Fault ride-through control method and system for electrochemical energy storage electromechanical transient model

Abstract

The invention discloses a fault ride-through control method and system for an electrochemical energy storage electromechanical transient model, and belongs to the technical field of power systems and automation thereof. The method comprises the following steps: setting the characteristics of a fault ride-through recovery process in a fault ride-through recovery process stage under different charging and discharging states and different fault ride-through control strategy scenes; after the fault ride-through recovery process characteristics are set, in the fault ride-through ending stage, the ending moment of the fault ride-through ending stage is determined based on the recorded current active power instruction value and the current reactive power instruction value of the electrochemical energy storage system and the set power requirement; and based on the ending moment, determining a power instruction after the fault ride-through is ended, and controlling the electrochemical energy storage system after the fault according to the power instruction. According to the method, the simulation calculation requirements of the chemical energy storage system under different charging and discharging states and different fault ride-through control strategy scenes can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems and automation thereof, and more specifically, to a fault ride-through control method and system for an electrochemical energy storage electromechanical transient model. Background Art

[0002] As a flexible adjustment resource for the power system, the energy storage system plays a significant role in participating in the consumption of new energy, the operation of the power system, and safe and stable control. Electrochemical energy storage has comprehensive advantages in power density, response time, and operating life. It has become an important part of the new power system and is increasingly involved in system planning and operation. For large power grids, electrochemical energy storage has great advantages in terms of technical maturity and economy, and has reached engineering applications, such as peak shaving, flow control, smoothing new energy fluctuations, system voltage regulation function, system frequency regulation function, power control and other application scenarios.

[0003] In the research work on the participation of energy storage power stations in large power grids, it is first necessary to build an electromechanical transient simulation model of the electrochemical energy storage system. At present, models suitable for large power grid simulation have been proposed both at home and abroad and developed and implemented in large power grid simulation software. For example, based on the general control model of the new energy model proposed by the Western Electricity Coordinating Council (WECC) of the United States, the generator control model REGC_A, the electrical control model REEC_C and the plant-level control model REPC_A, the electromechanical transient simulation model of the energy storage power station was built; my country's PSD and PSASP simulation software have also preliminarily built an electromechanical transient simulation model of the energy storage power station and used it for simulation calculation and analysis of actual large power grids. However, these models mainly follow the control strategies of wind power and photovoltaic power, and are not perfect in terms of power control during fault voltage ride-through, and there are still the following deficiencies.

[0004] Fault ride-through characteristics are the key to the stable grid connection of energy storage systems to realize the grid support function. Similar to photovoltaic and wind power generation systems, large-scale electrochemical energy storage systems need to have a certain ability to tolerate abnormal voltages and frequencies. When the tolerance range is exceeded, the protection system will be activated to cut off the energy storage system. Currently, national and industry standards have standardized the technical requirements for low voltage ride-through or high voltage ride-through of energy storage systems, and clarified the thresholds for energy storage power stations to enter and exit high and low voltage ride-through. However, during the fault ride-through period, (1) the power support regulation strategy of the energy storage system lacks unified standards, resulting in different power control strategies for the electrochemical energy storage power stations actually put into operation during the voltage ride-through period; (2) when designing the fault ride-through control strategy, the manufacturer's equipment mainly refers to the fault ride-through control strategy of conventional wind power and photovoltaic (output power) for the discharge state (output power) of the energy storage power station, but it is difficult to directly apply it to the fault ride-through control strategy of the energy storage system in the charging state (absorption power); (3) in the power recovery stage, the manufacturer's parameters generally give the absolute value of the recovery rate, but depending on the fault ride-through control strategy, the recovery process may have a positive slope or a negative slope. In combination with the different charging and discharging states, it leads to complex logic and lack of a universal line of sight method. Summary of the invention

[0005] In view of the above problems, the present invention proposes a fault ride-through control method for an electromechanical transient model of an electrochemical energy storage device, comprising:

[0006] Under different charge and discharge states and different fault ride-through control strategy scenarios, at the beginning of the fault ride-through phase, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded, during the fault ride-through phase, the power demand is set, and during the fault ride-through recovery phase, the fault ride-through recovery process characteristics are set;

[0007] After the fault ride-through recovery process characteristics are set, at the end of the fault ride-through phase, the end time of the fault ride-through phase is determined based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system;

[0008] Based on the end time, a power instruction after the fault ride-through is completed is determined, and the electrochemical energy storage system after the fault is controlled by the power instruction.

