CN206807150U - A kind of expansible group string data large-scale energy storage system - Google Patents

Abstract

The utility model discloses an expandable string type large-scale energy storage system, which is composed of multiple single-cluster energy storage systems connected in parallel, and each cluster energy storage system consists of 4 to 13 battery modules, a high-voltage box and Inverters are connected in series, in which the positive and negative terminals of the power supply of 4 to 13 battery modules and the positive and negative terminals of the input of the high voltage box are connected in series to form a loop. The positive and negative terminals of the output of the high voltage box and the DC positive and negative terminals of the inverter connection, and each battery module and high-voltage box is connected to the communication port through the communication power bus for communication; the high-voltage box and the inverter communicate through the 485 bus; The neutral wires are connected in parallel.

Description

A scalable string-type large-scale energy storage system

technical field

The utility model relates to an energy storage system, in particular to an expandable string type large-scale energy storage system.

Background technique

Large-scale energy storage technology is a key technology for smart grids, power dispatching, power grid peak-shaving and valley-filling, and peak-shaving and frequency-regulation. Lithium-ion batteries have been widely used in many fields due to their advantages such as high energy density, low self-discharge rate, stable discharge voltage, and long cycle life. The application of lithium batteries in large-scale power storage systems will become an inevitable trend of technological development. trend. A large-scale energy storage system requires thousands of lithium-ion single cells to be connected in series and parallel to form a system. The failure of any single cell will affect the operation of the entire energy storage system. Therefore, how to ensure the safety, reliability and efficiency of the energy storage system The operation of large-scale energy storage system is the key technology.

At the same time, the existing energy storage systems do not operate independently. When the capacity needs to be increased, the system needs to be suspended and redesigned, and the connection of the subsystem will cause a total voltage difference between the battery packs and damage the high-voltage devices. .

Utility model content

In order to overcome the defects of the prior art, the utility model provides an expandable string-type large-scale energy storage system, which can reduce the impact of a single cell failure on the operation of the entire energy storage system, and reduce the cost of components such as inverters. A single failure affects the operation of the entire energy storage system, effectively ensuring the safe and stable operation of the entire energy storage system.

The utility model discloses an expandable string-type large-scale energy storage system, which is composed of multiple single-cluster energy storage systems connected in parallel, and each cluster energy storage system consists of 4 to 13 battery modules, a high-voltage box and Inverters are connected in series, in which the positive and negative terminals of the power supply of 4 to 13 battery modules and the positive and negative terminals of the input of the high voltage box are connected in series to form a loop. The positive and negative terminals of the output of the high voltage box and the DC positive and negative terminals of the inverter connection, and each battery module and high-voltage box is connected to the communication port through the communication power bus for communication; the high-voltage box and the inverter communicate through the 485 bus; The neutral wires are connected in parallel.

The battery module has DC positive and negative output terminals, 2 parallel 16-series single cells, a multi-channel voltage acquisition module, a multi-channel temperature acquisition module, a main control single-chip microcomputer, an active equalization module, a CAN communication module and a fuse, of which 2 parallel 16 strings of single cell positive electrode series fuses are connected to the DC positive output terminal. The multi-channel voltage acquisition module collects the voltage value of each single cell and sends it to the main control microcontroller. The temperature of the single cell is collected and sent to the main control single-chip microcomputer. The main control single-chip microcomputer sends the voltage value and temperature value of each single cell to the high-voltage box through the CAN communication module, and at the same time receives the control signal sent by the high-voltage box. The main control microcontroller adjusts the active equalization module to boost or lower the voltage of each single cell according to the received control signal.

The high-voltage box has a DC positive and negative input terminal, a DC positive and negative output terminal, a molded case circuit breaker, an AC circuit breaker, a main relay, a pre-charging relay, a pre-charging resistor, an AC/DC power supply module, a main control management module and an energy management module. Module, in which the molded case circuit breaker is connected in series between the DC input terminal and the DC output terminal, the pre-charging relay and the pre-charging group are connected in parallel with the main relay, and then connected in series between the DC input terminal and the DC output terminal, AC/DC The DC input terminal of the power supply module is connected to the DC positive and negative input terminals, and the output terminal is connected to the main control management module and the energy management module. The main control management module controls the main relay and the pre-charge relay through the built-in relay driver module, and the built-in CAN communication Communicate with the battery module, and communicate with the energy management module, and the energy management module communicates with the inverter through the built-in 485 communication module.

