High voltage ride through control method, device and equipment and storage medium

Abstract

The invention discloses a high voltage ride through control method, device and equipment and a storage medium, and the method comprises the steps: designing an initial control strategy for a single initial photovoltaic power generation unit, obtaining a preset photovoltaic power generation unit, and enabling the initial control strategy to comprise a steady-state current closed-loop control strategy and a fault reactive power control strategy; carrying out equivalent modeling on the actual photovoltaic power station by adopting a preset photovoltaic power generation unit to obtain an initial single-machine equivalent model; error source parameters are determined in a mode of performing root cause analysis on reactive power control errors of the initial single-machine equivalent model; updating a reactive current reference value in the fault reactive control strategy according to the error source parameter to obtain an updated single-machine equivalent model; and realizing high-voltage ride-through control during the fault period according to the updated single-machine equivalent model. The technical problems that an existing single-machine equivalence method cannot give consideration to accuracy and high efficiency, equivalence researches for high voltage ride through are few, and application requirements of variable scenes cannot be met can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy systems, and in particular to a high voltage ride-through control method, device, equipment and storage medium. Background Art

[0002] The output response characteristics of a photovoltaic power station are the combined effects of hundreds of photovoltaic power generation units, transformers and collector networks. Establishing a detailed photovoltaic power station model for a photovoltaic power station will cause the problem of dimensionality disaster. In order to improve the accuracy and efficiency of the photovoltaic power station model, this field usually uses a high-precision aggregation equivalent method for equivalent simulation.

[0003] The current single-machine multiplication method has certain differences in each stage during the high voltage ride-through fault, and it is difficult to simulate the output response characteristics of the actual photovoltaic power station. Moreover, neither the single-machine equivalent method nor the multi-machine grouping method can take into account both accuracy and efficiency; in addition, the current technology has little research and analysis on the equivalent of high voltage ride-through, and cannot adapt to the application needs of changing scenarios. Summary of the invention

[0004] The present application provides a high voltage crossing control method, device, equipment and storage medium, which are used to solve the technical problems that the existing single-machine equivalent method cannot take into account both accuracy and efficiency, and there is little equivalent research on high voltage crossing, and it cannot adapt to the application requirements of changing scenarios.

[0005] In view of this, a first aspect of the present application provides a high voltage ride through control method, comprising:

[0006] Designing an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy;

[0007] Using the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station to obtain an initial single-machine equivalent model;

[0008] Determine the error source parameter by performing root cause analysis on the reactive power control error of the initial single machine equivalent model;

[0009] Update the reactive current reference value in the fault reactive power control strategy according to the error source parameter to obtain an updated single machine equivalent model;

[0010] High voltage ride-through control during a fault is implemented based on the updated single-machine equivalent model.

[0011] Preferably, the initial control strategy is designed for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, including:

[0012] When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value;

[0013] Generating a steady-state current closed-loop control strategy according to the voltage outer-loop output value and the current inner-loop output value;

[0014] When the initial photovoltaic power generation unit operates in a fault high voltage ride-through, a reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain a reactive current reference value;

[0015] Generating a fault reactive power control strategy according to the reactive current reference value and the active current reference value in a steady state;

[0016] An initial control strategy consisting of the steady-state current closed-loop control strategy and the fault reactive power control strategy is used as the control strategy of the initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

[0017] Preferably, the use of the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station to obtain an initial single-machine equivalent model includes:

[0018] The preset photovoltaic power generation unit is used to simulate an actual photovoltaic power station by expanding the power of a single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with those of the actual photovoltaic power station, thereby obtaining an initial single-machine equivalent model.

[0019] Preferably, the implementing high voltage ride through control during a fault period according to the updated single machine equivalent model further includes:

[0020] Performing high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and collecting parameter response curves of the updated single-machine equivalent model at the exit of the photovoltaic power station;

[0021] The preset scenarios include multiple lighting scenarios and multiple degrees of high voltage ride-through scenarios, the preset fault duration is a standard non-offline operation time, and the parameter response curve includes a voltage response curve, a current response curve, an active power response curve, and a reactive power response curve.

[0022] A second aspect of the present application provides a high voltage ride through control device, comprising:

[0023] A strategy design unit, used to design an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy;

[0024] An equivalent modeling unit, used to perform equivalent modeling on an actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-machine equivalent model;

[0025] An error analysis unit, used to determine error source parameters by performing root cause analysis on the reactive power control error of the initial single-machine equivalent model;

[0026] A model updating unit, used for updating the reactive current reference value in the fault reactive current control strategy according to the error source parameter, to obtain an updated single machine equivalent model;

[0027] A ride-through control unit is used to implement high voltage ride-through control during a fault period according to the updated single-machine equivalent model.

