A real-time simulation method, device, medium and equipment for energy storage system

Abstract

The present invention discloses a real-time simulation method for an energy storage system, comprising: constructing a simulation model of the energy storage system based on the topological structure of the energy storage system to initiate electromagnetic transient simulation calculations; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit; obtaining the equivalent capacitance of each energy storage battery based on a preset charge-discharge characteristic curve; updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit; obtaining the bridge arm current of each bridge arm equivalent circuit at the current moment based on the bridge arm voltage of each bridge arm equivalent circuit; obtaining the capacitor voltage of each cascaded H-bridge module equivalent circuit at the current moment based on the equivalent capacitance; and determining whether the simulation duration at the current moment reaches a preset duration threshold, and if so, outputting the simulation result. The embodiments of the present invention can accurately simulate the dynamic characteristics of the energy storage system under various operating conditions, thereby completing a semi-physical simulation test of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a real-time simulation method, device, medium and equipment for an energy storage system. Background Art

[0002] With the development of new power systems, grid-connected energy storage systems are becoming increasingly widely used and playing an increasingly important role. Due to the limited capacity and voltage of a single battery, in order to increase the capacity of a single energy storage system and improve the power quality, it is often necessary to develop a multi-level energy storage system. One important structure is based on a cascaded H-bridge (CHB) converter and energy storage batteries. The cascaded H-bridge has the advantages of high modularity, excellent output characteristics, and convenient voltage expansion, making it suitable for high-voltage, large-capacity energy storage systems. As the system voltage and capacity increase, the energy storage system becomes more complex. To ensure the reliability of the energy storage system operation, it is necessary to use a digital real-time simulation system to conduct sufficient semi-physical simulation tests on the energy storage system during the design and commissioning phase to verify that the relevant functions and performance meet the design requirements. Among them, the digital real-time simulation model of the energy storage system is a key part of the entire simulation system.

[0003] Currently, there is no dedicated real-time simulation model for high-voltage, large-capacity energy storage systems, making it impossible to complete semi-physical simulation tests of energy storage systems based on cascaded H-bridge converters and energy storage batteries. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a real-time simulation method, apparatus, medium, and equipment for an energy storage system, which can accurately simulate the dynamic characteristics of an energy storage system based on a cascaded H-bridge converter and an energy storage battery under various operating conditions, thereby completing a semi-physical simulation test of the energy storage system while ensuring the reliability of the system operation.

[0005] To achieve the above objectives, an embodiment of the present invention provides a real-time simulation method for an energy storage system, comprising:

[0006] Constructing a simulation model of the energy storage system according to the topological structure of the energy storage system to start electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit;

[0007] Obtaining the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve;

[0008] Updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit;

[0009] Obtaining the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits;

[0010] According to the equivalent capacitance, obtaining the capacitance voltage of each of the cascaded H-bridge modules equivalent circuit at the current moment;

[0011] Determine whether the simulation duration at the current moment reaches a preset duration threshold. If so, output the simulation result and end the simulation; if not, increase the simulation duration at the current moment by a preset simulation step to continue the electromagnetic transient simulation calculation of the energy storage system.

[0012] As an improvement to the above solution, each bridge arm equivalent circuit includes a voltage source and an inductor connected in series with the voltage source, and each cascaded H-bridge module equivalent circuit includes a current source and a capacitor connected in parallel with the current source.

[0013] As an improvement to the above solution, the step of obtaining the equivalent capacitance of each energy storage battery according to a preset charge-discharge characteristic curve includes:

[0014] Calculate the equivalent capacitance of each energy storage battery according to the following formula:

[0015]

[0016] Among them, Q N is the rated capacity of the energy storage battery, dSOC is the change in the state of charge of the energy storage battery, and dU is the voltage change.

[0017] As an improvement to the above solution, updating the state of the power electronic switch of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit includes:

[0018] Update the power electronic switch state of each cascaded H-bridge module according to the switch control signal input by the simulation;

[0019] Obtaining the output voltage of each of the cascaded H-bridge modules according to the power electronic switch state;

[0020] The bridge arm voltage of each bridge arm equivalent circuit is obtained according to the output voltage of each cascaded H-bridge module.

