Phase jump fault recovery method and system for network-forming inverter

Abstract

The invention discloses a phase jump fault recovery method and system for a network-building type inverter, and the method comprises the steps: giving a-q-axis current component of a current loop reference value of the network-building type inverter as an allowable maximum current value in response to a phase jump fault of a power grid and triggering a current amplitude limiting request of the network-building type inverter, forming an amplitude limiting current loop reference value and limiting the amplitude of the output current of the grid-forming inverter; after the current amplitude limiting is relieved, the active power of the grid-forming type inverter is updated, a current loop reference value of the grid-forming type inverter is updated through the updated active power, and the current loop reference value is the current loop reference value obtained after the current amplitude limiting of the amplitude limiting current loop reference value is relieved; and under the condition that the current loop reference value is smaller than a preset current threshold value, the power grid is switched into a grid construction control state, so that the transient stability of the system is enhanced, the system can return to the balance point autonomously, and the grid construction operation state is recovered.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid equipment, and in particular to a phase jump fault recovery method and system for a grid-connected inverter. Background Art

[0002] As the interface between renewable energy power generation units and the power grid, the control performance of the grid-connected inverter is crucial to the stability of the power system. The control schemes of the grid-connected inverter include two types: grid-following control architecture and grid-building control architecture. The former controls the grid-connected inverter into a controlled current source, obtains the angle information in the machine-end voltage through a phase-locked loop, and then controls the active power and reactive power injected into the grid; while the latter controls the grid-connected inverter into a controlled voltage source, generates power angle information through a power synchronization mechanism, and then controls the active power injected into the grid.

[0003] When a grid voltage failure occurs, a grid-connected inverter is required to control its output current. However, the current control strategy of the current-connected inverter greatly reduces the limit cut-off angle of the grid-connected inverter system, weakening the transient stability of the system. At the same time, under phase jump fault conditions, it is difficult for the grid-connected inverter to autonomously desaturate and return to the voltage source state, affecting the stability of the grid operation. Summary of the invention

[0004] In view of this, the present invention provides a phase jump fault recovery method and system for a grid-connected inverter, which solves the technical problems that the current control strategy of the current grid-connected inverter greatly reduces the limit cut-off angle of the grid-connected inverter system, weakens the transient stability of the system, and at the same time, under the condition of a phase jump fault, it is difficult for the grid-connected inverter to autonomously desaturate and recover to the voltage source state, affecting the stability of the grid operation.

[0005] A first aspect of the present invention provides a phase jump fault recovery method for a grid-connected inverter, comprising:

[0006] In response to a phase jump fault occurring in the power grid and triggering a current limiting request of the grid-forming inverter, a -q-axis current component of a current loop reference value of the grid-forming inverter is set as an allowable maximum current value, a limiting current loop reference value is formed, and an output current of the grid-forming inverter is limited;

[0007] After releasing the current amplitude limiting, updating the active power of the grid-type inverter, and using the updated active power to update the current loop reference value of the grid-type inverter, the current loop reference value being the current loop reference value after releasing the current amplitude limiting of the amplitude limiting current loop reference value;

[0008] When the current loop reference value is less than a preset current threshold value, the power grid is switched to a grid control state.

[0009] Preferably, the condition for triggering the current limiting request of the grid-type inverter is that the modulus of the current loop reference value is greater than the allowable maximum current value.

[0010] Preferably, when the current amplitude limitation request of the grid-type inverter is triggered, the d-axis current component of the current loop reference value of the grid-type inverter is set to zero.

[0011] Preferably, the condition for releasing the current limitation is that the voltage of the public access point of the power grid is higher than a preset voltage threshold.

[0012] Preferably, the step of updating the active power of the grid-connected inverter comprises:

[0013] When the current active power of the grid-type inverter is less than the active power reference value, the active power reference value and the current active power are subtracted, and the active power of the grid-type inverter is updated using the subtraction result.

[0014] Preferably, the step of updating the current loop reference value of the grid-connected inverter using the updated active power comprises:

[0015] Perform power difference processing on the updated active power and the active power reference value, perform droop control on the power difference result, and obtain the angular frequency deviation;

[0016] Using the angular frequency deviation to perform integral control to obtain a power angle;

[0017] Determine the phase according to the power angle and the angular frequency, wherein the angular frequency is obtained by performing integral control on the angular frequency reference value;

[0018] The current loop reference value of the grid-type inverter is rotationally updated using the phase.

