Equalization mode electrical topology of series battery system

Abstract

The utility model discloses an equalization mode electrical topology of a series battery system, which comprises a battery system and a redundant battery, the battery system comprises a plurality of battery packs, the redundant battery is connected in parallel with each battery pack through a step-up and step-down module, and when a certain battery pack in the system needs to be equalized, after a DCDC bidirectional converter carries out step-up / step-down, the redundant battery is connected in parallel with the battery packs through the step-up and step-down module. The equalization relay K1 in a certain battery pack is controlled to be closed, the redundant battery charges or discharges the battery pack, the equalization relay K1 is disconnected when the voltage is consistent with the voltage of other battery packs, and equalization is completed; the equalization mode of the series battery system is an electrical topology, can control the boost or buck of the redundant battery, can be realized through charging and also can be realized through discharging, and is flexible and efficient.

Description

Technical Field

[0001] This utility model relates to the field of energy storage system technology, specifically to an electrical topology for balancing a series battery system. Background Technology

[0002] In current series battery systems, such as residential high-voltage stacked battery systems and industrial and commercial energy storage battery systems, when there is a voltage inconsistency in a certain battery module or battery box, the traditional method of BMS to balance individual cells is very slow. Generally, the consistency is achieved by replacing the battery or manually charging or discharging the module and battery pack individually, which results in a very slow balancing effect.

[0003] Therefore, it is necessary to design an electrical topology for balancing a series battery system. Utility Model Content

[0004] The purpose of this invention is to provide an electrical topology for balancing a series battery system, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an electrical topology for a series battery system with equalization, comprising: a battery system and redundant batteries, wherein the battery system comprises multiple battery packs, and the redundant batteries are connected in parallel with each battery pack through a boost / buck module.

[0006] Preferably, the BMU in each battery pack detects the battery pack voltage in real time through the HV2+ and HV2- voltage detection lines and uploads the data to the BCU in the high-voltage box in real time. The BCU detects the voltage of the redundant batteries through the HV+ and HV- detection lines, compares the data, and sends a balancing command to the battery pack BMU that needs to be balanced according to the set battery pack voltage difference value.

[0007] Preferably, the boost / buck module is a DC-DC bidirectional converter, and the positive and negative terminals of the redundant battery are connected to the HV+ and HV- detection lines respectively through the DC-DC bidirectional converter, and one terminal of the BCU is connected to the HV- detection line.

[0008] Preferably, the high-voltage box is further provided with an anti-reverse diode, which includes two diodes. The negative terminals of the two diodes are connected to the positive terminal of the K3 discharge relay. The negative terminal of the K3 discharge relay is connected to the positive terminal of the equalization relay K0. The negative terminal of the equalization relay K0 is connected to the HV+ detection line. The HV+ detection line is connected to another terminal of the BCU.

[0009] Preferably, the positive terminal of the discharge relay K3 is connected to the positive terminal of the precharge relay K4, the negative terminal of the precharge relay K4 is connected to the positive terminal of one of the diodes through a precharge resistor, the positive terminal of the other diode is connected to the negative terminal of the charging relay K2, and the positive terminal of the charging relay K2 is connected to the positive terminals of the discharge relay K3, the precharge relay K4, and the negative terminals of the two diodes.

[0010] Preferably, the battery pack includes battery pack 1, battery pack 2... battery pack n-1, battery pack n, and each battery pack further includes a balancing relay K1 and a balancing fuse.

[0011] Preferably, the BMU in each battery pack is connected to the positive terminal of the battery inside the battery pack via the HV2+ voltage detection line. The HV2+ voltage detection line is connected to the positive terminal of the equalization relay K1. The negative terminal of the equalization relay K1 is connected to the HV+ detection line. The controlled terminal of the equalization relay K1 is electrically connected to the BMU. The BMU is connected to the negative terminal of the battery inside the battery pack via the HV2- voltage detection line. The HV2- voltage detection line is connected to the HV- detection line via the equalization fuse.

[0012] Preferably, the HV2+ voltage detection line in the battery pack 1 is connected to the main fuse, and the main fuse is connected to the negative terminal of the K2 charging relay;

[0013] When n is not less than 2, the negative terminal of the battery in battery pack n-1 is connected to the positive terminal of the battery in battery pack n, the negative terminal of the battery in battery pack n is connected to the negative terminal of K4 negative relay through a shunt, and the positive terminal of K4 negative relay is connected to HV-detection line.