[0021] As an improvement to the above solution, obtaining the bridge arm voltage of each bridge arm equivalent circuit according to the output voltage of each cascaded H-bridge module includes:

[0022] The bridge arm voltage of each bridge arm equivalent circuit is calculated according to the following formula:

[0023]

[0024] Among them, U xk is the output voltage of the kth cascaded H-bridge module of the xth phase.

[0025] As an improvement to the above solution, obtaining the bridge arm current of each of the bridge arm equivalent circuits at the current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits includes:

[0026] The bridge arm current of each bridge arm equivalent circuit at the current moment is calculated according to the following formula:

[0027]

[0028] i a +i b +i c =0

[0029] Among them, i x is the bridge arm current of the bridge arm equivalent circuit of the xth phase, L is the phase inductance of the bridge arm equivalent circuit, v o is the neutral point voltage of the bridge arm equivalent circuit, v x is the phase voltage of the bridge arm equivalent circuit, U x is the bridge arm voltage of the bridge arm equivalent circuit, i a 、i b 、i c are the phase currents of the bridge arm equivalent circuit respectively.

[0030] As an improvement to the above solution, obtaining the capacitor voltage of each of the cascaded H-bridge module equivalent circuits at the current moment based on the equivalent capacitance includes:

[0031] The equivalent capacitance is used as the capacitance of the cascaded H-bridge module equivalent circuit, and the capacitance voltage of each cascaded H-bridge module equivalent circuit at the current moment is calculated according to the following formula:

[0032]

[0033] Among them, U ck is the capacitor voltage of the kth cascaded H-bridge module equivalent circuit, C k is the capacitance of the kth cascaded H-bridge module equivalent circuit, I k is the capacitive current of the kth cascaded H-bridge module equivalent circuit.

[0034] To achieve the above objectives, an embodiment of the present invention further provides a real-time simulation device for an energy storage system, comprising:

[0035] A simulation model construction module is used to construct a simulation model of the energy storage system according to the topological structure of the energy storage system to start the electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit;

[0036] An equivalent capacitance acquisition module is used to obtain the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve;

[0037] A bridge arm voltage acquisition module, used for updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit;

[0038] A bridge arm current acquisition module, configured to acquire the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits;

[0039] A capacitor voltage acquisition module, configured to acquire the capacitor voltage of the equivalent circuit of each of the cascaded H-bridge modules at a current moment based on the equivalent capacitance;

[0040] The simulation result output module is used to determine whether the simulation duration at the current moment reaches a preset duration threshold. If so, the simulation result is output and the simulation is terminated; if not, the simulation duration at the current moment is increased by a preset simulation step to continue the electromagnetic transient simulation calculation of the energy storage system.

[0041] To achieve the above-mentioned purpose, an embodiment of the present invention further provides a computer-readable storage medium, which includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the real-time simulation method of the energy storage system as described above.

[0042] To achieve the above objectives, an embodiment of the present invention further provides a device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the real-time simulation method of the energy storage system as described above when executing the computer program.

[0043] Compared with the prior art, the embodiment of the present invention provides a real-time simulation method, device, medium and equipment for an energy storage system, which starts the electromagnetic transient simulation calculation of the energy storage system by constructing a simulation model of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascade H-bridge module equivalent circuit; obtains the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve; updates the power electronic switch state of each cascade H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit; obtains the bridge arm current of each bridge arm equivalent circuit at the current moment according to the bridge arm voltage of each bridge arm equivalent circuit; obtains the capacitor voltage of each cascade H-bridge module equivalent circuit at the current moment according to the equivalent capacitance; when the simulation time at the current moment reaches the preset time threshold, outputs the simulation result and ends the simulation. As can be seen, the embodiment of the present invention can more accurately simulate the dynamic characteristics of the energy storage system based on the cascade H-bridge converter and the energy storage battery under various working conditions, thereby completing the semi-physical simulation test of the energy storage system and ensuring the reliability of the system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of a real-time simulation method for an energy storage system provided by an embodiment of the present invention;

[0045] Figure 2 This is a topological diagram of an energy storage system provided by an embodiment of the present invention;

[0046] Figure 3 is a circuit diagram of a bridge arm equivalent circuit of an energy storage system provided by an embodiment of the present invention;

[0047] Figure 4 1 is a circuit diagram of an equivalent circuit of a cascaded H-bridge module of an energy storage system provided by an embodiment of the present invention;