[0019] In a second aspect, the present invention further provides a phase jump fault recovery system for a grid-type inverter, comprising:

[0020] A current limiting module, for responding to a phase jump fault in the power grid and triggering a current limiting request of the grid-forming inverter, setting a -q axis current component of a current loop reference value of the grid-forming inverter as an allowable maximum current value, forming a limiting current loop reference value and limiting the output current of the grid-forming inverter;

[0021] A current updating module, used for updating the active power of the grid-type inverter after the current amplitude limiting is released, and using the updated active power to update the current loop reference value of the grid-type inverter, the current loop reference value being the current loop reference value after the current amplitude limiting is released from the amplitude limiting current loop reference value;

[0022] The state switching module is used to switch the power grid to a network control state when the current loop reference value is less than a preset current threshold value.

[0023] In a third aspect, the present invention further provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the phase jump fault recovery method of the grid-type inverter as described in the first aspect.

[0024] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the steps of the phase jump fault recovery method of the grid-connected inverter as described in the first aspect are implemented.

[0025] In a fifth aspect, the present invention further provides a computer program product, comprising a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, wherein when the program instructions are executed by a computer, the computer executes the steps of the phase jump fault recovery method of the grid-type inverter as described in the first aspect.

[0026] It can be seen from the above technical scheme that when the current limiting of the grid-forming inverter is triggered, the present invention preferentially sets the -q-axis current component of the current loop reference value of the grid-forming inverter as the maximum allowable current value, which greatly improves the limit cut-off angle of the system, enhances the transient stability of the system, and adopts a virtual power desaturation strategy to update the active power of the grid-forming inverter, thereby updating the current loop reference value of the grid-forming inverter, eliminating the hidden danger that the grid-forming inverter converges to an abnormal balance point and cannot return to the grid-forming state, ensuring that the grid-forming inverter has only one balance point and can autonomously return to the balance point, restore the grid-forming operation state, and ensure stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the system architecture diagram of the grid-connected inverter;

[0028] Figure 2 This is the control block diagram of the grid-connected inverter;

[0029] Figure 3 It is the control logic diagram of the d-axis priority current control strategy;

[0030] Figure 4 It is the voltage and current vector diagram under the current limiting mode based on the d-axis current priority strategy;

[0031] Figure 5The power angle-output power curve of the grid-type inverter before and after current limiting;

[0032] Figure 6 A flow chart of a phase jump fault recovery method for a grid-type inverter;

[0033] Figure 7 The relationship diagram between the output voltage vector and the current vector of the grid-type inverter under the strategy of giving priority to the -q axis current component;

[0034] Figure 8 The power angle-output power curve of the grid-connected inverter under the strategy of giving priority to the -q axis current component;

[0035] Fig. 9 A control logic diagram for phase jump fault recovery of a grid-type inverter;

[0036] Fig.10 The power angle-output power curve of the grid-type inverter;

[0037] Fig.11 This is a diagram showing the change in system power angle during the ride-through process when the power angle suddenly increases by π / 6;

[0038] Fig.12 The system output power value during the ride-through process when the power angle suddenly increases by π / 6;

[0039] Fig.13 It is a structural schematic diagram of a phase jump fault recovery system of a grid-type inverter;

[0040] Fig.14 The figure is a schematic diagram of the structure of an electronic device. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The present application provides a method for recovering from a phase jump fault of a grid-type inverter, which can be applied to Figure 1 In the system architecture of the grid-connected inverter shown in FIG. Figure 1 As shown, the inductor L f and capacitor C f The output LC filter is formed, L g Represents the line impedance. V dc and v gRepresent the DC link voltage and grid voltage respectively, e represents the voltage at the point of common coupling (PCC), and i represents the converter side current. The inner loop uses dual-loop vector control to make e track the voltage reference value e ref E and θ represent the voltage reference value e ref The amplitude and phase of P ref and P e Represents active power reference value and actual output power respectively. pf represents the droop coefficient of the active loop, Δω represents the angular frequency deviation, and δ is the power angle of the grid inverter, which is generated by integrating Δω. ref and Q e Respectively represent the reactive power reference value and the actual output reactive power value, k pf Represents the droop coefficient of the reactive loop, and E0 represents the rated grid voltage amplitude.

