DESC:TECHNICAL FIELD
[0001] The present subject matter relates generally to a charging system. More particularly but not exclusively the present subject matter relates to a fast-charging system in a vehicle.

BACKGROUND
[0002] Generally, in an electric vehicle or a hybrid electric vehicle, one or more battery pack is used to drive the vehicle. The health and charge of the battery pack is continuously monitored by a control unit of the vehicle to ensure that there is sufficient charge available to drive the vehicle to its destination. The battery pack used in the electric or hybrid electric vehicles is rechargeable type. So, it can be recharged, once the battery rans out of charge. To charge the battery pack of the vehicle, a charger is employed which is connected to a charging station to charge the vehicle, when the vehicle in non-operational. The charger can be an on-board charger or an off-board charger, depending upon the design of the vehicle and need of a consumer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The details are described with reference to an embodiment of a vehicle along with the accompanying figures. The same numbers are used throughout the drawings to reference similar features and components.
[0004] Figure 1 exemplarily illustrates a block diagram for a fast-charging system.
[0005] Figure 2 exemplarily illustrates a block diagram showing interaction between the power source management system, the control unit, and the charger unit.
[0006] Figure 3 exemplarily illustrates a flowchart for fast charging based on the SoC and voltage level of the one or more power source, as per an embodiment of the present invention.
[0007] Figure 4 exemplarily illustrates a flowchart for fast charging based on the temperature of the one or more power source as per another embodiment of the present invention.
[0008] Figure 5 exemplarily illustrates a flowchart in which one or more power source is not communicating, while charging, as per another embodiment of the present invention.
[0009] Figure 6 exemplarily illustrates a flowchart in which one or more power source exhibits pack to pack imbalance, as per another embodiment of the present invention.

DETAILED DESCRIPTION

[0001] Conventionally, an electric and a hybrid electric vehicle make use of rechargeable batteries to drive the vehicle. The rechargeable batteries need to be charged from time to time to ensure sufficient charge availability to drive the vehicle. Recharging is a tedious and time taking process as compared to refuelling an IC (Internal Combustion) engine. The existing electric or hybrid electric vehicle takes approximately 4 to 6 hours to charge the battery from roughly 3% to 80% SoC (state of charge). This time-consuming process decreases day time usability of the vehicle and thus limits the daily commuting capabilities beyond a range of the vehicle. In order to overcome the above-mentioned problem, many manufacturers have employed a fast-charging technique to charge the battery pack in less amount of time. However, fast-charging has its own limitations.
[0002] Fast-charging results in temperature rise of the battery which also results in increased rate of aging and premature aging of the battery, thus affecting the life of the battery of the vehicle. The high current drawn from the charger for fast charging also reduces life of the charger of the vehicle. In order to solve the problem of temperature rise and aging of the battery and the charger, in a known prior art, a charger having a battery monitoring controller is disclosed. The charger having the controller inside it controls the charging current, supply power to the vehicle and monitor the battery condition. The problem with these types of configurations is that a user will need a separate charger having the controller in it, as an additional component which is not cost effective, as a commonly used charger cannot be employed in this configuration. In another type of fast-charging, a charger is disclosed, the charger communicates with a battery control unit. The charger calculates the discharge timing of the battery and provides the charging accordingly. Since, the charger in this configuration should be configured in such a way that it should have a logic to calculate the discharge timing. As this is an onboard charger, so it will be vehicle specific charger and a common charger cannot be used.
[0003] In yet another prior art, an off-board charger is disclosed. The off-board charger determines the suitable algorithm for that particular vehicle based on the parameter which is communicated to the charger through any of a vehicle controller. The offboard charger should have a separate and specific algorithm to charge the battery pack, so a common off board charger cannot be used in this configuration. In known arts in which the vehicle includes a BMS, if the battery temperature goes beyond a threshold, a control unit will cut-off the battery charging. In another known arts, where multiple BMS are employed, the control unit itself will not be able to decide the correct charging current value based on the various inputs from the BMS, thus making the system more complex, and may also lead to a wrong communication between the charger and the BMS.
[0004] Apart from this, in a battery pack, having one or more batteries, a pack-to-pack imbalance occurs due to the presence of different level of charge, this also affects the life of the battery pack. Therefore, there is a need for a simpler, cost-effective system that provides a fast charging of the battery pack without overheating of the battery pack, decelerates the degradation of life of the battery pack, and eliminates the pack-to-pack imbalance. The fast-charging system should be such that it caters to the various requirements of platform of product variants while overcoming all above problems as well as other problems of known art.
