High-voltage battery pack equalization control circuit

Abstract

The utility model provides a high-voltage battery pack equalization control circuit, which comprises an isolation transformer module, a first bridge switch module, a second bridge switch module, an isolation driver module and a monitoring module, and is characterized in that energy transmission is realized by using a high-efficiency isolation transformer and an MOS (Metal Oxide Semiconductor) tube, the energy loss is reduced, and the service life of the high-voltage battery pack is prolonged. And meanwhile, the stability of energy conversion is ensured. The isolation driver module provides electrical isolation protection, avoids the influence of a high-voltage circuit on a low-voltage control circuit, improves the safety of the system, cooperates with the monitoring module, detects the current, voltage and balance state of a battery cell in real time, responds to an abnormal condition in time, and prevents a battery from being overcharged or overdischarged. The system adopts a modular design, and each battery pack is provided with a DC-DC circuit, so that the system can be conveniently expanded.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage battery pack control technology, and more specifically, it relates to a high-voltage battery pack equalization control circuit. Background Technology

[0002] In existing technologies, high-voltage battery packs typically achieve high voltage output by connecting multiple cells in series. While the series connection effectively increases the output voltage of the battery pack, it also presents several challenges: High cell consistency requirements: Series-connected cells need to be highly consistent; otherwise, individual cells may overcharge or over-discharge, affecting the battery pack's performance and lifespan. For systems with a large battery capacity, this results in higher maintenance costs. Regarding management complexity, series-connected batteries often require a centralized Battery Management System (BMS), where monitoring and management of all cells are concentrated in a single master control unit. However, this may limit the scalability of larger battery systems and introduce the possibility of single points of failure. Distributed BMSs are also commonly used, distributing battery pack monitoring and management functions across multiple slave control units. Each slave control unit manages a small number of cells, while the master control unit handles overall coordination and communication.

[0003] Existing high-voltage battery packs cannot achieve individual cell control and flexible adjustment, making it difficult to improve system management efficiency. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a high-voltage battery pack equalization control circuit to overcome the shortcomings of existing high-voltage battery packs that cannot achieve control and flexible adjustment of each battery pack, making it difficult to improve the management efficiency of the system.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a high-voltage battery pack equalization control circuit, comprising: an isolation transformer module for converting high voltage to low voltage and / or converting low voltage to high voltage; a first bridge switch module for at least converting DC to AC and / or AC to DC; the first bridge switch module includes a first side and a second side, the first side being electrically connected to the battery pack, and the second side being electrically connected to the primary side of the isolation transformer module; a second bridge switch module for at least converting DC to AC and / or AC to DC; the second bridge switch module includes a third side and a fourth side, the third side being electrically connected to an external circuit, and the fourth side being electrically connected to... The secondary side of the isolation transformer module is electrically connected; an isolation driver module is used to output control signals to control the first bridge switch module and / or the second bridge switch module to be turned on or off; the first output terminal of the isolation driver module is electrically connected to the control terminal of the first bridge switch module; the second output terminal of the isolation driver module is electrically connected to the control terminal of the second bridge switch module; a monitoring module is used to detect at least the first current of the battery pack, and determine whether there is a balancing requirement based on the first current. If so, a balancing command is sent to the isolation driver module; the negative terminal of the battery pack is electrically connected to the first bridge switch module after passing through the monitoring module, and the monitoring module is also communicatively connected to the isolation driver module.

[0006] In one embodiment, the first bridge switch module includes at least a first MOSFET, a second MOSFET, a third MOSFET, and a fourth MOSFET; the gates of the first MOSFET, the second MOSFET, the third MOSFET, and the fourth MOSFET are all connected to the isolation driver module; the drains of the first MOSFET and the second MOSFET are both electrically connected to the positive terminal of the battery pack; the sources of the third MOSFET and the fourth MOSFET are both electrically connected to the negative terminal of the battery pack; the source of the first MOSFET is electrically connected to the drain of the third MOSFET; the source of the second MOSFET is electrically connected to the drain of the fourth MOSFET; the source of the first MOSFET is electrically connected to the first terminal of the primary side of the isolation transformer module; and the source of the second MOSFET is electrically connected to the second terminal of the primary side of the isolation transformer module.