[0009] Optionally, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded, which are respectively denoted as P 0 and Q 0 ;

[0010] Among them, P 0 <0, P in discharge state 0 >0; emit reactive power Q 0>0, absorb reactive power Q 0 <0.

[0011] Optionally, during the fault ride-through phase, power requirements are set, including:

[0012] The active power command P is set during the fault ride-through period. 1 When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to the discharge condition and outputs active power, then P 1 > 0, if the electrochemical energy storage system is adjusted to the charging condition to absorb active power, then P 1 <0;

[0013] The reactive power command Q is set during the fault ride-through period. 1 During the fault ride-through period, when the electrochemical energy storage system lacks reactive power support, if the electrochemical energy storage system is adjusted to output reactive power, then Q 1 > 0, if the electrochemical energy storage system is adjusted to absorb reactive power, then Q 1 <0.

[0014] Optionally, during the fault ride-through recovery process phase, set the fault ride-through recovery process characteristics, including:

[0015] When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time;

[0016] Specify reactive power command value according to support requirements.

[0017] Optionally, when the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

[0018] Optionally, based on the end time, a calculation formula for determining a power command after the fault ride-through ends is as follows:

[0019] P 3 (t) = P 0 ,t>t 2

[0020] Q 3 (t) = Q 0 ,t>t 2

[0021] Among them, P 3 (t) and Q 3(t) are the active power command value and reactive power command value reset respectively, P 0 ,t and Q 0 , t are the initial active power command value and reactive power command value respectively, t 2 For the ending moment.

[0022] On the other hand, the present invention also proposes a fault ride-through control system for an electrochemical energy storage electromechanical transient model, comprising:

[0023] An initial unit is used to record the current active power command value and the current reactive power command value of the electrochemical energy storage system at the start time of the fault ride-through phase under different charge and discharge states and different fault ride-through control strategy scenarios, and to set the power demand during the fault ride-through phase, and to set the fault ride-through recovery process characteristics during the fault ride-through recovery phase;

[0024] A setting unit, for determining the end time of the fault ride-through end stage after setting the fault ride-through recovery process characteristics, based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system at the end stage of the fault ride-through;

[0025] The control unit is used to determine the power instruction after the fault ride-through is completed based on the end time, and control the electrochemical energy storage system after the fault with the power instruction.

[0026] Optionally, the current active power command value and the current reactive power command value of the electrochemical energy storage system recorded by the initial unit are respectively denoted as P 0 and Q 0 ;

[0027] Among them, P 0 <0, P in discharge state 0 >0; emit reactive power Q 0 >0, absorb reactive power Q 0 <0.

[0028] Optionally, during the fault ride-through phase, power requirements are set, including:

[0029] The active power command P is set during the fault ride-through period. 1 When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to the discharge condition and outputs active power, then P 1 > 0, if the electrochemical energy storage system is adjusted to the charging condition to absorb active power, then P 1 <0;

[0030] The reactive power command Q is set during the fault ride-through period. 1 During the fault ride-through period, when the electrochemical energy storage system lacks reactive power support, if the electrochemical energy storage system is adjusted to output reactive power, then Q 1 > 0, if the electrochemical energy storage system is adjusted to absorb reactive power, then Q 1 <0.

[0031] Optionally, during the fault ride-through recovery process phase, set the fault ride-through recovery process characteristics, including:

[0032] When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time;

[0033] Specify reactive power command value according to support requirements.

[0034] Optionally, when the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

[0035] Optionally, based on the end time, a calculation formula for determining a power command after the fault ride-through ends is as follows:

[0036] P 3 (t) = P 0 ,t>t 2

[0037] Q 3 (t) = Q 0 ,t>t 2

[0038] Among them, P 3 (t) and Q 3 (t) are the active power command value and reactive power command value reset respectively, P 0 ,t and Q 0 , t are the initial active power command value and reactive power command value respectively, t 2 For the ending moment.

