A control method, device and equipment for high voltage ride through and storage medium

Abstract

This application discloses a control method, apparatus, device, and storage medium for high-voltage ride-through. The method includes: 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 includes a steady-state current closed-loop control strategy and a fault reactive power control strategy; performing equivalent modeling of an actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-unit equivalent model; determining the error source parameters by performing root cause analysis on the reactive power control error of the initial single-unit equivalent model; updating the reactive current reference value in the fault reactive power control strategy according to the error source parameters to obtain an updated single-unit equivalent model; and realizing high-voltage ride-through control during a fault based on the updated single-unit equivalent model. This application can solve the technical problems that existing single-unit equivalent methods cannot simultaneously achieve accuracy and efficiency, and there is a lack of equivalent research on high-voltage ride-through, making them unable to adapt to the application requirements of variable scenarios.

Description

Technical Field

[0001] This application relates to the field of new energy system technology, and in particular to a control method, device, equipment and storage medium for high voltage ride-through. Background Technology

[0002] The output response characteristics of a photovoltaic (PV) power plant are the combined effect of hundreds of PV power generation units, transformers, and power collection networks. Establishing a detailed PV power plant model would lead to the curse of dimensionality. To improve the accuracy and efficiency of PV power plant models, the field typically employs highly accurate aggregated equivalent methods for equivalent simulation.

[0003] Current single-unit multiplication methods exhibit certain differences across different stages during high-voltage ride-through faults, making it difficult to accurately simulate the output response characteristics of actual photovoltaic power plants. Moreover, neither single-unit equivalent methods nor multi-unit clustering methods can simultaneously guarantee accuracy and efficiency. Furthermore, current technologies offer limited equivalent research and analysis on high-voltage ride-through, failing to meet the application requirements of diverse scenarios. Summary of the Invention

[0004] This application provides a control method, apparatus, device, and storage medium for high voltage ride-through, which addresses the technical problem that existing single-machine equivalent methods cannot simultaneously ensure accuracy and efficiency, and that there is limited equivalent research on high voltage ride-through, making them unable to adapt to the application requirements of diverse scenarios.

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

[0006] An initial control strategy is designed for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit. The initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy.

[0007] The preset photovoltaic power generation unit is used to perform equivalent modeling of the actual photovoltaic power station to obtain an initial single-unit equivalent model;

[0008] The error source parameters are determined 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 parameters to obtain the updated single-unit equivalent model;

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

[0011] Preferably, the step of designing an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit includes:

[0012] When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value.

[0013] A steady-state current closed-loop control strategy is generated based on the outer voltage loop output value and the inner current loop output value.

[0014] When the initial photovoltaic power generation unit is operating during high voltage fault ride-through, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value.

[0015] A fault reactive power control strategy is generated based on the aforementioned reactive current reference value and the steady-state active current reference value.

[0016] The 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 for the initial photovoltaic power generation unit to obtain the preset photovoltaic power generation unit.

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

[0018] The preset photovoltaic power generation unit is used to simulate the actual photovoltaic power station by increasing the power of the single-unit model, so that the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining the initial single-unit equivalent model.

[0019] Preferably, the step of implementing high-voltage ride-through control during a fault based on the updated single-machine equivalent model further includes:

[0020] High-voltage ride-through control is performed on faults within a preset fault duration under different preset scenarios, and the parameter response curves of the updated single-unit equivalent model at the photovoltaic power station outlet are collected.

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

[0022] A second aspect of this application provides a control device for high voltage ride-through, comprising:

[0023] The strategy design unit is used to design an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit. The initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy.

[0024] The equivalent modeling unit is used to perform equivalent modeling of the actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-unit equivalent model.

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

[0026] The model update unit is used to update the reactive current reference value in the fault reactive power control strategy according to the error source parameters, so as to obtain the updated single-unit equivalent model.

[0027] The ride-through control unit is used to implement high-voltage ride-through control during faults based on the updated single-machine equivalent model.

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

[0029] When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value.

[0030] A steady-state current closed-loop control strategy is generated based on the outer voltage loop output value and the inner current loop output value.

[0031] When the initial photovoltaic power generation unit is operating during high voltage fault ride-through, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value.

[0032] A fault reactive power control strategy is generated based on the aforementioned reactive current reference value and the steady-state active current reference value.

[0033] The 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 for the initial photovoltaic power generation unit to obtain the 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 the actual photovoltaic power station by increasing the power of the single-unit model, so that the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining the initial single-unit equivalent model.