[0007] In one embodiment, the second bridge switch module includes at least a fifth MOSFET, a sixth MOSFET, a seventh MOSFET, and an eighth MOSFET; the gates of the fifth MOSFET, the sixth MOSFET, the seventh MOSFET, and the eighth MOSFET are all connected to the isolation driver module; the drains of the fifth MOSFET and the sixth MOSFET are both electrically connected to the positive terminal of the external circuit; the sources of the seventh MOSFET and the eighth MOSFET are both electrically connected to the negative terminal of the external circuit; the source of the fifth MOSFET is electrically connected to the drain of the seventh MOSFET; the source of the sixth MOSFET is electrically connected to the drain of the eighth MOSFET; the source of the fifth MOSFET is electrically connected to the first terminal of the secondary side of the isolation transformer module; and the source of the second MOSFET is electrically connected to the second terminal of the secondary side of the isolation transformer module.

[0008] In one embodiment, the isolation driver module includes a first pin, a second pin, a third pin, and a fourth pin; the first pin is electrically connected to the gate of the first MOSFET; the second pin is electrically connected to the gate of the second MOSFET; the third pin is electrically connected to the gate of the third MOSFET; and the fourth pin is electrically connected to the gate of the fourth MOSFET. During the discharge of the battery pack, the first pin and the fourth pin output a first level signal; the second pin and the third pin output a second level signal, wherein the first level signal and the second level signal are complementary signals.

[0009] In one embodiment, the isolation driver module further includes a fifth pin, a sixth pin, a seventh pin, and an eighth pin; the fifth pin is electrically connected to the gate of the fifth MOSFET; the sixth pin is electrically connected to the gate of the sixth MOSFET; the seventh pin is electrically connected to the gate of the seventh MOSFET; and the eighth pin is electrically connected to the gate of the eighth MOSFET. During the discharge of the battery pack, the sixth and seventh pins output a third-level signal, and the fifth and eighth pins output a fourth-level signal, wherein the third-level signal and the fourth-level signal are complementary signals.

[0010] In one embodiment, the first bridge switch module further includes: a ninth MOSFET, a tenth MOSFET, an eleventh MOSFET, and a twelfth MOSFET; the gates of the ninth MOSFET, the tenth MOSFET, the eleventh MOSFET, and the twelfth MOSFET are all connected to the isolation driver module; the drains of the ninth MOSFET and the tenth MOSFET are both electrically connected to the positive terminal of the battery pack; the sources of the eleventh MOSFET and the twelfth MOSFET are both electrically connected to the negative terminal of the battery pack; the source of the ninth MOSFET is electrically connected to the drain of the eleventh MOSFET; the source of the tenth MOSFET is electrically connected to the drain of the twelfth MOSFET; the source of the ninth MOSFET is electrically connected to the third terminal of the primary side of the isolation transformer module; and the source of the tenth MOSFET is electrically connected to the fourth terminal of the primary side of the isolation transformer module.

[0011] In one embodiment, the monitoring module includes: a shunt and a comparator unit; the negative terminal of the battery pack is electrically connected to a first bridge switch module through the shunt; the output terminal of the shunt is electrically connected to the input terminal of the comparator unit; and the output terminal of the comparator unit is communicatively connected to an isolation driver module.

[0012] In one embodiment, the shunt includes: a first sampling resistor, a second sampling resistor, a third sampling resistor, and a fourth sampling resistor; a first terminal of the first sampling resistor, a first terminal of the second sampling resistor, a first terminal of the third sampling resistor, and a first terminal of the fourth sampling resistor are all electrically connected to the negative terminal of the battery pack; a second terminal of the first sampling resistor, a second terminal of the second sampling resistor, a second terminal of the third sampling resistor, and a second terminal of the fourth sampling resistor are all electrically connected to the first bridge switch module; a first terminal of the first sampling resistor, a first terminal of the second sampling resistor, a first terminal of the third sampling resistor, and a first terminal of the fourth sampling resistor are all electrically connected to a first pin of the comparator unit; a second terminal of the first sampling resistor, a second terminal of the second sampling resistor, a second terminal of the third sampling resistor, and a second terminal of the fourth sampling resistor are all electrically connected to a second pin of the comparator unit.

