Methods and apparatus for autonomous balancing and communication in battery systems

Abstract

This invention relates to a method and apparatus for autonomous balancing and communication in a battery system. The apparatus may include a battery pack connected to a management network. The management network may be configured to communicate with a main controller via a communication bus. The apparatus may be configured to operate in a communication mode and a balancing mode.

Description

Technical Field

[0001] This invention relates to methods and apparatus for autonomous balancing and communication in battery systems. Background Technology

[0002] Increasingly, battery-powered systems equipped with battery packs (i.e., batteries connected in series) utilize active balancing technology to improve the storage capacity and lifespan of the battery pack. Switched capacitor balancing technology is commonly used for this purpose. Furthermore, it is generally desirable to monitor each cell in the battery pack to prevent unsafe conditions such as overvoltage, undervoltage, and excessive temperature by activating safety mechanisms upon detection of such conditions. Routine monitoring of each cell in the battery pack requires additional wiring beyond the basic pack wiring. Summary of the Invention

[0003] This invention relates to methods and apparatus for autonomous balancing and communication in battery systems.

[0004] The device may include a battery pack connected to a management network. The management network may be configured to communicate with a main controller via a communication bus. The device may be configured to operate in a balanced mode, a communication mode, or both balanced and communication modes simultaneously.

[0005] The technical problem solved by this invention is that conventional battery systems with multiple interconnected batteries require additional wiring to monitor unsafe conditions of each battery, such as overvoltage, undervoltage, and overheating. This additional wiring increases the complexity and cost of the system.

[0006] According to a first aspect, an apparatus for autonomous balancing and communication in a battery pack having a plurality of series-connected batteries includes: a communication bus including a plurality of series-connected capacitors; a plurality of management units, wherein each management unit is: connected to the communication bus via a node; and directly connected to a corresponding battery in the battery pack and configured to perform autonomous balancing of the corresponding battery; and a first controller connected to the communication bus, wherein the first controller communicates with each management unit via the communication bus.

[0007] In one implementation, each capacitor is connected between two directly adjacent management units among the plurality of management units.

[0008] In one implementation, each of the plurality of management units includes: a second controller configured to: generate a first control signal; generate a second control signal; and communicate with the first controller.

[0009] In one embodiment, each of the plurality of management units includes a transceiver connected between the node and the second controller.

[0010] In one embodiment, each management unit further includes: a first switching element configured to selectively connect a first terminal of the corresponding battery to the communication bus; and a second switching element configured to selectively connect a second terminal of the corresponding battery to the communication bus.

[0011] In one embodiment, the first switching element responds to the first control signal; the second switching element responds to the second control signal; and the first control signal and the second control signal are non-overlapping signals.

[0012] In one implementation, each management unit is configured to: detect errors in the corresponding battery in the battery pack, wherein the error is related to at least one of: the temperature of the individual battery; the current of the individual battery; and the voltage of the individual battery; and generate an error signal based on the detected error.

[0013] According to another aspect, a method for autonomous balancing and communication in a battery system having multiple series-connected batteries connected to a communication bus includes performing autonomous balancing. Performing autonomous balancing includes transferring charge from a first battery among the multiple batteries to a second battery among the multiple batteries, the transfer including: generating a first control signal using a local control system associated with the first battery; selectively operating a first switch according to the first control signal; generating a second control signal using the local control system; selectively operating a second switch according to the second control signal; selectively connecting a first terminal of the first battery to a capacitor storage device using the first switch; and selectively connecting a second terminal of the first battery to the capacitor storage device using the second switch. The method further includes: detecting an error state in at least one of the multiple batteries; and activating communication between the local control system and a main controller in response to the error state, wherein the communication includes: generating a communication signal using the main controller; transmitting the communication signal to the local control system via the communication bus; generating a response signal using the local control system according to the error state; and transmitting the response signal to the main controller via the communication bus.

[0014] In one implementation, generating the first control signal and the second control signal includes counting a predetermined time period using a timer.

[0015] In one embodiment, generating the first control signal includes comparing the node voltage of the local control system with a threshold voltage; and generating the second control voltage includes comparing the node voltage with the threshold voltage.

