A control method of an energy storage system and an energy storage system

Abstract

The embodiment of the present application discloses a kind of control method and energy storage system of energy storage system.The energy storage system includes coordination controller and at least two energy storage cabinets, coordination controller is connected with each energy storage cabinet, each energy storage cabinet has battery, each energy storage cabinet is electrically connected with load;Control method is executed by coordination controller, and control method includes: obtaining the current capacity of each energy storage cabinet, output voltage, output current and the power required by load;According to current capacity, output voltage and the power required by load, the relationship between the output power of each energy storage cabinet and the power required by load is determined;According to current capacity, output current and the relationship between the output power of each energy storage cabinet and the power required by load, the use time of each energy storage cabinet is determined;According to current capacity, output voltage and use time, the output power allocated to each energy storage cabinet is determined, to control each energy storage cabinet according to the output power allocated.The technical scheme provided by the embodiment of the present application can improve energy utilization.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to energy storage technology, and in particular, to a control method of an energy storage system and the energy storage system. BACKGROUND

[0002] As a system that stores energy and releases energy when needed to meet the energy supply demand, the energy storage system plays an important role in many fields of production and life, and needs to be reliably controlled. At present, the energy utilization rate of the existing control method of the energy storage system needs to be further improved. SUMMARY

[0003] Embodiments of the present application provide a control method of an energy storage system and the energy storage system to improve the energy utilization rate.

[0004] In a first aspect, embodiments of the present application provide a control method of an energy storage system, the energy storage system comprising a coordination controller and at least two energy storage cabinets, the coordination controller being in communication connection with each of the energy storage cabinets, each of the energy storage cabinets having a battery, and each of the energy storage cabinets being electrically connected with a load; the control method being executed by the coordination controller, and the control method comprising:

[0005] obtaining a current capacity, an output voltage, and an output current of each of the energy storage cabinets, and a required power of the load;

[0006] determining a relationship between an output power of each of the energy storage cabinets and the required power of the load according to the current capacity, the output voltage, and the required power of the load;

[0007] determining a use time of each of the energy storage cabinets according to the current capacity, the output current, and the relationship between the output power of each of the energy storage cabinets and the required power of the load;

[0008] determining an allocated output power of each of the energy storage cabinets according to the current capacity, the output voltage, and the use time, so as to control each of the energy storage cabinets according to the allocated output power.

[0009] Optionally, the determining the relationship between the output power of each of the energy storage cabinets and the required power of the load according to the current capacity, the output voltage, and the required power of the load comprises:

[0010] determining the relationship between the output power of each of the energy storage cabinets and the required power of the load W TAC as ; wherein n is the number of the energy storage cabinets, W ACi is an alternating current side output power of an i-th energy storage cabinet, and U DCiLet be the DC output voltage of the i-th energy storage cabinet, Ci be the total capacity of the i-th energy storage cabinet, SOCi be the percentage of the current capacity of the i-th energy storage cabinet relative to the total capacity, and E be the current capacity of the i-th energy storage cabinet relative to the total capacity. DC / ACi Let be the AC / DC conversion efficiency of the i-th energy storage cabinet.

[0011] Optionally, determining the usage time of each energy storage cabinet based on the current capacity, the output current, and the relationship between the output power of each energy storage cabinet and the power required by the load includes:

[0012] Based on the current capacity, the output current, and the output power of each energy storage cabinet, and the power required by the load (W) TAC The relationship between the energy storage cabinets determines the usage time of each cabinet. Wherein, the usage time of each of the energy storage cabinets is the same, n is the number of energy storage cabinets, and U DCi Let be the DC output voltage of the i-th energy storage cabinet, Ci be the total capacity of the i-th energy storage cabinet, SOCi be the percentage of the current capacity of the i-th energy storage cabinet relative to the total capacity, and E be the current capacity of the i-th energy storage cabinet relative to the total capacity. DC / ACi Let be the AC / DC conversion efficiency of the i-th energy storage cabinet.

[0013] Optionally, before obtaining the current capacity, output voltage, output current of each of the energy storage cabinets, and the power required by the load, the following steps are included:

[0014] Control the input / output synchronization and carrier synchronization of each of the energy storage cabinets.

