CN116418023A

CN116418023A - Control method of energy storage system, energy storage control system and energy storage system

Info

Publication number: CN116418023A
Application number: CN202111677283.XA
Authority: CN
Inventors: 王伟佳; 李善鹏; 曹虎; 尹雪芹
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11

Abstract

The invention discloses a control method of an energy storage system, the energy storage control system and the energy storage system, wherein the control method of the energy storage system comprises the following steps: controlling the plurality of battery clusters to be sequentially connected with the converging unit, and controlling the first insulation detection unit to detect a first insulation state between the battery clusters and the converging unit while each battery cluster is connected with the converging unit; the control target energy storage module is connected with the power conversion module and controls the first insulation detection unit to detect a second insulation state between the target energy storage module and the power conversion module; controlling a power conversion module in the energy storage system to be connected with a power grid, and controlling a second insulation detection unit to detect a third insulation state between the power conversion module in the energy storage system and the power grid; and determining that the third insulation state has no insulation fault, and controlling the energy storage system to charge or discharge with the power grid according to the charge-discharge control signal. By adopting the control method, the energy storage system can be started while the insulation detection function is finished, and the insulation detection efficiency can be improved.

Description

Control method of energy storage system, energy storage control system and energy storage system

Technical Field

The present invention relates to the field of energy storage technologies, and in particular, to a control method of an energy storage system, an energy storage control system, and an energy storage system.

Background

In the related art, for insulation detection of an energy storage system, the insulation detection is divided into three stages, so that independent insulation detection functions exist in a battery cluster, BCP (Battery Collection Panel, battery bus cabinet) and PCS (Power Conversion System, energy storage converter), and then the insulation condition of specific equipment can be effectively and accurately positioned, and the on-line positioning function of insulation faults of the energy storage system is realized.

However, in the above insulation detection mode, when the insulation state of each sub-component in the energy storage system is independently detected, the switch is turned off after the detection of the battery cluster is completed, and then the insulation detection of the battery bus cabinet and the energy storage converter is performed, so that the whole insulation detection process is complicated, and the switch needs to be repeatedly opened and closed, so that the mechanical life of the device is influenced.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide a control method of an energy storage system, by which the energy storage system can be started while the insulation detection function is completed, and the insulation detection efficiency can be improved.

The second objective of the present invention is to provide an energy storage control system.

The third objective of the present invention is to provide an energy storage system.

In order to solve the above-mentioned problems, an embodiment of a first aspect of the present invention provides a control method of an energy storage system, the control method including: receiving a starting instruction and a charging and discharging control signal of an energy storage module comprising a plurality of battery clusters and a confluence unit; acquiring voltage information of each battery cluster in a target energy storage module; according to the charge and discharge control signals and the ordering of the voltage information of the battery clusters in the target energy storage module, controlling the battery clusters to be sequentially connected with the converging unit, controlling a first insulation detection unit in the target energy storage module to detect a first insulation state between the battery clusters and the converging unit while each battery cluster is connected with the converging unit, and simultaneously controlling the connection relation between the battery clusters and the converging unit based on the first insulation state, wherein when the first insulation state is an insulation fault, the connection relation between the battery clusters and the converging unit is disconnected; when the first insulation state is no insulation fault, the connection relation between the battery cluster and the confluence unit is communicated; when the detection of the first insulation states between all the battery clusters in the target energy storage module and the converging unit is finished and the connection relation between at least one battery cluster and the converging unit is determined to be communicated, controlling the target energy storage module to be connected with a power conversion module and controlling the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module; when the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system are detected and the second insulation states have no insulation fault, controlling the power conversion modules in the energy storage system to be connected with a power grid, and controlling a second insulation detection unit in the power conversion modules to detect a third insulation state between the power conversion modules and the power grid in the energy storage system; and determining that the third insulation state has no insulation fault, and controlling the energy storage system and the power grid to charge or discharge according to the charge and discharge control signal.

According to the control method of the energy storage system, after a starting instruction of the energy storage module is received, the first insulation detection unit is controlled to detect the first insulation state between the battery clusters and the converging unit while controlling each battery cluster to be connected with the converging unit, and when the first insulation state between all the battery clusters and the converging unit in the target energy storage module is detected and the connection relation between at least one battery cluster and the converging unit is determined to be communicated, the target energy storage module is controlled to be connected with the power conversion module while controlling the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module, and when the second insulation state between all the energy storage modules and the power conversion module in the energy storage system is detected and the second insulation state is not provided with insulation faults, the power conversion module is controlled to be connected with a power grid while controlling the second insulation detection unit to detect the third insulation state between the power conversion module and the power grid.

An embodiment of a third aspect of the present invention provides an energy storage system, comprising: each energy storage module comprises a confluence unit and a plurality of battery clusters which are arranged in parallel, each battery cluster is connected with the confluence unit, a battery cluster contactor is arranged between each battery cluster and the confluence unit, and the confluence unit comprises a first insulation detection unit and a disconnecting switch; the power conversion module comprises a power device and a second insulation detection unit, the direct current side of the power device is connected with each converging unit, the isolating switch is arranged between the power device and each converging unit, and the alternating current side of the power device is provided with an alternating current side breaker; the control module is connected with the energy storage module and the power conversion module and is used for executing the control method of the energy storage system.

According to the energy storage system provided by the embodiment of the invention, based on the topological structure of the energy storage system, the control module is used for executing the control method of the energy storage system provided by the embodiment of the invention, so that the starting of the energy storage system can be realized while the insulation detection function is finished, and the insulation detection efficiency can be improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a structural topology of an energy storage system according to one embodiment of the present invention;

FIG. 2 is a flow chart of a method of controlling an energy storage system according to one embodiment of the invention;

FIG. 3 is a block diagram of an energy storage control system according to one embodiment of the present invention;

fig. 4 is a flow chart of a method of controlling an energy storage system according to another embodiment of the present invention.

Reference numerals:

an energy storage system 100; an energy storage control system 50;

an energy storage module 10; a power conversion module 20; a control module 30; a field total control unit 31; an energy management system 40;

a confluence unit 1; a battery cluster 2; a battery manager 3; a power device 4; a second insulation detection unit 5; a power control unit 6;

a first insulation detection unit 11; a confluence control unit 12; a battery management control unit 13; a direct current conversion unit 14;

a processor 51; a memory 52.

Detailed Description

Embodiments of the present invention will be described in detail below, by way of example with reference to the accompanying drawings.

In the related art, with the continuous improvement of the output power of the power devices in the energy storage system, in order to match the requirement of the power grid, multiple battery clusters are connected in parallel in the energy storage system so as to improve the output power of the energy storage system. However, due to the influence of the consistency of the batteries, different problems such as internal resistance and pressure difference must exist between the battery clusters arranged in parallel, and the characteristic difference between the battery clusters is gradually enlarged when the multi-cluster battery clusters are operated in parallel for a long time, which is particularly shown in that the SOC (State of Charge) deviation between the battery clusters is increased or the output current difference between the battery clusters is increased. In addition, as the number of battery clusters increases, the insulation detection method of the energy storage system is more complex.

In order to solve the above-mentioned problems, an embodiment of the first aspect of the present invention provides a control method of an energy storage system, by adopting the control method, the energy storage system can be started while the insulation detection function is completed, and the efficiency of insulation detection can be improved.