[0016] The technical effect achieved by this invention is to provide autonomous balancing and communication among multiple batteries in a battery system, which allows for individual monitoring of each battery and provides detection of unsafe conditions without additional wiring. Attached Figure Description

[0017] The present invention can be more fully understood by referring to the specific embodiments when considered in conjunction with the following exemplary drawings. Throughout the following drawings, similar reference numerals are used to refer to similar elements and steps in the various drawings.

[0018] Figure 1 This is a block diagram of a battery-driven system according to an exemplary embodiment of the present technology;

[0019] Figure 2 A circuit diagram of a management unit according to an exemplary embodiment of the present technology;

[0020] Figure 3A A timing diagram of the first balancing signal during an autonomous balancing mode according to an exemplary embodiment of the present technology;

[0021] Figure 3B A timing diagram of the second balancing signal during an autonomous balancing mode according to an exemplary embodiment of the present technology;

[0022] Figure 3C The voltage waveforms of multiple management units during autonomous balancing mode are shown in an exemplary embodiment according to the present technology;

[0023] Figure 4 A timing diagram of the management unit during the autonomous balancing mode according to an exemplary embodiment of the present technology;

[0024] Figure 5A A timing diagram of the first balance signal in the event of an error occurring during autonomous balancing mode, according to an exemplary embodiment of the present technology;

[0025] Figure 5B A timing diagram of the second balance signal in the event of an error occurring during autonomous balancing mode, according to an exemplary embodiment of the present technology;

[0026] Figure 5C The following diagram illustrates voltage waveforms of multiple management units in the event of an error occurring during autonomous balancing mode, according to an exemplary embodiment of the present technology; and

[0027] Figure 6A A timing diagram of communication signals during a communication mode according to an exemplary embodiment of the present technology; and

[0028] Figure 6BThe voltage waveforms of multiple management units during communication mode are shown according to an exemplary embodiment of the present technology. Detailed Implementation

[0029] This technology can be described in terms of functional block components and various processing steps. Such functional blocks can be implemented by any number of components configured to perform specified functions and achieve various results. For example, this technology can employ a variety of filters, amplifiers, transistors, resistive elements, switching devices, capacitor storage elements, microcontrollers, logic circuits, etc., capable of performing various functions. Furthermore, this technology can be implemented in conjunction with any number of systems, such as automobiles, aviation, battery-powered equipment (e.g., lawnmowers, power tools, e-bikes), energy storage systems for solar and wind power, charging stations, and any other systems that utilize battery stacks to increase system voltage.

[0030] The methods and apparatus for autonomous balancing and communication in battery systems according to various aspects of this technology can be operated in conjunction with any suitable battery-powered device. For example, see Figure 1 and Figure 2 An exemplary battery system 100 may include a battery pack 105, a management network 110, a communication bus 115, and a main controller 120 (i.e., a first controller), which together operate to perform active capacitor balancing, enable monitoring of the battery pack 120, and provide communication between the management network 110 and the main controller 120. According to an exemplary embodiment, system 100 may operate in an autonomous balancing mode and a communication mode.

[0031] Battery pack 105 can be configured to generate the desired output voltage Vpack. For example, battery pack 105 may include multiple batteries 135 connected in series, such as batteries 135(1), 135(2), and 135(N). The number of batteries 135 in battery pack 105 can be selected according to the desired output voltage, the desired application, etc. Batteries 135 may include rechargeable batteries, such as lithium-ion, lead-acid, nickel-cadmium, nickel metal hydride, or any other suitable battery type.

[0032] The management network 110 can be configured to monitor various conditions of the battery pack 105 and / or individual batteries 135. For example, the management network 110 can be configured to monitor the voltage, current and temperature of each battery 135 individually and / or the voltage, current and temperature of the overall battery pack 105.

[0033] Management network 110 can operate in conjunction with communication bus 115 to perform balancing. For example, management network 110 can be configured to operate in conjunction with communication bus 115 to transfer charge from one battery 135 to one or more different batteries 135 in battery pack 105. According to an exemplary embodiment, management network 110 and communication bus 115 together perform active capacitor balancing.