[0015] Optionally, determining the output power allocated to each energy storage cabinet based on the current capacity, output voltage, and usage time, and controlling each energy storage cabinet according to the allocated output power, includes:

[0016] The AC side output power allocated to each energy storage cabinet is determined based on the current capacity, output voltage, and usage time; the AC side output power allocated to each energy storage cabinet is the ratio of the product of the current capacity and AC side output voltage of the energy storage cabinet to the usage time.

[0017] If at least one of the energy storage cabinets is allocated AC side output power W ACx If the power exceeds the current maximum output power of each load, then the power required by the load is reduced by W. ACx The obtained power is used as the power required for the new load; where x represents the energy storage cabinet whose allocated AC side output power exceeds its current maximum output power on the AC side.

[0018] redetermining the output power allocated to each of the energy storage cabinets according to the new required power of the load until the output power allocated to each of the energy storage cabinets does not exceed the current maximum output power of each of the energy storage cabinets, and sending the output power allocated to each of the energy storage cabinets to each of the energy storage cabinets respectively.

[0019] Optionally, the control method of the energy storage system further comprises:

[0020] If the output power allocated to each of the energy storage cabinets does not exceed the current maximum output power of each of the energy storage cabinets, the output power allocated to each of the energy storage cabinets is sent to each of the energy storage cabinets respectively.

[0021] Optionally, the control method of the energy storage system further comprises:

[0022] The maximum output power of each of the energy storage cabinets is acquired in real time.

[0023] In a second aspect, an embodiment of the present application provides an energy storage system, comprising: a coordination controller and at least two energy storage cabinets, the coordination controller being in communication connection with each of the energy storage cabinets, each of the energy storage cabinets having a battery, and each of the energy storage cabinets being electrically connected with a load; the coordination controller is configured to execute the control method of the energy storage system as described in the first aspect.

[0024] Optionally, an integrated module is arranged in the energy storage cabinet, the integrated module being electrically connected with the battery, the integrated module being in communication connection with the coordination controller, and the integrated module integrating an energy storage converter and a battery management unit.

[0025] Optionally, the energy storage system further comprises a power meter, the power meter being arranged in a line in which the energy storage cabinet is connected with the load.

[0026] The control method of the energy storage system and the energy storage system provided by the embodiment of the present application, the energy storage system comprises a coordination controller and at least two energy storage cabinets, the coordination controller is in communication connection with each energy storage cabinet, each energy storage cabinet has a battery, and each energy storage cabinet is electrically connected with a load; the control method is executed by the coordination controller, and the control method comprises the following steps: obtaining the current capacity, output voltage, output current of each energy storage cabinet, and the required power of the load; determining the relationship between the output power of each energy storage cabinet and the required power of the load according to the current capacity, output voltage and required power of the load; determining the use time of each energy storage cabinet according to the current capacity, output current and the relationship between the output power of each energy storage cabinet and the required power of the load; determining the output power allocated to each energy storage cabinet according to the current capacity, output voltage and use time, so as to control each energy storage cabinet according to the allocated output power. The control method of the energy storage system and the energy storage system provided by the embodiment of the present application are based on the current capacity, output current, output voltage, use time of each energy storage cabinet and the required power of the load, the output power allocated to each energy storage cabinet is determined, if the output power allocated to each energy storage cabinet does not exceed the current maximum output power of each energy storage cabinet, the output power allocated to each energy storage cabinet is sent to each energy storage cabinet respectively, so that the output power of each energy storage cabinet is controlled to be the output power allocated to each energy storage cabinet, and the energy utilization rate of the battery in each energy storage cabinet is improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a flow chart of a control method of an energy storage system provided by an embodiment of the present application;

[0028] Figure 2 is a flow chart of a control method of an energy storage system provided by an embodiment of the present application;

[0029] Figure 3 is a structural block diagram of an energy storage system provided by an embodiment of the present application;

[0030] Figure 4 is a structural block diagram of an energy storage cabinet provided by an embodiment of the present application;

[0031] Figure 5 is a structural block diagram of an energy storage cabinet provided by an embodiment of the present application;

[0032] Figure 6 is a schematic diagram of the coordination controller controlling the synchronization of each energy storage cabinet provided by an embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, in order to facilitate the description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0034] Embodiment One

[0035] Figure 1 is a flowchart of a control method of an energy storage system provided by Embodiment One of the present application. The present embodiment can be applied to control an energy storage system and the like, and the energy storage system comprises a coordination controller and at least two energy storage cabinets. The coordination controller is in communication connection with each energy storage cabinet. Each energy storage cabinet has a battery, and each energy storage cabinet is electrically connected with a load. The control method of the energy storage system is executed by the coordination controller, which can be realized by software and / or hardware. The method specifically comprises the following steps:

[0036] Step 110: Obtain the current capacity, output voltage, output current of each energy storage cabinet, and the required power of the load.

