Claims:We claim
1. A multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of :
a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle;
atleast a charger (142), which is in direct communication with the said BMS (141) of the battery pack; and
a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user,
wherein the said BMS (141) is provided with a plurality of memory units for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the plurality of data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack.

2. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein said operational parameters of the electric vehicle, includes but not limited to, States of Charge (SoC), temperature of the battery pack, States of Health (SoH), cell voltages, current.

3. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein said plurality of memory units of the BMS (141) includes erasable memory units, Non Erasable memory units and/or combinations thereof.

4. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein said erasable memory units of the BMS (141) stores operational parameters including SoC %, temperature of the current battery state and prior data point values.

5. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein said non-erasable memory units of the BMS (141) stores operational parameters including SoH%, pre-charge circuit operation logs from the initial operation of the battery pack.

6. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein said information stored in the erasable memory units and non- erasable memory units of the BMS (141) serves as main drivers for the charger (142) for regulating the charge current rates.

7. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, the battery pack is charged at any level of SoC%, the said BMS (141) continuously communicates the SoC% information to the charger and as per the predefined SoC % of the battery the charger (142) provides the current as per the capability of the cell at that state.

8. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the said BMS (141) is configured with cell current threshold values for each SoC% level, based on the cell current values the Charger (142) charges the battery pack at much higher rate upto a predefined SoC% window and reduces the charger current as the SoC% increases towards 100%, thereby reducing the charge time for charging the battery pack.

9. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the charger (142) charge current rate is also governed by considering the temperature of the battery cell and SoH.

10. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the said charger (142) is additionally provided with a charge current input panel (144), wherein the user provides the input charge current at which the battery pack is to be charged.

11. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the said charger (142) is provided with the capability to accommodate all voltage range from 48V to 72V battery packs of any chemistries.

12. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the said charger (142) is applicable to all battery packs irrespective of its chemistries.

13. The multi-voltage and current based smart electric vehicle charger, as claimed in claim 1, wherein the said charger (142) is applicable to all types of electric vehicles.

14. A method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising steps of :

configuring the BMS (141) of the battery pack with a plurality of operational parameters of the electric vehicle;
establishing a direct communication with the Charger (142) and the BMS (141) of the battery pack, thereby enabling continuous flow of data exchange between the charger and the BMS;
atleast a SoC % check unit (145), wherein the SoC % level of the battery pack is checked and compared with the predefined values; Wherein, if the SoC % remains within the predefined window the charging is continued at the same rate of charge current, Wherein, if the SoC % is different the charger current rate is altered based on the predefined SoC % window.

15. The method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), as claimed in claim 14, further comprises steps of :
receiving the input charge current from the user via the said charge current input panel (145), wherein the user provides the input charge current at which the battery pack is to be charged,
evaluating the input charge current provided by the user by BMS (141);
Wherein if the predefined SoC % limit is satisfied by the input charge current then the user input charge current is accepted and the charger charges the battery pack based on the user input charge current rate, if the predefined SoC % limit is not satisfied, the BMS (141) automatically corrects the charge current rate to predefined optimum configured charge current values based SoC, SoH and temperature of the pack.

16. The method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), as claimed in claim 14, Wherein if the temperature of the battery pack exceeds a predefined set points the charger (142) reduces the charge current rate irrespective of SoC%, thereby the temperature of the battery pack is well maintained within the optimum operating limits.

17. The method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), as claimed in claim 14, Wherein the charger (142) is also operated based on the SoH of the battery pack, if the SoH or the Internal Resistance (IR) of the battery cell is within the predefined optimum range the charger is operated at its normal operating condition, if there is an increase in Internal Resistance (IR) or SoH of the battery cell the charger current is adjusted to avoid usage of high current charging.

