A battery management circuit based on dynamic series connection

Abstract

This application relates to a battery management circuit based on dynamic series connection, including a switch control circuit, an enable circuit, a power supply circuit, and multiple power supply control circuits. This battery management circuit combines the series design of the power supply control circuits with the control signal generation of the switch control circuit. When a battery pack malfunctions, the corresponding power supply control circuit can quickly receive the first control signal and bypass the faulty unit. Simultaneously, the power supply control circuits of redundant battery packs can be put into operation synchronously, ensuring that the main transmission circuit bus voltage remains constant. This avoids overall system shutdown caused by a single battery pack failure, enabling the system to maintain stable output even under fault scenarios, significantly improving its resilience, and making it particularly suitable for scenarios with stringent reliability requirements, such as energy storage power stations and vehicle power systems.

Description

Technical Field

[0001] This application relates to the field of energy storage management technology, specifically to a battery management circuit based on dynamic series connection. Background Technology

[0002] With the rapid development of new energy technologies, battery packs using single cells as the core energy storage have been widely used in automobiles, energy storage power stations, portable electronic devices, and many other fields. The battery management circuit, as a key component ensuring the safe, stable, and efficient operation of the battery pack, directly affects the battery pack's cycle life, charge / discharge efficiency, and safety.

[0003] Currently, traditional battery management circuits mostly use a fixed series battery pack topology. However, due to this series design, when a battery pack in the circuit experiences a voltage anomaly or a precursor to thermal runaway, the faulty unit cannot be quickly bypassed and isolated. The fault will directly propagate to the entire series circuit, causing a sudden drop in the energy storage system's output power, unbalanced power supply, and even leading to a complete system shutdown and thermal runaway safety risks. Furthermore, the charging and discharging actions of traditional battery management circuits mostly rely on the characteristics of the battery pack itself or simple switching, lacking a buffer control mechanism. Instantaneous current surges can easily damage the battery pack or the battery management circuit. Moreover, the power supply of the battery management circuit depends on the series-connected battery pack. Once the battery pack malfunctions or reaches low charge, the battery management circuit will simultaneously lose power, causing serious malfunctions in the battery management circuit.

[0004] Therefore, to address the aforementioned shortcomings, there is an urgent need for a battery management circuit that is dynamically adjustable and stable and safe, in order to meet the requirements for high-performance operation of energy storage systems. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this application provides a battery management circuit based on dynamic series connection, specifically adopting the following technical solution: A battery management circuit based on dynamic series connection, the battery management circuit includes a switch control circuit, an enable circuit, a power supply circuit and multiple power supply control circuits; the power supply control circuit and the enable circuit are connected in series to form the main power transmission circuit; The power supply control circuit is used to bypass or connect the battery pack according to the first control signal, and multiple power supply control circuits are connected in series in sequence. The switch control circuit is used to collect the first data of the battery pack and send the first control signal to the power supply control circuit based on the first data; The enable circuit is used to control the charging and discharging operation of the main transmission circuit; The power supply circuit is used to supply power to the switch control circuit, the enable circuit, and the power supply control circuit, respectively.

[0006] Optional: The power supply control circuit includes a first driver and a half-bridge circuit; the half-bridge circuit is connected in series with the battery pack; the first driver is connected to the gate of the power switch of the half-bridge circuit, and the half-bridge circuit is controlled by the first driver to bypass or engage the battery pack.

[0007] Furthermore, the switch control circuit includes a first controller, a second controller, and multiple first acquisition units; Each first acquisition unit is connected to a battery pack. The first acquisition unit is used to acquire the first data of the battery pack. The first controller is communicatively connected to the first acquisition unit. The first controller is used to receive the first data and process it to generate a first control signal and a second control signal. The second controller is communicatively connected to the first controller. The second controller is used to receive the first control signal and the second control signal, and according to the second control signal, controls the second controller to communicate with the corresponding power supply control circuit so that the first control signal is sent to the power supply control circuit.

[0008] Furthermore, the power supply control circuit also includes a first timing circuit, which is connected to the first driver and is used to control the delay interval of the power switch action in the half-bridge circuit.

[0009] Optional: The enabling circuit includes a first enabling switch, a first relay, a second relay, and a third relay; The first enable switch includes a first enable interface, a second enable interface, and a third enable interface. The first enable interface is connected to a first relay, which is located in a charging circuit and is used to control the main transmission circuit to perform a charging operation. The second enable interface is connected to a second relay, which is located in a discharging circuit and is used to control the main transmission circuit to perform a discharging operation. The third enable interface is connected to a third relay, which is located in a pre-charge circuit and is used to control the main transmission circuit to perform a pre-charge operation.

[0010] Optional: The enabling circuit also includes a second enabling switch and a fourth relay. The second enabling switch is connected to the fourth relay, and the fourth relay is connected in series to the main control circuit, which is used to control the main power transmission circuit to be connected or disconnected.

[0011] Optional: The power supply circuit includes a pulse modulation inverter circuit, a first transformer, a buffer circuit, a DC filter circuit, and a power supply sub-circuit; the primary winding of the first transformer is connected to the pulse modulation inverter circuit, which is used to output a high-frequency pulse signal to the primary winding of the first transformer; the secondary winding of the first transformer is connected in sequence to the buffer circuit and the DC filter circuit, which is used to suppress voltage spikes of the first transformer and to convert the high-frequency pulse signal output by the first transformer into a DC output voltage; the DC filter circuit is connected in parallel to at least one power supply sub-circuit.