[0037] The output voltage of the energy storage cabinet is the DC side output voltage of the energy storage cabinet, and the output current of the energy storage cabinet is the DC side output current of the energy storage cabinet. The current capacity, output voltage, and output current of the energy storage cabinet can be sent to the coordination controller by sending a control signal to the energy storage cabinet, and the current capacity, output voltage, and output current of the energy storage cabinet can be sent to the coordination controller according to the received control signal. The required power of the load can be input externally to the coordination controller.

[0038] Step 120: Determine the relationship between the output power of each energy storage cabinet and the required power of the load according to the current capacity, output voltage, and required power of the load.

[0039] Exemplarily, the relationship between the output power of each energy storage cabinet and the required power of the load W TAC is ; wherein n is the number of energy storage cabinets, W ACi is the AC side output power of the i th energy storage cabinet, U DCi is the output voltage of the i th energy storage cabinet, Ci is the total capacity of the i th energy storage cabinet, SOCi is the percentage of the current capacity of the i th energy storage cabinet to the total capacity, and E DC / ACi is the AC / DC conversion efficiency of the i th energy storage cabinet. As can be seen from the above formula, the required power of the load is the sum of the DC side output power of each energy storage cabinet and the product of the AC / DC conversion efficiency of each energy storage cabinet.

[0040] Step 130: Determine the use time of each energy storage cabinet according to the current capacity, output current, and the relationship between the output power of each energy storage cabinet and the required power of the load.

[0041] Exemplarily, according to the relationship formula between the output power of each energy storage cabinet and the required power of the load W DC / AC , the use time of each energy storage cabinet Since it is necessary to use as much as possible the remaining power in the battery of each energy storage cabinet, the use time of each energy storage cabinet needs to be the same, i.e., the use time of each energy storage cabinet is t.

[0042] Step 140, according to the current capacity, output voltage and use time, determine the output power allocated to each energy storage cabinet, to control each energy storage cabinet according to the allocated output power.

[0043] Specifically, if there is at least one energy storage cabinet allocated to the AC side output power W ACx exceeds the current maximum output power of the respective AC side, the required power of the load is reduced by W ACx The obtained power is taken as the new required power of the load. According to the new required power of the load, the AC side output power allocated to each energy storage cabinet is re-determined until the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of the respective AC side, and the AC side output power allocated to each energy storage cabinet at this time is sent to each energy storage cabinet respectively. In addition, if the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of the respective AC side, the AC side output power allocated to each energy storage cabinet is sent to each energy storage cabinet respectively, so as to control the AC side output power of each energy storage cabinet to be the AC side output power allocated to each energy storage cabinet, and improve the energy utilization rate of the battery in each energy storage cabinet.

[0044] It should be noted that the specific size of each parameter in the embodiment can be determined according to actual control requirements, which is not limited here.

[0045] The control method of the energy storage system provided in the embodiment includes: obtaining the current capacity, output voltage, output current of each energy storage cabinet, and the required power of the load; determining the relationship between the output power of each energy storage cabinet and the required power of the load according to the current capacity, output voltage and required power of the load; determining the use time of each energy storage cabinet according to the current capacity, output current and the relationship between the output power of each energy storage cabinet and the required power of the load; and determining the output power allocated to each energy storage cabinet according to the current capacity, output voltage and use time, to control each energy storage cabinet according to the allocated output power. The control method of the energy storage system provided in the embodiment determines the output power allocated to each energy storage cabinet based on the current capacity, output current, output voltage, use time of each energy storage cabinet and the required power of the load. If the output power allocated to each energy storage cabinet does not exceed the current maximum output power of the respective AC side, the output power allocated to each energy storage cabinet is sent to each energy storage cabinet respectively, so as to control the output power of each energy storage cabinet to be the output power allocated to each energy storage cabinet, and improve the energy utilization rate of the battery in each energy storage cabinet.

