onboard charging system, by providing better protection and performance across a range of operating conditions.
Figure 3, in accordance with an embodiment, describes a method 300 of charging a battery of an electric vehicle via an onboard charger (such as onboard charger 100 of Fig. 1). The method 300 starts at a step 302. At the step 302, the method comprises sensing an output voltage value of the onboard charger 100, via a voltage sensing module (such as voltage sensing module 102 of Fig. 1). At the step 304, the method comprises sensing an output current value of the onboard charger 100, via a current sensing module (such as current sensing module 104 of Fig.1). At the step 306, the method comprises sensing a temperature value of at least one switching device(s) (such as switching devices 202 – 202a, 202b….202l of Fig.2) of onboard charger 100, via a temperature sensing module (such as temperature sensing module 106 of Fig.1). At the step 308, the method comprises computing an output power value of the onboard charger 100, based on the sensed output voltage value and the sensed output current value, via a processing unit (such as processing unit 108 of Fig.1). At the step 310, the method comprises deriving an input current value corresponding to the computed output power value and/or the sensed temperature value, using a lookup table, via the processing unit 108. At the step 312, the method comprises performing current derating based on the derived input current value. The method 300 ends at the step 312.
In an embodiment, the method 300 comprises sensing an output voltage value of the onboard charger 100, via a voltage sensing module 102, sensing an output current value of the onboard charger 100, via a current sensing module 104, sensing a temperature value of at least one switching device of the onboard charger 100, 200, via a temperature sensing module 106. Further, method 300 comprises computing an output power value of the onboard charger 100, based on the sensed output voltage value and the sensed output current value, via a processing unit 108. Furthermore, the method 300 comprises deriving an input current value corresponding to the computed output power value and/or the sensed temperature value, using a lookup table, via the processing unit 108 and performing current derating based on the derived input current value. Beneficially, the method 300 allows efficient charging of the battery as per power demand computed using the processing unit 108. The incorporation of a lookup table to derive the input current value based on the output power and temperature enables the onboard charger 100 to dynamically adjust its charging parameters in response to changing conditions. Further, the method 300 helps mitigate the risk of overheating or excessive current, which could otherwise damage the battery or charger components. Furthermore, the method ensures that the onboard charger 100 operates within safe thermal limits by performing current derating based on the derived input current value, reducing the likelihood of component failure and extending the life of both the onboard charger 100 and the battery.
It would be appreciated that all the explanations and embodiments of the onboard charger 100 also apply mutatis-mutandis to the method 300.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combinations of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, and “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings, and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:We Claim:
1. An onboard charger (100, 200) for an electric vehicle, wherein the onboard charger (100, 200) comprises:
- a voltage sensing module (102);
- a current sensing module (104);
- a temperature sensing module (106); and
- a processing unit (108) communicably coupled with the voltage sensing module (102), the current sensing module (104), and the temperature sensing module (106);
wherein the processing unit (108) is configured to perform current derating based on at least data received from the voltage sensing module (102), the current sensing module (104), and the temperature sensing module (106).
2. The onboard charger (100, 200) as claimed in claim 1, wherein the voltage sensing module (102) is configured to sense an output voltage value of the onboard charger (100, 200).
3. The onboard charger (100, 200) as claimed in claim 1, wherein the current sensing module (104) is configured to sense an output current value of the onboard charger (100, 200).
4. The onboard charger (100, 200) as claimed in claim 1, wherein the temperature sensing module (106) is configured to sense a temperature value of at least one switching device (202) of the onboard charger (100, 200).
5. The onboard charger (100, 200) as claimed in claim 1, wherein the processing unit (108) is configured to compute an output power value of the onboard charger (100, 200), based on the sensed output voltage value and the sensed output current value.
6. The onboard charger (100, 200) as claimed in claim 1, wherein the processing unit (108) is configured to derive an input current value corresponding to the computed output power value and/or the sensed temperature value, via a lookup table.
7. The onboard charger (100, 200) as claimed in claim 1, wherein the processing unit (108) is configured to perform current derating based on the derived input current value.
8. A method (300) of charging a battery of an electric vehicle via an onboard charger (100, 200), the method comprising:
- sensing an output voltage value of the onboard charger (100, 200), via a voltage sensing module (102);
- sensing an output current value of the onboard charger (100, 200), via a current sensing module (104);
- sensing a temperature value of at least one switching device of the onboard charger (100, 200), via a temperature sensing module (106);
- computing an output power value of the onboard charger (100, 200), based on the sensed output voltage value and the sensed output current value, via a processing unit (108);
- deriving an input current value corresponding to the computed output power value and/or the sensed temperature value, using a lookup table, via the processing unit (108); and
- performing current derating based on the derived input current value.