[0013] In one embodiment, a fuse is also included; the positive terminal of the battery pack is electrically connected to the first bridge switch module via the fuse.

[0014] In summary, this utility model has the following beneficial effects: A high-voltage battery pack balancing control circuit includes: an isolation transformer module, a first bridge switch module, a second bridge switch module, an isolation driver module, and a monitoring module. The circuit of this utility model uses a high-efficiency isolation transformer and MOSFETs for energy transmission, reducing energy loss while ensuring the stability of energy conversion. The isolation driver module provides electrical isolation protection, preventing the high-voltage circuit from affecting the low-voltage control circuit and improving system safety. Combined with the monitoring module, it monitors the current, voltage, and balancing status of the battery cells in real time, responding promptly to abnormal situations and preventing overcharging or over-discharging. The system adopts a modular design, equipping each battery cell with a DC-DC circuit, which facilitates system expansion. When the battery packs are connected in parallel, each battery pack can act as a master to control the remaining battery packs for power balancing, avoiding the disadvantage that the remaining battery packs cannot achieve power balancing when the master battery pack is offline. Attached Figure Description

[0015] Figure 1 This is a circuit topology diagram of a high-voltage battery pack balancing control circuit according to the present invention;

[0016] Figure 2 This is a circuit diagram of a high-voltage battery pack equalization control circuit according to the present invention.

[0017] Figure 3 This is the circuit schematic diagram of the first bridge switch module of this utility model;

[0018] Figure 4 This is a circuit schematic diagram of the monitoring module of this utility model;

[0019] Figure 5 This is the circuit schematic diagram of the second bridge switch module of this utility model.

[0020] Figure 6 This is a circuit diagram of the temperature detection module of this utility model;

[0021] Figure 7 This is a schematic diagram of the MCU chip circuit of this utility model;

[0022] Figure 8 This is a schematic diagram of the high-speed sampling circuit of this utility model;

[0023] In the diagram: 1. Isolation transformer module; 2. First bridge switch module; 3. Second bridge switch module; 4. Isolation driver module; 5. Monitoring module. Detailed Implementation

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0025] In this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. The terms "vertical," "horizontal," "left," "right," "above," "below," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Example 1

[0027] To solve the above problems, this utility model provides a high-voltage battery pack equalization control circuit, such as... Figure 1 As shown, it includes:

[0028] Isolation transformer module 1 is used to convert high voltage to low voltage and / or convert low voltage to high voltage;

[0029] The first bridge switch module 2 is used at least to convert direct current to alternating current and / or to convert alternating current to direct current; the first bridge switch module 2 includes a first side and a second side, the first side being electrically connected to the battery pack and the second side being electrically connected to the primary side of the isolation transformer module 1.

[0030] The second bridge switch module 3 is used at least to convert direct current to alternating current and / or to convert alternating current to direct current; the second bridge switch module 3 includes a third side and a fourth side, the third side being electrically connected to an external circuit, and the fourth side being electrically connected to the secondary side of the isolation transformer module 1;

[0031] The isolation driver module 4 is used to output control signals to control the first bridge switch module and / or the second bridge switch module to be turned on or off; the first output terminal of the isolation driver module 4 is electrically connected to the control terminal of the first bridge switch module 2; the second output terminal of the isolation driver module 4 is electrically connected to the control terminal of the second bridge switch module 3.

[0032] The monitoring module 5 is used to detect at least the first current of the battery pack and determine whether there is a balancing requirement based on the first current. If so, it sends a balancing command to the isolation driver module 4. The negative terminal of the battery pack is electrically connected to the first bridge switch module 2 after passing through the monitoring module 5. The monitoring module 5 is also communicatively connected to the isolation driver module 4.