[0034] According to an exemplary embodiment, management network 110 includes a plurality of management units 125, such as management units 125(1), 125(2), and 125(N). In various embodiments, communication and balancing may occur between all batteries 135 in battery pack 105 or between subgroups of batteries 135. In one embodiment, one battery 135 corresponds to one management unit 125. For example, if battery pack 105 includes 10 batteries 135 connected in series, management network 110 includes 10 management units 125. In another embodiment, a group of batteries 135 corresponds to one management unit 125. For example, each management unit 125 may communicate with two or more batteries 135.

[0035] According to an exemplary embodiment, each management unit 125 can be configured to monitor various conditions of the corresponding battery 135, such as overvoltage, undervoltage, temperature, etc. Furthermore, multiple management units 125(1):125(N) can operate together to perform autonomous balancing of each battery 135. For example, and see... Figure 2 Each management unit 125 may include a first switching element SH, a second switching element SL, and a corresponding local control system 140.

[0036] According to an exemplary embodiment, each management unit 125 can be connected to the positive terminal and the negative terminal of a corresponding battery 135 to monitor the voltage of the corresponding battery 135. Furthermore, each management unit 125 can be connected to a communication bus 115.

[0037] Each management unit 125 can be controlled to selectively connect a corresponding battery 135 to the communication bus 115. For example, each management unit 125 can selectively connect the battery 135 to the communication bus 115 using a first switching element SH and a second switching element SL. According to an exemplary embodiment, each management unit 125 can be connected to the communication bus 115 via a corresponding node SWT. For example, a first management unit 125(1) can be connected to the communication bus 115 via a first node SWT(1), a second management unit 125(2) can be connected to the communication bus 115 via a second node SWT(2), and a last management unit 125(N) can be connected to the communication bus via a last node SWT(N).

[0038] According to an exemplary embodiment, the first switching element SH is connected between the positive terminal of the battery 135 and the communication bus 115, and is responsive to the first control signal V. T The second switching element SL is connected between the negative terminal of battery 135 and communication bus 115 and responds to the second control signal V. B Therefore, the first switching element SH is based on the first control signal V.T The value is used to selectively connect / disconnect the positive terminal of battery 135 to communication bus 115, and the second switching element SL is based on the second control signal V. B The value is used to selectively connect / disconnect the negative terminal of battery 135 to communication bus 115. The first switching element SH and the second switching element SL can be connected to each other at node SWT and connected to communication bus 115.

[0039] In one exemplary embodiment, the first switching element SH has a low resistance (e.g., 25 mOhm), and the second switching element SL has a low resistance (e.g., 20 mOhm). The first switching element SH and the second switching element SL may include transistors configured to have the desired resistance.

[0040] According to an exemplary embodiment, the local control system 140 can be configured to coordinate the autonomous balancing between batteries 135(1):135(N), monitor the respective batteries 135, and communicate with the main controller 120. The local control system 140 can be directly connected to the first switching element SH, the second switching element SL, and the respective batteries 135. Furthermore, the local control system 140 can be connected to the communication bus 115 at node SWT.

[0041] According to an exemplary embodiment, the local control system 140 may be configured to measure voltage, current, and temperature, and generate error signals under any undesired operating conditions, such as undervoltage, overvoltage, overcurrent, undercurrent, short circuit, undertemperature, overtemperature, undertemperature, bare wire, etc. The terms undervoltage, overvoltage, overcurrent, undercurrent, overtemperature, and undertemperature may be associated with predetermined values, and these values ​​may be based on a specific application, total battery count, predetermined maintenance thresholds, and / or other predetermined safety thresholds.

[0042] The local control system 140 can be further configured to communicate with the main controller 120 to enable or otherwise provide error signaling. For example, the local control system can transmit an error signal to the main controller 120, which responds to the local control system 140.

[0043] According to an exemplary embodiment, the local control system 140 may include transceiver circuitry 210 and a local controller 205 (i.e., a second controller), such as an FPGA, a microcontroller, a state machine in an integrated circuit, etc.

[0044] The local controller 205 can be individually addressed and operated according to serial communication protocols such as Local Interconnect Network (LIN) protocol, Single-sided Position Modulation (SEPM) technology, Single-Wire protocol, Controller Area Network (CAN) protocol, etc. Depending on the implementation, the local controller 205 may include any addressable device and / or system suitable for operation according to serial communication protocols, such as microcontrollers, FPGAs, FSM devices, etc.