[0014] Preferably, the redundant battery is a conventional lead-acid, gel, or lithium-ion battery.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] The balancing electrical topology of this series battery system can control the boost or buck of redundant batteries. The balancing can be achieved through charging or discharging, making it flexible and efficient. Attached Figure Description

[0017] Figure 1 Partial circuit diagram of the balancing electrical topology of the series battery system of this invention. Figure 1 ;

[0018] Figure 2 Partial circuit diagram of the balancing electrical topology of the series battery system of this invention. Figure 2 . Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] See Figures 1-2 An electrical topology for balancing a series battery system includes: a battery system and redundant batteries. The battery system includes multiple battery packs. The redundant batteries are connected in parallel with each battery pack through a boost / buck module. When a battery pack in the battery system needs to be balanced, the boost / buck module boosts / bucks the voltage, and the redundant batteries charge or discharge it. When the voltage reaches the same level as the voltage of other battery packs, the balancing relay is disconnected, and balancing is completed.

[0021] Each battery pack's BMU (Battery Management Unit) monitors the battery pack voltage in real time via HV2+ and HV2- voltage detection lines and uploads the data to the BCU (Battery Control Unit) in the high-voltage box. The BCU then monitors the voltage of redundant batteries via HV+ and HV- detection lines, compares the data, and issues balancing commands to the BMUs of the battery packs that need balancing based on the set battery pack voltage difference value. When the voltage of a battery pack is too high, the redundant batteries are charged; when the voltage is too low, the redundant batteries are used to replenish the power.

[0022] The following is the specific connection relationship of the electrical topology of the equalization method of this series battery system: the boost and buck modules are DC-DC bidirectional converters, the positive and negative terminals of the redundant batteries are connected to the HV+ and HV- detection lines respectively through the DC-DC bidirectional converter, and one terminal of the BCU is connected to the HV- detection line;

[0023] The high-voltage box is also equipped with an anti-reverse diode, which consists of two diodes. The negative terminals of the two diodes are connected to the positive terminal of the K3 discharge relay. The negative terminal of the K3 discharge relay is connected to the positive terminal of the equalization relay K0. The negative terminal of the equalization relay K0 is connected to the HV+ detection line. The HV+ detection line is connected to another terminal of the BCU.

[0024] The positive terminal of the K3 discharge relay is connected to the positive terminal of the K4 precharge relay. The negative terminal of the K4 precharge relay is connected to the positive terminal of one of the diodes through the precharge resistor. The positive terminal of the other diode is connected to the negative terminal of the K2 charging relay. The positive terminal of the K2 charging relay is connected to the positive terminals of the K3 discharge relay, the K4 precharge relay, and the negative terminals of the two diodes.

[0025] The battery pack includes battery pack 1, battery pack 2, ... battery pack n-1, battery pack n (n is a positive integer greater than or equal to 2), and each battery pack also includes a balancing relay K1 and a balancing fuse;

[0026] The BMU in each battery pack is connected to the positive terminal of the battery inside the battery pack via the HV2+ voltage detection line. The HV2+ voltage detection line is connected to the positive terminal of the equalization relay K1. The negative terminal of the equalization relay K1 is connected to the HV+ detection line. The controlled terminal of the equalization relay K1 is electrically connected to the BMU. The BMU is connected to the negative terminal of the battery inside the battery pack via the HV2- voltage detection line. The HV2- voltage detection line is connected to the HV- detection line through the equalization fuse.

[0027] The HV2+ voltage detection line in battery pack 1 is connected to the main fuse, and the main fuse is connected to the negative terminal of the K2 charging relay.

[0028] When n is not less than 2, the negative terminal of the battery in battery pack n-1 is connected to the positive terminal of the battery in battery pack n, the negative terminal of the battery in battery pack n is connected to the negative terminal of the K4 negative relay through the shunt, and the positive terminal of the K4 negative relay is connected to the HV-detection line.

[0029] Detailed explanation:

[0030] Outside the battery system, a redundant battery is designed. The redundant battery is connected in parallel with each battery pack. A balancing control relay or MOS switch and a balancing fuse are added to the parallel connection line. This solution uses a balancing control relay. When a battery pack in the system needs to be balanced, the DC-DC bidirectional converter boosts / bucks the voltage and controls the balancing relay K1 in that battery pack to close. The redundant battery charges or discharges it. When the voltage reaches the same level as the voltage of other battery packs, the balancing relay K1 is opened, and the balancing is completed.

[0031] Each battery pack's BMU monitors the battery pack voltage in real time via HV2+ and HV2- voltage detection lines and uploads the data to the BCU in the high-voltage box. The BCU monitors the voltage of redundant batteries via HV+ and HV- detection lines, compares the data, and issues balancing commands to the battery pack BMUs that need balancing based on the set battery pack voltage difference value. When the voltage of a battery pack is too high, the redundant batteries are charged; when the voltage is too low, the redundant batteries are used to replenish the power.

[0032] The BCU can replenish the redundant battery by controlling the equalization relay K0, keeping the redundant battery power within a set range.

[0033] Redundant batteries can use conventional lead-acid or gel or lithium-ion batteries (lithium iron phosphate, ternary lithium, lithium cobalt phosphate, lithium manganese phosphate, lithium nickel phosphate, and sodium-ion or other rechargeable batteries).