[0046] Embodiment two

[0047] Figure 2is a flow chart of a control method of a storage system provided by Embodiment Two of the present application. The present embodiment can be applied to control of a storage system and the like, and the storage system comprises a coordination controller and at least two storage cabinets. The coordination controller is in communication connection with each storage cabinet. Each storage cabinet has a battery, and each storage cabinet is electrically connected with a load. The control method of the storage system is executed by the coordination controller, which can be realized in the form of software and / or hardware. The method specifically comprises the following steps:

[0048] In step 210, the current capacity, output voltage, output current of each storage cabinet, and the required power of the load are obtained.

[0049] The output voltage of the storage cabinet is the DC side output voltage of the storage cabinet, and the output current of the storage cabinet is the DC side output current of the storage cabinet. The current capacity, output voltage, and output current of the storage cabinet can be obtained by the coordination controller sending a control signal to the storage cabinet, and the storage cabinet sending the current capacity, output voltage, and output current of the storage cabinet to the coordination controller according to the received control signal. The required power of the load can be input externally to the coordination controller.

[0050] In addition, before obtaining the current capacity, output voltage, and output current of each storage cabinet, and the required power of the load, the input and output of each storage cabinet are synchronized, and the carrier wave is synchronized, so as to ensure that the obtained current capacity of each storage device is the remaining capacity of each storage device at the same time, and the obtained output voltage and output current of each storage cabinet are the output voltage and output current of each storage device at the same time.

[0051] In step 220, according to the current capacity, output voltage, and required power of the load, the relationship between the output power of each storage cabinet and the required power W TAC of the load is determined as ; wherein n is the number of storage cabinets, W ACi is the AC side output power of the i th storage cabinet, U DCi is the DC side output voltage of the i th storage cabinet, Ci is the total capacity of the i th storage cabinet, SOCi is the percentage of the current capacity of the i th storage cabinet to the total capacity, and E DC / ACi is the AC / DC conversion efficiency of the i th storage cabinet.

[0052] Specifically, taking n storage cabinets as an example, the time for the first storage cabinet to the n th storage cabinet to consume the remaining power is t1, t2, …, t n , and the relationship between the DC side output power W DCi and the AC side output power W ACi of the i th storage cabinet is: In order to use the remaining power in the storage cabinet battery as much as possible, it is required that t1=t2=…=t n= t, the output current of the first energy storage cabinet to the output current of the nth energy storage cabinet is respectively , the output power of the first energy storage cabinet to the output power of the nth energy storage cabinet is respectively . According to the relationship formula of the output power of each energy storage cabinet and the required power W TAC of the load, the required power of the load is the sum of the output power of each energy storage cabinet and the product of the respective AC-DC conversion efficiency. For example, if the current capacity ratio of the first energy storage cabinet, i.e., the percentage of the current capacity to the total capacity, is 50%, the current capacity of the first energy storage cabinet is half of the total capacity of the first energy storage cabinet.

[0053] Step 230, according to the current capacity, the output current, and the relationship between the output power of each energy storage cabinet and the required power W TAC of the load, the use time of each energy storage cabinet is determined ; wherein the use time of each energy storage cabinet is the same, n is the number of energy storage cabinets, U DCi is the output voltage of the ith energy storage cabinet, Ci is the total capacity of the ith energy storage cabinet, SOCi is the percentage of the current capacity of the ith energy storage cabinet to the total capacity, E DC / ACi is the AC-DC conversion efficiency of the ith energy storage cabinet.

[0054] Specifically, in the formula of the use time of the energy storage cabinet, only the use time is an unknown quantity, and other parameters are known quantities, and the AC-DC conversion efficiency of the energy storage cabinet can be obtained in advance. Therefore, by substituting the specific values of the known parameters in the formula of the use time of the energy storage cabinet, the use time of the energy storage cabinet can be calculated. Since it is necessary to use as much as possible the remaining power in the battery of each energy storage cabinet, the use time of each energy storage cabinet needs to be the same, i.e., the use time of each energy storage cabinet is t.

[0055] Step 240, according to the current capacity, the output voltage, and the use time, the AC side output power allocated to each energy storage cabinet is determined; the AC side output power allocated to the energy storage cabinet is the ratio of the product of the current capacity of the energy storage cabinet and the AC side output voltage to the use time.