[0048] Figure 5 This is a structural block diagram of a real-time simulation device for an energy storage system provided by an embodiment of the present invention;

[0049] Figure 6 This is a structural block diagram of a device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] See also Figure 1 , Figure 11 is a flow chart of a real-time simulation method for an energy storage system provided by an embodiment of the present invention, the real-time simulation method for an energy storage system comprising:

[0052] S1. Constructing a simulation model of the energy storage system according to the topological structure of the energy storage system to start electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit;

[0053] S2. Obtaining the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve;

[0054] S3, updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit;

[0055] S4. Obtaining the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits;

[0056] S5. Obtaining the capacitance voltage of each of the cascaded H-bridge module equivalent circuits at a current moment based on the equivalent capacitance;

[0057] S6. Determine whether the simulation duration at the current moment reaches a preset duration threshold. If so, output the simulation result and end the simulation; if not, increase the simulation duration at the current moment by a preset simulation step to continue the electromagnetic transient simulation calculation of the energy storage system.

[0058] It is understood that when the simulation duration at the current moment reaches a preset duration threshold, the simulation result is output and the simulation ends; optionally, the simulation result includes at least one of the following: bridge arm voltage, bridge arm current, module voltage, module current, and the simulation result may be a variable of interest, which is not specifically limited here;

[0059] When the simulation duration at the current moment does not reach the preset duration threshold, t=t+Δt is executed, and the process returns to step S2 to continue the electromagnetic transient simulation calculation of the energy storage system.

[0060] Specifically, each bridge arm equivalent circuit includes a voltage source and an inductor connected in series with the voltage source, and each cascade H-bridge module equivalent circuit includes a current source and a capacitor connected in parallel with the current source.

[0061] It should be noted that if Figure 2-4 As shown, the topological structure, bridge arm equivalent circuit, and cascaded H-bridge module equivalent circuit of an energy storage system provided by an embodiment of the present invention are described in detail.

[0062] Depend on Figure 2As can be seen, the energy storage system has a three-phase AC port connected to the external power grid; each energy storage system includes three bridge arms, each bridge arm includes a bridge arm inductor L and n series-connected cascaded H-bridge (CHB) modules. Each CHB includes four power electronic switches and an energy storage battery U C Each power electronic switch is composed of an IGBT and a diode connected in anti-parallel. By controlling the on / off of the four power electronic switches, the energy storage battery U can be controlled. C The input or output of the bridge arm is used to control the bridge arm voltage and bridge arm current, and realize AC / DC power conversion; Figure 2 In the example, CHB represents the cascaded H-bridge module, v a 、v b 、v c is the AC three-phase voltage, i a 、i b 、i c is the AC three-phase current, L is the bridge arm inductance, U C For module batteries, I C is the energy storage battery current, S1, S2, S3, and S4 are power electronic switches composed of IGBTs and diodes connected in anti-parallel.

[0063] Depend on Figure 3 It can be seen that each bridge arm equivalent circuit of the energy storage system includes a voltage source and an inductor connected in series with the voltage source; Figure 3 Middle,U a 、U b 、U c It is the sum of the total voltage of each cascaded H-bridge module.

[0064] Depend on Figure 4 It can be seen that the equivalent circuit of each cascade H-bridge module of the energy storage system includes a current source and a capacitor connected in parallel with the current source; Figure 4 In the figure, the rectangular box refers to the equivalent model of the H-bridge switching circuit, U xk is the output voltage of the kth cascaded H-bridge module of the xth phase, U Ck is the internal capacitor voltage of the cascaded H-bridge module, I k It is understandable that the embodiment of the present invention uses a nonlinear capacitor to simulate the energy storage battery, that is, U Ck is the battery voltage, I k is the battery current.

[0065] Specifically, obtaining the equivalent capacitance of each energy storage battery according to a preset charge-discharge characteristic curve includes:

[0066] Calculate the equivalent capacitance of each energy storage battery according to the following formula:

[0067]

[0068] Among them, Q N is the rated capacity of the energy storage battery, dSOC is the change in the state of charge of the energy storage battery, and dU is the voltage change.

[0069] Specifically, the charge-discharge characteristic curve is a charge-discharge characteristic curve of the battery's state of charge (SOC) versus terminal voltage U, and the charge-discharge characteristic curve is provided by the manufacturer or obtained by actual measurement in advance.