[0039] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0040] a processor for executing one or more programs;

[0041] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0042] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides a fault ride-through control method for an electrochemical energy storage electromechanical transient model, including: under different charge and discharge states and different fault ride-through control strategy scenarios, at the beginning of the fault ride-through phase, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded, and during the fault ride-through phase, the power demand is set, and during the fault ride-through recovery process phase, the fault ride-through recovery process characteristics are set; after setting the fault ride-through recovery process characteristics, at the end of the fault ride-through phase, based on the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system, the end time of the fault ride-through end phase is determined; based on the end time, the power command after the end of the fault ride-through is determined, and the electrochemical energy storage system after the fault is controlled with the power command. The present invention can support the simulation calculation requirements of the electrochemical energy storage system under different charge and discharge states and different fault ride-through control strategy scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flow chart of the method of the present invention;

[0046] Figure 2 A diagram for dividing the energy storage power station fault through different stages according to an embodiment of the method of the present invention;

[0047] Figure 3 3a and 3b are diagrams showing the active power change process and reactive power change process of the typical fault ride-through simulation results of the method embodiment of the present invention, which are immediately restored;

[0048] Figure 4 a and 4b are typical fault ride-through simulation results of the method embodiment of the present invention, diagrams of enhanced active support during the fault in the discharge state and absorption surplus power during the fault;

[0049] Figure 5 a and 5b are typical fault ride-through simulation results of the method embodiment of the present invention, showing enhanced active power support during a fault in a charging state and surplus power absorption during a fault;

[0050] Figure 6 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0051] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0052] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0053] Embodiment 1:

[0054] The present invention proposes a fault ride-through control method for an electromechanical transient model of electrochemical energy storage, such as Figure 1 As shown, including:

[0055] Step 1: Under different charge and discharge states and different fault ride-through control strategy scenarios, at the beginning of the fault ride-through phase, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded; during the fault ride-through phase, the power demand is set; during the fault ride-through recovery phase, the fault ride-through recovery process characteristics are set;

[0056] Step 2: After setting the fault ride-through recovery process characteristics, at the end of the fault ride-through phase, based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system, determine the end time of the fault ride-through phase;

[0057] Step 3: Based on the end time, determine the power instruction after the fault ride-through is completed, and control the electrochemical energy storage system after the fault with the power instruction.

[0058] Among them, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded, which are respectively denoted as P 0 and Q 0 ;

[0059] Among them, P 0 <0, P in discharge state 0 >0; emit reactive power Q 0 >0, absorb reactive power Q 0 <0.

[0060] During the fault ride-through phase, the power demand is set, including:

[0061] The active power command P is set during the fault ride-through period. 1 When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to the discharge condition and outputs active power, then P 1 > 0, if the electrochemical energy storage system is adjusted to the charging condition to absorb active power, then P 1 <0;

[0062] The reactive power command Q is set during the fault ride-through period. 1 During the fault ride-through period, when the electrochemical energy storage system lacks reactive power support, if the electrochemical energy storage system is adjusted to output reactive power, then Q 1 > 0, if the electrochemical energy storage system is adjusted to absorb reactive power, then Q 1 <0.

[0063] In the fault ride-through recovery process stage, the fault ride-through recovery process characteristics are set, including:

[0064] When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time;

[0065] Specify reactive power command value according to support requirements.

[0066] When the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

[0067] Wherein, based on the end time, the calculation formula for determining the power command after the fault ride-through ends is as follows:

[0068] P 3 (t) = P 0 ,t>t 2

[0069] Q 3 (t) = Q 0 ,t>t 2

[0070] Among them, P 3 (t) and Q 3 (t) are the active power command value and reactive power command value reset respectively, P 0 ,t and Q 0 , t are the initial active power command value and reactive power command value respectively, t2 For the ending moment.

[0071] The present invention is further described below in conjunction with specific cases:

[0072] Step 1: First, divide the fault-crossing process into four stages, such as Figure 2 As shown in the figure, specifically, it includes the fault ride-through start time, fault ride-through period, fault ride-through recovery process, and fault ride-through end time. The fault ride-through start time is t 0 The end time of the fault ride-through period and the start time of the fault ride-through recovery are t 1 , the fault ride-through end time is t 2 , and then calculate the power command value of the energy storage system for different stages.

[0073] Step 2: At the start time t of fault ride-through 0 At this moment, record the current active power and reactive power command values ​​of the energy storage system, which are recorded as P 0 and Q 0 , active power and reactive power can be positive or negative depending on the application scenario. For active power, P 0 <0, P in discharge state 0 >0; emit reactive power Q 0 >0, absorb reactive power Q 0 <0.

[0074] Step 3: Specify the fault ride-through period (corresponding to t 0 Time to t 1 The active power P at the time 1 and reactive power command value Q 1 , both of which are input parameters of the strategy and can be set arbitrarily according to the power demand of the actual grid scenario (without considering the initial charge and discharge state), thereby realizing a flexible power support function, but the maximum power and maximum current restrictions must be met.

