Transient stability support method and apparatus based on grid-forming energy storage, terminal device, and computer-readable storage medium

Abstract

Disclosed are a transient stability support method and apparatus based on grid-forming energy storage, a terminal device, and a computer-readable storage medium. The method comprises: acquiring a reference active power, a reference reactive power, an actual active power, and an actual reactive power of a grid-forming converter; comparing a difference value between the reference active power and the actual active power with a preset saturation clipping threshold, when the difference value is less than or equal to the preset saturation clipping threshold, using the difference value as a saturation clipping output value, and when the difference value is greater than the preset saturation clipping threshold, using the preset saturation clipping threshold as a saturation clipping output value; calculating a control phase angle and a control reference voltage on the basis of the saturation clipping output value, a difference value between the reference reactive power and the actual reference reactive power, and preset droop control parameters; and generating a PWM signal, and controlling a voltage switch. By implementing the present invention, the deviation of an output power of a converter when a large disturbance occurs in the converter is limited, so as to ensure the synchronization stability of the system.

Description

A network-constructed energy storage transient stability support method and device, terminal equipment and computer readable storage medium TECHNICAL FIELD

[0001] The present application relates to the field of new energy power systems, and in particular to a network-constructed energy storage transient stability support method. BACKGROUND

[0002] There are a large number of short-time faults in the power grid, and the transient impact during the fault brings not small challenges to the new energy sending system relying on power electronic devices. When a short-circuit fault occurs in the onshore alternating current grid of the traditional offshore wind power direct current sending system, the alternating current bus voltage will drop, and the active output capability of the onshore receiving end converter station will be limited. At this time, the active power generated by the offshore wind farm will still be continuously transmitted to the receiving end converter station, and the surplus power generated between the sending end grid and the receiving end grid will continuously charge the sub-module capacitor of the converter, thereby causing the direct current bus voltage to rapidly rise, triggering the direct current protection, and in severe cases, causing large-scale wind turbine off-grid. The traditional offshore wind power direct current sending system generally uses a direct current energy dissipation device to dissipate the surplus power between the sending end grid and the receiving end grid caused by the fault, and cannot provide support for the transient voltage stability of the receiving end grid.

[0003] The rapid development of network-constructed energy storage technology brings a new solution, which can use energy storage to support the grid reactive power when the three-phase symmetrical voltage of the alternating current grid drops, and assist the offshore wind power direct current sending system to realize low voltage ride through. However, the off-grid operation of the network-constructed energy storage converter under alternating current voltage drop becomes a new challenge. The analysis of the existing network-constructed control scheme mainly focuses on small signal stability analysis near the steady state operating point, and the stability under large disturbance such as voltage drop is insufficient.

[0004] When the converter is subjected to a large disturbance, if the overshoot of the power angle after the disturbance is too large, the converter may lose synchronization with the power system, so it is of great significance to consider the transient stability of the converter. The existing transient stability enhancement strategies of the network-constructed converter, such as alternating inertia control, mode adaptive power angle control and additional active power error control loop, all have deficiencies, which may cause problems such as reduced system steady-state performance and over-modulation. Therefore, it is of great significance to study the transient stability enhancement strategy of the network-constructed converter. SUMMARY

[0005] The embodiment of the present application provides a network-constructed energy storage transient stability support method, device, terminal equipment and computer readable storage medium, which can limit the deviation of the output power of the converter when the converter is subjected to a large disturbance, control the power angle of the system, and ensure the synchronization stability of the system.

[0006] An embodiment of the present application provides a network-constructed energy storage transient stability support method, comprising:

[0007] acquire reference active power, reference reactive power of the grid-forming converter, actual active power of the grid-forming converter after being disturbed, and actual reactive power of the grid-forming converter after being disturbed;

[0008] calculate the difference between the reference active power and the actual active power to obtain a first power difference value, and calculate the difference between the reference reactive power and the actual reference reactive power to obtain a second power difference value;

[0009] compare the first power difference value with a preset saturation limiting threshold value, when the first power difference value is less than or equal to the preset saturation limiting threshold value, take the first power difference value as a saturation limiting output value, and when the first power difference value is greater than the preset saturation limiting threshold value, take the preset saturation limiting threshold value as the saturation limiting output value;

[0010] according to the saturation limiting output value, the second power difference value and a preset droop control parameter, calculate a control phase angle and a control reference voltage;

[0011] generate a PWM modulation signal according to the control phase angle and the control reference voltage, and control the voltage switch according to the PWM modulation signal.