An energy storage system provided in accordance with an embodiment of the present invention is described below with reference to fig. 1. As shown in fig. 1, an energy storage system 100 includes at least one energy storage module 10, a power conversion module 20, and a control module 30.

Each energy storage module 10 comprises a bus unit 1 and a plurality of battery clusters 2 which are arranged in parallel, each battery cluster 2 is connected with the bus unit 1, and a battery manager 3 is arranged between each battery cluster 2 and the bus unit 1. As shown in fig. 1, each energy storage module 10 includes a plurality of battery clusters 2 therein, which are respectively: l1, L2, L3 … Ln; each battery cluster 2 is formed by connecting a plurality of electric cells in series, and each battery cluster 2 is respectively provided with a battery manager 3: BMS1, BMS2, BMS3 … BMSn; all the battery managers 3 within the energy storage module 10 are connected to the confluence unit 1.

The bus unit 1 includes a first insulation detection unit 11 and a disconnecting switch Q1 for connecting the energy storage module 10 and the power conversion module 20.

The power conversion module 20 includes a power device 4 and a second insulation detection unit 5, a direct current side of the power device 4 is connected with each of the busbar units 1, a disconnecting switch Q1 is disposed between the power device 4 and the busbar unit 1, an alternating current side of the power device 4 is provided with an alternating current side breaker QF1, and a direct current side of the power device 4 is provided with a direct current side breaker QF2.

From the above, the plurality of battery clusters 2, the confluence unit 1 and the power conversion module 20 in each energy storage module 10 form a main loop of the whole energy storage system, and in a normal state, when the energy storage system 100 is started, the control module 30 controls the direct current main loop of at least one energy storage module 10 to be connected to the direct current side of the power conversion module 20 in parallel, and the alternating current side of the power conversion module 20 is connected to the power grid, so that the energy storage system 100 is connected to the power grid.

In practical applications, the energy storage system 100 further includes a temperature control system, a fire protection system, an EMS40 (Energy ManagementSystem, an energy management system), etc., which are not described herein.

The battery manager 3 includes a battery management control unit 13, a battery cluster contactor KM connecting the battery clusters 2 and the bus unit 1. As shown in fig. 1, the battery management control unit 13 is communicatively connected to the bus unit 1, and each battery cluster 2 is correspondingly connected to a battery cluster contactor KM: KM1, KM2, KM3 … KMn, each battery cluster contactor KM is controlled by a correspondingly connected battery management control unit 13, i.e. the battery management control unit 13 controls the opening or closing of the corresponding battery cluster contactor KM.

Based on the structural topology diagram of the energy storage system shown in fig. 1, an embodiment of the present invention proposes a control method of the energy storage system, and the control method is applied to the control module 30. The basic idea of the control method of the energy storage system provided by the embodiment of the invention is that the insulation detection logic is combined with the start operation control strategy of the energy storage system so as to gradually connect all components in the energy storage system and detect the insulation state of the energy storage system by controlling the first insulation detection unit or the second insulation detection unit, thus after the insulation detection work of all the components is completed, the energy storage system also completes the start flow, and the energy storage system can directly output target power so as to match the requirement of a power grid.

The following specifically describes a control method of an energy storage system according to an embodiment of the present invention with reference to fig. 2, where the control method at least includes step S1 to step S6.

Step S1, a starting instruction and a charging and discharging control signal of an energy storage module comprising a plurality of battery clusters and a converging unit are received.

The starting instruction or the charging and discharging control signal of the energy storage module can be directly sent by the control module, or can be sent by an upper controller of the control module and an energy management system, and the starting instruction or the charging and discharging control signal of the energy storage module is sent to the control module through the upper controller so as to start a plurality of energy storage modules in the energy storage system.

Specifically, referring to fig. 1, since the energy storage system includes a plurality of energy storage modules, when the energy storage system is started, each energy storage module may be started in sequence according to a certain sequence, for example, the starting sequence of each energy storage module may be preset according to needs, or the starting sequence may be determined according to characteristic state information of each energy storage module, such as total voltage information, which is not limited, so that the control module may sequentially send a starting instruction according to the starting sequence of each energy storage module, so that each energy storage module is started and connected into a main loop of the energy storage system.

And S2, acquiring voltage information of each battery cluster in the target energy storage module.

The target energy storage module may be understood as an energy storage module that is in a starting state in response to a starting command of the energy storage module. For example, taking fig. 1 as an example, the energy storage system 100 includes two energy storage modules 10: the first energy storage module 101 and the second energy storage module 102, if the first energy storage module 101 receives the starting instruction, the first energy storage module 101 is used as a target energy storage module to execute the starting operation; if the second energy storage module 102 receives the start command, the second energy storage module 102 is used as the target energy storage module to execute the start operation.

Step S3, controlling the plurality of battery clusters to be sequentially connected with the converging unit according to the charge and discharge control signals and the ordering of the voltage information of the plurality of battery clusters in the target energy storage module, controlling a first insulation detection unit in the target energy storage module to detect a first insulation state between the battery clusters and the converging unit while each battery cluster is connected with the converging unit, and simultaneously controlling the connection relationship between the battery clusters and the converging unit based on the first insulation state, wherein the connection relationship between the battery clusters and the converging unit is disconnected when the first insulation state is an insulation fault; when the first insulation state is no insulation fault, the connection relation between the battery cluster and the confluence unit is communicated.

Specifically, since each energy storage module includes a plurality of battery clusters that are arranged in parallel, when each energy storage module is started, the plurality of battery clusters in each energy storage module need to be started in sequence according to a certain sequence, so as to improve the reliability of control logic, for example, the starting sequence of each battery cluster can be preset according to needs, or the starting sequence can be determined according to characteristic state information, such as voltage information or SOC information, of each battery cluster, and the like, and is not limited, therefore, based on the sequence of the plurality of battery clusters in the target energy storage module, the plurality of battery clusters are controlled to be connected with the confluence unit in sequence, so that each battery cluster is connected to a main loop of the target energy storage module, and the starting of the target energy storage module is realized. It can be understood that, for each energy storage module, before the energy storage module is started, all the battery clusters in the energy storage module are in a disconnected state with the converging units, and the first insulation detection unit and the second insulation detection unit are in a standby state, i.e. the first insulation detection unit and the second insulation detection unit are not operated.

In addition, in the process of controlling a plurality of battery clusters in the target energy storage module to be connected into the main loop, a first insulation detection unit in the target energy storage module is controlled to detect a first insulation state between the battery clusters and the converging unit while each battery cluster is connected with the converging unit, that is, before the target energy storage module is not started, the battery clusters are in a disconnection state with the converging unit, the first insulation detection unit in the converging unit does not work, after the target energy storage module receives a starting instruction, the control module controls the plurality of battery clusters to be connected with the converging unit in sequence, and after each battery cluster is connected with the converging unit, the control module controls the first insulation detection unit to start and execute insulation detection once so as to determine the first insulation state between the battery clusters connected with the converging unit at this time, thereby completing the operation of connecting the battery clusters into the main loop of the target energy storage module and the detection of the insulation state between the battery clusters and the converging unit in the process of controlling the starting of the battery clusters. It can be understood that after each battery cluster is connected to the current collecting unit, a direct current voltage exists in the current collecting unit, so that the first insulation detecting unit in the current collecting unit can work normally to detect the insulation state between the battery cluster and the current collecting unit.