[0028] Preferably, the strategy design unit is specifically used to:

[0029] When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value;

[0030] Generating a steady-state current closed-loop control strategy according to the voltage outer-loop output value and the current inner-loop output value;

[0031] When the initial photovoltaic power generation unit operates in a fault high voltage ride-through, a reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain a reactive current reference value;

[0032] Generating a fault reactive power control strategy according to the reactive current reference value and the active current reference value in a steady state;

[0033] An initial control strategy consisting of the steady-state current closed-loop control strategy and the fault reactive power control strategy is used as the control strategy of the initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

[0034] Preferably, the equivalent modeling unit is specifically used for:

[0035] The preset photovoltaic power generation unit is used to simulate an actual photovoltaic power station by expanding the power of a single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with those of the actual photovoltaic power station, thereby obtaining an initial single-machine equivalent model.

[0036] Preferably, it also includes:

[0037] A control verification unit, used to perform high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and collect parameter response curves of the updated single-machine equivalent model at the exit of the photovoltaic power station;

[0038] The preset scenarios include multiple lighting scenarios and multiple degrees of high voltage ride-through scenarios, the preset fault duration is a standard non-offline operation time, and the parameter response curve includes a voltage response curve, a current response curve, an active power response curve, and a reactive power response curve.

[0039] A third aspect of the present application provides a high voltage ride-through control device, the device comprising a processor and a memory;

[0040] The memory is used to store program code and transmit the program code to the processor;

[0041] The processor is used to execute the high voltage ride-through control method described in the first aspect according to the instructions in the program code.

[0042] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and the program code is used to execute the high voltage ride-through control method described in the first aspect.

[0043] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0044] In the present application, a high voltage ride-through control method is provided, comprising: designing an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, the initial control strategy comprising a steady-state current closed-loop control strategy and a fault reactive control strategy; using the preset photovoltaic power generation unit to perform equivalent modeling on an actual photovoltaic power station to obtain an initial single-machine equivalent model; determining error source parameters by performing root cause analysis on the reactive control error of the initial single-machine equivalent model; updating a reactive current reference value in the fault reactive control strategy according to the error source parameters to obtain an updated single-machine equivalent model; and realizing high voltage ride-through control during a fault period based on the updated single-machine equivalent model.

[0045] The control method of high voltage crossing provided by the present application comprehensively considers the error of the equivalent model on reactive power during fault crossing and the influence of the overall control strategy, and performs root cause analysis on the reactive control error to determine the specific error source, and corrects and updates the reactive current reference value in the control strategy based on this error source, thereby improving the accuracy of the equivalent model while retaining the efficiency of the equivalent model; moreover, this improved operation can significantly improve the performance of the equivalent model, realize stable high voltage crossing control according to different scene requirements, and meet the control requirements of multiple scenes. Therefore, the present application can solve the technical problems that the existing single-machine equivalent method cannot take into account both accuracy and efficiency, and there is little equivalent research on high voltage crossing, which cannot adapt to the application requirements of changing scenes. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1A schematic flow chart of a high voltage ride-through control method provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of the structure of a high voltage ride through control device provided in an embodiment of the present application;

[0048] Figure 3 Output response characteristic curve diagram of active power and reactive power at various stages during high voltage ride-through provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of the topological structure of a photovoltaic power generation unit provided in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the topological structure of an actual photovoltaic power station provided in an embodiment of the present application;

[0051] Figure 6 An output characteristic curve diagram of a photovoltaic power station under high voltage ride-through based on a traditional single-machine equivalent method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] For easier understanding, see Figure 1 , an embodiment of a high voltage ride through control method provided by the present application includes:

[0054] Step 101 : designing an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy.

[0055] Furthermore, step 101 includes:

[0056] When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value;

[0057] Generate a steady-state current closed-loop control strategy based on the voltage outer loop output value and the current inner loop output value;

[0058] When the initial photovoltaic power generation unit operates in the fault high voltage ride-through, the reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value;

[0059] Generate a fault reactive power control strategy according to a reactive current reference value and an active current reference value in a steady state;

[0060] An initial control strategy consisting of a steady-state current closed-loop control strategy and a fault reactive power control strategy is used as a control strategy for an initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

[0061] It should be noted that when designing the control strategy of the equivalent model, it is necessary to consider both steady-state and transient conditions. The transient state refers to the situation where the system is in a fault state and needs to be subjected to fault high voltage ride-through; and both steady-state and transient control need to consider active control and reactive control. Specifically, in the steady-state stage of this embodiment, the current closed-loop vector control based on the grid voltage orientation can be used to independently control the overall output power in the dq0 coordinate system by controlling the active power through the d-axis and the reactive power through the q-axis.

