Circuit and method for eliminating fault battery pack in energy storage battery system

Abstract

The invention discloses a circuit and a method for removing a fault battery pack in an energy storage battery system, the energy storage battery system is formed by connecting a plurality of battery packs in parallel, and the plurality of battery packs comprise a battery pack host and a plurality of battery pack slaves; comprising the following steps that when an energy storage battery system is discharged or static, a battery pack host monitors the state of each battery pack, and when it is monitored that X battery pack slaves have discharge faults, the battery pack host sends an instruction to enable MOS transistors only connected with the X battery packs to be disconnected; when the energy storage battery system is charged, the battery pack host monitors the state of each battery pack, and when it is monitored that charging faults occur in the Y battery packs, the battery pack host sends an instruction to enable the MOS tubes only connected with the Y battery packs to be disconnected.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage lithium batteries or lithium battery applications, and specifically relates to a circuit and method for removing faulty battery packs in an energy storage battery system. Background Art

[0002] With the development of energy storage technology and market demand, energy storage systems often consist of more than one battery pack, but multiple battery packs connected in parallel or in series. When multiple battery packs are used in parallel, one or more battery packs may fail. The existing processing steps are as follows: Figure 1 As shown, it is mainly: when any battery pack has a discharge fault, a discharge MOS disconnection instruction is sent to command all battery packs in the energy storage system to disconnect the discharge MOS, and a discharge prohibition instruction is sent to the inverter; when any battery has a charging fault, a charge MOS disconnection instruction is sent to command all battery packs in the energy storage system to disconnect the charging MOS, and a charge prohibition instruction is sent to the inverter.

[0003] All batteries in the energy storage system are disconnected from MOS. Although this processing method can eliminate faulty battery packs, when one or more battery packs have a discharge failure, all battery packs will be unable to discharge, making the entire energy storage system unusable; when one or more battery packs have a charging failure, all battery packs will be unable to charge, making the entire energy storage system unusable, thus greatly reducing the efficiency of the energy storage system. Summary of the invention

[0004] Purpose of the invention: In order to solve the problem mentioned in the background technology that the existing processing steps will cause the entire energy storage system to be unusable, greatly reducing the efficiency of the energy storage system, the present invention proposes a circuit and method for removing faulty battery packs in an energy storage battery system. During parallel use, when one or several battery packs fail, only the faulty battery pack is disconnected to ensure that other battery packs can continue to be used.

[0005] Technical solution: A faulty battery pack rejection circuit in an energy storage battery system, comprising: an inverter, a battery pack host, a plurality of battery pack slaves, a host MOS tube and a slave MOS tube; the battery pack host communicates with the inverter, and the battery pack host is connected to the inverter through the host MOS tube; each battery pack slave is connected in series with its own slave MOS tube, and then connected in parallel with the battery pack host and the host MOS tube in series;

[0006] By controlling the disconnection of the slave MOS tube, the faulty battery pack can be removed from the machine.

[0007] The present invention also discloses a method for removing a faulty battery pack in an energy storage battery system, comprising the following steps:

[0008] Step 1: construct a faulty battery pack rejection circuit; the faulty battery pack rejection circuit is a faulty battery pack rejection circuit in the energy storage battery system disclosed above;

[0009] Step 2: The battery pack host monitors the status of each battery pack slave. When it is detected that X battery packs have discharge / charging faults, the MOS tubes connected to only the X battery packs are disconnected.

[0010] Furthermore, when a discharge fault occurs, the MOS tubes connected to only X battery packs are disconnected, and the battery pack host sends a command to the inverter to change the maximum discharge current to I MaxDis ×(NX),I MacDis The maximum discharge current allowed for a single battery pack.

[0011] Furthermore, when a charging fault occurs, the MOS tube connected to only X battery packs is disconnected, and the battery pack host sends a command to the inverter to change the maximum discharge current to I MaxCh ×(NX),I MaxCh The maximum charging current allowed for a single battery pack.