Furthermore, after each time of insulation detection, the first insulation detection unit sends the detected first insulation state to the control module, the control module controls the connection relation between the detected battery cluster and the converging unit according to the first insulation state, and if the control module determines that the first insulation state is an insulation fault, the control module controls the detected battery cluster to disconnect from the converging unit so as to avoid insulation risk in the whole loop after the energy storage system is connected with a power grid, and improve the use safety of the energy storage system; otherwise, the detected battery cluster is controlled to be connected with the confluence unit.

And S4, when the detection of the first insulation state between all the battery clusters and the converging unit in the target energy storage module is completed and the connection relation between at least one battery cluster and the converging unit is determined to be communicated, the control target energy storage module is connected with the power conversion module and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module.

Specifically, each energy storage module in the energy storage system is in an off state with the power conversion module before the energy storage system is started. When the control target energy storage module is started, the control module firstly controls a plurality of battery clusters in the target energy storage module to be connected with the converging unit and detects the insulation state between each battery cluster and the converging unit, and then when the detection of the first insulation state between all battery clusters in the target energy storage module and the converging unit is completed and the connection relation between at least one battery cluster and the converging unit is determined to be communicated, the control module controls the target energy storage module to be connected with the power conversion module and immediately controls the first insulation detection unit to execute one-time insulation detection after the target energy storage module is connected with the power conversion module so as to determine the second insulation state between the target energy storage module and the power conversion module.

It can be understood that after the first insulation state between all the battery clusters and the converging unit in the target energy storage module is detected, if the connection relationship between each battery cluster and the converging unit in the target energy storage module is disconnected, it is indicated that the target energy storage module has an insulation fault, the starting of the target energy storage module is stopped, and the next energy storage module is started according to the starting sequence of the energy storage modules in the energy storage system.

And S5, controlling the power conversion module in the energy storage system to be connected with the power grid after the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system are detected and the second insulation states have no insulation faults, and controlling a second insulation detection unit in the power conversion module to detect a third insulation state between the power conversion module and the power grid in the energy storage system.

Specifically, in the starting process of the energy storage system, the control module controls the plurality of energy storage modules of the energy storage system to be started in sequence, and when each energy storage module is started, the starting operation is completed by executing the steps S2-S4, so that all the energy storage modules in the energy storage system are connected in parallel to the direct current side of the power conversion module, further, after the second insulation states among all the energy storage modules and the power conversion module in the energy storage system are detected, and the second insulation states are free from insulation faults, the control module controls the power conversion module to be connected with the power grid, so that the connection of the energy storage system and the power grid is realized, meanwhile, the second insulation detection unit is controlled to be started immediately after the power conversion module is connected with the power grid, and the first insulation detection is executed, so that the third insulation state between the power conversion module and the power grid is determined, therefore, in the process of controlling the power conversion module to be connected with the power grid, the operation of connecting the power conversion module to the main circuit of the energy storage system is completed, the starting operation of the whole energy storage system is completed, and the detection of the insulation states between the power conversion module and the power grid is completed.

And step S6, if the third insulation state is determined to have no insulation fault, the whole energy storage system is indicated to be insulated normally, and then the energy storage system is controlled to output target power according to the charge and discharge control signals, so that charging or discharging between the energy storage system and a power grid is completed.

Therefore, through the steps S1-S6, the insulation state inside the whole energy storage system can be confirmed, and a loop is formed between the main loop of the energy storage system and the power grid while the insulation detection work of all components is completed, and the energy storage system also completes the starting process, so that the energy storage system has operating conditions, and accordingly, in response to the requirement of the power grid, the energy storage system can directly output target power through the power conversion module, and meanwhile, the whole insulation detection process is simpler and more convenient and the insulation detection efficiency is improved by a control mode combining the insulation detection process of the energy storage system and the system starting process compared with a mode of separately controlling the insulation detection process and the system starting process.

In some embodiments, since the existing control manner of the energy storage system is to directly enter the system running state after the insulation detection is completed, and the problem of impact current caused by the existence of a pressure difference between the battery clusters is not considered, in this embodiment of the present invention, the running condition of the energy storage system is considered, and the plurality of battery clusters arranged in parallel are controlled to be started in sequence by sequencing the voltage information of the plurality of battery clusters in the target energy storage module, so as to avoid the problem of current impact. Specifically, according to the charge and discharge control signals, determining a first ordering of voltage information of a plurality of battery clusters in the target energy storage module; sequentially closing battery cluster contactors correspondingly connected with the battery clusters in the target energy storage module according to the first sequencing control, so that the battery clusters are connected with the converging unit; in response to each of the battery cluster contactors being closed, the first insulation detection unit is controlled to detect a first insulation state between the corresponding battery cluster and the bus unit. Therefore, the control module controls the battery clusters to be started in sequence according to the first sequence, so that the voltage difference between the battery clusters can be balanced in the process of sequentially starting the battery clusters, the problem that devices are damaged due to the fact that impact current is formed due to overlarge voltage difference between the battery clusters is avoided, and the battery clusters are gradually connected with the confluence unit and simultaneously insulation detection between the battery clusters and the confluence unit is completed through the first insulation detection unit.

Specifically, referring to fig. 1, a plurality of battery clusters are arranged in parallel, a control module is used for collecting or summarizing voltage information of all battery clusters in each energy storage module, if a voltage difference between the battery clusters is too large, when the battery clusters are connected into a main loop of the energy storage system, larger impact current can be generated between the battery clusters instantly, and the battery clusters with lower voltage are easy to damage due to the impact current, so that in order to avoid the problem of impact current caused by the voltage difference between the battery clusters, an acquisition unit is arranged inside each battery cluster and used for acquiring the battery voltage information in real time, and transmitting acquired data to the control module, and the control module gathers according to the received voltage information. And the control module sequences the battery clusters according to the charge and discharge control signals and the electric information of each battery cluster in the target energy storage module to obtain a first sequence, so that the control module sequentially sends a battery cluster starting instruction according to the first sequence to control the corresponding battery cluster contactor to be attracted, and the battery cluster corresponding to the battery cluster contactor is connected into a main loop of the target energy storage module. Therefore, the control module sequentially starts the battery clusters according to the first sequence, so that the battery clusters with lower voltage can be started first or then according to the first sequence, the purpose of charging first or discharging later is achieved, the voltage difference between the battery clusters is effectively balanced to a certain extent, and the risk of damage to devices caused by impact current is reduced.

In some embodiments, when the charge and discharge control signal is a charge control signal, it is determined that the voltages of the plurality of battery clusters in the target energy storage module are in a first order according to a low-to-high order, that is, when the energy storage system charges, the control module orders the voltages of each battery cluster according to a low-to-high order, and sequentially sends a battery cluster starting instruction according to the low-to-high order, so that the battery cluster contactor corresponding to each battery cluster is sequentially attracted, and therefore, compared with the battery cluster with the higher voltage in the energy storage module, the battery cluster with the lower voltage in the energy storage module can be firstly connected into the main loop of the energy storage system for charging, so that when the battery cluster with the higher voltage in the energy storage module is connected into the main loop of the energy storage system, partial electric energy is charged into the battery cluster with the lower voltage in the energy storage module, and therefore, the pressure difference between the battery cluster with the lower voltage and the battery cluster with the higher voltage is reduced, and the risk of damaging devices due to impact current is reduced.