[0012] Optional: The power supply sub-circuit includes a first power supply sub-circuit and a second power supply sub-circuit, wherein the first power supply sub-circuit provides a first voltage to the switch control circuit, and the second power supply sub-circuit provides a second voltage to the enable circuit and the switch control circuit, respectively.

[0013] Optional: The first power supply sub-circuit uses a low-dropout linear regulator to provide the first voltage to the switching control circuit; The second power supply sub-circuit includes an input filter circuit, a switch drive circuit, a second transformer, and a rectifier filter circuit. The primary winding of the second transformer is connected in parallel with two switch drive circuits, and each switch drive circuit is connected to the output terminal of the DC filter circuit via the input filter circuit. The two switch drive circuits alternately switch on and off to supply alternating voltage to the primary winding of the second transformer. The secondary winding of the second transformer is connected to two sets of rectifier filter circuits, which are respectively connected to the first driver. The rectifier filter circuits convert the alternating voltage output by the second transformer into a stable DC voltage and supply power to the first driver.

[0014] Optional: The above power supply circuit is provided in two sets, one set of power supply circuit is connected in parallel to the battery pack, and the other set of power supply circuit is connected in parallel to the output side of the main power transmission circuit.

[0015] The technical solution of this application achieves the following beneficial effects: The battery management circuit of this application employs a series design of power supply control circuits combined with a switch control circuit that collects data to generate switch control signals. When a battery pack malfunctions, the corresponding power supply control circuit can quickly receive the switch control signal and bypass the faulty unit. Simultaneously, the power supply control circuits of redundant battery packs can be put into operation synchronously, ensuring that the main transmission circuit bus voltage remains constant. This design avoids the complete shutdown of the battery management circuit due to the failure of a single battery pack, enabling the system to maintain stable output even under fault scenarios, significantly improving its resilience. It is particularly suitable for scenarios with stringent reliability requirements, such as energy storage power stations and vehicle power systems. Furthermore, the enabling circuit can orderly schedule the charging and discharging process, avoiding the disordered charging and discharging problems of traditional circuits. Simultaneously, it controls the charging and discharging process, effectively buffering the instantaneous current surges from loads such as energy storage converters, reducing losses in the battery packs and battery management circuits, and extending their service life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the power supply control circuit in an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the switch control circuit in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram of the enabling circuit in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the power supply circuit in an embodiment of this application.

[0020] Figure 5 This is a schematic diagram of the switch drive circuit in the second power supply sub-circuit in the embodiments of this application.

[0021] Figure 6 This is a schematic diagram illustrating the structure of the second power supply sub-circuit supplying power to multiple sets of switch control circuits in an embodiment of this application.

[0022] Figure 7 This is a schematic diagram of the detection unit in an embodiment of this application.

[0023] Specific explanation of the reference numerals in the attached figures: First driver-U1, first power switch Q1, second power switch Q2, battery pack BAT, fuse F1, two first input ports INA and INB, two first output ports OUTA and OUTB, second input port DT, first resistor R1, first capacitor C1, first controller P1, second controller P2, first acquisition unit AFE, unit processing modules AS1~AS4, chip select signal channels CS_1~CS_4, first enable switch S1, second enable switch S2, second resistor R2, first relay KT1, second relay KT2, third relay KT3, and the... Four relays KT4, first diode D1, second diode D2, first transformer T1, third power switch Q3, third resistor R3, third controller P3, third diode D3, capacitor E1, capacitor E2, inductor L1, capacitor C2, resistor R4, second transformer T2, fourth power switch Q4, fifth power switch Q5, diode D4, resistor R5, resistor R6, diode D5, resistor R7, resistor R8, capacitors C3~C10, diode D8, diode D9, capacitor C15, capacitor C16, diode D10, diode D11, capacitor C17, capacitor C18. Detailed Implementation

[0024] The present application will now be further described with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application and should not be construed as limiting the scope of protection of the present application. It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present application.

[0025] This embodiment uses an energy storage system constructed with 40 battery packs connected in series as an example to illustrate the battery management circuit of this application. In this embodiment, a single battery pack BAT is composed of four lithium iron phosphate cells connected in series. The output voltage of a single battery pack is about 12V. Among them, 31 battery packs are used as working batteries, which can build a DC bus voltage of about 400V. The remaining 9 battery packs are used as backup batteries. When one of the 31 battery packs fails, it will automatically disconnect under the control of the battery management circuit of this application, and a new one will be connected from the 9 backup battery packs to maintain the 400V system voltage.

[0026] Example 1: Combination Figure 1-6 As shown in Embodiment 1, a battery management circuit based on dynamic series connection includes at least a switch control circuit, an enable circuit, a power supply circuit, and a power supply control circuit. The power supply control circuit bypasses or engages the battery pack according to a first control signal. The switch control circuit collects first data from the battery pack and generates a first control signal, which is then sent to the power supply control circuit. The power supply control circuit and the enable circuit form a main power transmission loop, through which the enable circuit can control the charging and discharging operations of the main power transmission loop. The power supply circuit supplies power to the switch control circuit, the enable circuit, and the power supply control circuit respectively. In this embodiment, 40 battery packs correspond to 40 power supply control circuits, which are connected in series sequentially.