[0012] Further, the grid-forming energy storage transient stability support method comprises: acquiring the actual active power of the grid-forming converter after being disturbed by the following method:

[0013] acquire the converter point of common coupling voltage, the grid voltage, the phase angle after being disturbed, and the inductance reactance of the grid connection line;

[0014] according to the converter point of common coupling voltage, the grid voltage, the reference value of the voltage and current inner loop after being disturbed, and the inductance reactance of the grid connection line, calculate the actual active power of the grid-forming converter after being disturbed by the following formula:

[0015] wherein, P e represents the actual power of the converter, V represents the converter point of common coupling voltage, V g represents the grid voltage, θ r represents the phase angle after being disturbed, and X g represents the inductance reactance of the grid connection line.

[0016] Further, the preset droop control parameter comprises: a preset active power droop control parameter and a preset reactive power droop control parameter;

[0017] according to the saturation limiting output value, the second power difference value and the preset droop control parameter, calculate a control phase angle and a control reference voltage, comprising:

[0018] The saturated amplitude limiting output value is multiplied by a preset droop control parameter of active power to obtain an angular velocity output by a droop control link;

[0019] The angular velocity output by the droop control link is integrated to obtain a control phase angle;

[0020] The second power difference value is multiplied by a preset droop control parameter of reactive power and then added to a converter output voltage reference value to obtain a control reference voltage.

[0021] Further, a PWM modulation signal is generated according to the control phase angle and the control reference voltage, and the voltage switch is controlled according to the PWM modulation signal, including:

[0022] The converter common connection point voltage and the converter side current are obtained, and a control signal is obtained according to the converter common connection point voltage, the converter side current, the control phase angle and the control reference voltage;

[0023] The control signal is used to generate a PWM modulation signal by a PWM modulator;

[0024] The voltage switch is controlled by the PWM modulation signal.

[0025] On the basis of the above method embodiment, the application provides a device embodiment, including a data acquisition module, a power difference calculation module, a saturation amplitude limiting module, a control parameter calculation module and a PWM control module;

[0026] The data acquisition module is used to obtain a reference active power, a reference reactive power, an actual active power after the grid-connected converter is disturbed and an actual reactive power after the grid-connected converter is disturbed.

[0027] The power difference calculation module is used to calculate a difference between the reference active power and the actual active power to obtain a first power difference value, and calculate a difference between the reference reactive power and the actual reference reactive power to obtain a second power difference value.

[0028] The saturation amplitude limiting module is used to compare the first power difference value with a preset saturation amplitude limiting threshold value, when the first power difference value is less than or equal to the preset saturation amplitude limiting threshold value, the first power difference value is taken as a saturation amplitude limiting output value, and when the first power difference value is greater than the preset saturation amplitude limiting threshold value, the preset saturation amplitude limiting threshold value is taken as the saturation amplitude limiting output value.

[0029] The control parameter calculation module is used to calculate a control phase angle and a control reference voltage according to the saturation amplitude limiting output value, the second power difference value and a preset droop control parameter.

[0030] The PWM control module is used to generate a PWM modulation signal according to the control phase angle and the control reference voltage, and control the voltage switch according to the PWM modulation signal.

[0031] Further, the grid-constructed energy storage transient stability support device further comprises an actual active power calculation module;

[0032] The actual active power calculation module is configured to obtain the actual active power of the grid-constructed converter after the disturbance by the following manner:

[0033] Obtaining the common connection point voltage of the converter, the grid voltage, the phase angle after the disturbance, and the inductive reactance of the grid connection line inductance;

[0034] According to the common connection point voltage of the converter, the grid voltage, the reference value of the voltage and current inner loop after the disturbance, and the inductive reactance of the grid connection line inductance, the actual active power of the grid-constructed converter after the disturbance is calculated by the following formula:

[0035] Wherein, P e represents the actual power of the converter, V represents the common connection point voltage of the converter, V g represents the grid voltage, θ r represents the phase angle after the disturbance, and X g represents the inductive reactance of the grid connection line inductance.