Or when the charge and discharge control signals are the discharge control signals, determining that the voltages of the plurality of battery clusters in the target energy storage module are in a first order according to the order from high to low, that is, when the energy storage system discharges, the control module orders the voltages of the battery clusters according to the order from high to low, and sequentially sends a battery cluster starting command element according to the order from high to low, so that the battery cluster contactor corresponding to each battery cluster is sequentially attracted, and therefore, compared with the battery cluster with lower voltage in the energy storage module, the battery cluster with higher voltage in the energy storage module can be firstly connected into a main loop of the energy storage system to perform discharge, and therefore when the battery cluster with lower voltage in the energy storage module is connected into the main loop of the energy storage system, part of electric energy is released from the battery cluster with higher voltage in the energy storage module, the pressure difference between the battery cluster with lower voltage and the battery cluster with higher voltage is reduced, and the risk of damaging devices due to impact current is reduced.

In some embodiments, when it is determined that an insulation fault exists between the currently detected battery cluster and the bus unit according to the first insulation state, the battery cluster contactor correspondingly connected to the currently detected battery cluster is controlled to be opened, so that the connection relationship between the battery cluster and the bus unit is opened, and further, the battery cluster contactor correspondingly connected to the next battery cluster is controlled to be closed according to the first ordering, and the first insulation state between the next battery cluster and the bus unit is detected.

Specifically, after each battery cluster contactor is closed, the first insulation detection unit is started to determine the insulation state between the closed battery cluster and the confluence unit, so that when the insulation state is detected to be qualified, i.e. the detected first insulation state is no insulation fault, the control module continues to control the suction of the battery cluster contactor corresponding to the next battery cluster according to the first sequence; or when the detected battery cluster has abnormal insulation state, namely the first insulation state detected at the time is an insulation fault, the first insulation detection unit can rapidly position the current detected battery cluster according to the closing sequence of the battery cluster, upload feedback information of the insulation fault of the current detected battery cluster to the control module so as to carry out fault warning, send a disconnection control signal by the control module so as to cut off a battery cluster contactor corresponding to the current detected battery cluster, disconnect the battery cluster with the insulation fault from the energy storage system, ensure normal operation of the energy storage system after starting, and further, the control module continues to start the rest battery clusters according to the first sequence until all battery clusters without the insulation fault in the energy storage module are connected in parallel to a direct current main loop of the energy storage system so as to realize the charging or discharging function of the energy storage system subsequently.

For example, referring to fig. 1, a first energy storage module 101 is taken as a target energy storage module, and the first energy storage module 101 includes a plurality of battery clusters 2, which are respectively: l1, L2, L3 … Ln, the cell cluster contactors corresponding to each cell cluster 2 are respectively: KM1, KM2, KM3 … KMn, it will be appreciated that all of the battery contactors are in an open state prior to the start-up of the first energy storage module 101. Let the voltage information corresponding to each battery cluster 2 be: u1, U2 and U3 … Un, wherein the control module determines the first sequence of the voltage information of the plurality of battery clusters in the target energy storage module according to the charge and discharge control signals as follows: u1, U2, U3 … Un, and further, the control module controls the closing of the battery cluster contactor KM1 corresponding to the battery cluster L1 according to the first order, so that the battery cluster L1 is connected with the busbar unit 1, meanwhile, after the battery cluster contactor KM1 is closed, the control module immediately controls the first insulation detection unit 11 to start, and performs insulation detection on the battery cluster L1 and the busbar unit 1, so as to obtain a first insulation state between the corresponding battery cluster L1 and the busbar unit 1, and sends the first insulation state to the control module, the control module determines whether an insulation fault exists between the battery cluster L1 and the busbar unit 1 according to the received first insulation state, if the first insulation state is no insulation fault, the control module controls the closing of the battery cluster contactor KM2 corresponding to the battery cluster L2 according to the first order, otherwise, the control module controls the opening of the battery cluster contactor KM1 to cut off the connection between the battery cluster L1 and the busbar unit, and further controls the closing of the battery cluster contactor KM2 corresponding to the battery cluster L2 according to the first order; further, the control module controls the closing of the battery cluster contactor KM2 corresponding to the battery cluster L2, so that the battery cluster L2 is connected with the busbar unit 1, and meanwhile, after the battery cluster contactor KM2 is closed, the control module immediately controls the first insulation detection unit 11 to perform insulation detection on the battery cluster L2 and the busbar unit 1, so as to obtain a first insulation state between the corresponding battery cluster L2 and the busbar unit 1, and sends the first insulation state to the control module, the control module judges whether an insulation fault exists between the battery cluster L2 and the busbar unit 1 according to the received first insulation state, if the first insulation state is no insulation fault, the control module controls the closing of the battery cluster contactor KM3 corresponding to the battery cluster L3 according to the first order, otherwise, if the first insulation state is insulation fault, the control module controls the opening of the battery cluster contactor KM2, so as to cut off the connection between the battery cluster L2 and the busbar unit, and further controls the closing of the battery cluster contactor KM3 corresponding to the battery cluster L3 according to the first order; and the like, until the control module controls the closing of the battery cluster contactor KMn correspondingly connected with the battery clusters Ln according to the first sequence, so that the battery clusters Ln are connected with the bus unit, and immediately controls the first insulation detection unit to perform insulation detection on the battery clusters Ln and the bus unit 1 after the battery clusters Ln of the battery cluster contactor are closed, so as to obtain a first insulation state between the corresponding battery clusters Ln and the bus unit 1, and sends the first insulation state to the control module, the control module judges whether an insulation fault exists between the battery clusters Ln and the bus unit 1 according to the received first insulation state, if the first insulation state is the insulation fault, the battery cluster contactor KMn is kept closed, otherwise, if the first insulation state is the insulation fault, the control module controls the battery cluster contactor KMn to be opened, so as to cut off the connection between the battery clusters Ln and the bus unit. So far, the first energy storage module 101 completes the starting operation, and also completes the detection between each battery cluster and the bus unit during the starting process.

Similarly, the starting and insulation detection of other energy storage modules in the energy storage system are realized through the above process, and the details are not repeated.

In some embodiments, after detecting the first insulation state between all the battery clusters and the bus unit in the target energy storage module and determining that the first insulation state between at least one battery cluster and the bus unit is no insulation fault, the isolating switch of the bus unit in the target energy storage module is controlled to be closed, and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module.

Specifically, referring to fig. 1, one side of the current collecting unit 1 in each energy storage module is connected to a battery cluster through a battery cluster contactor, and the other side of the current collecting unit 1 is connected to the power conversion module 20 through a disconnecting switch Q1, wherein the disconnecting switch in each energy storage module is in an off state before the energy storage module is started. When the detection of the first insulation state between all the battery clusters in the target energy storage module and the converging unit is completed and the first insulation state between at least one battery cluster and the converging unit is determined to be an insulation fault-free state, that is, after all the battery clusters without insulation faults in the target energy storage module are connected in parallel to the main loop of the energy storage system, the disconnecting switch Q1 is controlled to be closed, and meanwhile, the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module, for example, the insulation state between the disconnecting switch Q1 and the direct-current side breaker QF2 shown in fig. 1. Therefore, when the isolating switch Q1 is controlled to be closed, the operation of connecting the converging unit to the main circuit of the target energy storage module is completed, so that the target energy storage module is connected to the main circuit of the power grid connected by the energy storage system, and the detection of the insulation state of the converging unit 1 and the power conversion module 20 is completed. Similarly, the above operation is performed when each energy storage module is started, so that all the energy storage modules in the energy storage system are connected in parallel to the direct current side of the power conversion module.