[0045] Furthermore, the local controller 205 can be configured to measure various characteristics of the corresponding battery 135, such as voltage, current, and temperature. For example, the local controller 205 can be directly connected to the positive and negative terminals of the corresponding battery 135 and can be equipped with at least one of a voltage sensor, a current sensor, and a temperature sensor.

[0046] The local controller 205 can also be configured to generate various signals, such as error signals, mode signals, control signals, etc. For example, each local controller 205 can be configured to generate a first control signal V based on measured battery characteristics (e.g., voltage, current, temperature). T Second control signal V B And respectively operate the first switching element SH and the second switching element SL. According to an exemplary embodiment, the first control signal and the second control signal are non-overlapping signals, for example, such as... Figures 3A to 3B As shown. Furthermore, in the first control signal V T Second control signal V B There may be a dead time between the two signals. The dead time can be defined as the period of time when the first and second signals are low (e.g., zero volts), such as 10 microseconds.

[0047] Each local controller 205 may include any circuitry or system suitable for individual addressing, performing various measurements, calculations, generating signals, etc. Because local controllers 205 are individually addressable, each management unit 125 is referred to as individually addressable via its corresponding local controller 205.

[0048] According to various implementations, each local controller 205 can operate synchronously with other controllers 205 based on a local clock signal (not shown) having approximately the same frequency as the other local controllers 205, to ensure that all local controllers 205 in the management network 105 count time in the same manner. For example, the battery system 100 may be equipped with a synchronization scheme, such as beacon synchronization or any other suitable synchronization function.

[0049] Transceiver 210 can operate with at least one of the first switching element SH and the second switching element SL to achieve autonomous balancing and communication. For example, transceiver 210 can be connected between communication bus 115 and local controller 205. For example, transceiver 210 can be connected to the communication bus at node SWT. Transceiver 210 can be configured to receive data from and / or transmit data to master controller 120. For example, transceiver 210 may include a pair of communication devices configured for bidirectional communication, such as transmitter 225 and receiver 230. According to an exemplary embodiment, both transmitter 225 and receiver 230 are used during autonomous balancing mode and communication mode. During communication mode, only the high side of transmitter 225 may be used.

[0050] The communication bus 115 can be used for both balancing (i.e., charge equalization) and communication. For example, the communication bus 115 may include one or more wires and may be configured to connect the main controller 120 from the management network 110 to each management unit 125.

[0051] Furthermore, the communication bus 115 may include multiple series-connected capacitors, such as capacitor 130(1):130(N-1), which can be used for both autonomous balancing and communication. During balancing mode, capacitor 130(1):130(N-1) may operate in conjunction with a first switching element SH and a second switching element SL to transfer charge from the higher voltage battery to the lower voltage battery. During communication mode, capacitor 130(1):130(N-1) acts as part of the physical communication bus 115.

[0052] According to an exemplary embodiment, management units 125(1):125(N) are connected to communication bus 115 such that any management unit 125 can communicate with any other management unit 125. Alternatively, management units 125 may be connected to communication bus 115 such that any management unit 125 can only communicate with its directly adjacent management unit 125.

[0053] The main controller 120 can be configured to communicate with and control the operation of each management unit 125. For example, the main controller 120 can operate the management unit 125 in either a balanced mode or a communication mode. Furthermore, the main controller 120 can be configured to send signals to and / or receive signals from each management unit 125. Since each local controller 140 is individually addressed, the main controller 120 can send communication signals to a specific management unit 125 and / or local controller 140, and subsequently receive response signals from a specific management unit 125 and / or local controller 140. For example, the main controller 120 can “receive” signals from the management unit 125 by monitoring the line voltage level of the communication bus 115. Additionally, the main controller 120 can receive error signals generated by a single local controller 140.

[0054] According to an exemplary embodiment, system 100 may be configured as a half-duplex communication system, wherein a main controller 120 and a local controller 140 can communicate with each other. The main controller 120 may include any circuitry and / or system suitable for controlling multiple devices, generating signals, and receiving signals, such as a microcontroller, FPGA, etc.