[0036] Preferably, it further includes:

[0037] The control verification unit is used to perform high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and to collect the parameter response curve of the updated single-unit equivalent model at the photovoltaic power station outlet.

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

[0039] A third aspect of this application provides a control device for high voltage ride-through, the device including 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 this application provides a computer-readable storage medium for storing program code for executing the high-voltage ride-through control method described in the first aspect.

[0043] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0044] This application provides a high-voltage ride-through control method, comprising: 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; performing equivalent modeling of an actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-unit equivalent model; determining the error source parameters by performing root cause analysis on the reactive power control error of the initial single-unit equivalent model; updating the reactive current reference value in the fault reactive power control strategy according to the error source parameters to obtain an updated single-unit equivalent model; and realizing high-voltage ride-through control during a fault based on the updated single-unit equivalent model.

[0045] The high-voltage ride-through control method provided in this application comprehensively considers the reactive power error of the equivalent model during fault ride-through and the impact of the overall control strategy. It performs root cause analysis on the reactive power control error to identify specific error sources, and corrects and updates the reactive current reference value in the control strategy based on these error sources. This improves the accuracy of the equivalent model while retaining its efficiency. Moreover, this improvement significantly enhances the performance of the equivalent model, enabling stable high-voltage ride-through control according to different scenario requirements and meeting the control needs of multiple scenarios. Therefore, this application solves the technical problems of existing single-machine equivalent methods failing to balance accuracy and efficiency, and the limited research on equivalent methods for high-voltage ride-through, making them unsuitable for application requirements in diverse scenarios. Attached Figure Description

[0046] Figure 1A schematic flowchart illustrating a high-voltage ride-through control method provided in an embodiment of this application;

[0047] Figure 2 This is a schematic diagram of a high-voltage ride-through control device provided in an embodiment of this application;

[0048] Figure 3 Output response characteristic curves of active and reactive power at various stages during high-voltage ride-through provided in the embodiments of this application;

[0049] Figure 4 This is a schematic diagram of the topology of a photovoltaic power generation unit provided in an embodiment of this application;

[0050] Figure 5 This is a schematic diagram of the topology of an actual photovoltaic power station provided in the embodiments of this application;

[0051] Figure 6 The output characteristic curve of a photovoltaic power station under high voltage ride-through based on the traditional single-machine equivalent method is provided for the embodiments of this application. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0053] For easier understanding, please refer to Figure 1 An embodiment of a high-voltage ride-through control method provided in this application includes:

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

[0055] Further, step 101 includes:

[0056] When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value.

[0057] A steady-state current closed-loop control strategy is generated based on the voltage outer loop output value and the current inner loop output value.

[0058] When the initial photovoltaic power generation unit is operating during high voltage ride-through of a fault, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value.

[0059] A fault reactive power control strategy is generated based on the reactive current reference value and the active current reference value under steady state.

[0060] The initial control strategy, consisting of a steady-state current closed-loop control strategy and a fault reactive power control strategy, is used as the control strategy for the initial photovoltaic power generation unit, thus obtaining the preset photovoltaic power generation unit.

[0061] It should be noted that when designing the control strategy for the equivalent model, both steady-state and transient scenarios need to be considered. The transient scenario refers to the system being in a fault state, requiring high-voltage ride-through. Regardless of whether the control is in steady-state or transient mode, active power control and reactive power control must be considered. Specifically, in the steady-state phase of this embodiment, current closed-loop vector control based on grid voltage orientation can be used. In the dq0 coordinate system, active power is controlled via the d-axis, and reactive power is controlled via the q-axis to independently control the overall output power.

[0062] The outer voltage loop compares the measured photovoltaic output voltage with a voltage reference value, and then uses a PI controller to adjust the inverter output voltage to maintain synchronization with the grid voltage. The output result of the outer voltage loop is the outer voltage loop output value, specifically expressed as:

[0063]

[0064] in, and These are the active current reference value and the reactive current reference value, respectively, which are the outer loop voltage output values. This is the voltage reference value. This is the actual bus voltage, i.e., the measured photovoltaic output voltage. and These are the proportional and integral coefficients of the voltage outer loop PI controller, respectively.