In some embodiments, after detection of the second insulation states between all the energy storage modules and the power conversion module in the energy storage system is completed and the second insulation states have no insulation fault, the ac side circuit breaker connected to the power grid in the power conversion module is controlled to be closed, and the second insulation detection unit is controlled to detect a third insulation state between the ac side of the power conversion module and the power grid.

Specifically, referring to fig. 1, the power conversion module 20 has an ac side breaker QF1 on the side to which the power grid is connected, and the ac side breaker QF1 is disconnected before the power conversion module 20 is connected to the power grid. When the second insulation state between all the energy storage modules and the power conversion module in the energy storage system is detected, that is, for all the energy storage modules in the energy storage system, all the energy storage modules except for the energy storage modules with insulation faults between all the battery clusters and the converging units in the energy storage modules are detected, after the second insulation state is free from insulation faults, the control module controls the closing of the alternating current side breaker QF1 and controls the second insulation detection unit 5 to detect the third insulation state between the alternating current side of the power conversion module and the power grid, that is, the insulation states from the alternating current side breaker QF1 to the power grid end shown in fig. 1 are detected, therefore, after the alternating current side breaker QF1 is controlled to be closed, the detection of the insulation state of the alternating current side of the power conversion module is completed while the power conversion module 20 is connected with the power grid, and the risks of insulation reduction, breakdown or short circuit and the like of a local power distribution network due to the fact that the insulation faults are introduced into the power grid in the connection process of the energy storage system and the power grid are avoided.

In some embodiments, before controlling the ac side circuit breakers of the power conversion module connected to the power grid to close, the control module controls the dc side circuit breakers of the power conversion module for connecting all the energy storage modules to close, and controls the second insulation detection unit to detect a fourth insulation state between the dc side of the power conversion module and all the energy storage modules, and determines that the fourth insulation state is insulation failure free.

Specifically, referring to fig. 1, the power conversion module 20 has a dc side breaker QF2 on the side to which the energy storage module 10 is connected, and the dc side breaker QF2 is opened before the power conversion module 20 is started. When the second insulation state between all the energy storage modules and the power conversion module in the energy storage system is detected, that is, for all the energy storage modules in the energy storage system, all the energy storage modules except for the energy storage module with insulation faults between all the battery clusters and the bus units in the energy storage system are detected, and after the second insulation state is free from insulation faults, the control module considers that all the energy storage modules except for the energy storage module with insulation faults between all the battery clusters and the bus units in the energy storage module are normal, and sends a power conversion starting command to control the power conversion module 20 to start, after the power conversion module 20 is started, the control module firstly controls the direct current side breaker QF2 to be closed, and controls the fourth insulation state between the direct current side breaker QF2 and the alternating current side breaker QF1 detected by the second insulation detection unit 5, that is, so that after the direct current side breaker QF2 is controlled to be closed and before the alternating current breaker is controlled to be closed, the direct current side breaker QF1 is controlled, the direct current side of the main circuit of the power conversion module 20 can be simultaneously detected, and the insulation state of the direct current side of the power conversion module 20 is also completed.

In some embodiments, when the fourth insulation state is determined to be that an insulation fault exists, it is indicated that insulation abnormality exists in a power device or other protection devices on the direct current side in the power conversion module, so that the control module controls the disconnection of the circuit breaker on the direct current side and sends feedback information that insulation fault exists on the direct current side of the power conversion module, and the control module controls all switching devices in the whole energy storage system to be disconnected according to the feedback information so as to cut off the direct current voltage of the energy storage system; when the third insulation state is determined to be the insulation fault, the control module controls the circuit breaker on the alternating current side to be disconnected and sends feedback information of the insulation fault on the alternating current side of the power conversion module, and the control module controls all switching devices in the whole energy storage system to be disconnected according to the feedback information so as to cut off the direct current voltage of the energy storage system.

In some embodiments, when the second insulation state corresponding to a part of the energy storage modules in the plurality of energy storage modules is an insulation fault, the plurality of energy storage modules are controlled to be disconnected from the power conversion module, and the insulation fault is reported to exist in the energy storage modules, that is, when the insulation fault exists in a part of the energy storage modules in the plurality of energy storage modules, the insulation fault exists in the energy storage modules reporting the insulation fault or the insulation fault does not exist in the energy storage modules, for example, the first insulation detection unit in the energy storage modules reporting the insulation fault has a fault to cause the second insulation state to be an insulation fault, or the first insulation detection unit in the energy storage modules not reporting the insulation fault has a fault to cause the second insulation state to be an insulation fault, and the first insulation detection unit in the energy storage modules reporting the insulation fault has a fault to be normal.

Or when the second insulation states of the energy storage modules are insulation faults, the energy storage modules are controlled to be disconnected from the power conversion module, and the insulation faults are reported to exist on the direct current side of the power conversion module. That is, when there is an insulation failure in each of the plurality of energy storage modules, it is indicated that there is an insulation failure in the line between the bus unit and the dc side of the power conversion module, and therefore, the isolating switch in each energy storage module is turned off or all the switching devices in each energy storage module are turned off, thereby disconnecting all the energy storage modules on the main circuit of the energy storage system.

In some embodiments, a start instruction to start the energy storage system and a charge-discharge control signal are received; acquiring total voltage information of each energy storage module in an energy storage system; determining a second ordering according to the charge-discharge control signal and the total voltage information of each energy storage module; and sequentially sending out a starting instruction for starting the energy storage module according to the second order.

Specifically, referring to fig. 1, a plurality of energy storage modules are arranged in parallel, in order to avoid the problem of impact current caused by pressure difference between the energy storage modules, the control module gathers the total voltage of each energy storage module 10, and orders the plurality of energy storage modules according to the charge and discharge control signal and the total voltage information of each energy storage module, so as to obtain a second sequence, so that the control module sequentially sends a start command of the energy storage modules according to the second sequence to control the corresponding energy storage modules to be connected into a direct current side main loop of the energy storage system. Therefore, the control module sequentially starts the energy storage modules according to the second sequence, so that the energy storage module with lower total voltage can be started first or then according to the second sequence, the purpose of charging first or discharging later is achieved, the voltage difference between the energy storage modules is effectively balanced to a certain extent, and the risk of damage to devices caused by impact current is reduced.

For example, referring to fig. 2, the energy storage system 100 includes a first energy storage module 101 and a second energy storage module 102, and it is assumed that the second order determined by the control module according to the charge and discharge control signal and the total voltage information of each energy storage module is: the control module firstly sends a starting instruction to the first energy storage module 101 to control the first energy storage module 101 to start, and after the first energy storage module 101 starts, the control module sends a starting instruction to the first energy storage module 102 to control the first energy storage module 102 to start.

In some embodiments, when the charge-discharge control signal is a charge control signal, it is determined that the total voltage of the plurality of energy storage modules in the energy storage system is ranked from low to high to be ranked second, that is, when the energy storage system is charged, the control module ranks the total voltage of each energy storage module in order from low to high, and sequentially sends a start command of the energy storage modules in order from low to high, so that the corresponding energy storage modules are connected to a direct current main circuit of the energy storage system, and therefore, compared with the energy storage modules with higher total voltage in the energy storage system, the energy storage modules with lower total voltage in the energy storage system can be connected to the main circuit of the energy storage system first for charging, and therefore when the energy storage modules with higher total voltage in the energy storage system are connected to the main circuit of the energy storage system, the energy storage modules with lower total voltage in the energy storage system are charged with partial electric energy, so that a pressure difference between the energy storage modules is reduced, and the risk of damage to devices due to impact currents is reduced.