[0036] Further, the preset droop control parameters include preset active power droop control parameters and preset reactive power droop control parameters;

[0037] The control parameter calculation module comprises an angular velocity calculation unit, a control phase angle calculation unit, and a control reference voltage calculation unit;

[0038] The angular velocity calculation unit is configured to multiply the saturation amplitude limiting output value and the preset active power droop control parameter to obtain the angular velocity output by the droop control link;

[0039] The control phase angle calculation unit is configured to integrate the angular velocity output by the droop control link to obtain the control phase angle;

[0040] The control reference voltage calculation unit is configured to multiply the second power difference value and the preset reactive power droop control parameter, and then add the converter output voltage reference value to obtain the control reference voltage.

[0041] Further, the PWM control module comprises a control signal generation unit, a PWM modulation signal generation unit, and a voltage switch control unit;

[0042] The control signal generation unit is configured to obtain the common connection point voltage of the converter and the converter side current, and obtain the control signal according to the common connection point voltage of the converter, the converter side current, the control phase angle, and the control reference voltage;

[0043] The PWM modulation signal generation unit is configured to generate a PWM modulation signal through a PWM modulator according to the control signal.

[0044] The voltage switch control unit is configured to control the voltage switch through the PWM modulation signal.

[0045] On the basis of the above-mentioned method embodiment, the application correspondingly provides a terminal device embodiment, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the computer program is executed by the processor, the steps of the network-configuration-type energy storage transient stability support method are implemented.

[0046] On the basis of the above-mentioned method embodiment, the application correspondingly provides a computer-readable storage medium embodiment, which comprises a stored computer program, and when the computer program is run, the device where the computer-readable storage medium is located executes the steps of the network-configuration-type energy storage transient stability support method.

[0047] Compared with the prior art, the beneficial effects of the present application embodiment are as follows:

[0048] The present application obtains the reference active power, the reference reactive power of the network-configuration-type converter, the actual active power after the network-configuration-type converter is disturbed, and the actual reactive power after the network-configuration-type converter is disturbed. Then, the difference between the reference active power and the actual active power is calculated to obtain a first power difference. The difference between the reference reactive power and the actual reference reactive power is calculated to obtain a second power difference, which is used to evaluate the output deviation of the converter. The first power difference is compared with a preset saturation limiting threshold to determine whether the converter works in a safe and stable range. When the first power difference is less than or equal to the preset saturation limiting threshold, the first power difference is taken as a saturation limiting output value. When the first power difference is greater than the preset saturation limiting threshold, the preset saturation limiting threshold is taken as the saturation limiting output value. By calculating the difference and comparing, the output power of the converter is limited to ensure that the active power output is within a reasonable range, and to prevent the power from falling too much when the converter is subjected to a large disturbance. According to the saturation limiting output value, the second power difference, and the preset droop control parameter, the control phase angle and the control reference voltage are calculated. According to the control phase angle and the control reference voltage, a PWM modulation signal is generated, and the voltage switch is controlled according to the PWM modulation signal to control and regulate the power electronic switching device, so as to regulate the output voltage and current of the converter.

[0049] In summary, the application compares the difference between the actual active power and the reference active power with the preset saturation limiting threshold, outputs the power adjustment value that does not exceed the preset saturation limiting threshold, limits the deviation of the output power of the converter when a large disturbance occurs, controls the power angle of the system, and ensures the synchronization stability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0050] Fig. 1 is a flowchart of a network-forming energy storage transient stability support method according to an embodiment of the application;

[0051] Fig. 2 is a basic control block diagram of a network-forming converter according to an embodiment of the application;

[0052] Fig. 3 is a structural diagram of a network-forming energy storage transient stability support device according to an embodiment of the application. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the application.

[0054] In the description of the application, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0055] As shown in Fig. 1, an embodiment of the application provides a network-forming energy storage transient stability support method, which at least includes the following steps:

[0056] Step S1: obtaining the reference active power, the reference reactive power of the network-forming converter, the actual active power of the network-forming converter after being disturbed, and the actual reactive power of the network-forming converter after being disturbed;

[0057] In a preferred embodiment, the network-forming energy storage transient stability support method includes: obtaining the actual active power of the network-forming converter after being disturbed by the following method:

[0058] obtaining the converter point of common coupling voltage, the grid voltage, the phase angle after being disturbed, and the inductance of the grid connection line;

[0059] According to the converter point of common coupling voltage, the grid voltage, the reference value of the voltage and current inner loop after being disturbed, and the inductance of the grid connection line, the actual active power of the network-forming converter after being disturbed is calculated by the following formula:

[0060] where P e represents the actual power of the converter, V represents the voltage of the converter common connection point, V g represents the grid voltage, θ r represents the phase angle after the disturbance, X g represents the inductive reactance of the grid connection line.