[0033] In practical applications, the isolation transformer module 1 can convert high voltage to low voltage or vice versa, enabling effective energy transfer between different voltage levels and ensuring system flexibility and efficiency. The isolation transformer also ensures isolation between the battery pack and external circuits, improving circuit safety. The first bridge switch module 2 and the second bridge switch module 3 can perform bidirectional conversion between DC and AC power, enabling the system to achieve DC-DC voltage conversion. The bridge switch modules can be controlled to open or close as needed to achieve power balance among the battery packs. The isolation driver module 4 provides drive signals to the first and second bridge switches, ensuring precise control of the switch states. The isolation driver module 4 provides purely digital drive signals, offering high precision and high speed. Furthermore, by monitoring current and voltage and adjusting the battery pack's charging and discharging state according to real-time conditions, overcharging or over-discharging can be effectively avoided, improving the battery pack's lifespan and safety.

[0034] In one embodiment, the first bridge switch module includes at least a first MOSFET MOS1, a second MOSFET MOS2, a third MOSFET MOS3, and a fourth MOSFET MOS4; the gates of the first MOSFET MOS1, the second MOSFET MOS2, the third MOSFET MOS3, and the fourth MOSFET MOS4 are all connected to the isolation driver module; the drains of the first MOSFET MOS1 and the second MOSFET MOS2 are both electrically connected to the positive terminal of the battery pack; the sources of the third MOSFET MOS3 and the fourth MOSFET MOS4 are both electrically connected to the negative terminal of the battery pack; the source of the first MOSFET MOS1 is electrically connected to the drain of the third MOSFET MOS3; the source of the second MOSFET MOS2 is electrically connected to the drain of the fourth MOSFET MOS4; the source of the first MOSFET MOS1 is electrically connected to the first terminal of the primary side of the isolation transformer module; and the source of the second MOSFET MOS2 is electrically connected to the second terminal of the primary side of the isolation transformer module.

[0035] In one embodiment, the second bridge switch module includes at least a fifth MOSFET MOS5, a sixth MOSFET MOS6, a seventh MOSFET MOS7, and an eighth MOSFET MOS8; the gates of the fifth MOSFET MOS5, the sixth MOSFET MOS6, the seventh MOSFET MOS7, and the eighth MOSFET MOS8 are all connected to the isolation driver module; the drains of the fifth MOSFET MOS5 and the sixth MOSFET MOS6 are both electrically connected to the positive terminal of the external circuit; the sources of the seventh MOSFET MOS7 and the eighth MOSFET MOS8 are both electrically connected to the negative terminal of the external circuit; the source of the fifth MOSFET MOS5 is electrically connected to the drain of the seventh MOSFET MOS7; the source of the sixth MOSFET MOS6 is electrically connected to the drain of the eighth MOSFET MOS8; the source of the fifth MOSFET MOS5 is electrically connected to the first terminal of the secondary side of the isolation transformer module; and the source of the second MOSFET MOS2 is electrically connected to the second terminal of the secondary side of the isolation transformer module.

[0036] In one embodiment, the isolation driver module includes a first pin, a second pin, a third pin, and a fourth pin; the first pin is electrically connected to the gate of the first MOSFET MOS1; the second pin is electrically connected to the gate of the second MOSFET MOS2; the third pin is electrically connected to the gate of the third MOSFET MOS3; and the fourth pin is electrically connected to the gate of the fourth MOSFET MOS4; during the discharge of the battery pack, the first pin and the fourth pin output a first level signal; the second pin and the third pin output a second level signal, wherein the first level signal and the second level signal are complementary signals.

[0037] In one embodiment, the isolation driver module further includes a fifth pin, a sixth pin, a seventh pin, and an eighth pin; the fifth pin is electrically connected to the gate of the fifth MOS transistor MOS5; the sixth pin is electrically connected to the gate of the sixth MOS transistor MOS6; the seventh pin is electrically connected to the gate of the seventh MOS transistor MOS7; and the eighth pin is electrically connected to the gate of the eighth MOS transistor MOS8. During the discharge of the battery pack, the sixth and seventh pins output a third-level signal, and the fifth and eighth pins output a fourth-level signal, wherein the third-level signal and the fourth-level signal are complementary signals.