[0043] From the public access point, the overall output characteristics of the grid-connected inverter can be regarded as a controlled voltage loop series resistor. Figure 2 The control block diagram shown treats the grid-connected inverter as a controlled voltage source, generates power angle information through a power synchronization mechanism, and then controls the active power injected into the grid.

[0044] When the grid voltage fails, it is necessary to limit the output current of the grid-connected inverter, such as Figure 3 As shown, d-axis priority current control (d-axis Priority-Current Control) is when various grid voltage faults cause the grid-type inverter to trigger current limiting, the power angle generated by the active loop is directly given to the current loop. The current capacity of the system is all allocated to the d-axis. At this time, the expression of the current reference is as follows:

[0045] Formula 1

[0046] In formula 1, , are the d-axis and q-axis current components of the current loop reference value of the grid-type inverter, It is the maximum allowable current value of the grid-connected inverter, that is, the grid-connected inverter operates within the maximum allowable current value and does not trigger current limiting.

[0047] Under the d-axis priority current control strategy, when the current limiting condition is completed, it enters the normal condition, such as Figure 3 The control logic shown in the figure, the output power of the grid-type inverter under the d-axis priority current control strategy is expressed as follows:

[0048] Formula 2

[0049] In formula 2, is the output power.

[0050] Under the grid-forming control strategy without triggering the current limit, the output power of the grid-forming inverter is:

[0051] Formula 3

[0052] In formula 3, is the rated grid voltage amplitude, is the line impedance between the grid-connected inverter and the grid.

[0053] The voltage and current vector diagram under the current limiting mode based on the d-axis current priority strategy is as follows Figure 4 As shown, V g Represents the output voltage vector of the grid-connected inverter, I c Represents the output current vector of the grid-connected inverter.

[0054] The d-axis priority current control strategy can greatly reduce the limit cut-off angle of the grid-type inverter. The power angle-output power curve of the grid-type inverter before and after current limiting is shown in the figure below: Figure 5 shown. Figure 5 In the figure, the system works at point a before the fault. When the grid voltage phase angle jump fault occurs, the grid-connected inverter will jump to the red curve due to current limiting. The limit cut-off angle corresponding to the red curve is point b. Before saturation, the critical cut-off angle of the system corresponds to point c. Point b is at and point c is between Therefore, when the d-axis priority current control strategy is adopted, the power angle δ of the system is finally stabilized at As a result, the limit cut-off angle of the grid-connected inverter system will be greatly reduced, and the transient stability of the system will be weakened.

[0055] When a grid voltage phase angle jump fault occurs, the grid-connected inverter cannot desaturate autonomously. Figure 5 As shown in the figure, when current limiting occurs, the balance point of the system will move from point b to point d. If the fault is a phase jump fault, the system will always work at point d after the fault occurs, and will always be in the current limiting state. It cannot independently exit saturation and recover to the rated working point a of the voltage source state.

[0056] For this reason, Figure 6 As shown, a phase jump fault recovery method of a grid-type inverter provided in an embodiment of the present application includes the following steps S1 to S3. Among them:

[0057] Step S1, in response to a phase jump fault in the power grid triggering a current limiting request for the grid-forming inverter, the -q-axis current component of the current loop reference value of the grid-forming inverter is set as the maximum allowable current value, a limiting current loop reference value is formed, and the output current of the grid-forming inverter is limited.

[0058] The condition for triggering the current limit request of the grid-type inverter is that the modulus of the current loop reference value is greater than the maximum allowable current value. When the condition for the current limit request of the grid-type inverter is not triggered, the grid-type inverter will automatically return to the original balance point.