[0056] Specifically, in the calculation formula of the AC side output power of the energy storage cabinet, the current capacity and the output voltage are known quantities, and the specific value of the use time of the energy storage cabinet is substituted into the calculation formula of the AC side output power of the energy storage cabinet to obtain the AC side output power allocated to the energy storage cabinet.

[0057] In addition, the coordination controller obtains the maximum output power of each energy storage cabinet in real time, and each energy storage cabinet can send the maximum output power of the AC side of itself to the coordination controller. The maximum output power of the AC side of the same energy storage cabinet at different times may be different.

[0058] Step 250: If at least one energy storage cabinet is allocated AC side output power W ACx If the current maximum output power exceeds the current AC output power of each side, then subtract W from the power required by the load. ACx The obtained power is used as the power required for the new load; where x represents the energy storage cabinet whose output power on the AC side exceeds the current maximum output power of its own AC side.

[0059] For example, the AC side output power W allocated to the first energy storage cabinet AC1 Exceeding its own current maximum output power (W) on the AC side l1 The AC output power W allocated to the second energy storage cabinet AC2 Exceeding its own current maximum output power (W) on the AC side l2 If the AC output power allocated to other energy storage cabinets does not exceed their own current maximum AC output power, then the power required by the load (W) will be... TAC -W AC1 -W AC2 The obtained power is used as the power required for the new load.

[0060] Furthermore, Figure 3 This is a schematic diagram illustrating the maximum output power and capacity of an energy storage cabinet according to Embodiment 2 of the present invention. (Reference) Figure 3 The lower the capacity of the energy storage cabinet, the less power it is allocated. The maximum output power of the AC side of the energy storage cabinet increases as the capacity gradually increases from zero. After the capacity reaches a certain value, the maximum output power of the energy storage cabinet no longer changes. The lower capacity of the energy storage cabinet is allocated less power, which allows the energy storage cabinet to maintain the maximum output power for a longer period of time.

[0061] In addition, if the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of its respective AC side, the AC side output power allocated to each energy storage cabinet will be sent to each energy storage cabinet to control the AC side output power of each energy storage cabinet to be the AC side output power allocated to each energy storage cabinet.

[0062] Step 260: Based on the power required by the new load, redetermine the AC side output power allocated to each energy storage cabinet until the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of its respective AC side, and send the AC side output power allocated to each energy storage cabinet at this time to each energy storage cabinet.

[0063] Specifically, steps 220-250 are re-executed according to the required power of the new load until the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of the AC side of each energy storage cabinet, at which time the AC side output power allocated to each energy storage cabinet is sent to each energy storage cabinet, so as to control the AC side output power of each energy storage cabinet to be the final AC side output power allocated to each energy storage cabinet, thereby improving the energy utilization rate of the battery in each energy storage cabinet.

[0064] It should be noted that the specific values of the parameters in the embodiment can be determined according to actual control requirements, which are not limited herein.

[0065] The control method of the energy storage system provided in the embodiment determines the AC side output power allocated to each energy storage cabinet based on the current capacity, output current, output voltage, use time of each energy storage cabinet, and required power of the load. If the AC side output power W ACx allocated to at least one energy storage cabinet exceeds the current maximum output power of the AC side of the energy storage cabinet, the required power of the load is reduced by W ACx , and the obtained power is taken as the new required power of the load. The AC side output power allocated to each energy storage cabinet is re-determined according to the new required power of the load until the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of the AC side of each energy storage cabinet, and the AC side output power allocated to each energy storage cabinet at this time is sent to each energy storage cabinet. If the AC side output power allocated to each energy storage cabinet does not exceed the current maximum output power of the AC side of each energy storage cabinet, the AC side output power allocated to each energy storage cabinet is sent to each energy storage cabinet to control the AC side output power of each energy storage cabinet to be the AC side output power allocated to each energy storage cabinet, thereby improving the energy utilization rate of the battery in each energy storage cabinet.

[0066] Embodiment Three

[0067] Figure 4 is a structural block diagram of an energy storage system provided in Embodiment Three of the present application. Referring to Figure 4 , the energy storage system comprises a coordination controller 10 and at least two energy storage cabinets 20. The coordination controller 10 is in communication connection with each energy storage cabinet 20. Each energy storage cabinet 20 has a battery, and each energy storage cabinet 20 is electrically connected with a load. The coordination controller 10 is used to execute the control method of the energy storage system as described in any embodiment of the present application. Among them, Figure 4 a plurality of parallel energy storage cabinets 20 are shown in the figure. The coordination controller 10 is used to control each energy storage cabinet 20. The specific control process can be referred to in any of the above embodiments, which will not be described herein.