[0062] The voltage outer loop compares the measured photovoltaic output voltage with the voltage reference value, and then adjusts the inverter output voltage through the PI controller to keep it synchronized with the grid voltage. The output result of the voltage outer loop is the voltage outer loop output value, which is specifically expressed as:

[0063]

[0064] in, and They are active current reference value and reactive current reference value, that is, the voltage outer loop output value. is the voltage reference value, is the actual bus voltage, that is, the measured photovoltaic output voltage, and They are the proportional coefficient and integral coefficient of the voltage outer loop PI controller respectively.

[0065] The output result of the voltage outer loop can be used as the current reference value of the current inner loop, and based on this value, the output value of the current inner loop can be calculated. Specifically, the current inner loop is divided into an active current inner loop and a reactive current inner loop. The active current reference value, reactive current reference value, and actual measured values ​​of active current and reactive current are used as inputs of the inner loop PI controller. Combined with feedforward decoupling, the output result of the current inner loop can be calculated, that is, the output value of the current inner loop:

[0066]

[0067] in, and are respectively the active output value and reactive output value of the inner current loop, and are the proportional coefficient and integral coefficient of the current inner loop PI controller respectively, and are active current reference value and actual value respectively, and are the reactive current reference value and actual value respectively, ω is the synchronous angular frequency, L is the AC measured inductance, e d is the d-axis component of the grid voltage, e q It is the q-axis component of the grid-side voltage.

[0068] The voltage outer loop output value and the current inner loop output value obtained by the above calculation can realize the system control under the stable operation state, that is, the steady-state current closed-loop control strategy is adopted to control the photovoltaic power generation unit in the stable operation state.

[0069] Figure 3 It is the output response characteristics of active power and reactive power in each stage during high voltage ride-through; when the photovoltaic power generation unit operates in high voltage ride-through, that is, in a fault state, the reactive current reference value in the control mode during the fault period is obtained by fitting the relationship between the steady-state current and voltage during the fault period, and the inverter reactive power control is realized through the current inner loop controller. The active current reference value is the same as that in the steady-state period and is obtained by the voltage outer loop.

[0070] The calculation process of reactive current reference value is:

[0071]

[0072] Among them, U G is the voltage per unit value at the photovoltaic power generation unit grid connection point, I N is the rated current of the photovoltaic power generation unit.

[0073] Since the active power remains unchanged during the fault ride-through control, the active power control strategy before and after the fault does not switch, that is, the active current control strategy during the high voltage ride-through is the same as the control strategy during the steady state period, and the details are not repeated. Therefore, based on the calculated reactive current reference value and the active current reference value calculated in the steady state, the fault reactive power control strategy can be generated to realize the fault ride-through control.

[0074] After designing a complete control strategy for the initial photovoltaic power generation unit, the preset photovoltaic power generation unit can be obtained. The topology of the photovoltaic power generation unit can be found in Figure 4 , a single preset photovoltaic power generation unit can be used to perform equivalent modeling of the actual photovoltaic power station, and then the steady-state and transient characteristics of the entire photovoltaic grid-connected system can be analyzed.

[0075] Step 102: Use the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station to obtain an initial single-machine equivalent model.

[0076] Furthermore, step 102 includes:

[0077] The preset photovoltaic power generation unit is used to simulate the actual photovoltaic power station by expanding the power of the single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with the actual photovoltaic power station, and the initial single-machine equivalent model is obtained.

[0078] In this embodiment, the process of using a preset photovoltaic power generation unit to perform equivalent modeling on an actual photovoltaic power station includes model building and model parameter calculation; the model building is similar to a single photovoltaic power generation unit, and a high-power photovoltaic power station is simulated by expanding the power of a single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with the actual photovoltaic power station. The model parameter calculation needs to be calculated based on the model obtained by the actual equivalent operation, and the calculated model parameters are the equivalent parameters.