18. The method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), as claimed in claim 14, Wherein the charging is done based on the health of pre-charge circuit, if any errors exists in the pre-charge circuit the charger will not charge the battery pack until the error is rectified, this acts as a safety feature to de-risk the system failure due to failed pre-charge circuit and system damage due to inrush current.
, Description:Field of Invention
The present invention relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to battery system for electrical vehicles with interactive charging management system and method thereof.
Background of the Invention
Automobiles and vehicles employing internal combustion engine uses gasoline or diesel as its primary fuel source which causes severe environmental pollution such as air pollution. In order to reduce such environmental pollution, much effort has recently been made to develop electric vehicles. An electric vehicle is a vehicle that uses battery engine operated by electrical energy outputted from a battery has its major fuel source. Every electric vehicle uses a battery having a plurality of secondary cells that is discharged under use, recharged and formed as a pack, it is advantageous in that it does not generate any exhaust gas and has little noise.
With ever increasing concern about environmental pollution, electric vehicles have recently been receiving more and more attention. The battery system is a critical component of an electric vehicle, affecting its performance and safety. The battery system of an electric vehicle typically includes two major parts—the batteries and the battery management system. For a vehicle using a battery engine in order to improve the efficiency or environmental impact of the driving source, the number of battery cells in the battery must be large, so a battery management system (BMS) is required to effectively manage the plurality of battery cells. A BMS, or Battery Management System is a device that control some or all aspects of an energy storage system. Some aspects that may be controlled include monitoring voltages of each cell or groups of energy storage cells, monitoring current, monitoring temperatures throughout energy storage units(s), calculating States of Charge (SoC), calculating and/or tracking States of Health (SoH), and/or modifying State of Charge to balance the storage unit voltages or SoC's.
A BMS may be used in any number of applications ranging from vehicles to cell phones to laptops to large stationary grid balancing plants. A BMS will typically be used on an advanced battery system consisting of many cells connected in a series/parallel configuration, although occasionally a BMS may also be used on a less advanced battery system that needs a longer lifespan from the batteries such as in a vehicle application requiring precise control over its cell voltages and SoC's.
The Battery Management System in any system may report information about the system back to a central computer or ECU of the battery system itself. It is always useful to collect data about the battery system and calculate important parameters, then either transmit or use that data to adjust aspects of the energy storage system.
Battery cells using lead-acid, nickel metal hydride and lithium ion chemistries have all been used in the past. Among them, lithium ion cells have been highly valued for its high specific energy density and large cycle life. However, lithium ion cells are known to degrade if operated outside certain voltage and temperature range. In extreme situations, this degradation may lead to a safety hazard, e.g. fire or even explosion. The high voltage and capacity of any battery pack are typically achieved by connecting many batteries in series, wherein each battery may comprise a plurality of battery cells. In such designs the discharge capacity of a battery pack is only as large as the battery member that has the lowest capacity, thus it is important to keep all the battery members balanced in their capacities. To ensure a long and safe operating life in an EV, a lithium ion battery pack requires a management system that can monitor in real time the voltage and temperature of the various cell in the battery pack, keep the cells operating in a predetermined range, and also keep their capacities balanced.
Battery stacks using Li-Ion technology can comprise a large number of individual cells totaling hundreds of cells at different voltages. Each cell must be properly monitored and balanced to ensure user safety, improve battery performance and extend battery life. Therefore, the battery management system (BMS) is one of critical components for small and large-scaled battery applications. The main objectives of a BMS are: (1) to guarantee appropriate use of the battery, (2) to guarantee maximum performance of the battery, (3) to monitor necessary battery state data, and (4) to permit diagnosis. The BMS architecture should overcome the three major hurdles of state-of-the-art Li-Ion batteries: life cycle, cost and scalability. There exists lot of prior arts showing a battery management system to better balance and manage cells.
US patent application 20120105001A1 provides a battery management system including several subsystem blocks, an Energy Storage Master unit, and several battery pack systems. The Energy Storage Master may interface with the Vehicle Master Controller by way of CAN or other communication method to an External Charger. Each battery module within a battery pack may include a Local Module Unit which may communicate with a Pack Master. The Pack Master may communicate with and may be controlled by the Energy Storage Master. Thus, there is a processor to monitor groups of battery cells, a second processor to collect further information about the cell groups, and a third module that takes high-level information from each cell group processor to process and pass on to other vehicle controllers or charger controllers. An integrated BMS may enable cell monitoring, temperature monitoring, cell balancing, string current monitoring, and charger control integration.