[0005] An objective of the present subject matter is to provide a fast-charging system and a method which decelerates the degradation of the life of the battery pack while monitoring and controlling the battery operating parameters for providing the fast-charging of the battery pack. The present subject matter is described using an exemplary battery pack used in a vehicle whereas the claimed subject matter is applicable to any such application using such battery pack for fast-charging, with required changes and without deviating from the scope of invention.
[0006] As per an aspect of the present subject matter, a fast-charging system having one or more power source; one or more power source management system to monitor the operating parameters of the one or more power source; a control unit being configured to communicate to the power source management system; and a charger unit being configured to communicate to the control unit for charging of the one or more power source. The control unit being configured to determine a charging current required through the charger unit, based on one or more input signals from the power source management system.
[0007] As per an aspect of the present subject matter, the charging current is determined by the power source management system based on the one or more input signals received from one or more sensors.
[0008] As per an aspect of the present subject matter, the one or more input signals includes one of the voltage, temperature, state of health, state of charge, error in the control unit, and the charging current while the vehicle is in running condition.
[0009] As per an aspect of the present subject matter, a method for fast charging of one or more power source, the method comprising the steps of sensing, by one or more sensor, one or more parameters of the one or more power source of a pack; monitoring and controlling, by one or more power source management system, the one or more parameters of the one or more power source; calculating a required charging current, by the power source management system, for the one or more power source based on the sensed one or more parameters; communicating, by the power source management system, the required charging current for the corresponding power source to a control unit; and communicating the required charging current, by the control unit to a charger unit for fast charging of the one or more power source.
[00010] As per an aspect of the present subject matter, the for fast charging includes method comprises the steps of comparing by the control unit, an SoC of the power source with a SoC1; requesting to the control unit by the power source management system, a first charging current I1, if the power source SoC being less than SoC1; comparing by the control unit, a power source voltage with a cut-off voltage, if the power source SoC being greater than SoC1; allowing a constant voltage by the control unit, to charge the power source to its full capacity, if the power source voltage being equal to the cut-off voltage; and allowing by the control unit, a second charging current I2, if the power source voltage being not equal to the cut-off voltage.
[00011] As per an aspect of the present subject matter, the method for fast charging includes the steps of comparing by the power source management system, a power source temperature with a threshold temperature; allowing the corresponding power source management system, a maximum charging current as per the SoC level of the power source, if the power source temperature being less than the threshold temperature; allowing the corresponding power source management system, a minimum charging current for the power source, if the power source temperature being greater or equal to the threshold temperature; comparing, the power source temperature with a maximum temperature; allowing by the control unit, the corresponding power source management system, a maximum charging current as per the SoC level of the power source, if the power source temperature being less than the maximum temperature; and allowing the corresponding power source management system, a minimum charging current for the power source, if the power source temperature being greater or equal to the maximum temperature.
[00012] As per an aspect of the present subject matter, the method for fast charging includes checking by the control unit, all the power source parameters being within the set limits or not; restricting by the corresponding power source management system, a charging current to the corresponding power source, if all the power source parameters being not within the set limits; communicating by the corresponding power source management system, a charging sequence to the control unit, if the power source parameters being within the limits; checking by the control unit, all the power source pack being communicating or not; communicating by the control unit to the charger unit, the charging sequence of the power source pack to the charger unit, if all the power source in the pack being communicating with each other; and indicating by the control unit, a power source error and allowing normal charging of the power source pack, if the power source pack not communicating.
[00013] As per an aspect of the present subject matter, the method for fast charging includes the steps of checking by the control unit, all the power source parameters being within the set limits or not; restricting by the corresponding power source management system, a charging current to the corresponding power source, if all the power source parameters being not within the set limits; allowing by the corresponding power source management system, charging of the power source pack, if the power source parameters being within the limits; checking by the control unit, an ignition switch being ON or OFF; allowing by the power source management system, charging of the power source having a lower SoC first and then charging all the power source pack equally, if the ignition switch being OFF; and allowing charging by the power source management system, the power source with higher SoC in case of pack-to-pack imbalance, if the ignition switch being ON. The embodiments of the present invention will now be described in detail with reference to an embodiment in a vehicle along with the accompanying drawings. However, the present invention is not limited to the present embodiments. The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[00014] Fig.1 exemplarily illustrates a block diagram for a fast-charging system 100. The fast-charging system 100 includes one or more power source 102, one or more power source management system 104, one or more control unit 106, and a charger unit 108. In the present embodiment, the one or more power source 102 provides power to drive a vehicle. The one or more power source 102 is a rechargeable type power source 102. The one or more power source 102 is connected to one or more power source management system 104. The one or more power source management system 104 monitors the health of the one or more power source 102. The power source management system 104 monitors and regulates the charging and discharging of the one or more power source 102. The power source 102 characteristics that are to be monitored may include one of the power source type, voltages, temperature, capacity, state of charge (SoC), power consumption, remaining operating time, charging cycles, state of health (SoH), and the like. The control unit 106 function as a bridge between the power source management system 104 and the charger unit 108. The control unit 106 takes inputs from one or more power source management system 104, and based on those inputs calculates the total required amount of charge. The control unit 106 supplies the charging current based on the requirement of the individual power source 102. In the present embodiment, the control unit 106 is a vehicle control unit. The charger unit 108 can be an off-board charger or an on-board charger. The charger unit 108 provides the charging current to the one or more power source 102, when plugged in for charging at a charging station or any docketing station.
