Description:TECHNICAL FIELD
[0001] Embodiments of the present disclosure relate to a voltage equalizer and more specifically to a battery voltage equalizer.

BACKGROUND
[0002] Generally, battery packs (referred to as cells, wherein a battery pack as referred herein may have one or more cells) and capacitor-based energy storage systems use multiple cells to store and provide voltage as required for use, where a device may be connected to these battery packs. Normally, these battery packs are connected in series to obtain sufficient voltage to power a device. Typically, series connected battery cells in a battery pack may not have same terminal voltages due to manufacturing tolerance and unequal aging of the cells. In general, in every charging-discharging unit containing several batteries forming a battery pack, and it is common that some cells are over-charged and over-discharged, leading to deterioration and life of the batteries in the battery pack. To prevent such effects, a voltage equalizer may be used to ensure longevity of the batteries. Normally, a voltage equalizer coupled to the batteries is used to make voltages of the batteries in a battery pack equal by controlling the charging and discharging and prolong life of the batteries in the battery pack. Typically, voltage equalizers are built as modules to support large number of batteries coupled together forming a unit to power certain devices.
[0003] A transformer-based voltage equalizer module uses multiple transformers for each module of battery pack and secondary windings of these transformers are connected to equalize the voltage between batteries in the battery pack. Although the layout and design is simple and passive, use of multiple transformers for each module makes the design of transformer-based voltage equalizer modules bulky and lossy.
[0004] On the other hand, a transformer less voltage equalizer module does not use any transformers and enables compact design of an equalizer module, saving space. Modularization for batteries using transformer less voltage equalizer module is done by performing equalization for the last battery of a module and the first battery of the next module. However, voltage equalization between modules becomes relatively slow as only the terminal batteries can participate in inter-module equalization. Another approach of transformer less equalizers is to use an additional equalizer to perform inter-module equalization. By using additional equalizer for inter-module equalization, the overall size of the equalizers increases and overall power loss becomes higher. Transformer less equalizers also require several additional active and passive components, thus increasing complexity of the modules and includes additional cost. Moreover, the design of the additional equalizer depends on the number of modules, which makes it application specific, thereby requiring different types of modules to be designed for different applications. Even though inter-module equalization is possible, a direct charge transfer from any battery (cell) of a module to any battery (cell) of another module is not possible with these methods. In view of the above, there is a need for ameliorating the design of a transformer less voltage equalizer module to overcome at least some of the design challenges above.