[0075] Step 3-1, set the active power command P 1 When the system lacks active power support during a fault, the energy storage system can be adjusted to a discharge condition to output active power, P 1 > 0, supporting the system frequency and preventing the frequency from falling further; otherwise, the energy storage system is adjusted to the charging condition to absorb active power, P 1 <0, reducing the system surplus power and helping to stabilize the power angle of the synchronous machine.

[0076] Step 3-2, set reactive power command Q 1 When the system lacks reactive power support during a fault, the energy storage system can be adjusted to output reactive power, Q 1> 0, it plays a role in supporting the system voltage; otherwise, the energy storage system is adjusted to absorb reactive power, Q 1 <0, which can suppress system overvoltage.

[0077] Step 4: Set up the fault-through recovery process (corresponding to t 1 Time to t 2 The manufacturer’s strategy is generally to set the active power recovery coefficient K p Achieve, and K p It is always positive and represents the rate of power recovery. For the simulation model and program implementation, the implementation method of this process is relatively complicated. It needs to be compatible with different charging and discharging states and different initial operating states, and calculate the command value P of active power and reactive power in real time. 2 (t) and Q 2 (t), t is the current simulation time. The detailed implementation is as follows.

[0078] Step 4.1: Determine the active power recovery method. During the fault period, the active power command of the energy storage system deviates greatly from the initial power due to the deviation of the terminal voltage of the energy storage system from the rated operating voltage and the limitation of the maximum overcurrent capacity of the converter. However, during the fault recovery process, the terminal voltage basically recovers to the rated voltage level. At this time, the energy storage system has the ability to restore the initial operating power. According to the differences in strategies of different manufacturers, it is necessary to clarify the active power recovery method, which is divided into immediate recovery and recovery by slope.

[0079] When set to restore immediately, the current active power command is set to the initial power, that is:

[0080] P 2 (t) = P 0 ,t=t 1

[0081] Q 2 (t) = Q 0 ,t=t 1

[0082] When setting to restore by slope, go to step 4.2.

[0083] Step 4.2: Calculate the active power reference value P in real time during the recovery process 2 (t). At this time, the power operation level of the fault situation needs to be processed according to the situation and calculated as follows:

[0084]

[0085] Step 4.3: Calculate the reactive power reference value Q in real time during the recovery process 2 (t) can be specified according to the support requirements.

[0086] Step 5: At the end of the fault ride-through, determine the end of the fault ride-through and reset the command values ​​P of the active power and reactive power. 3 (t) and P 3 (t).

[0087] Step 5.1: Determine the fault ride-through end time t 2 .

[0088] When setting to restore immediately in step 4:

[0089] t 2 =t 1

[0090] When the setting is set to restore by slope in step 4:

[0091]

[0092] Step 5.2: Set the power command after the fault ride-through is completed.

[0093] P 3 (t) = P 0 ,t>t 2

[0094] Q 3 (t) = Q 0 ,t>t 2

[0095] The simulation of typical control strategies for energy storage power station fault ride-through was carried out for typical scenarios such as different charging and discharging states, different control strategies, and different power operation levels. The simulated energy storage power station consists of 100 converters, each with a rated capacity of 1MVA, and a total capacity of 100MVA. The output power response characteristics of one of the converters were analyzed.

[0096] Attached Figure 3 The response process of active power and reactive power in a typical fault ride-through process with immediate recovery strategy is shown in the attached figure. Figure 3 (a) is the active power response process, Figure 3 (b) is the reactive power response process. It can be seen that at the moment of fault ride-through recovery, the active power instantly recovers to the initial power level.

[0097] Attached Figure 4 Figure 2 shows the simulation results of typical fault ride-through processes at different power operating levels and recovery rates under discharge conditions. Figure 4(a) is the response process of enhancing active support during the fault period. It can be seen that during the fault ride-through period, the active power of the energy storage system increased from 0.1pu before the fault to 0.2pu, which enhanced the active support capability of the energy storage system for the system. Figure 4 (b) is the active power response process of the energy storage system when absorbing surplus power during the fault. Before the fault, the initial active power is 0.5pu. During the fault, the active power is adjusted to -0.38pu, switching from the discharge state to the charging state, which helps to absorb the surplus power of the system.