[0079] For the topology of actual photovoltaic power plants, please refer to Figure 5 This embodiment uses a preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station based on the single-machine equivalent method, taking into account the operating characteristics of the actual photovoltaic power station. By simplifying the huge actual model, the output voltage and power system operating parameters can be analyzed more efficiently, which is helpful for in-depth analysis of the characteristics of the entire power grid system. In addition, the single-machine equivalent model can convert a complex photovoltaic power station model into an equivalent unit, simplifying the system operation process and reducing the calculation complexity.

[0080] Step 103: Determine the error source parameters by performing root cause analysis on the reactive power control error of the initial single-machine equivalent model.

[0081] Before conducting a root cause analysis of the reactive control error, we can first analyze the process of reactive control error generated by the initial single-machine equivalent model. According to the above active current calculation expression, the reactive power value during the fault is only related to the voltage. Since there are certain differences in the outlet voltage of each photovoltaic power generation unit, there must be an error between the outlet voltage of each photovoltaic power generation unit and the fault voltage of the equivalent model.

[0082] In the actual detailed model, the reactive power output value during the fault is the sum of the reactive powers of each photovoltaic power generation unit:

[0083]

[0084] in,

[0085]

[0086] in, represents the outlet voltage value of the i-th photovoltaic power generation unit during the fault period, For the The reactive current reference value of each photovoltaic power generation unit during the fault period, .

[0087] In the single-machine equivalent model, the grid connection point voltage after the reactive power output value during the fault is equal to the value is calculated by the reactive current control strategy under high voltage ride-through:

[0088]

[0089] in, is the voltage value during the fault period after equalization.

[0090] During a fault, since the distance from each photovoltaic unit to the grid is not equal and due to the existence of the collector network, the outlet voltage of each photovoltaic unit port is not completely equal, that is:

[0091]

[0092] Therefore, the calculation relationship of reactive power during the detailed model fault is:

[0093]

[0094] Among them, k i (i=1,…,n) and b i (i=1,…,n) is the control coefficient of the i-th photovoltaic unit.

[0095] It can be seen that due to ,have:

[0096]

[0097] Therefore, if the control method of reactive power in the equivalent model still follows the control logic and parameters of the original photovoltaic unit, the reactive power of the equivalent model during the fault period will produce a certain equivalent error.

[0098] In the HVRT active power control strategy, in order to maintain the active power unchanged during the fault, the control strategy of the active current before and after the fault remains unchanged, so the active power during the fault in the actual detailed model is expressed as:

[0099]

[0100] in, Represents the active power output before the fault in the detailed model.

[0101] In the single-machine equivalent model, the active power during the fault is the product of the active power after equivalent value and the number of photovoltaic power generation units:

[0102]

[0103] The equivalent light intensity is the sum of the light intensities of each photovoltaic power generation unit, and the initial active power is proportional to the light intensity, so it can be considered that the equivalent active power before the fault is the average value of each photovoltaic power generation unit, and the active power calculated using the single-machine equivalent model is equal to the actual active power, that is, .

[0104] After determining that the error of the single-machine equivalent model is the reactive control error, the source of the fault can be analyzed. This embodiment finds that during the fault period, due to a certain distance difference between the photovoltaic power generation units, the outlet voltages of the photovoltaic power generation units are also different, which in turn generates a reactive control error. That is, the source of the error analyzed in this embodiment is the outlet voltage difference caused by the distance between the photovoltaic power generation units.

[0105] Step 104: Update the reactive current reference value in the fault reactive power control strategy according to the error source parameter to obtain an updated single machine equivalent model.

[0106] The calculation process of updating the reactive current reference value is:

[0107]

[0108] After the reactive current reference value is updated, the active control strategy in the single-machine equivalent model remains unchanged, that is, it is consistent with the original active control strategy, while the fault reactive control strategy needs to be updated synchronously, so the initial single-machine equivalent model becomes the updated single-machine equivalent model.

[0109] Step 105: Implement high voltage ride through control during the fault period according to the updated single machine equivalent model.

[0110] Furthermore, step 105 further includes:

[0111] Perform high voltage ride-through control on faults within preset fault durations in different preset scenarios, and collect and update parameter response curves of the single-machine equivalent model at the exit of the PV power station;

[0112] The preset scenarios include various lighting scenarios and various degrees of high voltage ride-through scenarios. The preset fault duration is the standard non-offline operation time. The parameter response curves include voltage response curve, current response curve, active power response curve and reactive power response curve.