SUMMARY
[0005] Embodiments of the present disclosure relate to a voltage equalizer module for a plurality of energy devices (hereinafter energy devices may be broadly read as energy storage devices or a battery or a cell) of an energy device module. In an embodiment, the voltage equalizer module includes an energy device module. In an embodiment the energy device module has a plurality of energy devices connected in series, wherein the voltage equalizer module includes a sub-module and a transformer. In an embodiment, a primary winding of a transformer may be coupled to an equalizer module. In an embodiment, a sub-module may be coupled between a positive terminal and a negative terminal of an energy device. In a further embodiment, a plurality of voltage equalizer modules may be coupled together by coupling the secondary windings of each of the voltage equalizer module. Based on the voltage measurements from each of the voltage equalizer module and the average voltage of the module, a gate signal may be generated for transferring energy from one voltage equalization module to another voltage equalization module, thereby equalizing voltages across the voltage equalizer modules. Other embodiments are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The detailed description is described with reference to the accompanying figures. features, aspects, and advantages of the subject matter of the present disclosure will be better understood with regard to the following description and the accompanying drawings. The figures are intended to be illustrative, not limiting, and are generally described in context of the embodiments, and it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the figures, the same numbers may be used throughout the drawings to reference features and components. In order that the present disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages.
[0007] Figure 1A illustrates a voltage equalizer module in accordance with embodiments of the present disclosure.
[0008] Figure 1B illustrates a voltage equalizer module showing an upper and a lower half of the voltage equalizer module in accordance with embodiments of the present disclosure.
[0009] Figure 2 illustrates a voltage equalizer module implemented for a battery pack in accordance with embodiments of the present disclosure.
[0010] Figure 3 illustrates a controller circuit to control the operations of the voltage equalizer module in accordance with embodiments of the present disclosure.
[0011] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical elements. The figures as disclosed herein are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings are meant to only be provided as examples and/or implementations consistent with the description, and the description may not be limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION
[0012] The following describes technical solutions in exemplary embodiments of the subject matter of the present disclosure with reference to the accompanying drawings. In this application as disclosed herein, "at least one" means one or more, and "a plurality of" means two or more. The term "and/or" describes an association relationship for describing associated objects and represents that three relationships may exist. For example, A and/or B may represent the following cases: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character "/" usually indicates an "or" relationship between the associated objects. "At least one item (piece) of the following" or a similar expression thereof means any combination of the items, including any combination of singular items (piece) or plural items (pieces). For example, at least one item (piece) of a, b, or c may represent a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c each may be singular or plural.
[0013] It should be noted that in this application articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. Throughout this specification defined above, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps. The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably. In the structural formulae given herein and throughout the present disclosure, the following terms have been indicated meaning, unless specifically stated otherwise.
[0014] Unless otherwise defined, all terms used in the disclosure, including technical and scientific terms, have meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included for better understanding of the present disclosure. The term ‘about’ as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of ±10% or less, preferably ±5% or less, more preferably ±1% or less and still more preferably ±0.1% or less of and from the specified value, insofar such variations are appropriate to perform the present disclosure. It is to be understood that the value to which the modifier ‘about’ refers is itself also specifically, and preferably disclosed.
[0015] It should be noted that in this application, the term such as "example" or "for example" or “exemplary” is used to represent giving an example, an illustration, or descriptions. Any embodiment or design scheme described as an "example" or "for example" in this application should not be explained as being more preferable or having more advantages than another embodiment or design scheme. Exactly, use of the word such as "example" or "for example" is intended to present a related concept in only a specific manner.
[0016] It should be understood that in the embodiments of the present subject matter that "B corresponding to A" indicates that B is associated with A, and B can be determined based on A. However, it should be further understood that determining B based on A does not mean that B is determined based on only A. B may alternatively be determined based on A and/or other information.
[0017] In the embodiments of this application, "a plurality of" means two or more than two. Descriptions such as "first", "second" in the embodiments of this application are merely used for indicating and distinguishing between described objects, do not show a sequence, do not indicate a specific limitation on a quantity of devices in the embodiments of this application, and do not constitute any limitation on the embodiments of this application.
[0018] Exemplary embodiments of the present disclosure relate to a voltage equalizer module for a plurality of energy devices (energy device may also referred to as battery or cell in the present disclosure). An exemplary embodiment includes a voltage equalizer module for equalizing voltages across a plurality of energy device B1…B4, in an energy device module. In a further embodiment, the voltage equalizer module includes an energy device module, wherein the energy device module includes a plurality of energy devices B1…B4, and the plurality of energy devices B1…B4 in the energy device module are coupled in series. In an exemplary embodiment, the voltage equalizer modules includes an energy equalizer module, wherein the energy equalizer module comprises a plurality of sub-equalizer modules (also referred to as sub-modules) and the energy equalizer module being coupled to the energy device module. In an exemplary embodiment, the voltage equalizer module includes a transformer, wherein a first end of a primary winding of the transformer is coupled to a Node N1 of the equalizer module (reference to equalizer module may also be read as energy equalizer module) and a second end of the primary winding of the transformer is coupled to a Node N2 of the equalizer module.