[0027] Specifically, such as Figure 1 As shown, the power supply control circuit includes a first driver U1 and a half-bridge circuit. Each battery pack BAT requires at least one battery cell; in this embodiment, four cells are connected in series to construct a single battery pack BAT. The half-bridge circuit is connected in series with the battery pack BAT. The first driver U1 is connected to the gate of the power switch of the half-bridge circuit. The first driver U1 controls the half-bridge circuit, allowing the battery pack BAT to be bypassed or engaged.

[0028] In this embodiment 1, the switch control circuit collects the first data from the battery pack and generates a first control signal to be sent to the power supply control circuit based on the first data. The switch control circuit includes a first controller P1, a second controller P2, and multiple first acquisition units AFE. like Figure 2As shown, each first acquisition unit (AFE) corresponds to a set of power supply control circuits. The first acquisition unit (AFE) can acquire first data of the battery pack, such as the voltage and temperature of the cells in the battery pack. The first controller (P1) is communicatively connected to the first acquisition unit (AFE). The first controller (P1) can receive the first data and process it to generate a first control signal and a second control signal. The second controller (P2) is communicatively connected to the first controller (P1). The second controller (P2) can receive the first control signal and the second control signal, and the second controller (P2) can select the corresponding power supply control circuit to communicate with the second controller according to the second control signal, so that the first control signal is sent to the power supply control circuit. The first control signal is the drive signal that drives the power supply control circuit to bypass or engage the battery pack, while the second control signal is the chip select control signal of the second controller.

[0029] When a battery pack malfunctions, the abnormal data is rapidly transmitted to the corresponding first acquisition unit (AFE). The AFE then transmits the data to the first controller (P1) for analysis and processing, generating a corresponding control strategy according to preset rules. Based on this strategy, the first controller (P1) sends a first control signal and a second control signal to the second controller (P2). The second controller (P2) selectively activates the corresponding power supply control circuit based on the second control signal and sends the first control signal to bypass the faulty battery pack. Simultaneously, it controls the power supply control circuits of redundant battery packs to operate synchronously, ensuring that the main transmission circuit bus voltage remains constant. This prevents the entire battery management circuit from shutting down due to a single battery pack failure, allowing the battery management circuit to maintain stable output even in scenarios with partial battery malfunctions. This significantly improves the battery's resilience, making it particularly suitable for scenarios with stringent reliability requirements, such as energy storage power stations and vehicle power systems.

[0030] More specifically, such as Figure 3 As shown, in this embodiment 1, the enabling circuit includes a first enabling switch, a first relay, a second relay, and a third relay. The first enabling switch includes a first enabling interface, a second enabling interface, and a third enabling interface. The first enabling interface is connected to the first relay, which is located in a charging circuit. This charging circuit controls the main power transmission circuit to perform a charging operation. The second enabling interface is connected to the second relay, which is located in a discharging circuit. This discharging circuit controls the main power transmission circuit to perform a discharging operation. The third enabling interface is connected to the third relay, which is located in a pre-charge circuit. This pre-charge circuit controls the main power transmission circuit to perform a pre-charge operation.

[0031] In this embodiment 1, the enabling circuit can specifically control the charging and discharging actions of the main transmission circuit, and orderly schedule the charging and discharging process. Furthermore, based on the orderly switching of the pre-charge circuit, the discharge circuit, and the charging circuit, it can effectively buffer the instantaneous current impact of loads such as the energy storage converter, reduce the loss of the battery pack and battery management circuit, and extend the service life.

[0032] In addition, the above-mentioned enabling circuit also includes a second enabling switch and a fourth relay. The second enabling switch is connected to the fourth relay, and the fourth relay is connected in series to the main control circuit. The main control circuit can control the connection or disconnection of the main power transmission circuit.

[0033] Furthermore, such as Figure 4-6 As shown, in this embodiment 1, the power supply circuit includes a pulse modulation inverter circuit, a first transformer, a buffer circuit, a DC filter circuit, and a power supply sub-circuit. The primary winding of the first transformer is connected to the pulse modulation inverter circuit, which draws power from the battery pack and modulates the DC power into a high-frequency pulse signal, which is then output to the primary winding of the first transformer. The secondary winding of the first transformer is connected in sequence to the buffer circuit and the DC filter circuit. The buffer circuit suppresses voltage spikes at the output of the first transformer, while the DC filter circuit converts the high-frequency pulse signal at the output of the first transformer into a DC output voltage. The DC filter circuit is then connected in parallel to at least one power supply sub-circuit to provide base voltage to other components.

[0034] The aforementioned power supply circuit can supply power to the switch control circuit, enable circuit, and power supply control circuit respectively, avoiding the vicious cycle of battery failure and control power loss. It can also provide adaptive power supply according to the voltage requirements of different modules, ensuring that the battery management circuit can operate stably under both normal and fault conditions, and eliminating the hidden danger of poor power supply adaptability.