Or when the charge and discharge control signals are the discharge control signals, determining that the total voltage of the plurality of energy storage modules in the energy storage system is ranked from high to low as a second ranking, that is, when the energy storage system discharges, the control module ranks the total voltage of each energy storage module according to the order from high to low, and sequentially sends the energy storage modules according to the order from high to low to obtain a starting instruction, so that the corresponding energy storage modules are connected into a direct current main loop of the energy storage system, and therefore, compared with the energy storage modules with lower total voltage in the energy storage system, the energy storage modules with higher total voltage in the energy storage system can be connected into the main loop of the energy storage system first to discharge, so that when the energy storage modules with lower total voltage in the energy storage system are connected into the main loop of the energy storage system, partial electric energy is released by the energy storage modules with higher total voltage in the energy storage system, and the pressure difference between the energy storage modules is reduced, and the risk of device damage caused by impact current is reduced.

In some embodiments, the first insulation detection unit is controlled to be turned off after the second insulation states between all the energy storage modules and the power conversion modules are detected and the second insulation states are free of insulation faults.

Specifically, after each battery cluster contactor is closed, the isolating switch in the bus unit is still in an open state at this time, so the energy storage module is not connected with the power conversion module yet, and therefore, only the first insulation detection unit exists in the energy storage system to perform insulation detection; after the insulation detection in one energy storage module is finished, the first insulation detection unit in the energy storage module is firstly controlled to be cut off from the direct current main loop of the energy storage system, at the moment, no insulation detection unit exists in the energy storage system, and then the control module is used for controlling the next energy storage module to start according to the starting sequence of the energy storage module, the first insulation detection unit in the next energy storage module is used for detecting, and in the starting process of each energy storage module, only one insulation detection unit is always used for detecting, so that the insulation state in the battery cluster and the confluence unit in the corresponding energy storage module is detected; and after all the energy storage modules are determined to have no insulation faults, the power conversion module is started, and the second insulation detection unit is controlled to execute insulation detection so as to detect the insulation state in the power conversion module. Therefore, in the starting process of the energy storage system, only one insulation detection unit is always in an operating state in the same time, so that the problem of inaccurate insulation detection caused by mutual influence among a plurality of insulation detection loops can be avoided.

It can be understood that during the operation of the energy storage system, the second insulation detection unit is still in an operation state, so as to detect the insulation state during the operation of the energy storage system, and ensure insulation detection during the operation of the energy storage system.

A second aspect of the present invention provides an energy storage control system, as shown in fig. 3, the energy storage control system 50 comprising at least one processor 51 and a memory 52 communicatively coupled to the at least one processor 51.

The memory 52 stores a computer program executable by the at least one processor 51, and the at least one processor 51 implements the control method of the energy storage system provided in the foregoing embodiment when executing the computer program.

According to the energy storage control system 50 of the embodiment of the present invention, the processor 52 executes the control method of the energy storage system provided in the above embodiment, so that the energy storage system can be started while the insulation detection function is completed, and the insulation detection efficiency can be improved.

In some embodiments, as shown in fig. 1, the control module 30 includes a battery manager 3, a bus control unit 12, a power control unit 6, and a field master control unit 31.

The battery manager 3 is arranged between each battery cluster 2 and the corresponding bus unit 1, the battery manager 3 is used for acquiring voltage information of each battery cluster 2, controlling the closing of a battery cluster contactor corresponding to each battery cluster 2, and controlling the connection relationship between the battery cluster 2 and the bus unit 1 based on a first insulation state, wherein the connection relationship between the battery cluster 2 and the bus unit 1 is disconnected when the first insulation state is a fault; when the first insulating state is failure-free, the connection relationship between the battery cluster 2 and the bus unit 1 is communication.

The bus control unit 12 is disposed in the bus unit 1, the bus control unit 12 is communicatively connected with the first insulation detection unit 11, the isolating switch Q1 and each battery manager 3 in the bus unit 1, and the bus control unit 12 is configured to receive a start instruction and a charge/discharge control signal of the corresponding energy storage module 10, and control the plurality of battery clusters 2 to sequentially connect to the bus unit 1 according to the charge/discharge control signal and the ordering of the voltage information of the plurality of battery clusters 2 in the corresponding energy storage module 10, and control the first insulation detection unit 11 to detect a first insulation state between the battery clusters 2 and the bus unit 1 while each battery cluster 2 is connected to the bus unit 1, and control the isolating switch Q1 to close and control the first insulation detection unit 11 to detect a second insulation state between the corresponding energy storage module 10 and the power conversion module 20 when detecting a first insulation state between all the battery clusters 2 and the bus unit 1 in the corresponding energy storage module 10 is completed and determining that a connection relationship between at least one battery cluster 2 and the bus unit 1 is connected.

The power control unit 6 is disposed on the power conversion module 20, the power control unit 6 is connected with the power device 4 and the second insulation detection unit 5, and the power control unit 6 is configured to control the power conversion module 20 in the energy storage system 100 to connect to the power grid and control the second insulation detection unit 5 in the power conversion module 20 to detect a third insulation state between the power conversion module 20 and the power grid in the energy storage system 100 when all second insulation states between the energy storage module 10 and the power conversion module 20 are detected and the second insulation states have no insulation fault.

The field master control unit 31 is communicatively connected to each of the bus control units 12 and the power control unit 6, and the field master control unit 31 is configured to receive a start instruction and a charge/discharge control signal of the energy storage module 10, and after determining that the third insulation state has no insulation fault, control the energy storage system 100 to charge or discharge with the power grid according to the charge/discharge control signal.

In some embodiments, the battery manager 3 includes a battery management control unit 13 and a dc conversion unit 14 (not shown in the drawings).

Wherein the battery management control unit 13 is in communication connection with the corresponding bus control unit 12; and the direct current conversion unit 14 is connected with the battery management control unit 13 and the corresponding battery cluster 2, and is used for performing direct current voltage conversion on the corresponding battery cluster 2 so as to reduce grid-connected voltage difference.

In an embodiment, the battery manager 3 further comprises protection devices such as manual disconnectors, fuses, and maintenance switches.

In an embodiment, the energy storage system 100 further includes a dc conversion module, one end of which is connected to the plurality of energy storage modules 10, one end of which is further connected to the power conversion module 20, and one end of which is further connected to the field master control unit 31, for implementing a dc conversion function. If there is isolation between the dc conversion module and the power conversion module 20, an insulation detection unit is added in the dc conversion module to perform insulation detection when the dc conversion module is started; alternatively, if there is no isolation between the dc conversion module and the power conversion module 20, the dc conversion module may share a second insulation detection unit with the power conversion module 20 to perform insulation detection when the dc conversion module is started.

The following describes a control procedure of the energy storage system according to an embodiment of the present invention with reference to fig. 1 and 3, and the specific steps are as follows.

And S3, the field master control unit receives a starting instruction of the energy storage system issued by the energy management system.

And S4, the field total control unit receives a charge and discharge control signal sent by the energy management system.

And S5, determining the charge and discharge control signals as charge control signals, and determining the total voltage of each energy storage module by the field total control unit in response to the charge control signals.