[00015] Fig.2 exemplarily illustrates a block diagram showing interaction between the power source management system 104, the control unit 106, and the charger unit 108. In the present embodiment, the interaction and working of the internal mechanism of the power source management system 104 with the control unit 106 and the charger unit 108 is shown. The power source management system 104 includes one or more sensors 110, one or more comparators 112, and a controller 114. The one or more sensor 110 senses the power source temperature, SoC, voltage and the like and give it to the comparator 112. The comparator 112 compares the one or more inputs with the set inputs and sends the comparison result to the controller 114. The one or more inputs and set inputs may include one of the voltages, temperature, capacity, state of charge (SoC), power consumption, remaining operating time, charging cycles, state of health (SoH), and the like. The controller 114 then decides the amount of charging current required to charge the power source 102, based on the one or more inputs. The control unit 106 further receives the information from the individual power source management system 104 related to the charging current required by corresponding individual power source 102. The control unit 106 then calculates the overall amount of charging current required and sends the data to the charger unit 108. The charger unit 108, based on the data sent, provides the charging current to the control unit 106, which is further given to individual power source management system 104 to charge the individual power source 102 by the control unit 106.
[00016] Fig.3 exemplarily illustrates a flowchart for fast charging as per an embodiment of the present invention. In the present embodiment, the charging current is determined based on the SoC of the power source and voltage of the one or more power source. When a rider of the vehicle switches ON the ignition (at step 200), the one or more power source 102 is ON (at step 202) and is communicatively coupled to the control unit (at step 204). When the power source 102 is discharged, the charger unit 108 is connected to the vehicle to charge it (at step 206). The control unit 106 checks whether the one or more power source 102 SoC is less than or greater than a SoC1 (at step 208). If the one or more power source 102 SoC is less than SoC1, the power source management system 104 demands a first charging current I1 from the control unit 106, which is communicated to the charger unit 108 (at step 210). If the one or more power source 102 SoC is greater than SoC1, the control unit 106 checks whether the power source 102 voltage (V) is equal to power source voltage cut off (Vcut off) (at step 212). If the power source voltage (V) is equal to power source voltage cut off (Vcut off), then the power source management system (PSMS) 104 demands constant voltage (Cv) charging till the power source 102 gets fully charged (at step 214). If the power source voltage (V) is not equal to power source voltage cut off (Vcut off), then the power source management system (PSMS) 104 demands a second charging current I2 (at step 216). In the present embodiment, the first charging current is the maximum current for charging and the second charging current is the minimum required charging current.
[00017] Fig.4 exemplarily illustrates a flowchart for fast charging as per another embodiment of the present invention. In the present embodiment, the charging current is determined based on the temperature of the power source 102. When the rider connects the charger unit 108 at the charging station, the power source management system 104 enters the charging mode (at step 300). The control unit 106 checks the power source 102 temperature whether it is greater or lesser than a threshold temperature (at step 302). If the power source temperature is less than the threshold temperature, the power source management system 104 demands a maximum current as per the state of charge level of the power source 102 (at step 306). If the power source 102 temperature is greater or equal to the threshold temperature, the power source management system 104 demands a minimum charging current from the charger unit 108 (at step 304). The control unit 106 further checks whether the power source 102 temperature is greater or lesser than a maximum temperature (at step 308). If the power source 102 temperature is less than the maximum temperature, the power source management system 104 demands the maximum current as per the state of charge level of the power source 102 (at step 306). If the power source 102 temperature is greater than or is equal to the maximum temperature, the power source management system 104 demands the minimum charging current (at step 304).