[0113] It should be noted that in order to verify that the updated stand-alone equivalent model provided in this embodiment can cope with the control requirements of different scenarios, different verification scenarios can be set, and parameter measurements can be performed under the same non-offline operation conditions, and the system operation parameter curve can be drawn, so as to determine the superiority of the model of this embodiment by comparing the curves. For example, scenes with different light intensities can be set, and all photovoltaic power generation units in the photovoltaic power station can be set to operate under different light intensities, and the fault duration is set according to the non-offline operation time in the photovoltaic power station high voltage crossing standard regulations. Verify the voltage, current, active power and reactive power response curves of the existing actual detailed model, the traditional stand-alone equivalent model, and the updated stand-alone equivalent model at the exit of the photovoltaic power station; after comparative analysis, it is found that the updated stand-alone equivalent model provided in this embodiment has better control effect.

[0114] In addition, different degrees of high voltage ride-through scenarios can be set, and the voltage surge at the grid connection point can be set to 1.2pu, 1.25pu, and 1.3pu respectively. The fault duration is set according to the non-offline operation time in the standard regulations for high voltage ride-through of photovoltaic power stations, and the voltage, current, active power and reactive power response curves of the actual detailed model, the traditional single-machine equivalent model, and the updated single-machine equivalent model at the exit of the photovoltaic power station are verified; comparative analysis can also be performed to verify the superiority of the model of this embodiment. Specifically, the output characteristics of photovoltaic power stations under high voltage ride-through based on the traditional single-machine equivalent method can be found in Figure 6 .

[0115] The control method of high voltage ride-through provided in the embodiment of the present application comprehensively considers the error of the equivalent model on reactive power during fault ride-through and the influence of the overall control strategy, and performs root cause analysis on the reactive control error, determines the specific error source, and corrects and updates the reactive current reference value in the control strategy based on this error source, thereby improving the accuracy of the equivalent model and retaining the efficiency of the equivalent model; moreover, this improved operation can significantly improve the performance of the equivalent model, realize stable high voltage ride-through control according to different scene requirements, and meet the control requirements of multiple scenes. Therefore, the embodiment of the present application can solve the technical problems that the existing single-machine equivalent method cannot take into account both accuracy and efficiency, and there is little equivalent research on high voltage ride-through, and it cannot adapt to the application requirements of changing scenes.

[0116] For easier understanding, see Figure 2 The present application provides an embodiment of a high voltage ride through control device, including:

[0117] A strategy design unit 201 is used to design an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy;

[0118] The equivalent modeling unit 202 is used to perform equivalent modeling on the actual photovoltaic power station using a preset photovoltaic power generation unit to obtain an initial single-machine equivalent model;

[0119] The error analysis unit 203 is used to determine the error source parameter by performing root cause analysis on the reactive power control error of the initial single machine equivalent model;

[0120] A model updating unit 204 is used to update the reactive current reference value in the fault reactive control strategy according to the error source parameter to obtain an updated single machine equivalent model;

[0121] The ride-through control unit 205 is used to implement high voltage ride-through control during a fault period according to the updated single machine equivalent model.

[0122] Furthermore, the strategy design unit 201 is specifically used for:

[0123] When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value;

[0124] Generate a steady-state current closed-loop control strategy based on the voltage outer loop output value and the current inner loop output value;

[0125] When the initial photovoltaic power generation unit operates in the fault high voltage ride-through, the reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value;

[0126] Generate a fault reactive power control strategy according to a reactive current reference value and an active current reference value in a steady state;

[0127] An initial control strategy consisting of a steady-state current closed-loop control strategy and a fault reactive power control strategy is used as a control strategy for an initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

[0128] Furthermore, the equivalent modeling unit 202 is specifically used for:

[0129] The preset photovoltaic power generation unit is used to simulate the actual photovoltaic power station by expanding the power of the single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with the actual photovoltaic power station, and the initial single-machine equivalent model is obtained.

[0130] Furthermore, it also includes:

[0131] The control verification unit 206 is used to perform high voltage ride-through control on faults within a preset fault duration in different preset scenarios, and collect and update the parameter response curve of the single-machine equivalent model at the exit of the photovoltaic power station;

[0132] The preset scenarios include various lighting scenarios and various degrees of high voltage ride-through scenarios. The preset fault duration is the standard non-offline operation time. The parameter response curves include voltage response curve, current response curve, active power response curve and reactive power response curve.

[0133] The present application also provides a high voltage ride-through control device, the device comprising a processor and a memory;

[0134] The memory is used to store the program code and transmit the program code to the processor;

[0135] The processor is used to execute the high voltage ride-through control method in the above method embodiment according to the instructions in the program code.