Step S6, the field total control unit sequentially sends starting instructions of the energy storage modules according to the sequence from low to high of the total voltage of the energy storage modules so as to start each energy storage module, and after the confluence control unit in each energy storage module receives the starting instructions, the field total control unit sequentially sends the starting instructions of the battery clusters to the battery management control unit according to the sequence from low to high of the voltage of each battery cluster in the energy storage module, and the battery management control unit controls the corresponding battery cluster contactor to be closed.

Step S7, determining the charge and discharge control signals as discharge control signals, and responding to the discharge control signals, determining the total voltage of each energy storage module by the field total control unit.

Step S8, the field total control unit sequentially sends starting instructions of the energy storage modules according to the sequence from high to low of the total voltage of the energy storage modules so as to start each energy storage module, and after the confluence control unit in each energy storage module receives the starting instructions, the field total control unit sequentially sends the starting instructions of the battery clusters according to the sequence from high to low of the voltage of each battery cluster in the energy storage module to the battery management control unit, and the battery management control unit controls the corresponding battery cluster contactor to be closed.

Step S9, after each battery cluster contactor is closed, the bus control unit controls the corresponding first insulation detection unit to perform insulation detection, and the first insulation detection unit sends the first insulation state detected each time to the bus control unit.

In step S10, the bus control unit determines whether an insulation fault exists between each battery cluster and the bus unit according to the first insulation state. Wherein, for the battery cluster with insulation fault, executing step S11; for all the battery clusters in the energy storage module, after the detection of the first insulation state between all the battery clusters and the bus unit in the target energy storage module is completed and the determination of the first insulation state between at least one battery cluster and the bus unit as no insulation fault is performed, step S12 is performed.

And S11, the confluence control unit sends insulation fault feedback information to a battery management control unit and a field total control unit corresponding to the currently detected battery cluster, and the battery management control unit controls the corresponding battery cluster contactor to be disconnected after receiving the insulation fault feedback information and reports that the currently detected battery cluster has insulation faults.

In step S12, the bus control unit controls the isolating switch in the bus unit to be closed.

In step S13, the bus control unit controls the first insulation detection unit to perform insulation detection, and the first insulation detection unit sends the second insulation state detected each time to the bus control unit.

Step S14, the confluence control unit in each energy storage module judges whether each energy storage module has insulation faults according to the second insulation state.

And S15, when the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system are detected and the second insulation states are free from insulation faults, namely, after all the energy storage modules are free from insulation faults, the field total control unit sends a power conversion starting instruction to the power control unit, the power control unit controls the direct current side circuit breaker to be closed, meanwhile, after the direct current side circuit breaker is closed, the second insulation detection unit is controlled to execute insulation detection, the second insulation detection unit sends a detected fourth insulation state to the power control unit, after the power control unit determines that the fourth insulation state is free from insulation faults, the alternating current side circuit breaker is controlled to be closed, meanwhile, after the direct current side circuit breaker is closed, the second insulation detection unit is controlled to execute insulation detection, the second insulation detection unit sends a detected third insulation state to the power control unit, and after the power control unit determines that the third insulation state is free from insulation faults, the step S18 is executed.

And S16, when an insulation fault exists in a second insulation state between part of the energy storage modules and the power conversion modules in the energy storage system, each confluence control unit controls all switching devices in the corresponding energy storage modules to be disconnected, and the fault of the energy storage modules is reported.

And S17, when insulation faults exist in the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system, each confluence control unit controls all the switching devices in the corresponding energy storage modules to be disconnected, and reports that the insulation faults exist on the direct current side of the power conversion modules.

And S18, detecting all insulation in the energy storage system to be qualified, and responding to the operation target power by the power conversion module.

In summary, according to the control method of the energy storage system, the energy storage control system and the energy storage system according to the embodiments of the present invention, based on the topology structure of the energy storage system 100 shown in fig. 1, by associating the insulation detection process of the energy storage system with the system start process, the insulation state of the system is detected in the closing sequence of the switching devices of each component of the energy storage system, so that the energy storage system completes the start process while implementing the insulation detection function of the energy storage system, and compared with the mode of implementing the independent detection of the insulation state by controlling the connection or disconnection of each component in the energy storage system, the embodiment of the present invention adopts the mode of combining the insulation detection process of the energy storage system with the system start process, so that the connection relation between each component is not required to be repeatedly controlled, the whole insulation detection process is simpler and more convenient, the efficiency of insulation detection is effectively improved, the switching devices are not required to be repeatedly controlled, the service life of the devices is prolonged, and in this process, the operation working conditions of the energy storage system are considered, the battery cluster voltage is sequentially started from low to high under the charging working conditions, the discharging working conditions are sequentially started from high to low under the charging working conditions, so that the voltage of the battery cluster voltage can be balanced, and the problem of damaging the devices due to transient current difference caused by large cluster current is avoided.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of controlling an energy storage system, the method comprising:

receiving a starting instruction and a charging and discharging control signal of an energy storage module comprising a plurality of battery clusters and a confluence unit;

acquiring voltage information of each battery cluster in a target energy storage module;

according to the charge and discharge control signals and the ordering of the voltage information of the battery clusters in the target energy storage module, controlling the battery clusters to be sequentially connected with the converging unit, controlling a first insulation detection unit in the target energy storage module to detect a first insulation state between the battery clusters and the converging unit while each battery cluster is connected with the converging unit, and simultaneously controlling the connection relation between the battery clusters and the converging unit based on the first insulation state, wherein when the first insulation state is an insulation fault, the connection relation between the battery clusters and the converging unit is disconnected; when the first insulation state is no insulation fault, the connection relation between the battery cluster and the confluence unit is communicated;

When the detection of the first insulation states between all the battery clusters in the target energy storage module and the converging unit is finished and the connection relation between at least one battery cluster and the converging unit is determined to be communicated, controlling the target energy storage module to be connected with a power conversion module and controlling the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module;

when the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system are detected and the second insulation states have no insulation fault, controlling the power conversion modules in the energy storage system to be connected with a power grid, and controlling a second insulation detection unit in the power conversion modules to detect a third insulation state between the power conversion modules and the power grid in the energy storage system;

and determining that the third insulation state has no insulation fault, and controlling the energy storage system and the power grid to charge or discharge according to the charge and discharge control signal.

2. The control method of an energy storage system according to claim 1, wherein controlling a plurality of the battery clusters to sequentially connect the confluence unit according to the charge and discharge control signal and the ordering of the voltage information of the plurality of the battery clusters in the target energy storage module, and controlling a first insulation detection unit in the target energy storage module to detect a first insulation state between the battery clusters and the confluence unit while each of the battery clusters is connected to the confluence unit, comprises:

Determining a first ordering of voltage information of a plurality of battery clusters in the target energy storage module according to the charge-discharge control signals;

sequentially closing battery cluster contactors correspondingly connected with the battery clusters in the target energy storage module according to the first sequencing, so that the battery clusters are connected with the confluence unit;

and controlling the first insulation detecting unit to detect the first insulation state between the corresponding battery cluster and the bus unit in response to each of the battery cluster contactors being closed.

3. The method of claim 2, wherein determining a first ordering of voltage information for a plurality of the battery clusters in the target energy storage module based on the charge-discharge control signal comprises:

when the charge and discharge control signal is a charge control signal, determining that the voltages of a plurality of battery clusters in the target energy storage module are in the first order according to the order from low to high;

or when the charge and discharge control signal is a discharge control signal, determining that the voltages of the plurality of battery clusters in the target energy storage module are in the first order according to the order from high to low.