Another US patent application 20090027009 provides a system and method for battery management managing a plurality of batteries and useable by way of example with a partially or completely electrically powered vehicle (EV) includes a plurality of monitor modules each coupled to at least one of the plurality of batteries and configured to monitor the voltage and temperature thereof, a master controller, and a non-conductive fiber optic network coupling the plurality of monitor modules to one another and to the master controller. The master controller commands the transmission of battery voltage and temperature information from the plurality of monitor modules over the network, receives battery voltage and temperature information from the monitor modules over the network, and perform calculations based on the received information to determine if any of the plurality of batteries require balancing measures, and based thereon, commands the corresponding monitor modules to implement balancing measures over the network.
Another US patent application 20130175976 provides a Battery Management System for the propulsion batteries of an electric vehicle comprises means for voltage sensing, temperature sensing, voltage limit sensing, and current limit sensing. Charge control is employed for optimal system operation and ensures cell balancing by detecting the lowest charged cells in a cell stack and charging those cells first, thereby ensuring that all cells charge uniformly. Charge control is accomplished on a battery management circuit board associated with battery cells in a battery box, while control of the battery management board is governed by a system controller board through a controller area network interface. The system controller board uses data from the battery management board to govern charge characteristics of the batteries, and supply data and control functions to a driver interface computer.
Korean patent 100740097 discloses a battery management system which estimates the SOC of the current battery using the total battery capacity corresponding to the total discharge accumulated amount. The battery management system that manages a battery that outputs the SOC of the battery to an ECU of an automobile using electricity, and includes a sensing unit, an SOH estimating unit, an SOC estimating unit, a total battery capacity determining unit, and an output unit. The sensing unit measures the pack current and the pack voltage of the battery, the SOH estimator outputs the SOH using the pack current and the pack voltage, and the SOC estimator calculates and outputs the SOC using the pack current and the total battery capacity of the battery. The total battery capacity determiner accumulates the total discharge accumulated amount using the pack current, determines the total battery capacity according to the accumulated total discharge accumulated amount, and transmits the total battery capacity to the SOC estimator. The output unit outputs the calculated SOC or SOH to the ECU.
The current Lithium Ion battery chargers work on the basic charging protocol of CC-CV charge, where the battery pack is always charged at a constant current rate until the battery pack reaches the maximum voltage and then shifts to constant voltage where the battery packs voltage is kept constant to build up the remaining capacity. The minimum and maximum voltage are defined by the BMS of the battery and the chargers are not intelligent to pass information and control the charge current rate.
Hence during discharge the temperature of the battery pack increases due to internal heat generation and the similar phenomena is observed during charging, as the charge rates are relatively lower at 0.25C or 0.5C, the temperature build up inside is not significant, but the same chargers are used with faster charge rate, the temperature raise would be very high and can cause capacity degradation faster leads to fall in the lifecycles.
Most chargers are based on a Single operating Voltage, a charger can be only a 48V or 60V or 72V, but they are not multi voltage charger, where the flexibility of using such chargers for another system voltage becomes very difficult. Therefore the battery pack needs to be well conditioned while charging by having a proper communication between the BMS (of the battery pack) and the charge controller by constantly monitoring the SoC, temperature, SoH and other safety functionalities.
None of the prior-arts provides a charger which is capable of reading the values from the BMS and control current parameters by continuous interaction with the BMS of the battery pack.
The present invention provides a multi-voltage and current based smart charger and the charging techniques which can help in improving the life of the battery pack along with the safety. The smart charger of the present invention is always connected with the BMS of the battery pack to seek required information, to control the charging rates in order to improve and prolong the operational life of battery cells and operate the battery safely. The present invention provides a smart charger which continuously interacts with BMS of the battery pack enabling the charger to read and control the current parameter such as SoC, SoH, and temperature of the battery pack and operate at an optimum window. The present invention address the charging limitations faced by the Electric vehicle users currently, such as slow charging, charger’s incapability on monitoring the battery operational and health parameters.
Objects of the Invention:
The main object of the present invention is to provide a smart charger and a charging technique which can improve the life of the battery pack along with the safe operation.
The primary object of the present invention to provide a multi-voltage and current based smart electric vehicle charger with interactive BMS.
It is another object of the present invention to provide a charger which has continuous interaction with BMS of the battery pack enabling the charger to read and control the current parameter.