[00018] Fig.5 exemplarily illustrates a flowchart in which one or more power source 102 is not communicating, while charging, as per another embodiment of the present invention. In the present embodiment, when a rider of the vehicle switches ON the ignition (at step 400), the one or more power source 102 is ON (at step 402) and is communicatively coupled to the control unit 106 (at step 404). when the power source 102 is discharged, the charger unit 108 is connected to the vehicle to charge it (at step 406). The control unit 106 checks whether all the power source 102 parameters are within the set limits (at step 408). The power source 102 parameters may include one of a voltage, temperature, capacity, state of charge (SoC), power consumption, remaining operating time, charging cycles, state of health (SoH), and the like. If all the power source 102 parameters are not within the set limits, then the power source management system 104 will not allow charging of that individual power source 102 (at step 410). If all the power source 102 parameters are within the set limits, then the power source management system 104 communicates a charging sequence to the control unit 106 (at step 412). The control unit 106 further checks if all the power source 102 are communicating with each other (at step 414). If all the power source pack 102 are communicating to each other, then the control unit 106 communicates the charging sequence to the charger unit 106 (at step 416). If all the power source pack 102 are not communicating to each other, then the control unit 106 shows an indication to the user that there is a power source error, and continues to provide normal charging of the one or more power source 102 of the pack (at step 418).
[00019] Fig.6 exemplarily illustrates a flowchart in which one or more power source 102 exhibits pack to pack imbalance, as per another embodiment of the present invention. In the present embodiment, a problem of pack-to pack imbalance has been addressed. In Pack-to-Pack balance, all the power source 102 should have same charging level i.e. 100%. If one pack has charging 100% and the other pack has charging 50%, it is called as pack to pack imbalance. Each pack communicates with other power source pack through CAN. The power source pack 102 having lowest charge will start charging first and when it reaches to the level of other power source pack 102, then charging of all the other power source pack 102 starts charging together. When a rider of the vehicle switches ON the ignition (at step 500), the one or more power source 102 is ON (at step 502) and is communicatively coupled to the control unit 106 (at step 504). When the power source 102 is discharged, the charger unit 108 is connected to the vehicle to charge it (at step 506). The control unit 106 checks whether all the power source 102 parameters are within the set limits (at step 508). The power source 102 parameters may include one of a voltage, temperature, capacity, state of charge (SoC), power consumption, remaining operating time, charging cycles, state of health (SoH), and the like. If all the power source 102 parameters are not within the set limits, then the power source management system 104 will not allow charging of that individual power source 102 (at step 512). If all the power source 102 parameters are within the set limits, then the power source management system 104 allows the charging of the pack (at step 510). The control unit 106 further checks if the ignition switch is ON or not (at step 514). If the ignition switch is not ON, the power source management system 104 charges the power source 102 with lower SoC first, and then charges the other power source 102 when the power source 102 with lower SoC charge had reached to the level of the other power sources in the pack, and is further continued to be charged equally (at step 516). If the ignition switch is ON, the power source management system 104 charges the higher SoC pack in case of pack-to-pack imbalance (at step 518). In another embodiment, the working of control unit 106 can be performed by a master power source management system.
[00020] Whenever an individual power source 102 SoC, voltage or temperature reaches to a threshold, the corresponding power source management system 104 communicates the control unit 106 to allow reduced charging current that is minimal current to charge that individual power source 102. This preserves the life and durability of the power source 102 and prevents it from getting damage as higher charging current at higher SoC impacts the life of the power source pack 102. This mechanism aims to provide more charging capacity of the one or more power source 102 without affecting the life span of the power source 102. Also, the present invention ensures compatibility of any standard charger unit having a communication system to be used with the vehicle and thus do not need a dedicated charger unit 108. In case, if the power source management system 104 fails, the vehicle control unit 106 senses that the power source management system 104 is not communicating and thus has malfunctioned, so the control unit 106 will not allow the fast charging for safety purposes and will only allow normal charging. In another embodiment, the control unit 106 can assume the place of the power source management system 104, if the PSMS 104 fails to continue the function of charging, thus providing a second level of protection. Thus, the present invention avoids the high temperature issues and imbalance issues, while fast charging of the power source pack 102. This mechanism reduces the charging time by providing fast charging in a controlled way, while protecting the power source pack 102 from overheating and without reducing the efficiency of the one or more power source of the pack 102. Also, this invention eliminates any cooling period for which the rider has to wait for the power source to get cooled before plugging it into the charging again. Many other improvements and modifications may be incorporated herein without deviating from the scope of the invention.
List of Reference numerals
100: Fast charging system
102: One or more power source
104: One or more power source management system
106: One or more control unit
108: Charger unit
110: One or more sensors
112: One or more comparator
114: Controller
,CLAIMS:We claim:
1. A fast-charging system (100) for a vehicle, the fast-charging system (100) comprising:
One or more power source (102);
One or more power source management system (104) to monitor the operating parameters of the one or more power source (102);
a control unit (106), the control unit (106) being configured to communicate to the power source management system (104); and
a charger unit (108) being configured to communicate to the control unit (106) for charging of the one or more power source (102);
wherein,
the control unit (106) being configured to determine a charging current required through the charger unit (108), based on one or more input signals from the power source management system (104).