[0055] In one embodiment, system 100 may be equipped with a Local Interconnect Network (LIN) protocol, wherein the master controller 120 operates as a "master device" and each local controller 140 operates as a "slave device," and the master controller 120 and local controllers 140 communicate with each other via a communication bus 115. Alternatively, the master controller 120 and each local controller 140 may communicate with each other using Single-sided Position Modulation (SEPM) technology. Alternatively, system 100 may be equipped with a single-wire protocol or a CAN protocol.

[0056] During operation, and see also Figure 1 As shown in Figure 6, system 100 can be configured to operate in autonomous balancing mode and / or communication mode. According to exemplary operation, each management unit 125 operates independently of the other management units 125. In other words, each management unit 125 is responsible for generating a set of various control signals for its own control. However, each management unit 125 can communicate with other management units 125, and each management unit 125 can make decisions based on information it receives from the other management units 125.

[0057] According to exemplary operation, system 100 utilizes communication bus 115 during communication mode and autonomous balancing mode. For example, the main controller 120 and each individual management unit 125 may communicate with each other using communication bus 115. Furthermore, management units 125 may use communication bus 115 to transfer charge from one management unit 125 to one or more different management units 125. For example, during a balancing cycle, a management unit 125 may transfer charge to a directly adjacent management unit 125. However, over multiple balancing cycles, charge will gradually shift from stronger batteries 135 to weaker batteries 135, at which point charge balancing is required across all batteries 135.

[0058] During the balanced mode, and see also Figures 3A to 3C During normal balancing operation (error-free), each management unit 125 generates non-overlapping signals spaced by dead time intervals, such as the first control signal V. T Second control signal V B To achieve autonomous balancing. The first switching element SH of the corresponding management unit 125 operates according to the first control signal V. T To operate, and the second switching element SL of the same management unit 125 according to the second control signal V B When the switching elements SH and SL are activated / deactivated, the charge from the higher voltage battery 135 can be transferred to the lower voltage battery via capacitors 130(1):130(N-1).

[0059] Receiver 230 can act as a comparator or other logic device to sense the voltage (i.e., the SWT signal) at the corresponding node SWT. Transmitter 225 can be used to initiate high-to-low and low-to-high transitions at node SWT. Local controller 205 can use the node voltage data, in conjunction with the measured voltage of battery 135, to determine whether battery 135 needs charging or discharging. Local controller 205 can then operate the first switching element SH and the second switching element SL accordingly.

[0060] During the balanced mode, and see also Figure 4 and Figures 5A-5C A management unit 125 can detect errors in the corresponding battery 135, such as undervoltage, overvoltage, overcurrent, undercurrent, short circuit, undertemperature, overtemperature, bare wire, etc. In this case, the local controller 205 can generate an error signal in response to the error. The error signal can be transmitted via the first control signal V. T Second control signal V B Generate. For example, and see also Figures 5A to 5BWhen the local controller 205 detects an error, it keeps the first switching element SH on (ON) while keeping the second switching element SL off (OFF). This can be achieved by changing the first control signal V... T Maintain high voltage and send the second control signal V B This is achieved by maintaining a low (or zero) voltage. The voltage at node SWT associated with the faulty management unit 125 will then deviate from the expected voltage. For example, the voltage at node SWT will remain high for a longer period than expected. Therefore, this longer duration of the SWT signal (referred to as a timeout) can indicate an error.

[0061] Then, other management units 125 can detect timeouts and abort the balancing operation. The battery system 100 can then initiate communication mode.

[0062] In an exemplary implementation, and see Figure 1 , Figure 2 and Figure 4 The first switching element SH can be implemented as a P-channel MOSFET, the second switching element SL can be implemented as an N-channel MOSFET, and the receiver 230 can be implemented as a comparator. During balancing, the local controller 205 can generate a first signal STG and control the operation of the first switching element SH and the charging / discharging of the corresponding battery 135. Furthermore, the local controller 205 can generate a second signal SBG and control the operation of the second switching element SL and the charging / discharging of the battery 135. Specifically, when the first signal STG is high, the first switching element SH is off (and when the first signal STG is low, it is on), and when the second signal SBG is high, the second switch SL is on (and when the second signal SBG is low, it is off). The periods during which the first switching element SH and the second switching element SL are on can be controlled according to a predetermined time counted by a timer (not shown). Furthermore, the on-time periods of each switch SH and SL can be the same.