Still another object of the present invention is to provide a charger which has continuous interaction with BMS seeking the required information, to control the charging rates in order to improve the battery life’s and operates the battery safely.
It is another object of the present invention is to provide the BMS of the battery pack with an erasable memory (EPROM) and non-erasable memory unit.
It is another object of the present invention is to provide the BMS which supports the Charger with frequent status sharing through CAN or any other communication protocol.
It is another object of the present invention to provide a multi-voltage and current based smart charger which eliminates the charging limitations faced by the Electric vehicle users, such as slow charging, charger’s incapability on monitoring the battery operational and health parameters.
Unlike the conventional charger which can be used only for a single voltage system like either 48V or 60V or 72V, the multi-voltage charger of the present invention is capable of accommodating all the voltages from 48V to 72V battery packs of any chemistries and is applicable irrespective of battery chemistries and not limited to Li-Ion. And can be applicable to all the electric vehicles.
SUMMARY OF THE INVENTION
The present invention provides a multi-voltage and current based smart charger and the charging techniques which can help in improving the life of the battery pack along with the safety. The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger, which is in direct communication with the said BMS of the battery pack; and a current display unit, placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS is provided with a plurality of memory units includes erasable memory units and non-erasable memory units for storing the operational parameters of the electric vehicle, wherein the said charger which is in direct communication with the said BMS is configured to continuously access the data stored in the said plurality of memory units of the BMS and thereby controlling the charging current rate of the battery pack.
In the preferred embodiment of the present invention, the battery pack is charged at any level of SoC%. BMS will be continuously communicating the SoC% information to the charger and as per the SoC % of the battery the charger would provide the current as per the capability of the cell at that state.
In the preferred embodiment of the present invention, the charger charge current is also governed by considering the temperature of the battery cell and SoH.
In an embodiment of the present invention, the said charger is additionally provided with charge current input panel, wherein the user provides the input charge current at which the battery pack is to be charged.
The present invention also provides a method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising steps of : configuring BMS of the battery pack with a plurality of operational parameters of the electric vehicle; establishing a direct communication with the charger and the BMS of the battery pack, thereby enabling continuous flow of data exchange between the charger and the BMS; atleast a SoC % check unit, wherein the SoC % level of the battery pack is checked and compared with the predefined values; Wherein, if the SoC % remains within the predefined window the charging is continued at the same rate of charge current, Wherein, if the SoC % is different the charger current rate is altered based SoC % window.
The multi-voltage and current based smart electric vehicle charger of the present invention is provided with the capability to accommodate all voltage range from 48V to 72V battery packs of any chemistries. The said charger is applicable to all battery packs irrespective of its chemistries and is also applicable to all types of electric vehicles.
Other features and advantages of embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
Brief Description of the Drawings
Figure 1 represents the decision flow chart on SoC check during the charging process comprising of a multi-voltage and current based smart charger (142), interactive BMS (141), current display unit (143) and SoC check unit (145) in accordance with an embodiment of the present invention.
Figure 2 represents Smart BMS (141) capabilities embedded flowchart for charging according to the present invention.
Figure 3 represents decision flow chart at the start of charging process during user current input comprising of a multi-voltage and current based smart charger (142), interactive BMS (141) and charge current input panel (144) in accordance with an embodiment of the present invention.
Figure 4 represents the decision flow chart on temperature operating conditions during the charging process comprising of a multi-voltage and current based smart charger and an interactive BMS (141) in accordance with an embodiment of the present invention.
Figure 5 represents the decision flow chart on internal resistance/SoH check during the charging process comprising of a multi-voltage and current based smart charger (142) and an interactive BMS (141) in accordance with an embodiment of the present invention.
Figure 6 represents the decision flow chart on pre-charge circuit error detection during the charging process comprising of a multi-voltage and current based smart charger (142) and an interactive BMS (141) in accordance with an embodiment of the present invention.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concept of the term appropriately to describe its own invention in the best way. The present invention should be construed as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, it should be understood that equivalents and modifications are possible.
Detailed Description of the Invention with Respect to the Drawings
The present invention as embodied by "Multi-Voltage smart Charger with interactive BMS and charging method thereof" succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/ modification(s) applied to the structural alternative(s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The term “electric vehicle” or “EV” as used herein, includes vehicles having an electric motor for vehicle propulsion, such as battery electric vehicles (BEV), hybrid electric vehicles (HEV), and plug-in hybrid electric vehicles (PHEV).