[0035] Example 2: The battery management circuit based on dynamic series connection disclosed in Embodiment 2, specifically for the power supply control circuit, preferably comprises a first driver U1, a first power switch Q1, and a second power switch Q2. Specifically, both the first power switch Q1 and the second power switch Q2 are MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) with body diodes. The two MOSFETs form the aforementioned half-bridge circuit, which is connected in series with a battery pack. The power supply control circuit of Embodiment 2 achieves switch-type control of the battery pack by controlling the time-division multiplexing of the two power switches. Combined with… Figure 1As shown, in this embodiment 2, each power supply control circuit is equipped with two power switches, forming a half-bridge circuit. Taking a single power supply control circuit as an example, this power supply control circuit is equipped with a first power switch Q1 and a second power switch Q2. The first power switch Q1 and the second power switch Q2 form a half-bridge circuit structure, with the first power switch Q1 being the upper bridge arm and the second power switch Q2 being the lower bridge arm. When the first power switch Q1 is turned on and the second power switch Q2 is turned off, the power supply control circuit controls the battery pack BAT to connect to the main transmission circuit and charge and discharge to a target, such as a PCS (Power Conversion System, i.e., energy storage converter). When the power switch Q1 is turned off and the power switch Q2 is turned on, the power supply control circuit will control the battery pack BAT to be short-circuited to disconnect it from the main transmission circuit.

[0036] In conjunction with the battery redundancy design in Embodiment 2, if one or more operating battery packs fail, the power switches in the corresponding power supply control circuit can work together to bypass and disconnect the faulty battery packs. Of course, to maintain a constant bus voltage, an equal number of redundant battery packs can also be activated to prevent a small number of battery pack malfunctions from causing a drop in bus voltage, thereby maintaining the stable operation of the entire energy storage system.

[0037] Furthermore, in this embodiment 2, the two power switches are directly controlled by the first driver U1. The first driver U1 is preferably an isolated gate driver, which includes at least one first input port and two first output ports. Preferably, in this embodiment 2, there are two first input ports (i.e., INA, INB) and two first output ports (i.e., OUTA, OUTB). The first input port is used to receive an external first control signal. The first output ports are respectively connected to the gates of the first power switch Q1 and the second power switch Q2. When the first input port receives the external first control signal, the first driver U1 will output a gate control signal to the corresponding first output port and control the first power switch Q1 and the second power switch Q2 to be turned on or off.

[0038] More detailed, such as Figure 1 As shown, in this embodiment 2, a fuse F1 can also be connected in series in the power supply control circuit. Once the current in the power supply control circuit exceeds the rated value of the fuse F1, the fuse F1 will melt to cut off the circuit conduction, which can prevent other devices from being damaged due to overload.

[0039] It should be noted that, in this embodiment 2, to avoid the simultaneous conduction of the first power switch Q1 and the second power switch Q2, which could cause component damage, a dead time period needs to be inserted between the conduction sequences of the two power switches, i.e., the time period during which both power switches are in the off state. For example... Figure 1As shown, the first driver in this embodiment 2 is also equipped with a second input port DT. This second input port DT is the dead-time control terminal of the first driver and is connected to the first timing circuit. The first timing circuit includes a first resistor R1 and a first capacitor C1 connected in parallel. One end of the first resistor R1 and one end of the first capacitor C1 are connected in parallel to the second input port, and the other end of the first resistor R1 and the other end of the first capacitor C1 are connected in parallel to ground. The parallel connection of the first resistor R1 and the first capacitor C1 forms an RC charging and discharging circuit, which is used to set the dead-time length, thereby precisely controlling the conduction interval of the upper and lower bridge arms and avoiding short-circuit risks.

[0040] It should be noted that in this embodiment 2, by connecting multiple power supply control circuits in series and utilizing internal power switches to collaboratively control the dynamic connection or bypass of the battery pack, the problems of difficulty in isolating faulty cells and rigid system output characteristics in traditional topologies are solved. Furthermore, combined with the battery pack redundancy design in this embodiment 2, when a battery pack fails, the faulty battery pack can be bypassed through the collaborative action of the power switches, and redundant battery packs can be connected to maintain a constant bus voltage, preventing the entire system from stopping due to a single battery pack malfunction, and avoiding the impact of a fault on the stability of the entire system. In addition, the power supply control circuit can control the number of battery packs connected to control the expected target output voltage and boost the bus voltage when it is low.

[0041] Example 3: The battery management circuit based on dynamic series connection disclosed in Embodiment 3, specifically for the switch control circuit, includes a first controller P1, a second controller P2, and multiple first acquisition units AFE. More specifically, in Embodiment 3, the first acquisition unit AFE preferably adopts an AFE module (Analog Front-End), and each first acquisition unit AFE is connected to a corresponding battery pack BAT, such as... Figure 2 As shown, this embodiment 3 is configured with 40 battery packs (BAT), corresponding to 40 AFE modules (AFE1_1~AFE4_40). These 40 AFE modules are grouped into four groups: AFE1_1~AFE1_10, AFE2_11~AFE2_20, AFE3_21~AFE3_30, and AFE4_31~AFE4_40. The AFE module primarily connects the internal sensors of the battery packs to the subsequent data processing unit for data interaction. It is mainly used for signal conditioning and analog-to-digital conversion. The AFE module receives the weak analog signals output by the sensors and performs amplification, filtering, and noise reduction conditioning. Then, through its built-in analog-to-digital converter, it converts the conditioned analog signals into digital signals for processing by the subsequent data processing unit. By using the AFE module, weak analog signals can be converted into reliable digital signals, ensuring the accuracy of the collected data and providing precise basis for subsequent control decisions.