[0061] In an embodiment of the present application, FIG. 2 shows a basic control block diagram of the grid-forming converter. First, the reference active power P ref , the reference reactive power Q ref , the actual active power P e of the grid-forming converter after the disturbance, and the actual reactive power Q d of the grid-forming converter after the disturbance are obtained. e The actual active power P g of the grid-forming converter after the disturbance is calculated by the following process: in the power calculation of FIG. 2, the voltage V of the converter common connection point, the grid voltage V r , the phase angle θ g after the disturbance, and the inductive reactance X ref of the grid connection line are obtained; then the actual active power of the grid-forming converter after the disturbance is calculated according to the calculation formula

[0062] Step S2: calculate the difference between the reference active power and the actual active power to obtain a first power difference; calculate the difference between the reference reactive power and the actual reference reactive power to obtain a second power difference.

[0063] In an embodiment of the present application, the reference active power P ref of the grid-forming converter and the actual active power P e of the grid-forming converter after the disturbance are subtracted to obtain the first power difference ΔP, i.e. ΔP=P ref -P e ; at the same time, the reference reactive power Q ref and the actual reactive power Q d of the grid-forming converter after the disturbance are subtracted to obtain the second power difference ΔQ, i.e. ΔQ=Q ref -Q d ;

[0064] Step S3: compare the first power difference with a preset saturation limiting threshold value; when the first power difference is less than or equal to the preset saturation limiting threshold value, the first power difference is taken as the saturation limiting output value; when the first power difference is greater than the preset saturation limiting threshold value, the preset saturation limiting threshold value is taken as the saturation limiting output value.

[0065] In an embodiment of the present application, different from the conventional network-structured converter, a saturation limiting module is added to the conventional structure to limit the first power difference: first, the first power difference ΔP obtained in step S2 is compared with a preset saturation limiting threshold ΔP max , if ΔP is less than or equal to the preset saturation limiting threshold ΔP max , then ΔP is taken as the saturation limiting output value ΔP', and if ΔP is greater than the preset saturation limiting threshold, then the preset saturation limiting threshold ΔP max is taken as the saturation limiting output value ΔP'. The saturation limiting checks whether the first power difference exceeds the preset saturation limiting threshold, and if it does, the threshold is output as the saturation limiting output value, otherwise the first power difference is output as the saturation limiting output value, thereby ensuring that the first power difference is within a certain range to avoid excessive power fluctuation affecting the stability of the system.

[0066] Step S4: according to the saturation limiting output value, the second power difference and the preset droop control parameter, the control phase angle and the control reference voltage are calculated;

[0067] In a preferred embodiment, the preset droop control parameter includes a preset active power droop control parameter and a preset reactive power droop control parameter;

[0068] According to the saturation limiting output value, the second power difference and the preset droop control parameter, the control phase angle and the control reference voltage are calculated, including:

[0069] The saturation limiting output value is multiplied by the preset active power droop control parameter to obtain the angular velocity output by the droop control link;

[0070] The angular velocity output by the droop control link is integrated to obtain the control phase angle;

[0071] The second power difference is multiplied by the preset reactive power droop control parameter and then added to the converter output voltage reference value to obtain the control reference voltage.

[0072] In an embodiment of the present application, according to the saturation limiting output value, the second power difference and the preset droop control parameter, the control phase angle and the control reference voltage are calculated to adjust the control signal of the network-structured converter, and the specific steps are as follows: first, the saturation limiting output value ΔP' is multiplied by the preset active power droop control parameter m to obtain the angular velocity ω d output by the droop control link, i.e. ω d = mΔP'; secondly, the angular velocity ω d output by the droop control link is integrated by 1 / s in FIG. 2 to obtain the control phase angle θ f, that is, θ f =∫ω d Finally, multiply the second power difference ΔQ by the preset reactive power droop control parameter n, and then multiply it by the converter output voltage reference value V. n Add them together to obtain the control reference voltage V. dqref V dqref =V n +nΔQ.