[0019] In an exemplary embodiment, each of the plurality of energy device B1…B4 comprises a sub-module. In an exemplary embodiment, each sub-module includes an energy device B4. In an exemplary embodiment, a positive terminal of the energy device B4 may be coupled to a first transistor T1, and a negative terminal of the energy device B4 may be coupled to a second transistor T2. In an exemplary embodiment, a first arm of a first capacitor C4 may be coupled between the first transistor T1 and the second transistor T2, and a second arm of the first capacitor C4 may be coupled to a first end of an inductor L4. In an exemplary embodiment, a second end of the inductor L4 may be coupled to the node N2, wherein the node N2 may be coupled to the first end of the primary winding of the transformer 130.
[0020] In an exemplary embodiment, in the sub-module, in the upper half 122, a first arm of a second capacitor Cdc4 may be coupled to the transistor T1, and a second arm of the capacitor Cdc4 may be coupled to the Node N1. In an exemplary embodiment, in the sub-module 140 for a lower half 124 of the module 100, a first arm of a second capacitor Cdc4 is coupled to the transistor T2, and a second arm of the capacitor Cdc4 is coupled to the Node N1. In an exemplary embodiment, the Node N1 is coupled to a mid-point of energy device module. In an exemplary embodiment, the first capacitor C4 may be a DC blocking capacitor and the second capacitor Cdc4 may be DC bus capacitor, wherein the first capacitor C4 and the second capacitor Cdc4 block DC currents, such that the node N2 cannot have a DC current. In an exemplary embodiment, an equalization current in the sub module is controlled using phase shifts among gate drive signals of half-bridges based on measured energy device voltages and average energy device module voltage. In an exemplary embodiment, the transformer may be configured with a low leakage inductance, wherein a turn ratio may be chosen to be in a range close to unity (1).
[0021] An exemplary embodiment includes voltage equalizer module for coupling a plurality of modules, wherein each module includes a transformer, and each of the transformers includes a primary winding and a secondary winding, wherein a first end of the primary winding of the transformer may be coupled to a Node N1 and a second end of the primary winding may be coupled to a Node N2, In an exemplary embodiment, a first end of a secondary winding of the first transformer of a first module may be coupled to a first end of the secondary winding of the second transformer of a second module, and a second end of the secondary winding of the first transformer may be coupled to a second end of the secondary winding of the second transformer, wherein the secondary winding of each of the transformers of the voltage equalizer module may be coupled in parallel.
[0022] In an exemplary embodiment, each of the modules may be coupled in series to form an voltage equalizer, wherein the inter-module voltage equalizer may be coupled via the secondary winding of each of the plurality of transformers of the modules. In an exemplary embodiment, energy flows from an energy device in a first module to any other energy device in another module via the transformers coupling each of the modules. In an exemplary embodiment, each of the modules includes a controller, wherein each of the controllers may be configured to provide a gate signal to each of the corresponding modules. In an exemplary embodiment, a synchronization signal may be generated by at least one controller, and the synchronization signal may be transmitted to other controllers, wherein the other controllers use the synchronization signal to generate a synchronized gate pulse. In an exemplary embodiment, an output of each energy device voltage sensor may be connected to a common node using a resistor Ra, and the common node may be connected between the modules to sense the average voltage of the plurality of energy devices in the plurality of energy device modules for controlling each equalizer module.
[0023] In an exemplary embodiment, the voltage equalizer module may be a transformer less that may be implemented for a battery pack which includes a plurality of energy devices. In an exemplary case, the voltage equalizer module may be configured for equalizing voltage across a plurality of energy devices in an energy device module (battery pack). In an exemplary case, the energy devices are connected in series and coupled to an equalizer module. In an exemplary case, the equalizer module may have equalizer sub-modules, which are connected to the energy devices. In an exemplary case, a transformer may be connected between two nodes of the equalizer module. In an exemplary case, the transformer may be configured with a low leakage inductance, wherein a turn ratio is chosen to be in the range close to unity.
[0024] Exemplary embodiments of the present disclosure relate to a voltage equalizer module for a plurality of voltage equalizer modules. In an exemplary case, each of these voltage equalizer modules may have a transformer. In an exemplary case, the secondary windings of the transformer of each voltage equalizer modules may be connected in parallel to each other. In an exemplary case, the individual voltage equalizer modules may be connected in series with each other and energy flows from each module to the other through the transformers. In an exemplary case, each of the individual voltage equalization modules may be controlled by a controller. In an exemplary case, a controller may generate a control signal, which may be synchronized with the other modules that is used to generate a synchronized gate pulse.
[0025] Reference is now made to Figure 1A, which illustrates a voltage equalizer module 100 in accordance with embodiments of the present disclosure. Voltage equalizer module 100 has a energy device module 110, equalizer module 120 coupled to energy device module 110 and transformer 130 coupled to equalizer module 120. A first end of the primary winding of transformer 130 is coupled to Node N1 of equalizer module 120 and a second end of the primary winding of transformer 130 is coupled to node N2 of equalizer module 120. As illustrated in the Figure, for simplicity and illustration, each of the energy device has sub-module 140 and each sub-module 140 includes a sub-equalizer module 125.
[0026] As illustrated in exemplary Figure 1A, each energy device B1-B4 will have a sub-module 140. The number of sub-modules will be proportional to the number of energy devices. In an exemplary case, four energy devices are shown in the Figure and each of the four energy devices will have a specific sub-module 140. The connections in sub-module 140 is explained with respect to battery B4, and it should be obvious to a person skilled in the art that for every energy device, sub-module 140 may be replicated, and the illustration provided here is only with respect to a single energy device B4 from amongst the plurality of energy device B1-B4 forming voltage equalizer module 100. As illustrated, each energy device B1-B4 will consist of sub-module 140. Considering a specific energy device B4, a positive terminal of the energy device B4 is coupled to a first transistor T1 and the negative terminal of the energy device B4 is connected to a second transistor T2 in equalizer module 120. In equalizer module 120, a first arm of a first capacitor C4 is coupled between the first transistor T1 and the second transistor T2, and a second arm of the first capacitor C4 is coupled to a first end of an inductor L4. A second end of the inductor L4 is connected to node N2 of equalizer module 120. A first end of a capacitor Cdc4 is coupled to the transistor T1 and a second end of the capacitor Cdc4 is connected to the node N1 of equalizer module 120. Although the connection is shown for one such sub-module, it may be replicated for the energy devices B1-B3 as well. Every energy device will be coupled similarly to form the voltage equalizer module.