[0098] Attached Figure 5 The following are the simulation results of typical fault ride-through processes at different power operating levels and different recovery rates under charging conditions. Figure 5 (a) is the response process of enhancing active power support during the fault. It can be seen that during the fault ride-through period, the active power of the energy storage system quickly increased from -0.2pu before the fault to 0.6pu, and quickly switched from the charging state to the discharging state, which greatly enhanced the active power support capability of the energy storage system for the system. The fault recovery process recovered to the initial power operation level with a negative slope. Figure 5 (b) is the active power response process when the energy storage system absorbs surplus power during the fault. Before the fault, the initial active power is -0.2pu. During the fault, the active power is adjusted to -0.55pu, which helps to quickly absorb the surplus power of the system. The fault recovery process recovers to the initial power operating level with a positive slope.

[0099] It can be seen from the simulation results that the constructed universal fault ride-through control strategy and program implementation method can be applied to the simulation of typical energy storage power station application scenarios such as different charging and discharging states, different control strategies and different power operation levels.

[0100] In summary, the method of the present invention has good operability and adaptability, and a simulation model of a universal fault ride-through control strategy suitable for dynamic simulation of large power grids is constructed, which can support the simulation calculation needs of energy storage systems under different charging and discharging states and different fault ride-through control strategy scenarios.

[0101] Embodiment 2:

[0102] The present invention also proposes a fault ride-through control system 200 for an electrochemical energy storage electromechanical transient model, such as Figure 6 As shown, including:

[0103] The initialization unit 201 is used to record the current active power command value and the current reactive power command value of the electrochemical energy storage system at the start time of the fault ride-through phase under different charge and discharge states and different fault ride-through control strategy scenarios, and to set the power demand during the fault ride-through phase, and to set the fault ride-through recovery process characteristics during the fault ride-through recovery phase;

[0104] A setting unit 202 is used to determine the end time of the fault ride-through end stage after setting the fault ride-through recovery process characteristics, based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system at the end stage of the fault ride-through;

[0105] The control unit 203 is used to determine the power instruction after the fault ride-through is completed based on the end time, and control the electrochemical energy storage system after the fault with the power instruction.

[0106] The current active power command value and the current reactive power command value of the electrochemical energy storage system recorded by the initial unit 201 are respectively denoted as P 0 and Q 0 ;

[0107] Among them, P 0 <0, P in discharge state 0 >0; emit reactive power Q 0 >0, absorb reactive power Q 0 <0.

[0108] During the fault ride-through phase, the power demand is set, including:

[0109] The active power command P is set during the fault ride-through period. 1 When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to the discharge condition and outputs active power, then P 1 > 0, if the electrochemical energy storage system is adjusted to the charging condition to absorb active power, then P 1 <0;

[0110] The reactive power command Q is set during the fault ride-through period. 1 During the fault ride-through period, when the electrochemical energy storage system lacks reactive power support, if the electrochemical energy storage system is adjusted to output reactive power, then Q 1 > 0, if the electrochemical energy storage system is adjusted to absorb reactive power, then Q 1 <0.

[0111] In the fault ride-through recovery process stage, the fault ride-through recovery process characteristics are set, including:

[0112] When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time;

[0113] Specify reactive power command value according to support requirements.

[0114] When the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

[0115] Wherein, based on the end time, the calculation formula for determining the power command after the fault ride-through ends is as follows:

[0116] P 3 (t) = P 0 ,t>t 2

[0117] Q 3 (t) = Q 0 ,t>t 2

[0118] Among them, P 3 (t) and Q 3 (t) are the active power command value and reactive power command value reset respectively, P 0 ,t and Q 0 , t are the initial active power command value and reactive power command value respectively, t 2 For the ending moment.

[0119] The present invention can support the simulation calculation requirements of point chemical energy storage systems under different charging and discharging states and different fault ride-through control strategy scenarios.

[0120] Embodiment 3:

[0121] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0122] Embodiment 4:

[0123] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0124] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0125] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0126] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0127] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0128] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0129] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A fault ride-through control method for an electromechanical transient model of electrochemical energy storage, characterized in that: include: Under different charge and discharge states and different fault ride-through control strategy scenarios, at the beginning of the fault ride-through phase, the current active power command value and the current reactive power command value of the electrochemical energy storage system are recorded, during the fault ride-through phase, the power demand is set, and during the fault ride-through recovery phase, the fault ride-through recovery process characteristics are set; After the fault ride-through recovery process characteristics are set, at the end of the fault ride-through phase, the end time of the fault ride-through phase is determined based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system; Based on the end time, a power instruction after the fault ride-through is completed is determined, and the electrochemical energy storage system after the fault is controlled by the power instruction.