[0068] Specifically, as Figure 4As shown, the micro-grid is connected with the power grid through an STS (Static Transfer Switch), and each energy storage cabinet communicates with each other through an EtherCAT (Ethernet for Control Automation Technology) network, and a coordination controller is used to coordinate the work of each energy storage cabinet.

[0069] Figure 5 is a structural diagram of an energy storage cabinet provided in Embodiment Three of the present application. Refer to Figure 4 and Figure 5 Optionally, the energy storage cabinet is provided with an integrated module 21, the integrated module 21 is electrically connected with the battery, the integrated module 21 is in communication connection with the coordination controller 10, and the integrated module 21 integrates an energy storage converter and a battery management unit.

[0070] The energy storage converter and the battery management unit are both in communication connection with the coordination controller 10, and the coordination controller 10 controls the battery through the energy storage converter and the battery management unit. The integrated module 21 integrates the energy storage converter and the battery management unit, which facilitates the coordination controller 10 to simultaneously acquire information of the battery management unit and information of the energy storage converter, so as to simultaneously control the energy storage cabinet 20 according to the battery state and the energy storage converter state. Further, the coordination controller 10 controls the carrier wave synchronization of the energy storage converter in each energy storage cabinet 20: the coordination controller 10 controls the carrier wave synchronization based on the clock synchronization function of the EtherCAT protocol, modifies the synchronization mode of each energy storage cabinet to the distributed clock synchronization mode of the EtherCAT, and configures the synchronization period to be 4ms (which needs to be an integer multiple of the carrier wave period of the energy storage converter). At this time, the EtherCAT protocol stack can take the system clock of the first energy storage cabinet (the signal sent by the coordination controller to each energy storage cabinet is transmitted to the rear one by one by the first energy storage cabinet) as the reference clock to synchronize other energy storage cabinets, and provide a copy of the reference clock for other energy storage cabinets. All energy storage cabinets can generate a synchronization signal with the same phase, the same period and the same synchronization period according to the reference clock. The period of the synchronization signal is configured to be 400us. The energy storage converter uses the synchronization signal provided by the energy storage cabinet as the clock synchronization signal for pulse width adjustment, so that the energy storage converters in all energy storage cabinets achieve carrier wave synchronization. Exemplarily, the actual test shows that the carrier wave phase deviation after synchronization is ±100ns, the carrier wave frequency of the energy storage converter is 16K, and the synchronization error is , which can meet the requirement of carrier wave synchronization. Figure 6 is a schematic diagram of the coordination controller controlling the synchronization of each energy storage cabinet provided in Embodiment Three of the present application. Refer to Figure 6The coordination controller 10 controls the energy storage cabinets 20 to be synchronized: since all the energy storage cabinets can generate synchronization signals with the same phase period in the distributed clock synchronization mode, the coordination controller sends control data to all the energy storage cabinets in each synchronization period, and makes the output valid and triggers the input sampling when the synchronization signal triggers, so that the input and output control of all the energy storage cabinets are synchronized. In order to reduce the influence of control synchronization on the communication bandwidth, the object dictionary data of the receiving process data object and the sending process data object mapped to the EtherCAT protocol are sent once per period, the control register of the energy storage converter, the power setting register are added to the receiving process data object mapping, and the state register, the power feedback register, the current remaining capacity register, and the current total capacity register are added to the sending process data object mapping, so as to realize control synchronization.

[0071] With reference to Figure 4 Optionally, the energy storage system further comprises a power meter, and the power meter is arranged in a line connected between the energy storage cabinet and the load.