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of: a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS (141) of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS (141) is provided with a plurality of memory units for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack.
In the preferred embodiment of the present invention, wherein said operational parameters of the electric vehicle, includes but not limited to, States of Charge (SoC), temperature of the battery pack, States of Health (SoH), cell voltages, current.
In the preferred embodiment of the present invention, wherein said plurality of memory units of the BMS (141) includes erasable memory units, non-erasable memory units and/or combinations thereof.
In the preferred embodiment of the present invention, wherein said erasable memory units of the BMS (141) stores operational parameters including SoC %, temperature of the current battery state and prior data point values.
In the preferred embodiment of the present invention, wherein said non-erasable memory units of the BMS (141) stores operational parameters including SoH%, precharge circuit operation logs from the initial operation of the battery pack.
The information stored in the erasable memory units and non- erasable memory units serves as main drivers for the charger for regulating the charge current rates.
In the preferred embodiment of the present invention, the battery pack is charged at any level of SoC%. BMS (141) will be continuously communicating the SoC% information to the charger (142) and as per the SoC % of the battery the charger would provide the current as per the capability of the cell at that state. Whereas in the traditional method the charger would charge at a constant rate irrespective of the SoC % level.
In the preferred embodiment of the present invention, as shown in Fig.2 the BMS (141) is configured with a plurality of operational parameters after performing the cell study. Wherein the cell study include but is not limited to temperature measurements at various SoC windows, SoC window and the cell ability to take charge current, Internal Resistance (IR) build-up at various SoC window in a cell during charging.
In the preferred embodiment of the present invention, the BMS (141) is configured with cell current threshold values at each SoC% level and based on the cell current values the charger (142) charges the battery pack at much higher rate upto a predefined SoC% window and thereby reduces the charger current as the SoC% increases towards 100%. In this way the charge time for charging the battery pack is reduced, as too frequent charging affects the SoH and the temperature of the cell.
In the preferred embodiment of the present invention, the charger charge current is also governed by considering the temperature of the battery cell and SoH.
In an embodiment of the present invention, the said charger (142) is additionally provided with charge current input panel (144), wherein the user provides the input charge current at which the battery pack is to be charged, the input charge current provided by the user is sent to the BMS (141) for evaluation, if the SoC % limit is satisfied by the input charge current then the user input charge current is accepted, if the SoC % limit is not satisfied, the BMS (141) automatically corrects the charge current rate to optimum configured charge current values based SoC, SoH and temperature of the pack.
A method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising steps of : configuring BMS (141) of the battery pack with a plurality of operational parameters of the electric vehicle; establishing a direct communication with the Charger (142) and the BMS (141) of the battery pack, thereby enabling continuous flow of data exchange between the charger (142) and the BMS (141); atleast a SoC % check unit (145), wherein the SoC % level of the cell current is checked and compared with the predefined values; Wherein, if the SoC % remains within the predefined window the charging is continued at the same rate of charge current, Wherein, if the SoC % is different the charger current rate is altered based SoC % window.
In an embodiment of the present invention, the method of operation of the multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising steps of : configuring BMS (141) of the battery pack with a plurality of operational parameters of the electric vehicle; establishing a direct communication with the Charger (142) and the BMS (141) of the battery pack, thereby enabling continuous flow of data exchange between the charger (142) and the BMS (141); the said charger (142) is provided with charge current input panel (144), wherein the user provides the input charge current at which the battery pack is to be charged, the input charge current provided by the user is sent to the BMS (141) for evaluation, if the SoC % limit is satisfied by the input charge current then the user input charge current is accepted, if the SoC % limit is not satisfied, the BMS (141) automatically corrects the charge current rate to optimum configured charge current values based SoC, SoH and temperature of the pack.
In the preferred embodiment of the present invention, if the temperature of the battery pack exceeds a predefined set points the charger (142) will reduce the charge current irrespective of SoC%, so that the temperature of the battery pack does not increase and is well maintained within the optimum operating limits. This avoids over heating of the battery pack and improves the battery performance.
In the preferred embodiment of the present invention, the charger (142) is also operated based on the SoH of the battery pack. SoH of the battery pack also is an important consideration in deciding the battery pack capability to absorb the charge rates. If the SoH or the Internal Resistance (IR) of the battery cell is within the predefined optimum range, the charger is operated at its normal operating condition; if there is an increase in Internal Resistance (IR) or SoH of the battery cell, the charger current is adjusted to avoid usage of high current charging.