[0136] The present application also provides a computer-readable storage medium, which is used to store program codes, and the program codes are used to execute the high voltage ride-through control method in the above method embodiment.

[0137] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0138] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions for executing all or part of the steps of the method described in each embodiment of the present application through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0141] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A high voltage ride through control method, characterized in that: include: Designing an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy; Using the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station to obtain an initial single-machine equivalent model; Determine the error source parameter by performing root cause analysis on the reactive power control error of the initial single machine equivalent model; Update the reactive current reference value in the fault reactive power control strategy according to the error source parameter to obtain an updated single machine equivalent model; High voltage ride-through control during a fault is implemented based on the updated single-machine equivalent model.

2. The high voltage ride through control method according to claim 1, characterized in that: The initial control strategy is designed for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, including: When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value; Generating a steady-state current closed-loop control strategy according to the voltage outer-loop output value and the current inner-loop output value; When the initial photovoltaic power generation unit operates in a fault high voltage ride-through, a reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain a reactive current reference value; Generating a fault reactive power control strategy according to the reactive current reference value and the active current reference value in a steady state; An initial control strategy consisting of the steady-state current closed-loop control strategy and the fault reactive power control strategy is used as the control strategy of the initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

3. The high voltage ride through control method according to claim 1, characterized in that: The method of using the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station to obtain an initial single-machine equivalent model includes: The preset photovoltaic power generation unit is used to simulate an actual photovoltaic power station by expanding the power of a single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with those of the actual photovoltaic power station, thereby obtaining an initial single-machine equivalent model.

4. The high voltage ride through control method according to claim 1, characterized in that: The method of implementing high voltage ride through control during a fault period according to the updated single machine equivalent model further includes: Performing high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and collecting parameter response curves of the updated single-machine equivalent model at the exit of the photovoltaic power station; The preset scenarios include multiple lighting scenarios and multiple degrees of high voltage ride-through scenarios, the preset fault duration is a standard non-offline operation time, and the parameter response curve includes a voltage response curve, a current response curve, an active power response curve, and a reactive power response curve.

5. A high voltage ride through control device, characterized in that: include: A strategy design unit, used to design an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit, wherein the initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy; An equivalent modeling unit, used to perform equivalent modeling on an actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-machine equivalent model; An error analysis unit, used to determine error source parameters by performing root cause analysis on the reactive power control error of the initial single-machine equivalent model; A model updating unit, used for updating the reactive current reference value in the fault reactive current control strategy according to the error source parameter, to obtain an updated single machine equivalent model; A ride-through control unit is used to implement high voltage ride-through control during a fault period according to the updated single-machine equivalent model.

6. The high voltage ride through control device according to claim 5, characterized in that: The strategy design unit is specifically used for: When the initial photovoltaic power generation unit operates in a stable state, the voltage outer loop output value and the current inner loop output value are calculated according to the photovoltaic output voltage and the voltage reference value; Generating a steady-state current closed-loop control strategy according to the voltage outer-loop output value and the current inner-loop output value; When the initial photovoltaic power generation unit operates in a fault high voltage ride-through, a reactive power control instruction of the inverter is calculated according to the steady-state current and steady-state voltage during the fault period to obtain a reactive current reference value; Generating a fault reactive power control strategy according to the reactive current reference value and the active current reference value in a steady state; An initial control strategy consisting of the steady-state current closed-loop control strategy and the fault reactive power control strategy is used as the control strategy of the initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit.

7. The high voltage ride through control device according to claim 5, characterized in that: The equivalent modeling unit is specifically used for: The preset photovoltaic power generation unit is used to simulate an actual photovoltaic power station by expanding the power of a single-machine model, so that the total power and grid-connected point voltage of the single-machine model are consistent with those of the actual photovoltaic power station, thereby obtaining an initial single-machine equivalent model.

8. The high voltage ride through control device according to claim 5, characterized in that: Also includes: A control verification unit, used to perform high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and collect parameter response curves of the updated single-machine equivalent model at the exit of the photovoltaic power station; The preset scenarios include multiple lighting scenarios and multiple degrees of high voltage ride-through scenarios, the preset fault duration is a standard non-offline operation time, and the parameter response curve includes a voltage response curve, a current response curve, an active power response curve, and a reactive power response curve.

9. A high voltage ride through control device, characterized in that: The device comprises a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the high voltage ride-through control method according to any one of claims 1 to 4 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the high voltage ride-through control method according to any one of claims 1 to 4.

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