[0072] The electric meter can be an alternating current electric meter, and is used to obtain the power required by the load. Specifically, the electric meter in the line connected with the load is a key device for monitoring and managing the energy flow between the energy storage system and the load. The function, type and technical characteristics of the electric meter are related to the operation mode of the energy storage system and the energy management requirements. When the energy storage cabinet is connected with the load such as industrial equipment, there is bidirectional energy flow: the energy storage cabinet supplies power to the load when discharging; when the power of the load is lower than the output power of the energy storage cabinet, the energy storage cabinet can be charged, and the electric meter needs to monitor the energy exchange in two directions in real time. The electric meter can measure the energy flow direction and the amount: accurately measuring the power supplied by the energy storage cabinet to the load and the feedback power of the load to the energy storage cabinet; supporting energy management: providing data support for the charging and discharging strategy of the energy storage system, such as the power required by the load; system monitoring and protection: monitoring parameters such as voltage, current and power to prevent overload or abnormal current from damaging the equipment in the system; data interaction: transmitting the metering data to the coordination controller to realize remote monitoring and optimization; safety and protection: the electric meter can be designed with lead sealing and data encryption to prevent tampering with the metering data; the electric meter has overcurrent and overvoltage protection functions to avoid damage to the electric meter or equipment caused by abnormal current. The electric meter can be a smart electric meter. In the energy storage system of the energy storage cabinet such as an industrial and commercial energy storage cabinet, the smart electric meter can record the electric quantity of the energy storage cabinet during the low valley period and the discharging period during the peak period, thereby reducing the electricity cost. The electric meter is connected in series in the main loop of the energy storage cabinet and the load to ensure that all the electric energy flowing through the load is measured by the electric meter. The data of the electric meter is connected to the control logic of the energy storage system. When the electric meter detects that the power of the load is lower than the output power of the energy storage cabinet, the coordination controller can control the energy storage cabinet to reduce discharging or start charging. For the industrial and commercial energy storage system, the electric meter monitors the discharging amount of the energy storage cabinet to the load during the peak period, calculates the income combined with the price difference, and records the charging amount during the valley period to optimize the energy cost. The electric meter can adopt a three-phase four-wire bidirectional electric meter to support multi-loop metering. The electric meter between the energy storage cabinet and the load is not only an energy metering tool, but also a core node of intelligent management of the energy storage system. The bidirectional metering, communication interaction and data support capability of the electric meter help users to realize the visualization of energy flow, optimize the charging and discharging strategy, and ensure the safe and efficient operation of the system. The selection of the electric meter can be determined according to the actual control requirements of the energy storage system, and is not limited herein.

[0073] The energy storage system provided by the embodiment and the control method of the energy storage system provided by any embodiment of the application belong to the same inventive concept and have corresponding beneficial effects. The detailed technical details of the embodiment are described in the control method of the energy storage system provided by any embodiment of the application.

[0074] Embodiment four

[0075] The computer readable storage medium provided by the embodiment four of the application stores a computer program, and the program is executed by the coordination controller to realize the control method of the energy storage system provided by the embodiment of the application. The control method of the energy storage system comprises:

[0076] acquire the current capacity, output voltage, output current of each energy storage cabinet, and the required power of the load;

[0077] determine the relationship between the output power of each energy storage cabinet and the required power of the load according to the current capacity, output voltage and required power of the load;

[0078] determine the use time of each energy storage cabinet according to the current capacity, output current and the relationship between the output power of each energy storage cabinet and the required power of the load;

[0079] determine the output power allocated to each energy storage cabinet according to the current capacity, output voltage and use time, so as to control each energy storage cabinet according to the allocated output power.

[0080] The computer storage medium of the embodiment of the application can adopt any combination of one or more computer readable media. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium may, for example, be but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination of the above. More specific examples (non-exhaustive list) of the computer readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, device or component.

[0081] The computer readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, in which a computer readable program code is carried. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination of the above. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium, which can send, propagate or transmit a program for use by or in connection with an instruction execution system, device or component.

[0082] The program code contained on the computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0083] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0084] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the application. The word "comprising" does not exclude the presence of elements or steps other than those listed and the word "a" or "an" preceding the usage of an element does not exclude the presence of a plurality of such elements. It is anticipated that, depending on the specific design choices made for a given embodiment, the application can be implemented in a variety of ways, all of which are intended to fall within the scope of the present application as defined by the subjoined claims.