[0065] The output of the voltage outer loop can be used as the current reference value for 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 the actual measured values ​​of active and reactive current are used as inputs to the inner loop PI controller. Combined with feedforward decoupling, the output value of the current inner loop can be calculated, i.e., the current inner loop output value:

[0066]

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

[0068] Based on the calculated voltage outer loop output value and current inner loop output value, system control under stable operating conditions can be achieved, that is, the steady-state current closed-loop control strategy is used to control the photovoltaic power generation unit in a stable operating state.

[0069] Figure 3 The output response characteristics of active and reactive power at various stages during high voltage ride-through are shown. When the photovoltaic power generation unit is operating during high voltage ride-through, i.e. 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. After the inverter reactive power control is achieved through the current inner loop controller, the active current reference value is the same as that in the steady-state period and is obtained from the voltage outer loop.

[0070] The calculation process for the reactive current reference value is as follows:

[0071]

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

[0073] Since the active power remains constant during fault ride-through control, the active power control strategy before and after the fault occurs does not switch. That is, the active current control strategy during high-voltage ride-through is the same as the steady-state control strategy, which will not be elaborated further. Therefore, based on the calculated reactive current reference value and the active current reference value calculated under steady-state conditions, a fault reactive power control strategy can be generated to achieve 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. Please refer to the topology of the photovoltaic power generation unit. Figure 4 By using a single pre-set photovoltaic power generation unit, an equivalent model of an actual photovoltaic power station can be performed, thereby analyzing the steady-state and transient characteristics of the entire photovoltaic grid-connected system.

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

[0076] Further, step 102 includes:

[0077] By using a pre-set photovoltaic power generation unit to simulate an actual photovoltaic power station by increasing the power of the single-unit model, the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining an initial single-unit equivalent model.

[0078] This embodiment uses a preset photovoltaic power generation unit to perform equivalent modeling of an actual photovoltaic power station. The process includes model building and model parameter calculation. Model building is similar to that of a single photovoltaic power generation unit. By increasing the power of the single-unit model, a high-power photovoltaic power station can be simulated, ensuring that the total power and grid connection voltage of the single-unit model are consistent with the actual photovoltaic power station. Model parameter calculation is performed based on the model obtained from the actual equivalent operation. The calculated model parameters are the equivalent parameters.

[0079] Please refer to the topology of an actual photovoltaic power station. Figure 5 This embodiment uses a single-unit equivalent method to perform equivalent modeling of an actual photovoltaic power station using pre-set photovoltaic power generation units. It considers the operational characteristics of the actual photovoltaic power station and simplifies the large actual model, enabling more efficient analysis of system operating parameters such as output voltage and power, thus facilitating a deeper analysis of the characteristics of the entire power grid system. Furthermore, the single-unit equivalent model can convert complex photovoltaic power station models into equivalent units, simplifying the system operation process and reducing computational 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 reactive power control error, we can first analyze the process by which the initial single-unit equivalent model generates reactive power control error. According to the active current calculation expression above, the reactive power value during the fault period is only related to the voltage. Since there is a certain difference in the output voltage of each photovoltaic power generation unit, there will definitely be an error between the output 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 during a fault is the sum of the reactive power of each photovoltaic power generation unit:

[0083]

[0084] in,

[0085]

[0086] in, This represents the output voltage value of the i-th photovoltaic power generation unit during a fault. For the first Reference value of reactive current for each photovoltaic power generation unit during a fault. .

[0087] In the single-machine equivalent model, the reactive power output during the fault period is calculated using the equivalent grid connection point voltage through a reactive current control strategy under high voltage ride-through.

[0088]

[0089] in, This represents the voltage value during the fault period after the equivalent value was obtained.

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

[0091]

[0092] Therefore, the detailed formula for calculating reactive power during a fault in the model is as follows:

[0093]

[0094] Where, k i (i=1,…,n) and b i (i=1,…,n) represents the control coefficients of the i-th photovoltaic unit.

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

[0096]

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

[0098] In the high-voltage ride-through active power control strategy, in order to maintain the active power constant during the fault period, the active current control strategy before and after the fault remains unchanged. Therefore, the active power during the fault period in the actual detailed model is expressed as follows:

[0099]

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

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

[0102]

[0103] The equivalent illuminance is the sum of the illuminance of each photovoltaic power generation unit. Since the initial active power is proportional to the illuminance, the equivalent active power before the fault can be considered the average value of each photovoltaic power generation unit. The active power calculated using the single-unit equivalent model is equal to the actual active power. .