[0038] In practical applications, the first and second bridge switching modules convert the DC power from the battery pack to AC power through the alternating switching of MOSFETs, either to charge the battery pack or to discharge it to external circuits. This bidirectional control method, especially the efficient power conversion achieved through MOSFETs, improves the utilization efficiency of the battery pack and enables the parallel battery system to operate stably under different conditions. By using multiple MOSFETs in the first and second bridge switching modules and connecting their gates to the isolation driver module, the on / off states of each MOSFET can be precisely controlled. The gate signal of each MOSFET is a complementary signal provided by the isolation driver module, ensuring coordinated operation of the switches and achieving precise control of the battery pack, avoiding uneven charge distribution among the batteries. The isolation driver module adjusts the switching states of the MOSFETs according to the charging and discharging state of the battery pack, ensuring a relatively balanced charge distribution during charging and discharging, thereby extending battery life and improving the overall efficiency of the battery system. The isolation driver module has multiple pins connected to the MOSFETs and can output different level signals during battery discharge to control the operating states of different bridge modules. Multi-channel control enables parallel power balancing of multiple battery packs, improving the charging and discharging efficiency and control accuracy of the entire battery system.

[0039] In one embodiment, the first bridge switch module further includes: a ninth MOSFET, a tenth MOSFET, an eleventh MOSFET, and a twelfth MOSFET; the gates of the ninth MOSFET, the tenth MOSFET, the eleventh MOSFET, and the twelfth MOSFET are all connected to the isolation driver module; the drains of the ninth MOSFET and the tenth MOSFET are both electrically connected to the positive terminal of the battery pack; the sources of the eleventh MOSFET and the twelfth MOSFET are both electrically connected to the negative terminal of the battery pack; the source of the ninth MOSFET is electrically connected to the drain of the eleventh MOSFET; the source of the tenth MOSFET is electrically connected to the drain of the twelfth MOSFET; the source of the ninth MOSFET is electrically connected to the third terminal of the primary side of the isolation transformer module; and the source of the tenth MOSFET is electrically connected to the fourth terminal of the primary side of the isolation transformer module.

[0040] In scenarios involving multiple battery packs connected in parallel, the current may be quite large. Therefore, designing an additional set of MOSFETs in parallel can significantly improve the current carrying capacity of the system, ensuring stable operation under high load conditions. In addition, by adding a set of parallel MOSFETs, if one MOSFET fails, the other parallel MOSFETs can still continue to work, increasing the redundancy and reliability of the system.

[0041] In one embodiment, the monitoring module includes: a shunt and a comparator unit; the negative terminal of the battery pack is electrically connected to a first bridge switch module through the shunt; the output terminal of the shunt is electrically connected to the input terminal of the comparator unit; and the output terminal of the comparator unit is communicatively connected to an isolation driver module.

[0042] In practical applications, negative electrode current detection can accurately monitor the charging and discharging process of a battery pack. Detecting the negative electrode current of the battery pack through methods such as shunts provides current data, allowing for an understanding of the battery pack's discharge status. Since current flows from the negative electrode, monitoring this current effectively reflects the battery pack's load condition and whether it is operating normally. When multiple battery packs are used in parallel, differences in charge capacity, charging status, and internal resistance can lead to uneven current distribution. Detecting the negative electrode current helps identify this imbalance. By detecting the negative electrode current, it's possible to determine which battery pack has a higher or lower current, thus determining whether a power balancing operation is needed. Timely detection and adjustment ensure consistent charge levels across multiple battery packs, preventing over-discharge or over-charge in some packs. The comparator unit not only has current detection capabilities but also a RS485 communication interface, enabling timely transmission of detection results to the main control device. The main control device then determines if power balancing is necessary and, if so, controls the corresponding battery pack to perform the balancing operation.