[0063] At the moment the first switching element SH is turned off, the SWT signal begins to decay from a high level to the threshold level TH. The decay of the SWT signal is caused by the discharge of the parasitic capacitor of the P-channel MOSFET into the weak pull-down circuit (e.g., transmitter 225).

[0064] Comparator 230 continuously monitors the SWT signal by comparing it with a threshold level TH and generating a corresponding comparator signal COMP. When the SWT signal falls below the threshold level TH, the comparator signal COMP goes low, allowing the timer to start counting again (this time for the second switching element SL) and setting the second signal SBG high (activating the second switching element SL), thus pulling the SWT signal low. After the timer reaches a predetermined time, the second signal SBG is set low again.

[0065] Next, the SWT signal rises from low to the threshold TH, and once it reaches the threshold TH, the comparator output COMP goes high again, allowing the timer to start counting again (this time for the first switching element SH) and setting the first signal STG low (activating the first switching element SH), thus pulling the SWT signal high. The rise of the SWT signal is due to the charging of the parasitic capacitor of the P-channel MOSFET through a weak pull-up circuit (e.g., emitter 225).

[0066] In this embodiment, a delay exists between the changes in the first signal STG and the second signal SBG to prevent a short circuit in battery 135. Management unit 125 can execute an on-delay-off sequence until battery pack 105 ( Figure 1 All cells 135(1):135(N) in the battery pack 105 have substantially the same voltage. Therefore, all cells 135(1):135(N) in the battery pack 105 are considered “balanced” once they all have substantially the same voltage.

[0067] During communication mode, and see also Figure 1 , Figures 6A to 6B The main controller 120 can detect or otherwise sense the SWT signal (e.g., V) on the communication bus 115. SWT(1) 、V SWT(2) 、V SWT(3) And respond accordingly. For example, the main controller 120 can use any suitable communication protocol to generate the communication signal V. COMM This information is then transmitted to each management unit 125. The main controller 120 can be configured to communicate with a specific management unit 125 using a separate address assigned to that particular management unit 125. The designated management unit 125 can then respond to the main controller 120, generating an appropriate response signal and transmitting the response signal via the communication bus 115. According to an exemplary embodiment, the communication signal V... COMM The system is in a recessive state when high and in a dominant state when low. In the recessive state, all management units 125 have both the first switching element SH and the second switching element SL open (OFF). Furthermore, and according to protocol requirements, only a single management unit 125 and / or local controller 205 will generate the dominant state by closing (activating) the second switching element SL. The dominant state generated by one management unit 125 will be detected by the other management units 125. Communication signal V COMM The system can switch between a dominant state and a recessive state in the sequence until all management units 125 have generated a dominant state. Once communication is complete, the battery system 100 can restart in balancing mode.

[0068] In the foregoing description, the technology has been described in conjunction with specific exemplary embodiments. The specific embodiments shown and described are for illustrative purposes only and are not intended to further limit the scope of the technology in any way. In fact, for the sake of brevity, conventional manufacturing, connection, fabrication, and other functional aspects of the methods and systems may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or steps between various components. In actual systems, multiple alternative or additional functional relationships or physical connections may exist.

[0069] The technology has been described in conjunction with specific exemplary embodiments. However, various modifications and variations may be made without departing from the scope of this technology. The descriptions and drawings are to be considered in an exemplary and non-limiting manner, and all such modifications are intended to be included within the scope of this technology. Therefore, the scope of the technology should be determined by the general embodiments described and their legally equivalent forms, rather than solely by the specific examples given above. For example, unless otherwise expressly stated, the steps listed in any method or process embodiment may be performed in any order, and are not limited to the explicit order provided in the specific examples. Furthermore, the components and / or elements listed in any apparatus embodiment may be assembled in various arrangements or otherwise configured to produce substantially the same results as this technology, and are therefore not limited to the specific configurations illustrated in the specific examples.

[0070] The beneficial effects, other advantages, and problem solutions have been described above for specific implementation schemes. However, any beneficial effect, advantage, problem solution, or any element that makes any specific beneficial effect, advantage, or solution appear or become more apparent should not be construed as a critical, required, or necessary feature or component.