[0104] After determining that the error of the single-unit equivalent model is the reactive power control error, the source of the fault can be analyzed. In this embodiment, it was found that during the fault, due to the certain distance difference between each photovoltaic power generation unit, the output voltage of each photovoltaic power generation unit also differs, which in turn causes the reactive power control error. That is, the source of error analyzed in this embodiment is the difference in output voltage caused by the distance between 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 parameters to obtain the updated single-unit equivalent model.

[0106] The reactive current reference value update calculation process is as follows:

[0107]

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

[0109] Step 105: Implement high-voltage ride-through control during faults based on the updated single-machine equivalent model.

[0110] Furthermore, step 105 also includes:

[0111] High-voltage ride-through control is performed on faults within the preset fault duration under different preset scenarios, and the parameter response curves of the single-unit equivalent model at the photovoltaic power station outlet are collected and updated.

[0112] The preset scenarios include various lighting scenarios and high voltage ride-through scenarios of various degrees. The preset fault duration is the standard non-disconnection 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, to verify that the updated single-unit equivalent model provided in this embodiment can meet the control requirements of different scenarios, different verification scenarios can be set, and parameter measurements can be performed under the same grid-connected operation conditions. System operating parameter curves can then be plotted, and the superiority of the model in this embodiment can be determined by comparing the curves. For example, scenarios with different light intensities can be set, with all photovoltaic power generation units in the photovoltaic power station operating under different light intensities. The fault duration is set according to the grid-connected operation time in the high-voltage ride-through standard procedure for photovoltaic power stations. The voltage, current, active power, and reactive power response curves at the photovoltaic power station outlet are verified using the existing detailed model, the traditional single-unit equivalent model, and the updated single-unit equivalent model. Comparative analysis shows that the updated single-unit equivalent model provided in this embodiment has better control performance.

[0114] Furthermore, different levels of high-voltage ride-through scenarios can be set, with grid connection point voltage surges set to 1.2 pu, 1.25 pu, and 1.3 pu, respectively. The fault duration is set according to the non-disconnection operation time in the photovoltaic power plant high-voltage ride-through standard procedure. The voltage, current, active power, and reactive power response curves at the photovoltaic power plant outlet are verified using the actual detailed model, the traditional single-unit equivalent model, and the updated single-unit equivalent model. Comparative analysis can also be performed to verify the superiority of the model in this embodiment. Specifically, for the output characteristics of photovoltaic power plants under high-voltage ride-through based on the traditional single-unit equivalent method, please refer to [link to relevant documentation]. Figure 6 .

[0115] The high-voltage ride-through control method provided in this application comprehensively considers the error in reactive power of the equivalent model during fault ride-through and the impact of the overall control strategy. It performs root cause analysis on the reactive power 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. This improves the accuracy of the equivalent model while retaining its efficiency. Furthermore, this improvement significantly enhances the performance of the equivalent model, enabling stable high-voltage ride-through control according to different scenario requirements and meeting the control needs of multiple scenarios. Therefore, this application can solve the technical problems of existing single-machine equivalent methods failing to balance accuracy and efficiency, and the limited equivalent research on high-voltage ride-through, making them unable to adapt to the application needs of diverse scenarios.

[0116] For easier understanding, please refer to Figure 2 This application provides an embodiment of a control device for high voltage ride-through, comprising:

[0117] The 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. 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 of the actual photovoltaic power station using preset photovoltaic power generation units to obtain an initial single-unit equivalent model.

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

[0120] Model update unit 204 is used to update the reactive current reference value in the fault reactive power control strategy according to the error source parameters, so as to obtain the updated single-unit equivalent model.

[0121] The ride-through control unit 205 is used to implement high-voltage ride-through control during faults based on an updated single-machine equivalent model.

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

[0123] When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value.

[0124] A steady-state current closed-loop control strategy is generated based on the voltage outer loop output value and the current inner loop output value.

[0125] When the initial photovoltaic power generation unit is operating during high voltage ride-through of a fault, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value.

[0126] A fault reactive power control strategy is generated based on the reactive current reference value and the active current reference value under steady state.

[0127] The initial control strategy, consisting of a steady-state current closed-loop control strategy and a fault reactive power control strategy, is used as the control strategy for the initial photovoltaic power generation unit, thus obtaining the preset photovoltaic power generation unit.

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

[0129] By using a pre-set photovoltaic power generation unit to simulate an actual photovoltaic power station by increasing the power of the single-unit model, the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining an initial single-unit equivalent model.