[0027] Voltage equalizer module also includes a Transformer module 130, containing a single transformer Tmod wherein a first end of the primary winding of the transformer is connected to Node N1 of equalizer module 120 and a second end of the primary winding of the transformer is connected to Node N2 of equalizer module 120. Energy device module 110, equalizer module 120 and transformer module 130 together make up voltage equalizer module 100, which is configured to efficiently charge and discharge energy devices within the module 100.
[0028] Reference is made to Figure 1B, showing an imaginary division of voltage equalizer module 100 into upper half 122 and lower half 124. The configuration to sub-module 140 in lower half 124 is different from that of the configuration in upper half 122. In upper half 122 of voltage equalizer module 100, sub-module 140 is configured to have a first arm of a second capacitor Cdc4 coupled to the transistor T1, and a second arm of the capacitor Cdc4 is coupled to the Node N1. In lower half 124 of voltage equalizer module 100, sub-module 140 for lower half of the module 100, a first arm of a second capacitor Cdc4 is coupled to the transistor T2, and a second arm of the capacitor Cdc4 is coupled to the Node N1. By configuring sub-modules 140 for upper half 122 and lower half 124, a midpoint of the voltage equalizer module is formed. The node N1 is coupled to the midpoint of the voltage equalizer module.
[0029] The operations of voltage equalizer module 100 is controlled by using gate pulses that may be issued by a controller. The operation of the controller is explained later with respect to Figure 3. The voltage of each energy devices B1-B4 as well as the average energy device voltage may be measured. A gate drive signal may be issued by the controller thereby activating the half bridge circuitry formed by transistors T1 and T2 of sub-module 140. Based on the gate bridge signal, the transistors T1 and T2 may be switched on/off creating a path for current to flow. The gate drive signal controls the on-time period thereby regulating the output equalization current. By determining voltage at each energy device and calculating average voltage at each energy device and issuing gate drive signal, the equalization current may be controlled. The manner in which the voltage equalization is performed between multiple voltage equalizer modules is explained with respect to Figure 2.
[0030] Reference is now made to Figure 2, showing a voltage equalizer module 200 for coupling a plurality of voltage equalizer modules. A plurality of voltage equalizer modules 200A…200C are coupled using transformers 230A…230C. Each of plurality of transformers 230A…230C coupling a voltage equalizer module have a primary winding and a secondary winding. The primary windings in each of the transformers are coupled to node N1 and N2 of their respective voltage equalizer modules. The secondary windings of the plurality of transformers 230A….230C are connected to each other in a manner described below. A first end of the secondary winding of transformer 230A is connected to the first end of the secondary winding of transformer 230B. A second end of the secondary winding of transformer 230A is connected to a second end of the secondary winding of transformer 230B. Similarly, the first end of the secondary winding of transformer 230B is connected to the first end of the secondary winding of transformer 230C. A second end of the secondary winding of transformer 230B is connected to a second end of the secondary winding of transformer 230C. Each of the secondary windings of the transformers 230A…230C are connected in parallel. It should be obvious to a person or ordinary skill in the art that the number of connections between the secondary windings depends on the number of transformers used in the voltage equalizer, and the secondary windings are connected in parallel.
[0031] By connecting the secondary windings of transformers 230A…230C in parallel, each voltage equalizer module 200A…200C are connected in series to form an inter-module equalizer. Energy from one module can flow to the other module via the transformers as they are now inter-connected. In an exemplary case, energy from module 200A can flow to any other module, such as other module 200B, through the transformers 230A and 230 B. Since the modules are inter-connected, energy can flow from any module to any other module in the voltage equalizer module. In this manner energy transfer between the voltage equalizer modules using the inter-module equalizer is performed using a controller circuitry implemented for each of the voltage equalizer module 200A…200C.
[0032] Reference is now made to Figure 3, showing a control circuits 310A….310C implemented for each of the voltage equalizer modules 200A…200C. Each of the control circuits includes a controller 315A…315C. Each of these control circuits provide a gate signal to their corresponding voltage equalizer modules 200A…200C. The control circuits 310A….310C have a controller 315A…315C each that control the operations of the voltage equalizer modules 200A…200C. The operations of voltage equalizer modules 200A…200C have to be synchronized to ensure effective voltage equalization. A common synchronizing signal may be generated by one of the controllers and sent to other controllers to generate a synchronized gate pulse. In an exemplary embodiment, the controller 315B generates the common synchronizing signal that may be transmitted to the other controllers 315A and 315C.
[0033] Each of energy devices B1…B4is coupled to a voltage sensor for each of these voltage equalization modules 200A…200C. An output of each voltage sensor is connected to a common node using a resistor Ra, and the common node is connected between the modules 200A …200C to sense the average voltage of the plurality of energy devices B1…B4 in the plurality of energy device modules 210A…210C for controlling each equalizer module. The voltage of the common node becomes equal to the average voltage of the all the energy device modules 210A…210C. Thus, each of the controllers 315A….315C accesses cell voltages of its respective equalizer module 120 as well as the average cell voltage of voltage equalizer modules 200A…200C without communicating with other controllers.
[0034] Although the present disclosure has been described with reference to several preferred embodiments, it should be understood that the present disclosure is not limited to the preferred embodiments disclosed here. Embodiments of the present disclosure are intended to cover various modifications and equivalent arrangements within the spirit and scope of the appended claims. Although the foregoing disclosure has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practised within the scope of the appended claims. Examples of the present disclosure have been described in language specific to structural features and/or methods. It should be noted that there are many alternative ways of implementing both the process and apparatus of the present invention. Accordingly, embodiments of the present disclosure are to be considered illustrative and not restrictive, and the invention is not to be limited to the details given herein but may be modified within the scope and equivalents of the appended claims. It should be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed and explained as examples of the present disclosure. , Claims:We Claim:

1. A voltage equalizer module 100 for equalizing voltages across a plurality of energy device B1…B4, in an energy device module 110, the voltage equalizer module 100 comprising:
- an energy device module 110, wherein the energy device module 110 comprises a plurality of energy devices B1…B4, wherein the plurality of energy devices B1…B4 in the energy device module 110 being coupled in series;
- an equalizer module 120, wherein the energy equalizer module 120 comprises a plurality of sub modules 125 and the equalizer module 120 being coupled to the energy device module 110; and
- a transformer 130, wherein a first end of a primary winding of the transformer 130 is coupled between a Node N1 of the equalizer module 120 and a second end of the primary winding of the transformer 130 is coupled to a Node N2 of the equalizer module 120.

2. The voltage equalizer module 100 as claimed in claim 1, wherein each of the plurality of energy device B1…B4 comprises a sub-module 140, wherein each sub-module 140 comprises:
- an energy device B4,
- a positive terminal of the energy device B4 coupled to a first transistor T1, and a negative terminal of the energy device B4 coupled to a second transistor T2;
- a first arm of a first capacitor C4 coupled between the first transistor T1 and the second transistor T2, and a second arm of the first capacitor C4 coupled to a first end of an inductor L4; and
- a second end of the inductor L4 coupled to the node N2, wherein the node N2 is coupled to the first end of the primary winding of the transformer 130.