[0042] Furthermore, the first controller P1 preferably adopts an ARM architecture microcontroller chip. The first controller P1 communicates with the first acquisition unit AFE. In this embodiment 3, the first controller P1 and the first acquisition unit AFE preferably adopt the SPI communication protocol (Serial Peripheral interface). The SPI communication protocol can provide fast, synchronous full-duplex communication, realize electromagnetic isolation of digital signals, prevent high voltage interference, and meet the needs of real-time monitoring and fast control of battery status, thereby improving data transmission efficiency and reliability.

[0043] Furthermore, the second controller P2 interacts with the first controller P1. In this embodiment 3, the second controller P2 uses an FPGA chip (Field-Programmable Gate Array). The second controller P2 can process parallel output signals, and based on the second control signal output by the first controller P1, it can control the second controller P2 to output a first control signal to the first driver of the corresponding power supply control circuit. Then, the first driver outputs a signal to the gate of the corresponding power switch to realize the conduction or cutoff of different power switches.

[0044] For example, combining Figure 2 As shown, when the first battery pack BAT malfunctions, the first acquisition unit AFE corresponding to the first battery pack BAT will acquire the voltage and temperature of the corresponding battery pack BAT and transmit the voltage and temperature to the first controller P1. At this time, the first controller P1 will analyze the voltage and temperature to determine the battery pack status and generate the first control signal of the corresponding power switch based on the battery pack status. Subsequently, the first control signal is transmitted to the second controller P2. At the same time, the second controller P2 will select the first driver U1 of the corresponding power supply control circuit to establish a communication channel with the second controller P2 and perform data interaction based on the second control signal sent by the first controller P1. At this time, the first control signal in the second controller P2 can be sent to the corresponding first driver U1, and the first driver U1 controls the corresponding power switch to be turned on or off.

[0045] In this embodiment 3, the first controller P1 is mainly responsible for complex data processing and control logic generation. It can analyze the voltage and temperature data collected by the first acquisition unit AFE and generate accurate control logic. The second controller P2 is responsible for parallel signal processing. It can quickly and accurately convert the control logic of the first controller P1 into different control signals, realize the parallel control of the multi-channel power supply control circuit, and greatly improve the response speed.

[0046] It should also be noted that, such as Figure 2As shown in Embodiment 3, the first controller P1 is configured with 40 first acquisition units (AFEs). To improve the efficiency of parallel data processing, the 40 first acquisition units (AFEs) can be divided into 4 groups. Simultaneously, the first controller P1 is configured with 4 groups of unit processing modules AS1-AS4, with every 10 first acquisition units (AFEs) connected to the same unit processing module. The first controller P1 is also configured with 4 chip select signal channels CS_1~CS_4, each corresponding to one unit processing module. When a battery pack malfunctions, the fault data is transmitted to the corresponding unit processing module, and the control signal is transmitted to the corresponding chip select interface of the second controller P2 through the corresponding chip select signal channel. The second controller P2 will selectively connect the corresponding power supply control circuit according to the chip select signal, realizing data interaction with the power supply control circuit. This grouping design achieves comprehensive coverage of the 40 first acquisition units (AFEs), facilitates fault location and group management, and improves the maintainability of the battery management circuit.

[0047] The battery management circuit in this embodiment 3 can monitor abnormal battery pack voltage and temperature in real time through a closed-loop process of acquisition-analysis-control, and quickly generate switching control signals to control the bypass or connection of the battery pack, and isolate faulty battery packs in a timely manner to prevent the fault from escalating. This can ensure the safe and stable operation of the battery pack in dynamic series scenarios.

[0048] Example 4: like Figure 3 As shown, the battery management circuit based on dynamic series connection disclosed in this embodiment 4, specifically for the enable circuit, may include a first enable switch S1, a second resistor R2, a first relay KT1, a second relay KT2, and a third relay KT3.

[0049] The contacts of the first relay KT1 and the second relay KT2 are connected in series to the main power transmission circuit. A first diode D1 is connected in parallel to the contacts of the first relay KT1, and a second diode D2 is connected in parallel to the contacts of the second relay KT2. One end of the second resistor R2 is connected between the contacts of the first relay KT1 and the second relay KT2; the other end of the second resistor R2 is connected in series with the contacts of the third relay KT3 and then connected to the main power transmission circuit.

[0050] Furthermore, in this embodiment 4, the first enable switch S1 is preferably a high-side switch, which includes a first enable interface, a second enable interface, and a third enable interface, wherein the first enable interface is a charging interface, the second enable interface is a discharging interface, and the third enable interface is a pre-charge interface. The first enable interface is connected to one end of the coil side of the first relay KT1, and the other end of the coil side of the first relay KT1 is grounded. The second enable interface is connected to one end of the coil side of the second relay KT2, and the other end of the coil side of the second relay KT2 is grounded; the third enable switch is connected to one end of the coil side of the third relay KT3, and the other end of the coil side of the third relay KT3 is grounded.