2. The fast-charging system (100) as claimed in claim 1, wherein the charging current being determined by the power source management system (104) based on the one or more input signals received from a one or more sensors (110).
3. The fast-charging system (100) as claimed in claim 2, wherein the one or more input signals includes one of the voltage, temperature, state of health, state of charge, error in the control unit (106), and the charging current while the vehicle (not shown) being in running condition.
4. A method for fast charging of one or more power source (102), the method comprising the steps of:
sensing, by one or more sensor (110), one or more parameters of the one or more power source (102);
monitoring and controlling, by one or more power source management system (104), the one or more parameters of the one or more power source (102);
calculating a required charging current, by the power source management system (104), for the one or more power source (102) based on the sensed one or more parameters;
communicating, by the power source management system (104), the required charging current for the corresponding power source (102) to a control unit (106); and
communicating the required charging current, by the control unit (106) to a charger unit (108) for fast charging of the one or more power source (102).

5. The method for fast charging as claimed in claim 4, wherein the method comprises the steps of:
comparing by the control unit (106), an State-of-Charge (SoC) of the power source (102) with a predetermined SoC1 (at step 208);
requesting to the control unit (106) by the power source management system (104), a first charging current I1, if the power source (102) SoC being less than SoC1(at step 210);
comparing by the control unit (106), a power source voltage with a cut-off voltage, if the power source (102) SoC being greater than SoC1 (at step 212);
allowing a constant voltage by the control unit (106), to charge the power source (102) to its full capacity, if the power source (102) voltage being equal to the cut-off voltage (at step 214); and
allowing by the control unit (106), a second charging current I2, if the power source (102) voltage being not equal to the cut-off voltage (at step 216).

6. The method for fast charging as claimed in claim 4, wherein the method comprises the steps of:
comparing by the power source management system (104), a power source (102) temperature with a threshold temperature (at step 302);
allowing the corresponding power source management system (104), a maximum charging current as per the SoC level of the power source (102) (at step 306), when the power source (102) temperature being less than the threshold temperature;
allowing the corresponding power source management system (104), a minimum charging current for the power source (102) (at step 304), when the power source (102) temperature being greater or equal to the threshold temperature;
comparing, the power source (102) temperature with a maximum temperature (at step 308);
allowing by the control unit (106), the corresponding power source management system (104), a maximum charging current as per the SoC level of the power source (102) (at step 306), when the power source (102) temperature being less than the maximum temperature; and
allowing the corresponding power source management system (104), a minimum charging current for the power source (102) (at step 304), when the power source (102) temperature being greater or equal to the maximum temperature.

7. The method for fast charging as claimed in claim 4, wherein the method comprises the steps of:
checking by the control unit (102), whether all the power source (102) parameters being within the set limits (at step 408);
restricting by the corresponding power source management system (104), a charging current to the corresponding power source (102) (at step 410), when all the power source (102) parameters being not within the set limits;
communicating by the corresponding power source management system (104), a charging sequence to the control unit (106) (at step 412), when the one or more power source (102) parameters being within the limits;
checking by the control unit (106), all the power sources(102) being in communication(at step 414);
communicating by the control unit (106) to the charger unit (108), the charging sequence of the power source pack (102) to the charger unit (108) (at step 416), when all the power source (102) in the pack being communicating with each other; and
indicating by the control unit (106), a power source error, and allowing normal charging of the one or more power source (102) (at step 418), when the one or more power source (102) not communicating.

8. The method for fast charging as claimed in claim 4, wherein the method comprises the steps of:
checking by the control unit (106), all the power source (102) parameters being within the set limits or not (at step 508);
restricting by the corresponding power source management system (104), a charging current to the corresponding power source (102) (at step 510), when all the power source (102) parameters being outside the set limits;
allowing by the corresponding power source management system (104), charging of the power source pack (102) (at step 512), when the one or more power source (102) parameters being within the limits;
checking by the control unit (106), an ignition switch being ON or OFF (at step 514);
allowing by the power source management system (104), charging of the one or more power source (102) having a lower SoC first and then charging all the remaining power source (102) equally, when the ignition switch being OFF (at step 516); and
allowing charging by the power source management system (104), the one or more power source (102) with higher SoC in case of imbalance (at step 518) between the one or more power source (102), when the ignition switch being ON.