[0073] Step S5: Generate a PWM modulation signal based on the control phase angle and control reference voltage, and control the voltage switch based on the PWM modulation signal.

[0074] In a preferred embodiment, a PWM modulation signal is generated based on a control phase angle and a control reference voltage, and a voltage switch is controlled based on the PWM modulation signal, including:

[0075] Obtain the converter common coupling point voltage and converter side current, and obtain the control signal based on the converter common coupling point voltage, converter side current, control phase angle and control reference voltage;

[0076] A PWM modulated signal is generated by a PWM modulator based on the control signal;

[0077] The voltage switch is controlled by a PWM modulation signal.

[0078] In one embodiment of the present invention, a control signal is generated based on the control phase angle and control reference voltage obtained in step S4. The control signal generates a PWM modulation signal in the PWM modulator, and then the voltage switch is controlled using this PWM modulation signal. The specific steps are as follows: First, the converter common connection point voltage V and the converter side current i are obtained. Based on the current voltage and current conditions of the system, the required control phase angle θ is combined at the voltage loop and current loop. f and control reference voltage V dqref The system generates a control signal to control the PWM modulator. Next, the control signal controls the PWM modulator, which outputs a corresponding PWM modulation signal based on the magnitude and frequency of the control signal, to control the voltage switch V. dc The on / off state; finally, the PWM modulation signal is used to control the voltage V. dc The switching action of the switch regulates the output voltage and current of the converter, thereby controlling the system.

[0079] As shown in Figure 3, based on the above method embodiments, corresponding device embodiments are provided;

[0080] The embodiment of the present application provides a network-constructing type energy storage transient stability support device, comprising a data acquisition module, a power difference calculation module, a saturation limiting module, a control parameter calculation module and a PWM control module.

[0081] The data acquisition module is used for acquiring reference active power and reference reactive power of the network-constructing type converter, actual active power of the network-constructing type converter after being disturbed and actual reactive power of the network-constructing type converter after being disturbed.

[0082] The power difference calculation module is used for calculating a difference value of the reference active power and the actual active power to obtain a first power difference value, and calculating a difference value of the reference reactive power and the actual reference reactive power to obtain a second power difference value.

[0083] The saturation limiting module is used for comparing the first power difference value with a preset saturation limiting threshold value, taking the first power difference value as a saturation limiting output value when the first power difference value is less than or equal to the preset saturation limiting threshold value, and taking the preset saturation limiting threshold value as the saturation limiting output value when the first power difference value is greater than the preset saturation limiting threshold value.

[0084] The control parameter calculation module is used for calculating a control phase angle and a control reference voltage according to the saturation limiting output value, the second power difference value and a preset droop control parameter.

[0085] The PWM control module is used for generating a PWM modulation signal according to the control phase angle and the control reference voltage, and controlling a voltage switch according to the PWM modulation signal.

[0086] In a preferred embodiment, the network-constructing type energy storage transient stability support device further comprises an actual active power calculation module.

[0087] The actual active power calculation module is used for acquiring the actual active power of the network-constructing type converter after being disturbed by the following method.

[0088] The converter point of common coupling voltage, the grid voltage, the phase angle after being disturbed and the inductance of the grid connection line are acquired.

[0089] The actual active power of the network-constructing type converter after being disturbed is calculated according to the converter point of common coupling voltage, the grid voltage, the reference value of the voltage and current inner loop after being disturbed and the inductance of the grid connection line by the following formula.

[0090] Wherein, P e represents the actual power of the converter, V represents the converter point of common coupling voltage, V g represents the grid voltage, θ r represents the phase angle after being disturbed, and X g represents the inductance of the grid connection line.

[0091] In a preferred embodiment, the preset droop control parameters include preset active power droop control parameters and preset reactive power droop control parameters.

[0092] The control parameter calculation module includes an angular velocity calculation unit, a control phase angle calculation unit, and a control reference voltage calculation unit.

[0093] The angular velocity calculation unit is configured to multiply the saturation-limited output value and the preset active power droop control parameters to obtain an angular velocity output by the droop control link.