[0051] Detailed, combined Figure 3 As shown, in this embodiment 4, power is supplied to the PCS through the main transmission circuit. Since the inverter in the PCS contains a capacitive load, a large current will be generated at the moment the main transmission circuit connects to the PCS, potentially damaging the battery management circuit and the battery pack. Therefore, the first enable switch S1 is equipped with a third enable interface, and the third power supply interface controls the third relay KT3 to conduct. During the power supply phase, the coil side of the third relay KT3 is first controlled to conduct through the third enable interface, thus closing the contact side of the third relay KT3. The second resistor R2 limits the current connected to the PCS, allowing the PCS to charge slowly and avoiding instantaneous electrical surges to the capacitor. Subsequently, after the PCS's current stabilizes, the first and second enable interfaces of the first enable switch S1 are sequentially connected, closing the contact sides of the first relay KT1 and the second relay KT2, achieving stable power supply to the PCS and ensuring the safety and lifespan of the system hardware.

[0052] Furthermore, in this embodiment 4, to further control the charging and discharging operation of the entire main transmission circuit, a second enable switch S2 and a fourth relay KT4 are configured in the enable circuit. The contact side of the fourth relay KT4 is connected in series to the main transmission circuit. The second enable switch S2 is configured with a fourth enable interface, which is connected in parallel with the contact side of the third relay KT3. The fourth enable interface is connected to one end of the coil side of the fourth relay KT4, while the other end of the coil side of the fourth relay KT4 is grounded. The on / off state of the entire main transmission circuit can be controlled by the second enable switch S2. By using the fourth enable interface to connect the coil side of the fourth relay KT4, the contact side of the fourth relay KT4 is closed and conductive, ensuring that the enable circuit is connected to the PCS. Subsequently, the first enable switch S1 is used to control the charging and discharging operation of the main transmission circuit. The battery management circuit uses the second enable switch S2 to achieve overall on / off control of the main power transmission circuit. Combined with the hierarchical charging and discharging control of the first enable switch S1, the entire main power transmission circuit is more stable in long-term charging and discharging cycles, reducing the risk of system failure and improving the overall reliability of the battery management circuit.

[0053] Example 5: like Figure 4 As shown in Embodiment 5, the battery management circuit based on dynamic series connection, specifically for the power supply circuit, includes a first transformer T1, a third power switch Q3, a third resistor R3, a third controller P3, a third diode D3, and at least one power supply sub-circuit. The input side of the first transformer T1 is connected in series with the third power switch Q3 and the third resistor R3 to form a conduction loop. The third resistor R3 is mainly used to divide the voltage of the third power switch Q3 to ensure its safe operation. The third controller P3 is connected to the gate of the third power switch Q3. In Embodiment 5, the third controller P3 is preferably a PWM controller. By generating high-frequency pulse signals, it can control the conduction or cutoff of the third power switch Q3, thereby converting the electrical energy input in the conduction loop on the input side of the first transformer T1 into high-frequency pulse energy and transmitting it to the output side of the first transformer T1 to achieve voltage transformation.

[0054] Furthermore, such as Figure 4 As shown, one end of the output side of the first transformer T1 is connected to the positive terminal of the third diode D3, and at least one second capacitor is connected in parallel between the negative terminal of the third diode D3 and the other end of the output side of the first transformer T1. For example, in this embodiment 3, two capacitors E1 and E2 are configured, and an inductor L1 is provided between capacitors E1 and E2. The AC pulse on the output side of the first transformer T1 is rectified by the third diode D3 and converted into pulsating DC. Then, through the LC filter network composed of capacitor E1, inductor L1, and capacitor E2, the pulsating DC can be gradually filtered out, and finally a stable 12V DC voltage is output.

[0055] It should be noted that in this embodiment 5, a capacitor C2 and a resistor R4 are connected in parallel on the side of the third diode D3 to form an absorption circuit, thereby suppressing the voltage spikes generated by the reverse recovery of the third diode D3 or the leakage inductance of the transformer, avoiding damage to components due to overvoltage, and improving circuit reliability.

[0056] Furthermore, the power supply circuit configured in this embodiment 5 has two sets. One set of power supply circuits is connected in parallel to both ends of the battery pack, while the other set is connected in parallel to the output end of the main transmission circuit. Through these two sets of power supply circuits, power can be consistently supplied to the switch control circuit, enable circuit, and power supply control circuit even under normal or fault conditions of the battery management circuit, thereby improving the reliability of the system power supply. In this embodiment 5, one set of power supply circuits draws power from the battery pack, providing stable power to the entire system control under normal battery management circuit conditions. The other set of power supply circuits draws power from the inverter of the PCS. Typically, in the event of a battery pack failure, since the PCS is connected to the grid, it can draw power from the grid to supply power to the control circuit of the battery management circuit in reverse, ensuring that the battery management circuit can still control the battery pack under fault conditions.

[0057] Furthermore, in this embodiment 5, the aforementioned power supply sub-circuit is generally connected in parallel across the two ends of the second capacitor to obtain a stable 12V DC voltage.