The AC/DC power supply module has a built-in DC/DC module and an AC/DC module, and the input terminal of the DC/DC module is connected to the positive and negative DC input terminals, and the input terminal of the AC/DC module is connected to the grid through an AC circuit breaker.

The main control management module has a built-in main control management single-chip microcomputer, a power conversion module connected with the main control management single-chip microcomputer, a relay drive module, a CAN communication module, a current sensor, and an output terminal of the AC/DC power supply module is connected with the power conversion module. The control and management single-chip microcomputer communicates with the battery module and the energy management module through the CAN communication module, and the current sensor detects the current of the output circuit and sends it to the main control and management single-chip microcomputer.

The energy management module has a built-in energy management single-chip microcomputer, a power conversion module connected to the energy management single-chip microcomputer, a CAN communication module and a 485 communication module, the output end of the AC/DC power supply module is connected to the power conversion module, and the energy management single-chip microcomputer passes through the CAN communication module Communicate with the main control management module, and communicate with the inverter through the 485 communication module.

The molded case circuit breaker is a double-circuit high-voltage molded case circuit breaker.

Compared with the prior art, an expandable string type large-scale energy storage system of the present utility model has the following advantages:

The usual large-scale energy storage system adopts a centralized solution, that is, multiple battery systems are directly connected in parallel on the DC side, and a 250kw or 500kw high-power inverter is connected externally. The utility model adopts a string mode, which is connected in parallel on the AC side of the inverter, and actively adjusts the charging and discharging current through the inverter, which can well ensure the current balance of different parallel systems.

The usual large-scale energy storage system adopts a centralized scheme. When any single cell fails, the entire system must stop working; the utility model adopts a string scheme. When any single cell fails, The main relay and high-voltage molded case circuit breaker of the cluster where the cell is located can be disconnected to cut off the charging and discharging circuit to ensure that other clusters continue to work.

The usual large-scale energy storage system adopts a centralized scheme. When the inverter fails, the whole system must also stop working; the utility model adopts a string scheme, and when one inverter fails, it can be shut down. Inverter, other clusters continue to work.

As a whole, it provides a safe, reliable and efficient operation solution for the scalable string large-scale energy storage system.

Description of drawings

Fig. 1 is a circuit module diagram of the scalable string type large-scale energy storage system disclosed by the utility model;

Fig. 2 is a circuit block diagram of the battery module disclosed by the utility model;

Fig. 3 is a circuit block diagram of the high voltage box disclosed by the utility model.

detailed description

The technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings of the utility model.

As shown in Figure 1, a scalable string-type large-scale energy storage system disclosed by the utility model is composed of multiple single-cluster energy storage systems connected in parallel. Specifically, each cluster of energy storage systems consists of 4 ~13 battery modules, a high-voltage box and an inverter are connected in series, in which the positive and negative terminals of the power supply of 4~13 battery modules and the positive and negative terminals of the high-voltage box input are connected in series to form a loop, and the output of the high-voltage box is positive and negative. The negative terminal is connected to the DC positive and negative terminals of the inverter, and each battery module and high-voltage box is connected to the communication port through the communication power bus for communication, and the high-voltage box and the inverter communicate through the 485 bus. Multi-cluster energy storage system The inverters are connected in parallel through the AC live wire and the AC neutral wire.

As shown in Figure 2, the battery module has DC positive and negative output terminals, 2 parallel 16-series single cells, a multi-channel voltage acquisition module, a multi-channel temperature acquisition module, a main control single-chip microcomputer, an active equalization module, and an AD conversion module , CAN communication module, power conversion module and fuse, in which 2 and 16 series of single cells form a battery pack with a rated voltage of 51.2V and a rated capacity of 112Ah, and the positive series fuse is connected to the DC positive output terminal, and multi-channel voltage acquisition The module is MAX14921, which collects the voltage value of each single cell and sends it to the main control microcontroller through the AD conversion module. The multi-channel temperature acquisition module collects the temperature of each single cell through the temperature sensor and converts it The module sends to the main control single-chip microcomputer, and the main control single-chip microcomputer sends the voltage value and temperature value of each single cell to the high-voltage box through the CAN communication module, and receives the control signal sent by the high-voltage box at the same time, and the main control single-chip microcomputer adjusts according to the received control signal. The active equalization module boosts or lowers the voltage of each single cell, and the power conversion module receives the 24V voltage provided by the high voltage box to supply power to the main control microcontroller.