4. The method of controlling an energy storage system according to claim 2, further comprising:

when determining that an insulation fault exists between the currently detected battery cluster and the confluence unit according to the first insulation state, controlling a battery cluster contactor correspondingly connected with the currently detected battery cluster to be disconnected, so that the connection relationship between the battery cluster and the confluence unit is disconnected;

and controlling the closing of the battery cluster contactor correspondingly connected with the next battery cluster according to the first sequencing, and detecting a first insulation state between the next battery cluster and the confluence unit.

5. The control method of an energy storage system according to claim 1, wherein when detecting first insulation states between all of the battery clusters and the current collecting unit in the target energy storage module and determining that a connection relationship between at least one of the battery clusters and the current collecting unit is connected, controlling the target energy storage module to connect with a power conversion module and controlling the first insulation detecting unit to detect second insulation states between the target energy storage module and the power conversion module includes:

And after the detection of the first insulation states between all the battery clusters and the converging units in the target energy storage module is finished and the fact that at least one first insulation state between the battery clusters and the converging units is determined to be free of insulation faults is determined, controlling the isolating switch of the converging units in the target energy storage module to be closed, and controlling the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module.

6. The method according to claim 1, wherein controlling the power conversion module in the energy storage system to connect to a power grid and controlling a second insulation detection unit in the power conversion module to detect a third insulation state between the power conversion module and the power grid in the energy storage system after the second insulation states between all the energy storage modules and the power conversion module in the energy storage system are detected and the second insulation states have no insulation fault, comprises:

and after the second insulation states between all the energy storage modules and the power conversion modules in the energy storage system are detected and the second insulation states have no insulation faults, controlling an alternating current side breaker connected with the power grid in the power conversion modules to be closed, and controlling a second insulation detection unit to detect the third insulation state between the alternating current side of the power conversion modules and the power grid.

7. The method of claim 6, further comprising, prior to controlling the ac side circuit breaker of the power conversion module that connects to the power grid to close:

and controlling the direct current side circuit breakers used for connecting all the energy storage modules in the power conversion module to be closed, controlling the second insulation detection unit to detect a fourth insulation state between the direct current side of the power conversion module and all the energy storage modules, and determining that the fourth insulation state is free of insulation faults.

8. The method of claim 7, further comprising:

when the fourth insulation state is determined to be an insulation fault, the direct current side breaker is controlled to be disconnected, and feedback information of the insulation fault on the direct current side of the power conversion module is sent;

and when the third insulation state is determined to be the insulation fault, the circuit breaker at the alternating current side is controlled to be disconnected, and feedback information of the insulation fault at the alternating current side of the power conversion module is sent.

9. The method of claim 1, further comprising:

When the second insulation state corresponding to part of the energy storage modules in the plurality of energy storage modules is insulation fault, the plurality of energy storage modules are controlled to be disconnected with the power conversion module, and the insulation fault of the energy storage modules is reported;

or when the second insulation states of the energy storage modules are insulation faults, controlling the energy storage modules to be disconnected from the power conversion module, and reporting that the insulation faults exist on the direct current side of the power conversion module.

10. The method of claim 1, further comprising:

receiving a starting instruction for starting the energy storage system and a charging and discharging control signal;

acquiring total voltage information of each energy storage module in the energy storage system;

determining the second order according to the charge and discharge control signals and the total voltage information of each energy storage module;

and sequentially sending out a starting instruction for starting the energy storage module according to the second ordering.

11. The method of claim 10, wherein determining the second rank based on the charge-discharge control signal and total voltage information for each of the energy storage modules comprises:

When the charge and discharge control signal is a charge control signal, determining that the sequence of the total voltage of the plurality of energy storage modules in the energy storage system from low to high is the second sequence;

or when the charge and discharge control signal is a discharge control signal, determining that the sequence of the total voltage of the energy storage modules in the energy storage system from high to low is the second sequence.

12. The control method of an energy storage system according to any one of claims 1 to 11, characterized in that after the second insulation states between all the energy storage modules and the power conversion modules are detected and none of the second insulation states has an insulation fault, the control method further comprises: and controlling the first insulation detection unit to be closed.

13. An energy storage control system, comprising:

at least one processor;

a memory communicatively coupled to at least one of the processors;

wherein said memory has stored therein a computer program executable by at least one of said processors, which when executing said computer program implements the method of controlling an energy storage system according to any of claims 1-12.

14. An energy storage system, comprising:

each energy storage module comprises a confluence unit and a plurality of battery clusters which are arranged in parallel, each battery cluster is connected with the confluence unit, a battery cluster contactor is arranged between each battery cluster and the confluence unit, and the confluence unit comprises a first insulation detection unit and a disconnecting switch;

the power conversion module comprises a power device and a second insulation detection unit, the direct current side of the power device is connected with each converging unit, the isolating switch is arranged between the power device and each converging unit, and the alternating current side of the power device is provided with an alternating current side breaker;

a control module, connected to the energy storage module and the power conversion module, for performing the control method of the energy storage system according to any one of claims 1-12.

15. The energy storage system of claim 14, wherein the dc side of the power device is provided with a dc side breaker.

16. The energy storage system of claim 14 or 15, wherein the control module comprises:

The battery manager is arranged between each battery cluster and the corresponding bus unit, and is used for acquiring voltage information of each battery cluster, controlling a battery cluster contactor corresponding to each battery cluster to be closed, and controlling the connection relation between the battery cluster and the bus unit based on the first insulation state, wherein the connection relation between the battery cluster and the bus unit is disconnected when the first insulation state is a fault; when the first insulating state is fault-free, the connection relation between the battery cluster and the confluence unit is communicated;

the bus control unit is in communication connection with the first insulation detection unit, the isolating switch and each battery manager in the bus unit, and is used for receiving a starting instruction and a charging and discharging control signal of the corresponding energy storage module, controlling the plurality of battery clusters to be sequentially connected with the bus unit according to the charging and discharging control signal and the ordering of voltage information of the plurality of battery clusters in the corresponding energy storage module, controlling the first insulation detection unit to detect a first insulation state between the battery clusters and the bus unit while each battery cluster is connected with the bus unit, and controlling the isolating switch to be closed and controlling the first insulation detection unit to detect a second insulation state between the corresponding energy storage module and the power conversion module when the first insulation state between all the battery clusters and the bus unit in the corresponding energy storage module is detected and the connection relation between at least one battery cluster and the bus unit is determined to be communicated;

The power control unit is arranged on the power conversion module, is connected with the power device and the second insulation detection unit, and is used for controlling the power conversion module in the energy storage system to be connected with a power grid and controlling the second insulation detection unit in the power conversion module to detect a third insulation state between the power conversion module and the power grid in the energy storage system when all the second insulation states between the energy storage module and the power conversion module are detected and the second insulation states have no insulation faults;

the field total control unit is in communication connection with each of the confluence control units and the power control units, and is used for receiving a starting instruction and a charging and discharging control signal of the energy storage module, and controlling the energy storage system to charge or discharge with the power grid according to the charging and discharging control signal after determining that the third insulation state has no insulation fault.

17. The energy storage system of claim 16, wherein the battery manager comprises:

The battery management control unit is in communication connection with the corresponding confluence control unit;

and the direct current conversion unit is connected with the battery management control unit and the corresponding battery cluster.