[0059] Among them, the -q-axis current component of the current loop reference value of the grid-type inverter is given priority as the maximum allowable current value compared to the d-axis current component, and at the same time, the d-axis current component of the current loop reference value of the grid-type inverter is given as zero. That is, the d-axis and q-axis current components of the current loop reference value of the grid-type inverter are given as follows:

[0060] Formula 4

[0061] Under the strategy of giving priority to the -q axis current component in the embodiment of the present invention, the relationship between the output voltage vector and the current vector of the grid-type inverter is as follows: Figure 7 As shown, the output current I c Along the -q axis. Then the output power of the grid-type inverter is:

[0062] Formula 5

[0063] The power angle-output power curve of the grid-connected inverter with the strategy of giving priority to the -q axis current component is as follows: Figure 8 Shown by the purple curve. Figure 8 In the figure, point d1 is the steady-state operating point under the current limiting state, and point b1 is the operating point corresponding to the limit cut-off angle under the current limiting state. Point b1 is located at Therefore, compared with the d-axis current priority limiting strategy, the -q-axis current priority limiting strategy can greatly increase the system's limit resection angle (increased by 90°) and improve the system's transient stability under phase jump faults.

[0064] like Fig. 9 The control logic of phase jump fault recovery of the meshed inverter shown in the figure, this embodiment sets the -q axis current component of the current loop reference value of the meshed inverter as the maximum allowable current value, forms a limiting current loop reference value and sends it to the current closed loop of the meshed inverter for control, and modulates the output current of the meshed inverter using the limiting current loop reference value through a PWM modulator, so that the output current of the meshed inverter follows the limiting current loop reference value and is limited to the maximum allowable current value.

[0065] Step S2, after releasing the current limiting, updating the active power of the grid-type inverter, and using the updated active power to update the current loop reference value of the grid-type inverter, the current loop reference value is the current loop reference value after releasing the current limiting.

[0066] It should be noted that the condition for releasing the current limiting is that the voltage at the public access point of the power grid is higher than the preset voltage threshold, that is, when it is detected that the voltage at the public access point of the power grid is higher than the preset voltage threshold, the current limiting is released, so that the grid-connected inverter enters normal operating conditions, where the voltage threshold can be set to 1.0pu.

[0067] After releasing the current limit, the power grid needs to be switched to the grid control state and slowly return to the original balance point, such as Figure 5 As shown in the figure, when current limiting occurs, the system's equilibrium point will move from point b to point d. If the fault is a phase jump fault, the system will always work at point d after the fault occurs, and will always be in the current limiting state. It cannot automatically exit saturation and return to the rated working point a of the voltage source state, that is, there are two equilibrium points ( Figure 5 Therefore, when a phase jump fault occurs and triggers circuit limiting, the system may still converge to the abnormal equilibrium point d1 and cannot autonomously exit saturation and return to the networking state.

[0068] Based on this, an embodiment of the present invention adopts a virtual power feedback strategy. Specifically, in the process of updating the active power of the grid-type inverter, when the current active power of the grid-type inverter is less than the active power reference value, the active power reference value and the current active power are subtracted, and the active power of the grid-type inverter is updated using the subtraction result.

[0069] Among them, the updated calculation method of the active power of the grid-connected inverter is:

[0070] Formula 6

[0071] In formula 6, is the updated active power of the grid-connected inverter, is the active power under the -q axis current component, It is the active current reference value.

[0072] like Fig. 9 As shown, the process of updating the current loop reference value of the grid-type inverter using the updated active power includes:

[0073] S201, performing power difference processing on the updated active power and the active power reference value, performing droop control on the power difference result, and obtaining an angular frequency deviation;

[0074] S202, using the angular frequency deviation to perform integral control to obtain a power angle;

[0075] S203, determining the phase according to the power angle and the angular frequency, wherein the angular frequency is obtained by performing integral control on the angular frequency reference value;

[0076] S204, using the phase to rotate and update the current loop reference value of the grid-type inverter.

[0077] Under this strategy, the power angle-output power curve of the grid-type inverter is as follows: Fig.10 As shown. Fig.10 It can be seen that the inherent equilibrium point d1 under the current limiting state becomes an unstable saddle point. After converging to point d1, the operating point of the system will continue to decrease until the current meets the exit condition and converges to the only equilibrium point a.

[0078] Step S3: When the current loop reference value is less than the preset current threshold value, the power grid is switched to the grid construction control state.

[0079] It should be noted that the embodiment of the present invention adopts a virtual power feedback strategy to continuously reduce the power angle value of the grid-connected inverter, and use the power angle to update the current loop reference value. In this process, the current reference value output by the voltage loop is continuously detected. When the current loop reference value is less than the preset current threshold value, the power grid is switched to the grid control state and slowly returns to the original balance point; when the current loop reference value is not less than the preset current threshold value, it is necessary to use the virtual power feedback strategy to further update the active power of the grid-connected inverter until the current loop reference value is less than the preset current threshold value, and the power grid is switched to the grid control state for stable operation.