[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 under different preset scenarios, and to collect and update the parameter response curve of the single-unit equivalent model at the photovoltaic power station outlet.

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

[0133] This application also provides a control device for high voltage ride-through, the device including a processor and a memory;

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

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

[0136] This application also provides a computer-readable storage medium for storing program code for executing the high-voltage ride-through control method described in the above method embodiments.

[0137] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

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

[0139] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0140] If the integrated unit is implemented as 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 this application, in essence, 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. This computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the methods described in the various embodiments of this application through a computer device (which may be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0141] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A control method for high voltage ride-through, characterized in that, include: An initial control strategy is designed for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit. The initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy. The specific process is as follows: When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value. A steady-state current closed-loop control strategy is generated based on the outer voltage loop output value and the inner current loop output value. When the initial photovoltaic power generation unit is operating during high voltage fault ride-through, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value. A fault reactive power control strategy is generated based on the aforementioned reactive current reference value and the steady-state active current reference value. The 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 for the initial photovoltaic power generation unit to obtain the preset photovoltaic power generation unit. The initial single-unit equivalent model is obtained by using the preset photovoltaic power generation unit to perform equivalent modeling on the actual photovoltaic power station. The specific process is as follows: The preset photovoltaic power generation unit is used to simulate the actual photovoltaic power station by expanding the power of the single-unit model, so that the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining the initial single-unit equivalent model; The error source parameters are determined 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 parameters to obtain the updated single-unit equivalent model; High-voltage ride-through control during faults is achieved based on the updated single-machine equivalent model. High-voltage ride-through control is performed on faults within a preset fault duration under different preset scenarios, and the parameter response curves of the updated single-unit equivalent model at the photovoltaic power station outlet are collected. The preset scenarios include various lighting scenarios and high voltage ride-through scenarios of various degrees. The preset fault duration is the standard non-disconnection operation time. The parameter response curves include voltage response curve, current response curve, active power response curve and reactive power response curve.

2. A control device for high voltage ride-through, characterized in that, include: The strategy design unit is used to design an initial control strategy for a single initial photovoltaic power generation unit to obtain a preset photovoltaic power generation unit. The initial control strategy includes a steady-state current closed-loop control strategy and a fault reactive power control strategy. Specifically, the strategy design unit is used for: When the initial photovoltaic power generation unit is operating in a stable state, the outer loop voltage output value and the inner loop current output value are calculated based on the photovoltaic output voltage and the voltage reference value. A steady-state current closed-loop control strategy is generated based on the outer voltage loop output value and the inner current loop output value. When the initial photovoltaic power generation unit is operating during high voltage fault ride-through, the reactive power control command of the inverter is calculated based on the steady-state current and steady-state voltage during the fault period to obtain the reactive current reference value. A fault reactive power control strategy is generated based on the aforementioned reactive current reference value and the steady-state active current reference value. The 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 for the initial photovoltaic power generation unit to obtain the preset photovoltaic power generation unit. The equivalent modeling unit is used to perform equivalent modeling of the actual photovoltaic power station using the preset photovoltaic power generation unit to obtain an initial single-unit equivalent model. Specifically, the equivalent modeling unit is used for: The preset photovoltaic power generation unit is used to simulate the actual photovoltaic power station by expanding the power of the single-unit model, so that the total power of the single-unit model and the grid connection point voltage are consistent with the actual photovoltaic power station, thus obtaining the initial single-unit equivalent model; The error analysis unit is used to determine the error source parameters by performing root cause analysis on the reactive power control error of the initial single-machine equivalent model. The model update unit is used to update the reactive current reference value in the fault reactive power control strategy according to the error source parameters, so as to obtain the updated single-unit equivalent model. A fault-crossing control unit is used to implement high-voltage ride-through control during faults based on the updated single-machine equivalent model. The control verification unit is used to perform high voltage ride-through control on faults within a preset fault duration under different preset scenarios, and to collect the parameter response curve of the updated single-unit equivalent model at the photovoltaic power station outlet. The preset scenarios include various lighting scenarios and high voltage ride-through scenarios of various degrees. The preset fault duration is the standard non-disconnection operation time. The parameter response curves include voltage response curve, current response curve, active power response curve and reactive power response curve.

3. A control device for high voltage ride-through, characterized in that, The device includes 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 of claim 1 according to the instructions in the program code.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the high-voltage ride-through control method of claim 1.

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