As shown in Figure 3, the high voltage box has a DC positive and negative input terminal, a DC positive and negative output terminal, a molded case circuit breaker, an AC circuit breaker, a main relay, a pre-charging relay, a pre-charging resistor, an AC/DC power supply module, a main control management module, energy management module and current sensor, among which the AC/DC power supply module has a built-in DC/DC module and AC/DC module, and the input terminal of the DC/DC module is connected to the DC positive and negative input terminals, and the input terminal of the AC/DC module The power grid is connected through an AC circuit breaker. The main control management module has a built-in main control management single-chip microcomputer, a power conversion module connected to the main control management single-chip microcomputer, a relay drive module, a CAN communication module and an AD sampling module. The energy management module has a built-in An energy management single-chip microcomputer, a power conversion module connected with the energy management single-chip computer, a CAN communication module and a 485 communication module.

Specifically, the molded case circuit breaker is a double-circuit high-voltage molded case circuit breaker, which is connected in series between the DC input terminal and the DC output terminal. Between the DC input terminal and the DC output terminal, the output terminals of the DC/DC module and the AC/DC module are respectively connected to the power conversion module of the main control management module and the power conversion module of the energy management module to convert the output 24V direct current into 5V direct current supplies power to the single-chip microcomputer. The CAN communication module in the main control management module realizes the CAN communication with the battery module and the CAN communication with the energy management module. The charging relay and the current sensor detect the current of the output circuit, which is converted by the AD sampling module and sent to the main control management single-chip microcomputer, and the energy management single-chip microcomputer communicates with the inverter through the 485 communication module.

The utility model discloses an expandable string-type large-scale energy storage system, the working process of which is as follows:

Close the molded case circuit breaker in the high-voltage box of each cluster, and the DC power supply in the high-voltage box outputs 24V voltage, and supplies power to all battery modules in the cluster;

The voltage acquisition module and temperature acquisition module in the battery module measure the voltage and temperature of each single battery cell in real time, and send them to the main control management module in the high voltage box through the communication power bus, so as to judge the consistency of the battery cells in real time; The voltage of any battery cell is significantly higher than that of other batteries, triggering the active equalization module in the battery module where the battery cell is located, boosting the voltage of the battery cell with high voltage to the total voltage of the battery module, and charging the battery module; If the voltage of any cell is significantly lower than other cells, the active equalization module will drop the total voltage of the battery module to charge the cell with the lower voltage;

All battery modules in the cluster communicate with the high-voltage box on the same communication power bus; the high-voltage box collects the status data of all batteries in the cluster. If there is no fault, first close the pre-charging relay with a delay of 5 seconds, and then close the main relay with a delay of 1 second. Then disconnect the pre-charging relay, and supply DC power to the inverter. If there is a fault, the alarm will be communicated, and the pre-charge and main relay will not be closed.

If the high-voltage box judges that the voltage between the battery modules is inconsistent according to the detected voltage value, the main control management module in the high-voltage box will communicate through the communication power bus and send it to the battery module with high voltage. Type passive equalization function, reduce its voltage.

The main control management module in the high-voltage box communicates with the energy management module through the CAN bus, and sends the voltage, temperature, state of charge information of all batteries in the cluster and the current maximum allowable charging and discharging current of the battery system to the energy management module in real time. Based on the received information, the module communicates with the inverter through the RS485 bus through calculation and management strategies to control the charging and discharging behavior of the inverter.

When the system has AC input, the high-voltage box closes the AC circuit breaker, and the internal DC/AC power supply automatically switches to AC power supply without consuming the power of the battery itself.

When the voltage is too high, the voltage is too low, the charging current is too large, the discharging current is too large, the temperature is too high, or the temperature is too low in a single cluster, the energy management module controls the charging of the inverter by reducing power and alarming. Discharge current.

When a battery cell in a single cluster fails, the main control management unit in the high-voltage box controls the dual-circuit high-voltage molded case circuit breaker to disconnect the charging and discharging circuit of the battery system in this cluster, ensuring that the entire energy storage system will not be affected.