[0070] Specifically, updating the state of the power electronic switch of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit includes:

[0071] Update the power electronic switch state of each cascaded H-bridge module according to the switch control signal input by the simulation;

[0072] Obtaining the output voltage of each of the cascaded H-bridge modules according to the power electronic switch state;

[0073] The bridge arm voltage of each bridge arm equivalent circuit is obtained according to the output voltage of each cascaded H-bridge module.

[0074] Specifically, obtaining the bridge arm voltage of each bridge arm equivalent circuit according to the output voltage of each cascaded H-bridge module includes:

[0075] The bridge arm voltage of each bridge arm equivalent circuit is calculated according to the following formula:

[0076]

[0077] Among them, U xk is the output voltage of the kth cascaded H-bridge module of the xth phase.

[0078] It can be understood that based on the relationship between the preset switch state and the bridge arm voltage, the output voltage of each of the cascaded H-bridge modules is obtained according to the power electronic switch state;

[0079] In order to more intuitively understand the relationship between the switch state and the bridge arm voltage, an embodiment of the present invention provides the relationship between the switch state and the bridge arm voltage as shown in Table 1. It can be understood that the relationship between the switch state and the bridge arm voltage can be expressed in the form of a table or in other ways, which is not limited here.

[0080] Table 1 Relationship between switch state and bridge arm voltage

[0081]

[0082] In Table 1, i xis the phase current. In the embodiment of the present invention, the phase current is equal to the bridge arm current. S1, S2, S3, and S4 are power electronic switches. The "1" in the S1-S4 column indicates an on signal and the "0" indicates an off signal. x The “+” in the column indicates that the bridge arm current is positive, and the “-” indicates that the bridge arm current is negative. For example, when the simulated input switch control signals S1-S4 are all 0, the power electronic switch states of S1-S4 are all turned off. At this time, the output voltage U xk is the capacitor voltage U inside the cascade H-bridge module Ck In Table 1, the battery current can also be obtained; when the power electronic switch states of S1-S4 are all off and the input phase current i x When it is positive, the battery current I Ck is the phase current i x .

[0083] Specifically, obtaining the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits includes:

[0084] The bridge arm current of each bridge arm equivalent circuit at the current moment is calculated according to the following formula:

[0085]

[0086] i a +i b +i c =0 (2)

[0087] Among them, i x is the bridge arm current of the bridge arm equivalent circuit of the xth phase, L is the phase inductance of the bridge arm equivalent circuit, v o is the neutral point voltage of the bridge arm equivalent circuit, v x is the phase voltage of the bridge arm equivalent circuit, U x is the bridge arm voltage of the bridge arm equivalent circuit, i a 、i b 、i c are the phase currents of the bridge arm equivalent circuit respectively.

[0088] It can be understood that by combining equations (1) and (2), the updated bridge arm current i can be obtained. x (t+Δt).

[0089] Specifically, obtaining the capacitor voltage of each of the cascaded H-bridge module equivalent circuits at a current moment based on the equivalent capacitance includes:

[0090] The equivalent capacitance is used as the capacitance of the cascaded H-bridge module equivalent circuit, and the capacitance voltage of each cascaded H-bridge module equivalent circuit at the current moment is calculated according to the following formula:

[0091]

[0092] Among them, U ck is the capacitor voltage of the kth cascaded H-bridge module equivalent circuit, C k is the capacitance of the kth cascaded H-bridge module equivalent circuit, I k is the capacitive current of the kth cascaded H-bridge module equivalent circuit.

[0093] It can be understood that by solving equation (3), the capacitor voltage U of the updated cascade H-bridge module equivalent circuit can be obtained. Ck (t+Δt).

[0094] The embodiments of the present invention can accurately simulate the switching state of each CHB and the battery charging and discharging process, and have the following beneficial effects: decoupling the CHB module from the bridge arm circuit is achieved based on the ideal transformer method; the equivalent capacitance parameters of the energy storage battery are obtained based on the curve method; the switching state of the power module is solved based on the table lookup method, avoiding iterative calculations; and natural commutation of the bridge arm current at the zero crossing point is achieved based on the anti-parallel switch branch, avoiding zero crossing errors.