[0094] The control phase angle calculation unit is configured to integrate the angular velocity output by the droop control link to obtain a control phase angle.

[0095] The control reference voltage calculation unit is configured to multiply the second power difference value and the preset reactive power droop control parameters, and then add the result to a converter output voltage reference value to obtain a control reference voltage.

[0096] In a preferred embodiment, the PWM control module includes a control signal generation unit, a PWM modulation signal generation unit, and a voltage switch control unit.

[0097] The control signal generation unit is configured to obtain a converter common connection point voltage and a converter side current, and obtain a control signal according to the converter common connection point voltage, the converter side current, a control phase angle, and a control reference voltage.

[0098] The PWM modulation signal generation unit is configured to generate a PWM modulation signal through a PWM modulator according to the control signal.

[0099] The voltage switch control unit is configured to control a voltage switch through the PWM modulation signal.

[0100] It can be understood that the above-mentioned device item embodiments correspond to the method item embodiments of the present application, and can realize the network-type energy storage transient stability support method provided by any one of the above-mentioned method item embodiments.

[0101] It should be noted that the device embodiments described above are only schematic, and some or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the device embodiment provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which can be realized as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0102] On the basis of the above-mentioned embodiment of the network-constructed energy storage transient stability support method, another embodiment of the present application provides a terminal device, which comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, and when the computer program is executed by the processor, the network-constructed energy storage transient stability support method of any one of the embodiments of the present application is realized.

[0103] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present application. The one or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the terminal device.

[0104] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server and other computing devices. The terminal device can include, but is not limited to, a processor and a memory.

[0105] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and connects all parts of the terminal device through various interfaces and lines.

[0106] On the basis of the above-mentioned method embodiment, another embodiment is provided: the computer readable storage medium provided by another embodiment of the present application comprises a stored computer program, wherein when the computer program runs, the device where the computer readable storage medium is located executes the network-constructed energy storage transient stability support method of any one of the above-mentioned method embodiments of the present application.

[0107] The module / unit of the network-constructed energy storage transient stability support device / terminal equipment integration, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0108] The above is the preferred embodiment of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which are also considered within the scope of protection of the present application.

Claims

1. A method for network configuration type energy storage transient stability support, characterized in that, The method comprises the following steps: acquiring reference active power and reference reactive power of the grid-forming converter, actual active power of the grid-forming converter after being disturbed, and actual reactive power of the grid-forming converter after being disturbed; calculating a difference between the reference active power and the actual active power to obtain a first power difference; calculating a difference between the reference reactive power and the actual reference reactive power to obtain a second power difference; comparing the first power difference with a preset saturation limiting threshold value, and when the first power difference is less than or equal to the preset saturation limiting threshold value, taking the first power difference as a saturation limiting output value; when the first power difference is greater than the preset saturation limiting threshold value, taking the preset saturation limiting threshold value as the saturation limiting output value; calculating a control phase angle and a control reference voltage according to the saturation limiting output value, the second power difference, and preset droop control parameters; generating a PWM modulation signal according to the control phase angle and the control reference voltage, and controlling voltage switches according to the PWM modulation signal.

2. The network constitution type energy storage transient stability support method according to claim 1, characterized in that, The method comprises the following steps: acquiring actual active power of the grid-forming converter after being disturbed by the following method: acquiring a converter point of common coupling voltage, a grid voltage, a phase angle after being disturbed, and a reactance of a grid connection inductance; According to the converter common connection point voltage, the grid voltage, the reference value of the voltage and current inner loop after the disturbance, and the inductance of the grid connection, the actual active power of the grid-connected converter after the disturbance is calculated by the following formula: where P e represents the actual power of the converter, V represents the voltage at the point of common coupling of the converter, V g represents the grid voltage, θ r represents the phase angle after the disturbance, X g represents the reactance of the grid line inductance. 3.The network-constructed energy storage transient stability supporting method according to claim 1, wherein, the preset droop control parameters comprise preset active power droop control parameters and preset reactive power droop control parameters; the calculation of the control phase angle and the control reference voltage according to the saturation limiting output value, the second power difference, and the preset droop control parameters comprises the following steps: multiplying the saturation limiting output value and the preset active power droop control parameters to obtain an angular velocity output by a droop control link; integrating the angular velocity output by the droop control link to obtain the control phase angle; multiplying the second power difference and the preset reactive power droop control parameters, and then adding the result to a converter output voltage reference value to obtain the control reference voltage. 4.The network-constructed energy storage transient stability supporting method according to claim 1, wherein, The generation of the PWM modulation signal according to the control phase angle and the control reference voltage, and the control of the voltage switches according to the PWM modulation signal, comprise the following steps: acquiring the converter point of common coupling voltage and a converter side current, and obtaining a control signal according to the converter point of common coupling voltage, the converter side current, the control phase angle, and the control reference voltage; generating the PWM modulation signal by a PWM modulator according to the control signal; controlling the voltage switches by the PWM modulation signal.