[0058] Specifically, in this embodiment 5, the power supply sub-circuit includes a first power supply sub-circuit and a second power supply sub-circuit. The first power supply sub-circuit preferably uses a conventional low-dropout linear regulator to provide a first voltage to the switch control circuit, such as the 3.3V voltage of the applicable controller.

[0059] The second power supply sub-circuit provides a second voltage, such as the 12V voltage suitable for driver operation, to the enable circuit and the switch control circuit respectively. Specifically, the second power supply sub-circuit includes a second transformer T2 and a rectifier and filter circuit. The primary winding of the second transformer T2 is connected in parallel with two switch drive circuits. Each switch drive circuit is connected to an input filter circuit. The input filter circuit adopts a multi-stage capacitor parallel structure. By alternately turning on the two sets of switch drive circuits, the DC voltage is inverted into an alternating voltage and then fed into the second transformer T2. The second transformer T2 has two secondary windings. Each secondary winding of the second transformer is connected to a rectifier and filter circuit, which provides DC voltage to the first driver respectively.

[0060] Detailed, such as Figure 5 As shown, the switch drive circuit includes a fourth power switch Q4 and a fifth power switch Q5, which form a push-pull circuit structure. When the fourth power switch Q4 is on and the fifth power switch Q5 is off, current flows from H-12V through the fourth power switch Q4 into one end of the primary winding of the second transformer T2; when the fifth power switch Q5 is on and the fourth power switch Q4 is off, current flows from H-12V through the fifth power switch Q5 into the other end of the primary winding of the second transformer T2. By repeatedly switching on and off, a high-frequency alternating current can be generated in the primary winding of the second transformer T2, realizing the conversion from DC to high-frequency AC. Diode D4, resistor R5, and resistor R6 constitute the gate drive protection circuit for the fourth power switch Q4. Similarly, diode D5, resistor R7, and resistor R8 constitute the gate drive protection circuit for the fifth power switch Q5. The above gate drive protection circuit can stabilize the gate voltage of the corresponding power switch and prevent the power switch from being damaged by voltage spikes.

[0061] Furthermore, such as Figure 5 As shown, capacitors C3-C10 form a multi-stage parallel capacitor structure, which can eliminate input voltage ripple and interference, making the input voltage stable. Consequently, when the second transformer T2 performs voltage transformation, the output voltage is more stable, which facilitates subsequent processing.

[0062] Furthermore, combining Figure 5 and Figure 6 As shown, since the second power supply sub-circuit needs to supply power to the power switches of the 40 sets of switch control circuits respectively, 40 sets of second transformers T2 are configured in this embodiment 5, and each second transformer T2 is configured with two secondary windings. Through the two secondary windings, independent voltages can be provided to the control modules of the corresponding two power switches in the first driver, thereby realizing multi-path electrical isolation.

[0063] In this embodiment 5, each secondary winding of the second transformer T2 is connected to a rectifier and filter circuit, which provides DC voltage to the first driver.

[0064] Specifically, such as Figure 6 As shown, a rectifier-filter circuit is used as an example for illustration. This rectifier-filter circuit includes diodes D8 and D9, and a capacitor. One end of the secondary winding of the second transformer T2 is connected to the positive terminal of diode D8, and the other end of the secondary winding of the second transformer T2 is connected to the positive terminal of diode D9. The negative terminals of diodes D8 and D9 are connected in parallel to form a parallel terminal. A lead interface is provided in the middle of the secondary winding of the second transformer T2. At least one capacitor is connected in parallel between the parallel terminal and the lead interface. For example, in this embodiment, capacitors C15 and C16 are provided between the parallel terminal and the lead interface. In the above circuit, diodes D8 and D9 form a full-wave rectifier circuit, which converts the AC output from the secondary winding of the second transformer T2 into pulsating DC. Then, the filter circuit composed of capacitors C15 and C16 is used to filter the unidirectional pulsating DC, making the unidirectional pulsating DC smooth, so as to output a stable DC voltage. Then, the DC voltage provides voltage to the corresponding VDDAHM1_1 and GNDAHM1_1 interfaces in the first driver U1. Similarly, for the rectifier and filter circuit connected to the other secondary winding, a full-wave rectifier circuit composed of diodes D10 and D11 is used to convert the AC voltage output by the second transformer T2 into unidirectional pulsating DC. Then, a filter circuit composed of capacitors C17 and C18 is used to filter the unidirectional pulsating DC, making the unidirectional pulsating DC smooth, so as to output a stable DC voltage. In turn, the DC voltage provides voltage to the VDDALM1_1 and GNDALM1_1 interfaces in the corresponding first driver U1.

[0065] Example 6: The battery management circuit based on dynamic series connection disclosed in Embodiment 6 further adds a detection unit to Embodiment 1, such as... Figure 7As shown, the detection unit includes at least a first detection unit and a second detection unit. In this embodiment 6, the first detection unit is used to collect the current value flowing through the main transmission circuit to drive the second enable switch to control the on / off state of the entire main transmission circuit; while the second detection unit is mainly used for insulation detection, internal total voltage detection, and charge / discharge adhesion detection, so as to realize real-time monitoring and fault early warning of the overall status of the battery management circuit.