[0095] To achieve the above objectives, an embodiment of the present invention further provides a real-time simulation device 10 for an energy storage system, comprising:

[0096] A simulation model construction module 11 is used to construct a simulation model of the energy storage system according to the topological structure of the energy storage system to start the electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit;

[0097] An equivalent capacitance acquisition module 12 is used to obtain the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve;

[0098] A bridge arm voltage acquisition module 13 is used to update the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit;

[0099] A bridge arm current acquisition module 14 is configured to acquire the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits;

[0100] A capacitor voltage acquisition module 15 is configured to acquire the capacitor voltage of each of the cascaded H-bridge module equivalent circuits at a current moment based on the equivalent capacitance;

[0101] The simulation result output module 16 is used to determine whether the simulation duration at the current moment reaches a preset duration threshold. If so, the simulation result is output and the simulation is terminated; if not, the simulation duration at the current moment is increased by a preset simulation step to continue the electromagnetic transient simulation calculation of the energy storage system.

[0102] Preferably, each bridge arm equivalent circuit includes a voltage source and an inductor connected in series with the voltage source, and each cascade H-bridge module equivalent circuit includes a current source and a capacitor connected in parallel with the current source.

[0103] Preferably, obtaining the equivalent capacitance of each energy storage battery according to a preset charge-discharge characteristic curve includes:

[0104] Calculate the equivalent capacitance of each energy storage battery according to the following formula:

[0105]

[0106] Among them, Q N is the rated capacity of the battery, dSOC is the change in the state of charge of the energy storage battery, and dU is the voltage change.

[0107] Preferably, updating the state of the power electronic switch of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit includes:

[0108] Update the power electronic switch state of each cascaded H-bridge module according to the switch control signal input by the simulation;

[0109] Obtaining the output voltage of each of the cascaded H-bridge modules according to the power electronic switch state;

[0110] The bridge arm voltage of each bridge arm equivalent circuit is obtained according to the output voltage of each cascaded H-bridge module.

[0111] Preferably, obtaining the bridge arm voltage of each bridge arm equivalent circuit according to the output voltage of each cascaded H-bridge module includes:

[0112] The bridge arm voltage of each bridge arm equivalent circuit is calculated according to the following formula:

[0113]

[0114] Among them, U xk is the output voltage of the kth cascaded H-bridge module of the xth phase.

[0115] Preferably, acquiring the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits includes:

[0116] The bridge arm current of each bridge arm equivalent circuit at the current moment is calculated according to the following formula:

[0117]

[0118] i a +i b +i c =0

[0119] Among them, i x is the bridge arm current of the bridge arm equivalent circuit of the xth phase, L is the phase inductance of the bridge arm equivalent circuit, v o is the neutral point voltage of the bridge arm equivalent circuit, v x is the phase voltage of the bridge arm equivalent circuit, U x is the bridge arm voltage of the bridge arm equivalent circuit, i a 、i b 、i c are the phase currents of the bridge arm equivalent circuit respectively.

[0120] Preferably, obtaining the capacitor voltage of each of the cascaded H-bridge module equivalent circuits at a current moment based on the equivalent capacitance includes:

[0121] The equivalent capacitance is used as the capacitance of the cascaded H-bridge module equivalent circuit, and the capacitance voltage of each cascaded H-bridge module equivalent circuit at the current moment is calculated according to the following formula:

[0122]

[0123] Among them, U Ck is the capacitor voltage of the kth cascaded H-bridge module equivalent circuit, C k is the capacitance of the kth cascaded H-bridge module equivalent circuit, I k is the capacitive current of the kth cascaded H-bridge module equivalent circuit.

[0124] It is worth noting that the working process of each module in the real-time simulation device 10 of the energy storage system according to the embodiment of the present invention can refer to the working process of the real-time simulation method of the energy storage system according to the above embodiment, and will not be repeated here.

[0125] An embodiment of the present invention further provides a computer-readable storage medium, which includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the real-time simulation method of the energy storage system as described in the above embodiment.

[0126] An embodiment of the present invention further provides a device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the real-time simulation method of the energy storage system as described in the above embodiment when executing the computer program.