[0080] It should be noted that when the current limiting of the meshing type inverter is triggered, the present invention preferentially sets the -q axis current component of the current loop reference value of the meshing type inverter as the maximum allowable current value, which greatly improves the limit cut-off angle of the system and enhances the transient stability of the system. The virtual power desaturation strategy adopted is used to update the active power of the meshing type inverter, thereby updating the current loop reference value of the meshing type inverter, eliminating the hidden danger that the meshing type inverter converges to an abnormal balance point and cannot return to the meshing state, ensuring that the meshing type inverter has only one balance point and can autonomously return to the balance point, restore the meshing operation state, and ensure stable operation of the power grid.

[0081] like Fig.11 and Fig.12They are respectively the system power angle change and system output power change when the phase jump fault recovery method of the grid-type inverter proposed in the embodiment of the present application is adopted when the phase suddenly increases by π / 6. Among them, the fault occurs at 4.5 seconds, and the signal that enables switching back to the grid control is enabled at 12 seconds. Figures 11-12 As shown in the figure, after the phase jump occurs, the current limit of the system is triggered, and the system converges to Fig.10 The abnormal balance point d1 is shown. When the signal (de-saturation signal) for switching back to grid control is enabled, the power angle of the grid-connected inverter continues to decrease, and when the current reference value is less than the threshold value, it switches back to grid control. At this time, the power angle and output power are restored to the power angle value before the fault. The system fault ride-through is successful.

[0082] Based on the same inventive concept, an embodiment of the present application also provides a phase jump fault recovery system of a meshed inverter for implementing the phase jump fault recovery method of the meshed inverter involved above.

[0083] The implementation solution for solving the problem provided by the system is similar to the implementation solution recorded in the above method. Therefore, the specific limitations in the phase jump fault recovery system embodiments of one or more grid-type inverters provided below can be referred to the limitations on the phase jump fault recovery method of the grid-type inverter in the above text, and will not be repeated here.

[0084] like Fig.13 As shown, an embodiment of the present application provides a phase jump fault recovery system for a grid-type inverter, comprising:

[0085] The current limiting module 100 is used to respond to a phase jump fault in the power grid and trigger a current limiting request of the grid-forming inverter, set the -q axis current component of the current loop reference value of the grid-forming inverter as the maximum allowable current value, form a limiting current loop reference value and limit the output current of the grid-forming inverter;

[0086] The current updating module 200 is used to update the active power of the grid-type inverter after the current amplitude limiting is released, and to update the current loop reference value of the grid-type inverter using the updated active power, wherein the current loop reference value is the current loop reference value after the amplitude limiting current loop reference value is released;

[0087] The state switching module 300 is used to switch the power grid to the grid construction control state when the current loop reference value is less than a preset current threshold value.

[0088] The condition for triggering the current limit request of the grid-type inverter is that the modulus of the current loop reference value is greater than the maximum allowable current value.

[0089] When the current amplitude limiting request of the grid-type inverter is triggered, the d-axis current component of the current loop reference value of the grid-type inverter is set to zero.

[0090] The condition for releasing the current limitation is that the voltage at the public access point of the power grid is higher than a preset voltage threshold.

[0091] Among them, the active power of the grid-connected inverter is updated, including:

[0092] When the current active power of the grid-forming inverter is less than the active power reference value, the active power reference value and the current active power are subtracted, and the active power of the grid-forming inverter is updated using the subtraction result.

[0093] The current loop reference value of the grid-connected inverter is updated using the updated active power, including:

[0094] Perform power difference processing on the updated active power and the active power reference value, perform droop control on the power difference result, and obtain the angular frequency deviation;

[0095] The power angle is obtained by performing integral control using the angular frequency deviation;

[0096] Determine the phase according to the power angle and the angular frequency, wherein the angular frequency is obtained by integral control of the angular frequency reference value;

[0097] The phase is used to rotate and update the current loop reference value of the grid-connected inverter.