[0071] The terms “comprising,” “including,” or any variations thereof are intended to refer to a non-exclusive inclusion, such that a process, method, article, composition, or apparatus that comprises a list of elements includes not only those listed but also other elements not expressly listed or inherent to such process, method, article, composition, or apparatus. Except for those not specifically referenced, other combinations and / or modifications of the above-described structures, arrangements, applications, proportions, elements, materials, or components used in the implementation of this technology may vary without departing from its general principles or be otherwise particularly suited to specific environments, manufacturing specifications, design parameters, or other operational requirements.

[0072] The present technology has been described above in conjunction with exemplary embodiments. However, changes and modifications may be made to the exemplary embodiments without departing from the scope of the present technology. These and other changes or modifications are intended to be included within the scope of the present technology, as set forth in the following claims.

[0073] According to a first aspect, an apparatus for a battery pack having a plurality of batteries connected in series includes: a communication bus including a plurality of capacitors connected in series; a plurality of management units, wherein each management unit is: connected to the communication bus via a node; and directly connected to a corresponding battery in the battery pack and configured to perform autonomous balancing of the corresponding battery; and a first controller connected to the communication bus, wherein the first controller communicates with each management unit via the communication bus.

[0074] In one implementation, each capacitor is connected between two directly adjacent management units among the plurality of management units.

[0075] In one implementation, each of the plurality of management units includes: a second controller configured to: generate a first control signal; generate a second control signal; and communicate with the first controller.

[0076] In one implementation, the first controller and the second controller communicate using at least one of the following: local interconnection network protocol, one-sided position modulation technology, controller area network protocol, and single-wire protocol.

[0077] In one embodiment, each of the plurality of management units includes a transceiver connected between the node and the second controller.

[0078] In one embodiment, each management unit further includes: a first switching element configured to selectively connect a first terminal of the corresponding battery to the communication bus; and a second switching element configured to selectively connect a second terminal of the corresponding battery to the communication bus.

[0079] In one embodiment, the first switching element responds to the first control signal; the second switching element responds to the second control signal; and the first control signal and the second control signal are non-overlapping signals.

[0080] In one embodiment, the first switching element includes a P-channel transistor; the second switching element includes an N-channel transistor.

[0081] In one implementation, each management unit is configured to: detect errors in the corresponding battery in the battery pack, wherein the error is related to at least one of: the temperature of the individual battery; the current of the individual battery; and the voltage of the individual battery; and generate an error signal based on the detected error.

[0082] According to a second aspect, a method for autonomous balancing and communication in a battery system having a plurality of series-connected batteries connected to a communication bus includes: performing autonomous balancing, comprising: transferring charge from a first battery of the plurality of batteries to a second battery of the plurality of batteries, the transfer comprising: generating a first control signal with a local control system associated with the first battery; selectively operating a first switch according to the first control signal; generating a second control signal with the local control system; selectively operating a second switch according to the second control signal; selectively connecting a first terminal of the first battery to a capacitor storage device with the first switch; and selectively connecting a second terminal of the first battery to the capacitor storage device with the second switch; detecting an error state in at least one of the plurality of batteries; and activating communication between the local control system and a main controller in response to the error state, wherein the communication comprises: generating a communication signal with the main controller; transmitting the communication signal to the local control system via the communication bus; generating a response signal with the local control system according to the error state; and transmitting the response signal to the main controller via the communication bus.

[0083] In one implementation, communication includes utilizing at least one of the following: local interconnection network protocol, one-sided location modulation technique, controller area network protocol, and single-wire protocol.

[0084] In one implementation, generating the first control signal and the second control signal includes counting a predetermined time period using a timer.

[0085] In one implementation, the error state is related to at least one of temperature, current, and voltage.

[0086] In one embodiment, generating the first control signal includes comparing the node voltage of the local control system with a threshold voltage; and generating the second control voltage includes comparing the node voltage with the threshold voltage.

[0087] According to a third aspect, a system includes: a battery pack having a plurality of batteries connected in series; and an autonomous balancing and communication circuit connected to the battery pack and including: a first controller, a communication bus, and a management network; wherein: the management network and the communication bus operate together to perform autonomous voltage balancing on each battery in the battery pack; and the first controller and the management network communicate with each other using the communication bus and monitor the error state of each battery in the battery pack; wherein the error is related to at least one of temperature, current, and voltage.