In the preferred embodiment of the present invention, the charging is done based on the health of pre-charge circuit. Any deviation or problem in the circuitry causes system failures due to exposure to high inrush currents. Therefore while charging the battery pack, the status of the pre-charge circuit operation and its history of operation stored in the permanent memory of the BMS (141) is transferred to the charger (142). If any errors exists in the pre-charge circuit the charger (142) will not charge the battery pack until the error is rectified. This is a safety feature to de-risk the system failure due to failed pre-charge circuit and system damage due to inrush current.
The present invention not only provides a smart charger, but also provides an interactive BMS (141) that supports the Charger (142) with frequent status sharing through CAN or any other communication system.
Unlike the currently available chargers which are used only for a single voltage system like either 48V or 60V or 72V, the present invention multi voltage smart charger has the capability to accommodate all voltage range from 48V to 72V battery packs of any chemistries and is applicable to all battery packs irrespective of its chemistries and not limited to Li-Ion. And is applicable to all the Electric vehicles.
EXAMPLE 1
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS (141) of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS (141) is provided with a plurality of memory units, erasable memory units and non-erasable memory unit for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack. The multi voltage smart charger of the present invention has the capability to accommodate all voltage range from 48V to 72V battery packs of any chemistries and is applicable to all battery packs irrespective of its chemistries and not limited to Li-Ion. For battery pack of 48V a multi-voltage charger battery system with 48V is operated, whereas the BMS (141) of the battery pack can be modified to operate in a 48V or 60V and 72V based on the series sensing pins on the BMS thereby provides us cost advantage. This is a great advantage with a charging station where currently a charging station with a single voltage is being operated. In near future if OEM strategize the charging stations to operate in a multi voltage charging stations, the multi voltage smart charger of the present invention provides a promising solution to the technology irrespective of voltages and can charge the battery pack. This gives a good flexibility in terms of capital investment and also standardization of the battery packs and charging stations.
EXAMPLE 2
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of: a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS (141) of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS (141) is provided with a plurality of memory units, erasable memory units and non-erasable memory unit for storing the operational parameters of the electric vehicle, wherein the said charger is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack. BMS (141) will be continuously communicating the SoC% information to the charger and as per the SoC % of the battery the charger (142) would provide the current as per the capability of the cell at that state. BMS (141) is configured with the cell current limits at each SoC% level. Based on the cell current limits at SoC % the Charger (142) charges the battery pack at a much higher rate than the continuous charger current up to certain SoC% window and thereby reduce the charger current as the SoC% increases towards 100%. This reduces the charge time for charging the battery pack because too frequent charging affects the SoH and temperature.
EXAMPLE 3
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS (141) of the battery pack. Wherein the said BMS (141) is provided with a plurality of memory units, erasable memory units and non-erasable memory unit for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS and thereby controls the charging current rate of the battery pack. The said charger is provided with a charge current input panel (144), wherein the user provides the input charge current at which the battery pack is to be charged, the input charge current provided by the user is sent to the BMS for evaluation, if the predefined SoC % limit is satisfied by the input charge current provided by the user then the input charge current is accepted and the charger charges the battery pack at the charge current rate provided by the user. If the SoC % limit is not satisfied by the input charge current provided by the user, the BMS (141) automatically corrects the charge current rate to the predefined optimum configured charge current values based SoC %, SoH% and temperature of the battery pack, and the charger charges the battery pack as defined by the BMS.
EXAMPLE 4