The technical content and technical features of the present utility model have been disclosed as above, but those skilled in the art may still make various replacements and modifications based on the disclosure of the present utility model without departing from the spirit of the present utility model. Therefore, the protection scope of the present utility model should be It is not limited to the content disclosed in the embodiment, but includes various replacements and modifications that do not deviate from the present utility model, and is covered by the claims of this patent application.

Claims (7)

1. An expandable string-type large-scale energy storage system, which is composed of multiple single-cluster energy storage systems connected in parallel, characterized in that each cluster energy storage system consists of 4 to 13 battery modules and a high-voltage box It is connected in series with the inverter, in which the positive and negative terminals of the power supply of 4~13 battery modules and the positive and negative terminals of the input of the high voltage box are connected in series to form a loop. The communication port is connected to each battery module and high-voltage box through the communication power bus, the communication between the high-voltage box and the inverter is through the 485 bus, and the inverters of the multi-cluster energy storage system are connected through the AC live wire and the inverter. The AC neutral line is connected in parallel. 2. A scalable large-scale string-type energy storage system according to claim 1, characterized in that: the battery module has DC positive and negative output terminals, 2 parallel to 16 strings of single cells, and multiple Voltage acquisition module, multi-channel temperature acquisition module, main control single-chip microcomputer, active equalization module, CAN communication module and fuse, in which 2 and 16 strings of single cell positive electrode series fuses are connected to the DC positive output terminal, and the multi-channel voltage acquisition module is connected to each The voltage value of the single cell is collected and sent to the main control single-chip microcomputer. The multi-channel temperature acquisition module collects the temperature of each single cell through the temperature sensor and sends it to the main control single-chip microcomputer. The main control single-chip The voltage value and temperature value of the battery cell are sent to the high voltage box through the CAN communication module, and at the same time receive the control signal sent by the high voltage box, the main control microcontroller adjusts the active equalization module to boost or drop the voltage of each single cell according to the received control signal. pressure treatment. 3. An expandable string-type large-scale energy storage system according to claim 1, characterized in that: the high-voltage box has DC positive and negative input terminals, DC positive and negative output terminals, molded case circuit breakers, AC Circuit breaker, main relay, pre-charging relay, pre-charging resistor, AC/DC power supply module, main control management module and energy management module, wherein the molded case circuit breaker is connected in series between the DC input terminal and the DC output terminal, and the pre-charging relay and The pre-charging group is connected in parallel with the main relay after being connected in series, and then connected in series between the DC input terminal and the DC output terminal. The DC input terminal of the AC/DC power supply module is connected to the DC positive and negative input terminals, and the output terminal is connected to the main control management module and energy management Module, the main control management module controls the main relay and pre-charge relay through the built-in relay driver module, and communicates with the battery module through the built-in CAN communication module, and communicates with the energy management module, which communicates with the built-in 485 The module communicates with the inverter. 4. The scalable large-scale string-type energy storage system according to claim 3, characterized in that: the AC/DC power supply module has a built-in DC/DC module and an AC/DC module, and the DC/DC The input terminal of the module is connected to the DC positive and negative input terminals, and the input terminal of the AC/DC module is connected to the power grid through the AC circuit breaker. 5. A scalable large-scale string-type energy storage system according to claim 3, characterized in that: the main control management module has a built-in main control management single-chip microcomputer, and a power conversion module connected to the main control management single-chip microcomputer , relay drive module, CAN communication module, current sensor, the output terminal of the AC/DC power supply module is connected to the power conversion module, the main control management microcontroller communicates with the battery module and the energy management module through the CAN communication module, and the current sensor controls the output circuit The current is detected and sent to the main control management microcontroller. 6. A scalable large-scale string-type energy storage system according to claim 3, characterized in that: said energy management module has a built-in energy management single-chip microcomputer, a power conversion module connected to the energy management single-chip microcomputer, CAN communication Module and 485 communication module, the output end of the AC/DC power supply module is connected to the power conversion module, the energy management microcontroller communicates with the main control management module through the CAN communication module, and communicates with the inverter through the 485 communication module. 7. An expandable string-type large-scale energy storage system according to claim 3, wherein the molded case circuit breaker is a double-circuit high-voltage molded case circuit breaker.