[0098] like Fig.14 As shown, an embodiment of the present application also provides an electronic device, the electronic device 10 includes a memory 20 and a processor 30, the memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 executes the steps of the phase jump fault recovery method of the grid-type inverter in any of the above embodiments.

[0099] An embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed, the steps of the phase jump fault recovery method of the grid-type inverter in any of the above embodiments are implemented.

[0100] An embodiment of the present application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the steps of the phase jump fault recovery method of the grid-type inverter in any of the above embodiments.

[0101] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, electronic devices, computer storage media and computer program products can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0102] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0103] In several embodiments provided by the present invention, it is understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and a part of a module, a program segment or a code includes one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved.

[0104] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, electronic devices, computer storage media, computer program products and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, 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.

[0105] 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.

[0106] In addition, each functional unit in each embodiment of the present invention 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.

[0107] 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 invention 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 several instructions for executing all or part of the steps of the method described in each embodiment of the present invention 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.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. 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 invention.

Claims

1. A phase jump fault recovery method for a grid-connected inverter, characterized in that: include: In response to a phase jump fault occurring in the power grid and triggering a current limiting request of the grid-forming inverter, a -q-axis current component of a current loop reference value of the grid-forming inverter is set as an allowable maximum current value, a limiting current loop reference value is formed, and an output current of the grid-forming inverter is limited; After releasing the current amplitude limiting, updating the active power of the grid-type inverter, and using the updated active power to update the current loop reference value of the grid-type inverter, the current loop reference value being the current loop reference value after releasing the current amplitude limiting of the amplitude limiting current loop reference value; When the current loop reference value is less than a preset current threshold value, the power grid is switched to a grid control state.

2. The phase jump fault recovery method of the grid-connected inverter according to claim 1, characterized in that: The condition for triggering the current limiting request of the grid-type inverter is that the modulus of the current loop reference value is greater than the allowable maximum current value.

3. The phase jump fault recovery method of the grid-connected inverter according to claim 1, characterized in that: When the current amplitude limiting request of the grid-type inverter is triggered, the d-axis current component of the current loop reference value of the grid-type inverter is set to zero.

4. The phase jump fault recovery method of the grid-connected inverter according to claim 1, characterized in that: The condition for releasing the current limitation is that the voltage of the public access point of the power grid is higher than a preset voltage threshold.

5. The phase jump fault recovery method of the grid-connected inverter according to claim 1, characterized in that: The step of updating the active power of the grid-connected inverter comprises: When the current active power of the grid-type inverter is less than the active power reference value, the active power reference value and the current active power are subtracted, and the active power of the grid-type inverter is updated using the subtraction result.

6. The phase jump fault recovery method of the grid-connected inverter according to claim 1, characterized in that: The step of updating the current loop reference value of the grid-connected inverter by using the updated active power comprises: Perform power difference processing on the updated active power and the active power reference value, perform droop control on the power difference result, and obtain the angular frequency deviation; Using the angular frequency deviation to perform integral control to obtain a power angle; Determine the phase according to the power angle and the angular frequency, wherein the angular frequency is obtained by performing integral control on the angular frequency reference value; The current loop reference value of the grid-type inverter is rotationally updated using the phase.

7. A phase jump fault recovery system for a grid-type inverter, characterized in that: include: A current limiting module, for responding to a phase jump fault in the power grid and triggering a current limiting request of the grid-forming inverter, setting a -q axis current component of a current loop reference value of the grid-forming inverter as an allowable maximum current value, forming a limiting current loop reference value and limiting the output current of the grid-forming inverter; A current updating module, used for updating the active power of the grid-type inverter after the current amplitude limiting is released, and using the updated active power to update the current loop reference value of the grid-type inverter, the current loop reference value being the current loop reference value after the current amplitude limiting is released from the amplitude limiting current loop reference value; The state switching module is used to switch the power grid to a network control state when the current loop reference value is less than a preset current threshold value.

8. An electronic device, characterized in that: The electronic device includes a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the phase jump fault recovery method of the grid-type inverter as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the steps of the phase jump fault recovery method of the grid-type inverter as described in any one of claims 1 to 6 are implemented.

10. A computer program product, characterized in that The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the steps of the phase jump fault recovery method of the grid-type inverter as described in any one of claims 1 to 6.

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