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS is provided with a plurality of memory units for storing the operational parameters of the electric vehicle, wherein the said charger is in direct communication with the said BMS is configured to continuously access the data stored in the said plurality of memory units of the BMS and thereby controls the charging current rate of the battery pack. If the temperature of the battery pack exceeds a predefined set points the charger will reduce the charge current irrespective of SoC%, so that the temperature of the battery pack does not increase and is well maintained within the optimum operating limits. This avoids over heating of the battery pack and improves the battery performance. Say when the battery pack is at SoC < 25%, the Current charge rate of the charger is at 3C and during charging the temperature of the battery pack rises from 25 °C to 35 °C. When the temperature of the battery pack rises to 35°C, which is the 1st predefined Set point the Charger reduces the current charge rate to a lower charge rate of 2C irrespective of SoC%. This eventually reduces the internal pack heat generation and also helps in building up the charge through charger at next optimum charge rate. Similarly once the temperature reaches a predefined set limit of 45°C, the charger will further reduce the current charge rate and operate only at a Continuous Current rate. This reduces the total charge time to reach 100% and also does not allow the temperature of the battery pack to raise even when it is charged at higher charge current rate.
EXAMPLE 5
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS (141) is provided with a plurality of memory units for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack. The charger (142) of the present invention is also operated based on the SoH of the battery pack. SoH of the battery pack also is an important consideration in deciding the battery pack capability to absorb the charge rates. If the SoH or the Internal Resistance (IR) of the battery cell is within the predefined optimum range, the charger is operated at its normal operating condition; if there is an increase in Internal Resistance (IR) or SoH of the battery cell, the charger current is adjusted to avoid usage of high current charging rates. In the present invention, if the battery pack is at lower SoC and current rate for the charger is more than the continuous current rate say 3C charger rate up to 25% SoC and after reaching 25% SoC, the charge current rate is reduced to say 2C or 1.5C charge rate. Simultaneously when SoH of the battery pack is less than 90% or 95%, this means the battery pack is healthy but the same Charge rates cannot be applied when the SoH is less than 85% or at 80%, which means the capacity has been degraded and by charging at such high C-rates even at lower SoC can lead to faster detoriation of the battery pack.
EXAMPLE 6
The present invention provides a multi-voltage and current based smart electric vehicle charger with interactive battery management system (BMS), comprising of : a battery pack with a battery management system (BMS) (141), which collects and stores a plurality of operational parameters of the electric vehicle; atleast a charger (142), which is in direct communication with the said BMS of the battery pack; and a current display unit (143), placed in direct connection with the battery pack displaying the State of Charge (SoC) % to the user, wherein the said BMS (141) is provided with a plurality of memory units for storing the operational parameters of the electric vehicle, wherein the said charger (142) is in direct communication with the said BMS (141) is configured to continuously access the data stored in the said plurality of memory units of the BMS (141) and thereby controls the charging current rate of the battery pack. The charging is also done based on the health of the pre-charge circuit. Any deviation or problem in the circuitry causes system failures due to exposure to high inrush currents. Therefore while charging the battery pack, the status of the pre-charge circuit operation and its history of operation stored in the permanent memory of the BMS is transferred to the charger. If any errors exists in the pre-charge circuit the charger will not charge the battery pack until the error is rectified. This is a safety feature to de-risk the system failure due to failed pre-charge circuit and system damage due to inrush current.
Although the proposed concept has been described as a way of example with reference to various models, it is not limited to the disclosed embodiment and that alternative designs could be constructed without deviating from the scope of invention as defined above.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the scope of the invention may be made by a person skilled in the art.