Claims

1. A control method of an energy storage system, characterized by, The energy storage system comprises a coordination controller and at least two energy storage cabinets, the coordination controller is in communication connection with each of the energy storage cabinets, each of the energy storage cabinets has a battery, and each of the energy storage cabinets is electrically connected with a load; the control method is executed by the coordination controller, and the control method comprises: obtaining the current capacity, output voltage, output current of each of the energy storage cabinets, and the required power of the load; determining the relationship between the output power of each of the energy storage cabinets and the required power of the load according to the current capacity, output voltage and required power of the load; determining the use time of each of the energy storage cabinets according to the current capacity, output current and relationship between the output power of each of the energy storage cabinets and the required power of the load; Based on the current capacity, output voltage, and usage time, the output power allocated to each energy storage cabinet is determined, and each energy storage cabinet is controlled according to the allocated output power; the output power of each energy storage cabinet is related to the power required by the load W. TAC The relationship is Where n is the number of energy storage cabinets, W ACi U represents the AC output power of the i-th energy storage cabinet. DCi Let be the DC output voltage of the i-th energy storage cabinet, Ci be the total capacity of the i-th energy storage cabinet, SOCi be the percentage of the current capacity of the i-th energy storage cabinet relative to the total capacity, and E be the current capacity of the i-th energy storage cabinet relative to the total capacity. DC / ACi Let be the AC / DC conversion efficiency of the i-th energy storage cabinet; the AC side output power allocated to the energy storage cabinet is the ratio of the product of the current capacity of the energy storage cabinet and the AC side output voltage to the usage time.

2. The control method of an energy storage system according to claim 1, wherein determining the use time of each of the energy storage cabinets according to the current capacity, output current and relationship between the output power of each of the energy storage cabinets and the required power of the load, comprising: Based on the current capacity, the output current, and the output power of each energy storage cabinet, and the power required by the load (W) TAC The relationship between the energy storage cabinets determines the usage time of each cabinet. Wherein, the usage time of each of the energy storage cabinets is the same, n is the number of energy storage cabinets, and U DCi Let be the DC output voltage of the i-th energy storage cabinet, Ci be the total capacity of the i-th energy storage cabinet, SOCi be the percentage of the current capacity of the i-th energy storage cabinet relative to the total capacity, and E be the current capacity of the i-th energy storage cabinet relative to the total capacity. DC / ACi Let be the AC / DC conversion efficiency of the i-th energy storage cabinet.

3. The control method of an energy storage system according to claim 1, wherein before the step of obtaining the current capacity, output voltage, output current of each of the energy storage cabinets, and the required power of the load, comprising: controlling the input and output synchronization and carrier synchronization of each of the energy storage cabinets.

4. The control method of an energy storage system according to claim 1, wherein determining the output power allocated to each of the energy storage cabinets according to the current capacity, output voltage and use time, and controlling each of the energy storage cabinets according to the allocated output power, comprising: determining the alternating current side output power allocated to each of the energy storage cabinets according to the current capacity, output voltage and use time; If there is at least one energy storage cabinet whose allocated AC side output power W ACx exceeds the current maximum output power of the respective AC side, the required power of the load is reduced by W ACx , and the obtained power is taken as the new required power of the load; wherein x represents the energy storage cabinet whose allocated AC side output power exceeds the current maximum output power of the respective AC side. redetermining the output power allocated to each of the energy storage cabinets according to the new required power of the load until the output power allocated to each of the energy storage cabinets does not exceed the current maximum output power of each of the energy storage cabinets, and sending the output power allocated to each of the energy storage cabinets to each of the energy storage cabinets at this time.

5. The control method of an energy storage system according to claim 4, wherein Further comprising: if the output power allocated to each of the energy storage cabinets does not exceed the current maximum output power of each of the energy storage cabinets, sending the output power allocated to each of the energy storage cabinets to each of the energy storage cabinets.

6. The control method of an energy storage system according to claim 4, wherein Further comprising: obtaining the maximum output power of each of the energy storage cabinets in real time.

7. An energy storage system characterized by, comprising: a coordination controller and at least two energy storage cabinets, the coordination controller is in communication connection with each of the energy storage cabinets, each of the energy storage cabinets has a battery, and each of the energy storage cabinets is electrically connected with a load; the coordination controller is used to execute the control method of the energy storage system as claimed in any one of claims 1-6.

8. The energy storage system of claim 7, wherein, An integrated module is arranged in the energy storage cabinet, the integrated module is electrically connected with the battery, the integrated module is in communication connection with the coordination controller, and the integrated module integrates an energy storage converter and a battery management unit.

9. The energy storage system of claim 7, wherein, Further comprising an electric meter, which is arranged in a line connecting the energy storage cabinet and the load.

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