2. The method according to claim 1, characterized in that Record the current active power command value and the current reactive power command value of the electrochemical energy storage system, which are recorded as P0 and Q0 respectively; Among them, P0 is less than 0 in the charging state, and P0 is greater than 0 in the discharging state; the reactive power emitted is Q0 is greater than 0, and the reactive power absorbed is Q0 is less than 0.

3. The method according to claim 1, characterized in that During the fault ride-through phase, the power demand is set, including: The active power instruction P1 is set during the fault ride-through period. When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to a discharge condition and outputs active power, P1>0 at this time. If the electrochemical energy storage system is adjusted to a charging condition and absorbs active power, P1<0 at this time. A reactive power instruction Q1 is set during the fault ride-through period. When the electrochemical energy storage system lacks reactive power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to output reactive power, Q1>0; if the electrochemical energy storage system is adjusted to absorb reactive power, Q1<0.

4. The method according to claim 1, characterized in that In the fault ride-through recovery process stage, the fault ride-through recovery process characteristics are set, including: When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time; Specify reactive power command value according to support requirements.

5. The method according to claim 4, characterized in that When the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

6. The method according to claim 1, characterized in that The calculation formula for determining the power command after the fault ride-through is completed based on the end time is as follows: P3(t)=P0,t>t2 Q3(t)=Q0,t>t2 Among them, P3(t) and Q3(t) are the reset active power command value and reactive power command value respectively, P0,t and Q0,t are the initial active power command value and reactive power command value respectively, and t2 is the end time.

7. A fault ride-through control system for an electrochemical energy storage electromechanical transient model, characterized in that: include: An initial unit is used to record the current active power command value and the current reactive power command value of the electrochemical energy storage system at the start time of the fault ride-through phase under different charge and discharge states and different fault ride-through control strategy scenarios, and to set the power demand during the fault ride-through phase, and to set the fault ride-through recovery process characteristics during the fault ride-through recovery phase; A setting unit, for determining the end time of the fault ride-through end stage after setting the fault ride-through recovery process characteristics, based on recording the current active power command value, the current reactive power command value and the set power demand of the electrochemical energy storage system at the end stage of the fault ride-through; The control unit is used to determine the power instruction after the fault ride-through is completed based on the end time, and control the electrochemical energy storage system after the fault with the power instruction.

8. The system according to claim 7, characterized in that The current active power command value and the current reactive power command value of the electrochemical energy storage system recorded by the initial unit are recorded as P0 and Q0 respectively; Among them, P0 is less than 0 in the charging state, and P0 is greater than 0 in the discharging state; the reactive power emitted is Q0 is greater than 0, and the reactive power absorbed is Q0 is less than 0.

9. The system according to claim 7, characterized in that During the fault ride-through phase, the power demand is set, including: The active power instruction P1 is set during the fault ride-through period. When the electrochemical energy storage system lacks active power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to a discharge condition and outputs active power, P1>0 at this time. If the electrochemical energy storage system is adjusted to a charging condition and absorbs active power, P1<0 at this time. A reactive power instruction Q1 is set during the fault ride-through period. When the electrochemical energy storage system lacks reactive power support during the fault ride-through period, if the electrochemical energy storage system is adjusted to output reactive power, Q1>0; if the electrochemical energy storage system is adjusted to absorb reactive power, Q1<0.

10. The system according to claim 7, characterized in that In the fault ride-through recovery process stage, the fault ride-through recovery process characteristics are set, including: When the active power recovery mode is set to immediate recovery, the active power instruction of the fault-through recovery process is set to the initial power; when the active power recovery mode is set to recovery according to the slope, the active power instruction value of the fault-through recovery process is calculated in real time; Specify reactive power command value according to support requirements.

11. The system according to claim 10, characterized in that When the active power recovery mode is set to immediate recovery, the start time of the fault ride-through recovery process phase is the same as the end time of the fault ride-through end phase.

12. The system according to claim 7, characterized in that The calculation formula for determining the power command after the fault ride-through is completed based on the end time is as follows: P3(t)=P0,t>t2 Q3(t)=Q0,t>t2 Among them, P3(t) and Q3(t) are the reset active power command value and reactive power command value respectively, P0,t and Q0,t are the initial active power command value and reactive power command value respectively, and t2 is the end time.

13. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 6 is implemented.

14. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 6 is implemented.

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