[0127] See also Figure 6 , Figure 6 This is a block diagram of a device 20 provided in an embodiment of the present invention. The device 20 includes a processor 21, a memory 22, and a computer program stored in the memory 22 and executable on the processor 21. When the processor 21 executes the computer program, the steps of the above-described embodiment of the real-time simulation method for an energy storage system are implemented. Alternatively, when the processor 21 executes the computer program, the functions of the modules / units in the above-described device embodiments are implemented.

[0128] For example, the computer program may be divided into one or more modules / units, which are stored in the memory 22 and executed by the processor 21 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program in the device 20.

[0129] Device 20 may be a computing device such as a desktop computer, laptop, PDA, or cloud server. Device 20 may include, but is not limited to, a processor 21 and a memory 22. Those skilled in the art will appreciate that the schematic diagram is merely an example of device 20 and does not limit device 20. Device 20 may include more or fewer components than shown, or a combination of certain components, or different components. For example, device 20 may also include input / output devices, network access devices, buses, and the like.

[0130] The processor 21 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor 21 is the control center of the device 20 and connects various parts of the entire device 20 using various interfaces and lines.

[0131] The memory 22 can be used to store the computer programs and / or modules. The processor 21 implements the various functions of the device 20 by running or executing the computer programs and / or modules stored in the memory 22 and accessing the data stored in the memory 22. The memory 22 may mainly include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as a sound playback function, an image playback function, etc.); the data storage area may store data generated based on the use of the mobile phone (such as audio data, a phone book, etc.). In addition, the memory 22 may include high-speed random access memory and non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0132] Wherein, if the module / unit integrated in the device 20 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor 21, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0133] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement the present invention without inventive effort.

[0134] The real-time simulation method, device, medium and equipment of the energy storage system provided by the embodiment of the present invention starts the electromagnetic transient simulation calculation of the energy storage system by constructing a simulation model of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascade H-bridge module equivalent circuit; obtains the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve; updates the power electronic switch state of each cascade H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit; obtains the bridge arm current of each bridge arm equivalent circuit at the current moment according to the bridge arm voltage of each bridge arm equivalent circuit; obtains the capacitor voltage of each cascade H-bridge module equivalent circuit at the current moment according to the equivalent capacitance; when the simulation time at the current moment reaches the preset time threshold, outputs the simulation result and ends the simulation. As can be seen, the embodiment of the present invention can more accurately simulate the dynamic characteristics of the energy storage system based on the cascade H-bridge converter and the energy storage battery under various working conditions, thereby completing the semi-physical simulation test of the energy storage system and ensuring the reliability of the system operation.

[0135] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A real-time simulation method for an energy storage system, characterized in that: include: Constructing a simulation model of the energy storage system according to the topological structure of the energy storage system to start electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit; Obtaining the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve; Updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit; Obtaining the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits; According to the equivalent capacitance, obtaining the capacitance voltage of each of the cascaded H-bridge modules equivalent circuit at the current moment; Determine whether the simulation duration at the current moment reaches a preset duration threshold; if so, output the simulation result and end the simulation; if not, increase the simulation duration at the current moment by a preset simulation step to continue the electromagnetic transient simulation calculation of the energy storage system; Wherein, each bridge arm equivalent circuit includes a voltage source and an inductor connected in series with the voltage source, and each cascaded H-bridge module equivalent circuit includes a current source and a capacitor connected in parallel with the current source; The step of obtaining the equivalent capacitance of each energy storage battery according to a preset charge-discharge characteristic curve includes: Calculate the equivalent capacitance of each energy storage battery according to the following formula: Among them, Q N is the rated capacity of the energy storage battery, dSOC is the change in the state of charge of the energy storage battery, and dU is the voltage change; The obtaining, based on the equivalent capacitance, the capacitance voltage of each of the cascaded H-bridge module equivalent circuits at a current moment includes: The equivalent capacitance is used as the capacitance of the cascaded H-bridge module equivalent circuit, and the capacitance voltage of each cascaded H-bridge module equivalent circuit at the current moment is calculated according to the following formula: Among them, U Ck is the capacitor voltage of the kth cascaded H-bridge module equivalent circuit, C k is the capacitance of the kth cascaded H-bridge module equivalent circuit, I k is the capacitive current of the kth cascaded H-bridge module equivalent circuit.