3. The voltage equalizer module 100 as claimed in claim 2, wherein in the sub-module 140 for an upper half 122 of the module 100, a first arm of a second capacitor Cdc4 is coupled to the transistor T1, and a second arm of the capacitor Cdc4 is coupled to the Node N1.

4. The voltage equalizer module 100 as claimed in claim 2, wherein in the sub-module 140 for a lower half 124 of the module 100, a first arm of a second capacitor Cdc4 is coupled to the transistor T2, and a second arm of the capacitor Cdc4 is coupled to the Node N1.

5. The voltage equalizer module 100 as claimed in claim 1, wherein the Node N1 is coupled to a mid-point of energy device module 110.

6. The voltage equalizer module 100 as claimed in claim 2, wherein the first capacitor C4 is a DC blocking capacitor and the second capacitor Cdc4 is a DC bus capacitor, wherein the first capacitor C4 and the second capacitor Cdc4 blocks DC current, and the node N2 cannot have a DC current.

7. The voltage equalizer module 100 as claimed in claim 1, wherein an equalization current in the sub module 140 is controlled using phase shifts among gate drive signals of half-bridges based on measured energy device voltages and average energy device module voltage.

8. The voltage equalizer module 100 as claimed in claim 1, wherein the transformer 130 is configured with a low leakage inductance, wherein a turn ratio is chosen to be in the range close to unity.

9. A voltage equalizer module 200 for coupling a plurality of modules 100A …100C as claimed in claims 1 to 8, wherein each module 100A… 100C comprises a transformer 130A …130C:
- each of the transformers 130A…130C comprises a primary winding and a secondary winding,
- a first end of the primary winding of the transformer 130A…130C coupled to a Node N1 and a second end of the primary winding coupled to a Node N2; and
- a first end of a secondary winding of the transformer 130A of module 100A coupled to a first end of the secondary winding of the transformer 130B of module 100B, and a second end of the secondary winding of the transformer 130A being coupled to a second end of the secondary winding of the transformer 130B, wherein the secondary winding of each of the transformers 130A, … 130C being coupled in parallel.

10. The voltage equalizer module 200 as claimed in claim 9, wherein each of the module 100A, 100B…100C coupled in series to form an inter-module voltage equalizer, wherein the inter-module voltage equalizer being coupled via the secondary winding of each of the plurality of transformers 130A…130C.

11. The voltage equalizer module 200 as claimed in claim 10, wherein energy flows from an energy device in one module 100A to any other energy device in another module 100B or 100C via the transformers.

12. The voltage equalizer module 200 as claimed in claims 9 to 11, wherein each of the modules 110A…110C comprises a controller 315A…315C, wherein each of the controllers 315A…315C is configured to provide gate signals to each of the corresponding modules 110A …110C.

13. The voltage equalizer module 200 as claimed in claim 12, wherein a synchronization signal is generated by at least one controller, and the synchronization signal is transmitted to other controllers, wherein the other controllers use the synchronization signal to generate a synchronized gate pulse.

14. The voltage equalizer module 200 as claimed in claim 12, wherein an output of each energy device voltage sensor is connected to a common node using a resistor Ra, and the common node is connected between the modules 110A …110C to sense the average voltage of the plurality of energy devices in the plurality of energy device modules 100A…100C for controlling each equalizer module.

Dated this 03rd day of April 2024 Indian Institute of Science
By their Agent & Attorney

Dr. Eric W B Dias/Reg No 1058
of Khaitan & Co