[0034] Redundant batteries can be series-connected high-voltage batteries, or they can be systems that convert low-voltage batteries to high-voltage batteries through boost technology, or systems that convert high-voltage batteries to low-voltage batteries through high-voltage buck technology, or battery systems that support bidirectional power conversion with integrated boost-buck conversion.

[0035] Redundant battery systems can charge or discharge one or more batteries simultaneously.

[0036] When the redundant battery system is out of power, it can be charged by the battery pack that needs to be balanced, or by an external power supply system, such as a DC charger, or by two or more charging methods at the same time.

[0037] Redundant battery systems can be controlled and managed by their own battery management system or by a separate third-party battery management system.

[0038] The battery system that needs to be balanced can be a high-voltage system formed by connecting lead-acid, gel, or lithium-ion batteries in series, with voltage platforms including but not limited to 1000V, 1500V, 2000V, etc.

[0039] Redundant batteries can be integrated into the battery system that needs balancing, or they can be independent of the battery system that needs balancing.

[0040] Therefore, the balancing electrical topology of this series battery system can control the boost or buck of redundant batteries. The balancing method can be achieved by charging or discharging, which is flexible and efficient.

[0041] The equalizing relay used in this scheme is the HFE80P-20C type equalizing relay, and the equalizing fuse is the RSZ306-00-L 30A equalizing fuse. The above is only one preferred option in this scheme. Specific circuit components can be selected according to actual needs.

[0042] All parts not described in this utility model are the same as or can be implemented using existing technology. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electrical topology for balancing a series battery system, characterized in that, include: The battery system includes multiple battery packs, and the redundant batteries are connected in parallel with each battery pack through a boost / buck module. Each battery pack also includes an equalization relay K1. The boost / buck module is a DC-DC bidirectional converter. The positive terminals of the batteries in each battery pack are connected to the boost / buck module through the equalization relay K1, so as to realize the charging or discharging of the battery packs that need to be equalized by the redundant batteries.

2. The electrical topology for balancing a series battery system according to claim 1, characterized in that: It also includes HV2+ and HV2- voltage detection lines for real-time monitoring of battery pack voltage.

3. The electrical topology for balancing a series battery system according to claim 2, characterized in that: The boost / buck module is a DC-DC bidirectional converter.

4. The electrical topology for balancing a series battery system according to claim 3, characterized in that: It also includes a high-voltage box, which is equipped with an anti-reverse diode. The anti-reverse diode consists of two diodes. The negative terminals of the two diodes are connected to the positive terminal of the K3 discharge relay. The negative terminal of the K3 discharge relay is connected to the positive terminal of the equalization relay K0. The negative terminal of the equalization relay K0 is connected to the HV+ detection line. The HV+ detection line is connected to another terminal of the BCU.

5. The electrical topology for balancing a series battery system according to claim 4, characterized in that: The positive terminal of the K3 discharge relay is connected to the positive terminal of the K4 precharge relay. The negative terminal of the K4 precharge relay is connected to the positive terminal of one of the diodes through a precharge resistor. The positive terminal of the other diode is connected to the negative terminal of the K2 charging relay. The positive terminal of the K2 charging relay is connected to the positive terminals of the K3 discharge relay, the K4 precharge relay, and the negative terminals of the two diodes.

6. The electrical topology for balancing a series battery system according to claim 5, characterized in that: The battery pack includes battery pack 1, battery pack 2... battery pack n-1, battery pack n, and each battery pack also includes a balancing fuse.

7. The electrical topology for balancing a series battery system according to claim 6, characterized in that: The BMU in each battery pack is connected to the positive terminal of the battery inside the battery pack via the HV2+ voltage detection line. The HV2+ voltage detection line is connected to the positive terminal of the equalization relay K1. The negative terminal of the equalization relay K1 is connected to the HV+ detection line. The controlled terminal of the equalization relay K1 is electrically connected to the BMU. The BMU is connected to the negative terminal of the battery inside the battery pack via the HV2- voltage detection line. The HV2- voltage detection line is connected to the HV- detection line through the equalization fuse.

8. The electrical topology for balancing a series battery system according to claim 7, characterized in that: The HV2+ voltage detection line in the battery pack 1 is connected to the main fuse, and the main fuse is connected to the negative terminal of the K2 charging relay; When n is not less than 2, the negative terminal of the battery in battery pack n-1 is connected to the positive terminal of the battery in battery pack n, the negative terminal of the battery in battery pack n is connected to the negative terminal of K4 negative relay through a shunt, and the positive terminal of K4 negative relay is connected to HV-detection line.

9. The electrical topology for balancing a series battery system according to claim 1, characterized in that: The redundant battery is a conventional lead-acid, gel, or lithium-ion battery.

Images