[0043] In one embodiment, such as Figure 3 As shown, each MOSFET has a gate capacitor connected in parallel between the gate and source to stabilize the gate voltage, suppress high-frequency noise, and prevent false triggering. Each MOSFET also has a source-drain capacitor connected between the source and drain and ground or power supply to smooth current fluctuations and reduce voltage spikes during switching transients. A capacitor bank is also connected in parallel at the output of the first bridge switching module to suppress high-frequency ripple and improve the quality of the output current. Each MOSFET also has a gate resistor to limit the gate charging current, prevent oscillations caused by parasitic capacitance, and optimize switching speed.

[0044] In one embodiment, such as Figure 4As shown, the shunt includes: a first sampling resistor RS1, a second sampling resistor RS2, a third sampling resistor RS3, and a fourth sampling resistor RS4; the first terminals of the first sampling resistor RS1, the second sampling resistor RS2, the third sampling resistor RS3, and the fourth sampling resistor RS4 are all electrically connected to the negative terminal of the battery pack; the second terminals of the first sampling resistor RS1, the second sampling resistor RS2, the third sampling resistor RS3, and the fourth sampling resistor RS4 are all electrically connected to the first bridge switch module; the first terminals of the first sampling resistor RS1, the second sampling resistor RS2, the third sampling resistor RS3, and the fourth sampling resistor RS4 are all electrically connected to the first pin of the comparator unit; the second terminals of the first sampling resistor RS1, the second sampling resistor RS2, the third sampling resistor RS3, and the fourth sampling resistor RS4 are all electrically connected to the second pin of the comparator unit.

[0045] In practical applications, by setting four sampling resistors in parallel, the total resistance is 1 / 4 of that of a single resistor (assuming four identical resistors). Based on the current shunt principle, the current is evenly distributed to the four branches. This reduces the impact of individual resistor errors on the overall measurement and significantly reduces resistance drift caused by overheating. The parallel design of four sampling resistors also provides redundancy to prevent open circuits; even if one resistor is open, the remaining three can continue to operate, avoiding a single point of failure that could cause the entire current measurement to fail. Figure 7 As shown, the comparator unit specifically includes: an MCU chip, specifically a TMS320F28034PNT MCU chip; wherein, the comparator unit can convert analog signals into digital signals based on the sampled data from the first and third pins, and remotely communicate the sampled data with external control devices through the eleventh and thirteenth pins, the eleventh and thirteenth pins being RS485 signal transmission pins, the comparator unit transmits differential signals through twisted pair cables, effectively suppressing common-mode interference and supporting long-distance communication.

[0046] like Figure 8 As shown, the high-speed sampling circuit includes a high-speed current sampling circuit and a high-speed voltage sampling circuit. The specific working principle of the high-speed voltage sampling circuit is as follows: the voltage signal to be measured enters the circuit through INP. If the input voltage exceeds the input range of the operational amplifier, the amplitude is adjusted by a resistor divider network. The operational amplifier U10A / S amplifies the differential signal to improve the signal-to-noise ratio of the small signal. The capacitor filters out high-frequency noise, and the Zener diode limits the upper limit of the output voltage to prevent overvoltage damage to subsequent circuits. Finally, a stable differential or single-ended voltage signal is output for the MCU chip to compare and process.

[0047] The high-speed current sampling circuit works as follows: sampling resistor R45 converts the input current into a small voltage signal. Operational amplifier U14A, acting as a transimpedance amplifier, amplifies the voltage signal across R45 and outputs it as a voltage signal suitable for subsequent processing. An adjustable voltage source adjusts the DC bias of the operational amplifier to eliminate input offset or zero-point drift, and capacitors filter out high-frequency noise. The power supply pins provide analog / digital power isolation to reduce interference. The final output signal (OUTN / OUTP) is a voltage signal proportional to the input current, which is then processed by the MCU chip.

[0048] In one embodiment, such as Figure 5 As shown, the monitoring module also includes a fifth sampling resistor RS5. The negative terminal of the second bridge switch module is electrically connected to the external circuit through the fifth sampling resistor RS5. The fifth sampling resistor is used to detect the current between the DC-DC module and the external circuit to determine whether the battery pack needs to be balanced.