5. A meshed energy storage transient stability support device, characterized by, The method comprises the following steps: a data acquisition module, a power difference calculation module, a saturation limiting module, a control parameter calculation module, and a PWM control module; the data acquisition module is used to acquire reference active power and reference reactive power of the grid-forming converter, actual active power of the grid-forming converter after being disturbed, and actual reactive power of the grid-forming converter after being disturbed; the power difference calculation module is used to calculate a difference between the reference active power and the actual active power to obtain a first power difference; a difference between the reference reactive power and the actual reference reactive power is calculated to obtain a second power difference; The saturation limiting module is configured to compare the first power difference with a preset saturation limiting threshold, and when the first power difference is less than or equal to the preset saturation limiting threshold, take the first power difference as a saturation limiting output value; and when the first power difference is greater than the preset saturation limiting threshold, take the preset saturation limiting threshold as the saturation limiting output value. The control parameter calculation module is configured to calculate a control phase angle and a control reference voltage according to the saturation limiting output value, a second power difference, and preset droop control parameters. The PWM control module is configured to generate a PWM modulation signal according to the control phase angle and the control reference voltage, and control the voltage switch according to the PWM modulation signal.

6. The network-forming energy storage transient stability support apparatus according to claim 5, characterized by, Further comprising: An actual active power calculation module; The actual active power calculation module is configured to obtain the actual active power of the grid-connected type converter after the disturbance by the following method: Obtain the converter point of common coupling voltage, grid voltage, phase angle after the disturbance, and inductance reactance of the grid connection line. According to the converter common connection point voltage, the grid voltage, the reference value of the voltage and current inner loop after the disturbance, and the inductance of the grid connection, the actual active power of the grid-connected converter after the disturbance is calculated by the following formula: where P e represents the actual power of the converter, V represents the voltage at the point of common coupling of the converter, V g represents the grid voltage, θ r represents the phase angle after the disturbance, X g represents the reactance of the grid line inductance. 7.The network constitution type energy storage transient stability supporting device according to claim 5, characterized in that, The preset droop control parameters include preset active power droop control parameters and preset reactive power droop control parameters. The control parameter calculation module includes an angular velocity calculation unit, a control phase angle calculation unit, and a control reference voltage calculation unit. The angular velocity calculation unit is configured to multiply the saturation limiting output value and the preset active power droop control parameters to obtain an angular velocity output by a droop control link. The control phase angle calculation unit is configured to integrate the angular velocity output by the droop control link to obtain the control phase angle. The control reference voltage calculation unit is configured to multiply the second power difference and the preset reactive power droop control parameters, and then add the converter output voltage reference value to obtain the control reference voltage. 8.The network-constructed energy storage transient stability supporting device according to claim 5, wherein, The PWM control module includes a control signal generation unit, a PWM modulation signal generation unit, and a voltage switch control unit. The control signal generation unit is configured to obtain the converter point of common coupling voltage and the converter side current, and obtain the control signal according to the converter point of common coupling voltage, the converter side current, the control phase angle, and the control reference voltage. The PWM modulation signal generation unit is configured to generate the PWM modulation signal by a PWM modulator according to the control signal. The voltage switch control unit is configured to control the voltage switch by the PWM modulation signal.

9. A terminal device, comprising: A processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, when the processor executes the computer program, the grid-connected type energy storage transient stability support method of any one of claims 1-4 is implemented.

10. A computer-readable storage medium, characterized in that, Further comprising: The computer program is stored, and when the computer program is running, the device where the computer readable storage medium is located executes the grid-connected type energy storage transient stability support method of any one of claims 1-4.

Images