2. The real-time simulation method for an energy storage system according to claim 1, wherein: The updating of the state of the power electronic switch of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit includes: Update the power electronic switch state of each cascaded H-bridge module according to the switch control signal input by the simulation; Obtaining the output voltage of each of the cascaded H-bridge modules according to the power electronic switch state; The bridge arm voltage of each bridge arm equivalent circuit is obtained according to the output voltage of each cascaded H-bridge module.

3. The real-time simulation method of the energy storage system according to claim 2, characterized in that: The obtaining, according to the output voltage of each of the cascaded H-bridge modules, a bridge arm voltage of each of the bridge arm equivalent circuits, comprises: The bridge arm voltage of each bridge arm equivalent circuit is calculated according to the following formula: Among them, U xk is the output voltage of the kth cascaded H-bridge module of the xth phase, a represents phase a, b represents phase b, and c represents phase c.

4. The real-time simulation method for an energy storage system according to claim 1, wherein: The obtaining, according to the bridge arm voltage of each bridge arm equivalent circuit, the bridge arm current of each bridge arm equivalent circuit at a current moment, includes: The bridge arm current of each bridge arm equivalent circuit at the current moment is calculated according to the following formula: i a +i b +i c =0 Among them, i x is the bridge arm current of the bridge arm equivalent circuit of phase x, a represents phase a, b represents phase b, c represents phase c, L is the phase inductance of the bridge arm equivalent circuit, v o is the neutral point voltage of the bridge arm equivalent circuit, v x is the phase voltage of the bridge arm equivalent circuit, U x is the bridge arm voltage of the bridge arm equivalent circuit, i a 、i b 、i c are the phase currents of the bridge arm equivalent circuit respectively.

5. A real-time simulation device for an energy storage system, characterized in that: include: A simulation model construction module is used to construct a simulation model of the energy storage system according to the topological structure of the energy storage system to start the electromagnetic transient simulation calculation of the energy storage system; wherein the simulation model includes a bridge arm equivalent circuit and a cascaded H-bridge module equivalent circuit; An equivalent capacitance acquisition module is used to obtain the equivalent capacitance of each energy storage battery according to a preset charge and discharge characteristic curve; A bridge arm voltage acquisition module, used for updating the power electronic switch state of each cascaded H-bridge module to obtain the bridge arm voltage of each bridge arm equivalent circuit; A bridge arm current acquisition module, configured to acquire the bridge arm current of each of the bridge arm equivalent circuits at a current moment according to the bridge arm voltage of each of the bridge arm equivalent circuits; A capacitor voltage acquisition module, configured to acquire the capacitor voltage of the equivalent circuit of each of the cascaded H-bridge modules at a current moment based on the equivalent capacitance; A simulation result output module is used to determine whether the simulation duration at the current moment reaches a preset duration threshold. If so, the simulation result is output and the simulation is terminated; if not, the simulation duration at the current moment is increased by a preset simulation step size to continue the electromagnetic transient simulation calculation of the energy storage system; Wherein, each bridge arm equivalent circuit includes a voltage source and an inductor connected in series with the voltage source, and each cascaded H-bridge module equivalent circuit includes a current source and a capacitor connected in parallel with the current source; The step of obtaining the equivalent capacitance of each energy storage battery according to a preset charge-discharge characteristic curve includes: Calculate the equivalent capacitance of each energy storage battery according to the following formula: Among them, Q N is the rated capacity of the energy storage battery, dSOC is the change in the state of charge of the energy storage battery, and dU is the voltage change; The obtaining, based on the equivalent capacitance, the capacitance voltage of each of the cascaded H-bridge module equivalent circuits at a current moment includes: The equivalent capacitance is used as the capacitance of the cascaded H-bridge module equivalent circuit, and the capacitance voltage of each cascaded H-bridge module equivalent circuit at the current moment is calculated according to the following formula: Among them, U Ck is the capacitor voltage of the kth cascaded H-bridge module equivalent circuit, C k is the capacitance of the kth cascaded H-bridge module equivalent circuit, I k is the capacitive current of the kth cascaded H-bridge module equivalent circuit.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored computer program; wherein, when the computer program is run, it controls the device where the computer-readable storage medium is located to execute the real-time simulation method of the energy storage system according to any one of claims 1 to 4.

7. A device, characterized in that The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the real-time simulation method of the energy storage system according to any one of claims 1 to 4 when executing the computer program.

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