[0012] Beneficial effect: Compared with the prior art, the method of the present invention can realize the individual removal of faulty battery packs, ensuring that other battery packs in the energy storage system can continue to be used, thereby greatly improving the utilization efficiency of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Flow chart for eliminating faulty battery packs;

[0014] Figure 2 Block diagram of the energy storage battery system. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is now further described in conjunction with the accompanying drawings and embodiments.

[0016] like Figure 2 As shown, the energy storage battery system involved in this embodiment is composed of N battery packs connected in parallel, and the maximum discharge current allowed by a single battery pack is I MacDis The maximum allowed charging current is I MaxCh . This embodiment proposes a circuit for removing a faulty battery pack in an energy storage battery system, which mainly includes: an inverter, a battery pack host, a plurality of battery pack slaves, and a MOS tube connected in series with each battery pack. The battery pack host is a battery pack selected arbitrarily from the energy storage battery system, and the remaining battery packs are battery pack slaves. The battery pack host communicates with the inverter. The battery pack host is connected to the inverter through a MOS tube.

[0017] like Figure 1As shown, a method for removing a faulty battery pack in an energy storage battery system proposed in this embodiment mainly includes: a host computer, an inverter, a battery pack host, a plurality of battery pack slaves, and a MOS tube connected in series with each battery pack. The battery pack host is a battery pack selected arbitrarily from the energy storage battery system, and the remaining battery packs are battery pack slaves. The host computer communicates with the inverter.

[0018] When discharging or at rest, the battery pack host monitors the status of each battery pack. When it detects that X battery packs have discharge faults, the battery pack host sends a command to disconnect the MOS tubes connected only to X battery packs, and the other battery packs do not perform any operation, that is, continue to discharge or remain at rest; at this time, the battery pack host sends a command to the inverter, and the maximum discharge current is changed to I MaxDis ×(NX).

[0019] During charging, the battery pack host monitors the status of each battery pack. When it detects that Y battery packs have charging faults, the battery pack host sends a command to disconnect the MOS tubes connected to only Y battery packs. The other battery packs do not perform any operation, that is, continue to charge. At this time, the battery pack host sends a command to the inverter, and the maximum charging current is changed to I MaxCh ×(NY).

Claims

1. A circuit for removing a faulty battery pack in an energy storage battery system, characterized in that: include: An inverter, a battery pack host, several battery pack slaves, a host MOS tube and a slave MOS tube; the battery pack host communicates with the inverter, and the battery pack host is connected to the inverter through the host MOS tube; each battery pack slave is connected in series with its own slave MOS tube, and then connected in parallel with the battery pack host and the host MOS tube connected in series; By controlling the disconnection of the slave MOS tube, the faulty battery pack can be removed from the machine.

2. A method for removing faulty battery packs in an energy storage battery system, characterized in that: The following steps are involved: Step 1: construct a faulty battery pack rejection circuit; the faulty battery pack rejection circuit is a faulty battery pack rejection circuit in an energy storage battery system as claimed in claim 1; Step 2: The battery pack host monitors the status of each battery pack slave. When it is detected that X battery packs have discharge / charging faults, the MOS tubes connected to only the X battery packs are disconnected.

3. A method for removing faulty battery packs in an energy storage battery system according to claim 2, characterized in that: When a discharge fault occurs, the MOS tubes connected to only X battery packs are disconnected, and the battery pack host sends a command to the inverter to change the maximum discharge current to I MaxDis ×(NX),I MacDis The maximum discharge current allowed for a single battery pack.

4. A method for removing faulty battery packs in an energy storage battery system according to claim 2, characterized in that: When a charging fault occurs, the MOS tubes connected to only X battery packs are disconnected, and the battery pack host sends a command to the inverter to change the maximum discharge current to I MaxCh ×(NX),I MaxCh The maximum charging current allowed for a single battery pack.

Images