[0088] In one implementation, the management network includes: a plurality of management units connected together via a communication bus, wherein each management unit is connected to the communication bus via a node; and the positive and negative terminals of the respective batteries in the battery pack.

[0089] In one embodiment, each of the plurality of management units includes: a first switching element connected to the node and configured to selectively connect the positive terminal to the communication bus; and a second switching element connected to the node and configured to selectively connect the negative terminal to the communication bus.

[0090] In one embodiment, each of the plurality of management units includes a second controller configured to: selectively operate a first switching element according to a first control signal; selectively operate a second switching element according to a second control signal; and communicate with the first controller.

[0091] In one implementation, each management unit further includes a comparator connected to the node and configured to: compare the voltage at the node with a threshold voltage; generate a comparator signal based on the comparison; and transmit the comparator signal to a second controller.

[0092] In one implementation, the first controller is connected to a communication bus and is configured to communicate with each battery in the battery pack via at least one of the following: a local interconnect network protocol and a one-sided position modulation technique.

Claims

1. A device for autonomous balancing and communication in a battery pack, the battery pack having a plurality of batteries connected in series, characterized in that, The device includes: A communication bus, the communication bus comprising a plurality of capacitors connected in series; Multiple management units, each connected to the communication bus via a node and directly connected to a corresponding battery in the battery pack and configured to perform autonomous balancing of that corresponding battery; and A first controller is connected to the communication bus, wherein the first controller communicates with each management unit via the communication bus. Each management unit includes at least one switching element configured to selectively connect the terminals of the corresponding battery to the communication bus.

2. The apparatus according to claim 1, characterized in that, Each capacitor is connected between two directly adjacent management units among the plurality of management units.

3. The apparatus according to claim 1, wherein, Each of the plurality of management units includes: The second controller is configured to: Generate the first control signal; Generate a second control signal; and Communicate with the first controller.

4. The apparatus according to claim 3, characterized in that, Each of the plurality of management units includes a transceiver connected between the node and the second controller.

5. The apparatus according to claim 4, characterized in that, Each management unit also includes: A first switching element, configured to selectively connect a first terminal of the respective battery to the communication bus; and A second switching element is configured to selectively connect a second terminal of the corresponding battery to the communication bus.

6. The apparatus according to claim 5, characterized in that: The first switching element responds to the first control signal; The second switching element responds to the second control signal; and The first control signal and the second control signal are non-overlapping signals.

7. The apparatus according to claim 1, characterized in that, Each management unit is configured as follows: Detecting errors in the respective cells of the battery pack, wherein the errors are related to at least one of the following: The temperature of the corresponding battery; The current of the corresponding battery; and The voltage of the corresponding battery; and An error signal is generated based on the detected error.

8. A method for autonomous balancing and communication in a battery system having a plurality of series-connected batteries connected to a communication bus, characterized in that, The method includes: Perform autonomous balancing; Detecting an error state in at least one of the plurality of batteries; and In response to the error state, communication between the local control system and the main controller is activated. Among them, autonomous balancing includes: Transferring charge from a first cell in the plurality of cells to a second cell in the plurality of cells, the transfer comprising: A first control signal is generated using the local control system associated with the first battery; The first switch is selectively operated according to the first control signal; The local control system generates a second control signal; The second switch is selectively operated according to the second control signal; The first terminal of the first battery is selectively connected to the capacitor storage device using the first switch; and The second terminal of the first battery is selectively connected to the capacitor storage device using the second switch; The communication includes: The main controller is used to generate communication signals; The communication signal is transmitted to the local control system via the communication bus; and Based on the error status, the local control system generates a response signal; and The response signal is transmitted to the main controller via the communication bus. The communication bus includes multiple capacitors connected in series, and the multiple capacitors connected in series include the capacitor storage device.

9. The method according to claim 8, characterized in that, Generating the first control signal and the second control signal includes: counting a predetermined time period using a timer.

10. The method according to claim 8, characterized in that, Generating the first control signal includes: The node voltage of the local control system is compared with a threshold voltage, and the first control signal is generated when the node voltage reaches the threshold voltage; and Generating the second control signal includes: The node voltage is compared with the threshold voltage, and the second control signal is generated when the node voltage is lower than the threshold voltage.

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