[0049] In one embodiment, such as Figure 5 As shown, it also includes a relay module. The positive terminal of the second bridge switch module is electrically connected to an external circuit through the relay module. The relay module can adjust according to the external device (i.e., Figure 1 The control signals of the MCU module in the DC-DC converter control the DC-DC module to be connected or disconnected from the external circuit.

[0050] In one embodiment, an AFE module is also included. The AFE module is used to collect analog signals such as voltage, current, and temperature of each cell in the battery pack and convert them into digital signals for processing by the main controller. The AFE module communicates with an external MCU module and can detect each cell in the battery pack. If a cell fails, it can also promptly feed back to the MCU to handle the battery pack offline, making it convenient for maintenance personnel to perform repairs.

[0051] In one embodiment, such as Figure 6 As shown, it also includes a temperature detection module, which can detect the temperature inside the battery pack. When the temperature of the battery cells is detected to be too low, the built-in heating film is activated to bring the battery to an efficient charging and discharging temperature. If the temperature is too high, the battery will trigger protection, preventing charging and discharging.

[0052] In summary, this application provides a battery pack control circuit that reduces energy loss and ensures stable energy conversion by using a high-efficiency isolation transformer and MOSFETs for energy transfer. The isolation driver module provides electrical isolation protection, preventing the high-voltage circuit from affecting the low-voltage control circuit and improving system safety. Combined with a monitoring module, it monitors the current, voltage, and balance status of the battery cells in real time, responding promptly to abnormal situations and preventing overcharging or over-discharging. The system adopts a modular design, equipping each battery cell with a DC-DC circuit, allowing for easy system expansion. When the battery packs are connected in parallel, each battery pack can act as a master unit to control the remaining battery packs for power balancing, avoiding the drawback of the remaining battery packs being unable to achieve power balancing when the master battery pack is offline.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A high voltage battery pack equalization control circuit, characterized in that, The application relates to a battery pack, which comprises: an isolation transformer module for converting high voltage into low voltage and / or converting low voltage into high voltage; a first bridge switch module for converting direct current into alternating current and / or converting alternating current into direct current; the first bridge switch module comprises a first side and a second side, the first side is electrically connected with a battery pack, and the second side is electrically connected with a primary side of the isolation transformer module; a second bridge switch module for converting direct current into alternating current and / or converting alternating current into direct current; the second bridge switch module comprises a third side and a fourth side, the third side is electrically connected with an external circuit, and the fourth side is electrically connected with a secondary side of the isolation transformer module; an isolation driver module for outputting control signals to control the first bridge switch module and / or the second bridge switch module to be turned on or turned off; a first output end of the isolation driver module is electrically connected with a control end of the first bridge switch module; a second output end of the isolation driver module is electrically connected with a control end of the second bridge switch module; a monitoring module for detecting at least a first current of the battery pack, judging whether there is a balancing demand based on the first current, and sending a balancing command to the isolation driver module if there is the balancing demand; a negative electrode of the battery pack is electrically connected with the first bridge switch module through the monitoring module, and the monitoring module is in communication connection with the isolation driver module.

2. The high voltage battery pack equalization control circuit of claim 1, wherein, The first bridge switch module comprises at least a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube; gates of the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are connected with the isolation driver module; drains of the first MOS tube and the second MOS tube are electrically connected with a positive electrode of the battery pack; sources of the third MOS tube and the fourth MOS tube are electrically connected with a negative electrode of the battery pack; a source of the first MOS tube is electrically connected with a drain of the third MOS tube; a source of the second MOS tube is electrically connected with a drain of the fourth MOS tube; a source of the first MOS tube is electrically connected with a first end of the primary side of the isolation transformer module, and a source of the second MOS tube is electrically connected with a second end of the primary side of the isolation transformer module.