[0066] Furthermore, it should be noted that in this embodiment 6, both the first detection unit and the second detection unit preferably use I2C communication (Inter-Integrated Circuit) to maintain communication with the first controller P1. The data collected by both units can be transmitted to the first controller P1 for processing and analysis via I2C communication.

[0067] The above are merely preferred embodiments of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A dynamic string-based battery management circuit, comprising: The battery management circuit includes a switch control circuit, an enable circuit, a power supply circuit, and multiple power supply control circuits; the power supply control circuit and the enable circuit are connected in series to form the main power transmission circuit. The power supply control circuit is used to bypass or connect the battery pack according to the first control signal, and multiple power supply control circuits are connected in series in sequence. The switch control circuit is used to collect the first data of the battery pack and send the first control signal to the power supply control circuit according to the first data; The enabling circuit is used to control the main power transmission circuit to perform charging and discharging operations. The power supply circuit is used to supply power to the switch control circuit, the enable circuit, and the power supply control circuit, respectively.

2. The dynamic string-based battery management circuit of claim 1, wherein, The power supply control circuit includes a first driver and a half-bridge circuit; the half-bridge circuit is connected in series with the battery pack; the first driver is connected to the gate of the power switch of the half-bridge circuit, and the half-bridge circuit is controlled by the first driver to bypass or engage the battery pack.

3. The dynamic string-based battery management circuit of claim 1, wherein, The switch control circuit includes a first controller, a second controller, and multiple first acquisition units; Each of the first acquisition units is connected to a group of the battery packs. The first acquisition unit is used to acquire first data of the battery packs. The first controller is communicatively connected to the first acquisition unit. The first controller is used to receive the first data and process it to generate a first control signal and a second control signal. The second controller is communicatively connected to the first controller. The second controller is used to receive the first control signal and the second control signal, and control the second controller to communicate with the corresponding power supply control circuit according to the second control signal, so that the first control signal is sent to the power supply control circuit.

4. The battery management circuit based on dynamic series connection according to claim 2, characterized in that, The power supply control circuit further includes a first timing circuit, which is connected to the first driver and is used to control the delay interval of the power switch action in the half-bridge circuit.

5. The dynamic string-based battery management circuit of claim 1, wherein, The enabling circuit includes a first enabling switch, a first relay, a second relay, and a third relay; The first enable switch includes a first enable interface, a second enable interface, and a third enable interface. The first enable interface is connected to the first relay, which is located in the charging circuit, and the charging circuit is used to control the main transmission circuit to perform a charging operation. The second enable interface is connected to the second relay, which is located in the discharging circuit, and the discharging circuit is used to control the main transmission circuit to perform a discharging operation. The third enable interface is connected to the third relay, which is located in the pre-charge circuit, and the pre-charge circuit is used to control the main transmission circuit to perform a pre-charge operation.

6. The dynamic string-based battery management circuit of claim 5, wherein, The enabling circuit further includes a second enabling switch and a fourth relay. The second enabling switch is connected to the fourth relay, and the fourth relay is connected in series to the main control circuit. The main control circuit is used to control the main power transmission circuit to be connected or disconnected.

7. The dynamic string-based battery management circuit of claim 2, wherein, The power supply circuit includes a pulse modulation inverter circuit, a first transformer, a buffer circuit, a DC filter circuit, and a power supply sub-circuit. The primary winding of the first transformer is connected to the pulse modulation inverter circuit, which outputs a high-frequency pulse signal to the primary winding of the first transformer. The secondary winding of the first transformer is connected in sequence to the buffer circuit and the DC filter circuit. The buffer circuit is used to suppress voltage spikes in the first transformer, and the DC filter circuit is used to convert the high-frequency pulse signal output by the first transformer into a DC output voltage. The DC filter circuit is connected in parallel to at least one of the power supply sub-circuits.

8. The dynamic string-based battery management circuit of claim 7, wherein, The power supply sub-circuit includes a first power supply sub-circuit and a second power supply sub-circuit. The first power supply sub-circuit provides a first voltage to the switch control circuit, and the second power supply sub-circuit provides a second voltage to the enable circuit and the switch control circuit, respectively.

9. The battery management circuit based on dynamic series connection according to claim 8, characterized in that, The first power supply sub-circuit uses a low-dropout linear regulator to provide the first voltage to the switch control circuit. The second power supply sub-circuit includes an input filter circuit, a switch drive circuit, a second transformer, and a rectifier filter circuit. The primary winding of the second transformer is connected in parallel with two of the switch drive circuits, and each of the switch drive circuits is connected to the output terminal of the DC filter circuit via the input filter circuit. Alternating voltage is supplied to the primary winding of the second transformer by the two switch drive circuits alternately switching on and off. The secondary winding of the second transformer is connected to two sets of rectifier and filter circuits, which are respectively connected to the first driver. The alternating voltage output by the second transformer is converted into a stable DC voltage through the rectifier and filter circuits, and then the voltage is supplied to the first driver.

10. The battery management circuit based on dynamic series connection according to claim 7, characterized in that, The power supply circuit is provided in two sets. One set of the power supply circuit is connected in parallel to the battery pack, and the other set of the power supply circuit is connected in parallel to the output side of the main power transmission circuit.

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