3. The high voltage battery pack equalization control circuit of claim 2, wherein, The second bridge switch module comprises at least a fifth MOS tube, a sixth MOS tube, a seventh MOS tube and an eighth MOS tube; gates of the fifth MOS tube, the sixth MOS tube, the seventh MOS tube and the eighth MOS tube are connected with the isolation driver module; drains of the fifth MOS tube and the sixth MOS tube are electrically connected with a positive electrode of the external circuit; sources of the seventh MOS tube and the eighth MOS tube are electrically connected with a negative electrode of the external circuit; a source of the fifth MOS tube is electrically connected with a drain of the seventh MOS tube; a source of the sixth MOS tube is electrically connected with a drain of the eighth MOS tube. The source of the fifth MOS tube is electrically connected with a first end of a secondary side of the isolation transformer module; and the source of the second MOS tube is electrically connected with a second end of the secondary side of the isolation transformer module.

4. The high voltage battery pack equalization control circuit of claim 3, wherein, The isolation driver module comprises a first pin, a second pin, a third pin and a fourth pin; The first pin is electrically connected with a gate of the first MOS tube; The second pin is electrically connected with a gate of the second MOS tube; The third pin is electrically connected with a gate of the third MOS tube; The fourth pin is electrically connected with a gate of the fourth MOS tube; During discharging of the battery pack, the first pin and the fourth pin output a first level signal; the second pin and the third pin output a second level signal, the first level signal and the second level signal being complementary signals.

5. The high voltage battery pack equalization control circuit of claim 3, wherein, The isolation driver module further comprises a fifth pin, a sixth pin, a seventh pin and an eighth pin; The fifth pin is electrically connected with a gate of the fifth MOS tube; The sixth pin is electrically connected with a gate of the sixth MOS tube; The seventh pin is electrically connected with a gate of the seventh MOS tube; The eighth pin is electrically connected with a gate of the eighth MOS tube; During discharging of the battery pack, the sixth pin and the seventh pin output a third level signal, the fifth pin and the eighth pin output a fourth level signal, the third level signal and the fourth level signal being complementary signals.

6. The high voltage battery pack equalization control circuit of claim 2, wherein, The first bridge switch module further comprises a ninth MOS tube, a tenth MOS tube, an eleventh MOS tube and a twelfth MOS tube; Gates of the ninth MOS tube, the tenth MOS tube, the eleventh MOS tube and the twelfth MOS tube are connected with the isolation driver module; Drains of the ninth MOS tube and the tenth MOS tube are electrically connected with a positive electrode of the battery pack; Sources of the eleventh MOS tube and the twelfth MOS tube are electrically connected with a negative electrode of the battery pack; The source of the ninth MOS tube is electrically connected with a drain of the eleventh MOS tube; The source of the tenth MOS tube is electrically connected with a drain of the twelfth MOS tube; The source of the ninth MOS tube is electrically connected with a third end of a primary side of the isolation transformer module; and the source of the tenth MOS tube is electrically connected with a fourth end of the primary side of the isolation transformer module.

7. The high voltage battery pack equalization control circuit of claim 1, wherein, The monitoring module comprises a shunt and a comparator unit; a negative electrode of the battery pack is electrically connected with the first bridge switch module through the shunt; An output end of the shunt is electrically connected with an input end of the comparator unit; and an output end of the comparator unit is communicatively connected with the isolation driver module.

8. The high voltage battery pack equalization control circuit of claim 7, wherein, The shunt comprises a first sampling resistor, a second sampling resistor, a third sampling resistor and a fourth sampling resistor; The first end of the first sampling resistor, the first end of the second sampling resistor, the first end of the third sampling resistor, and the first end of the fourth sampling resistor are electrically connected with the negative electrode of the battery pack; the second end of the first sampling resistor, the second end of the second sampling resistor, the second end of the third sampling resistor, and the second end of the fourth sampling resistor are electrically connected with the first bridge switch module; The first end of the first sampling resistor, the first end of the second sampling resistor, the first end of the third sampling resistor, and the first end of the fourth sampling resistor are electrically connected with the first pin of the comparator unit; The second end of the first sampling resistor, the second end of the second sampling resistor, the second end of the third sampling resistor, and the second end of the fourth sampling resistor are electrically connected with the second pin of the comparator unit.

9. The high voltage battery pack equalization control circuit of claim 8, wherein, Further comprising a fuse; the positive electrode of the battery pack is electrically connected with the first bridge switch module through the fuse.

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