Method and device for suppressing power frequency overvoltage of new energy inverter

Abstract

The invention provides a new energy inverter power frequency overvoltage suppression method and device, and the method comprises the steps: determining the additional reactive current of a new energy inverter according to the terminal voltage of the new energy inverter, calculating the first reactive current reference value of the new energy inverter according to the additional reactive current, and carrying out the suppression of the power frequency overvoltage according to the first current reference value. It can be seen that in combination with the additional reactive current of the new energy inverter, the first reactive current reference value can be reduced by absorbing the additional reactive current, then the terminal voltage of the new energy inverter can be remarkably reduced, the suppression effect on the power frequency overvoltage is good, the new energy inverter is prevented from being off-grid, and the service life of the new energy inverter is prolonged. And reliable operation of the new energy inverter is ensured.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a method and device for suppressing power frequency overvoltage of a new energy inverter. Background Art

[0002] In order to compensate for the reactive power consumed by new energy stations and their transmission lines, a large number of reactive power compensation equipment are usually installed in new energy stations, collection areas, DC converter stations and other locations. However, after an AC short circuit fault, DC commutation failure or DC lockout occurs in the power grid, the reactive power compensation equipment cannot be withdrawn in time and injects excess reactive power into the power grid, causing the power grid voltage to overvoltage. If the reactive current injected by the new energy inverter is unreasonable, it will cause serious power frequency overvoltage (referring to overvoltage lasting more than 20ms) in the new energy inverter. Power frequency overvoltage will cause new energy units to be disconnected from the grid, so the overvoltage problem has become the main factor restricting the development of new energy.

[0003] In order to suppress the power frequency overvoltage of the new energy inverter, the related technology usually directly reduces the reactive current reference command, and then realizes the power frequency overvoltage suppression of the new energy inverter by reducing the grid side voltage. Although the suppression method provided by the related technology can suppress the power frequency overvoltage to a certain extent, it only considers the amplitude of the power frequency overvoltage, and the suppression reliability is poor, and there is still a large risk of the new energy inverter being disconnected from the grid. Summary of the invention

[0004] In order to solve the problem of poor suppression reliability in the prior art, the present application provides a method for suppressing power frequency overvoltage of a new energy inverter, which may include:

[0005] The additional reactive current of the new energy inverter is determined according to the terminal voltage of the new energy inverter.

[0006] A first reactive current reference value of the new energy inverter is calculated according to the additional reactive current.

[0007] The power frequency overvoltage is suppressed according to the q-axis current reference value.

[0008] In some possible implementations, determining the additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter includes:

[0009] The additional reactive current flag is set according to the terminal voltage of the new energy inverter.

[0010] The additional reactive current is determined according to the additional reactive current flag.

[0011] Furthermore, the additional reactive current flag is set according to the terminal voltage of the new energy inverter, including:

[0012] If the terminal voltage of the new energy inverter exceeds a preset first voltage threshold, and the duration of the terminal voltage of the new energy inverter exceeding the first voltage threshold exceeds a preset delay, the additional reactive current flag is set to 1.

[0013] If the terminal voltage of the new energy inverter does not exceed the preset second voltage threshold, the additional reactive current flag is set to 0.

[0014] The second voltage threshold is smaller than the first voltage threshold.

[0015] Optionally, determining the additional reactive current according to the additional reactive current flag bit includes:

[0016] If the additional reactive current flag is 1, the additional reactive current is gradually reduced according to the preset rate of change of the additional reactive current. If the additional reactive current flag is 0, it is determined that the additional reactive current remains unchanged.

[0017] The additional reactive current is limited according to an upper limit of the additional reactive current and a lower limit of the additional reactive current.

[0018] Exemplarily, the additional reactive current satisfies:

[0019]

[0020] Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

[0021] Optionally, limiting the additional reactive current according to an upper limit of the additional reactive current and a lower limit of the additional reactive current includes:

[0022] If the additional reactive current is greater than the upper limit of the additional reactive current, the additional reactive current is set to the upper limit of the additional reactive current.

[0023] If the additional reactive current is less than the lower limit of the additional reactive current, the additional reactive current is set to the lower limit of the additional reactive current.

[0024] In some possible implementations, calculating a first reactive current reference value of the new energy inverter according to the additional reactive current includes:

[0025] The additional reactive current is superimposed on the preset second reactive current reference value to obtain the first reactive current reference value.

[0026] In some other possible implementations, the power frequency overvoltage of the new energy inverter is suppressed according to the q-axis current reference value, including:

[0027] The first reactive current reference value is inverted to obtain a q-axis current reference value.

[0028] The q-axis current component of the new energy inverter is current controlled according to the q-axis current reference value of the new energy inverter to obtain the q-axis modulation voltage component.

[0029] The d-axis current component of the new energy inverter is controlled according to the d-axis current reference value of the new energy inverter to obtain the d-axis modulation voltage component.

[0030] The q-axis modulation voltage component and the d-axis modulation voltage component are subjected to Park transformation to obtain the three-phase modulation voltage of the new energy inverter.

[0031] The three-phase modulation voltage is modulated to obtain a driving signal.

[0032] The power frequency overvoltage is suppressed according to the driving signal.

[0033] On the other hand, the present application provides a device for suppressing power frequency overvoltage of a new energy inverter, characterized in that it includes:

[0034] The determination module is used to determine the additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter.

[0035] The calculation module is used to calculate a first reactive current reference value of the new energy inverter according to the additional reactive current.

[0036] The suppression module is used to suppress the power frequency overvoltage according to the q-axis current reference value.

[0037] In some possible implementations, the determination module is specifically configured to:

[0038] The additional reactive current flag is set according to the terminal voltage of the new energy inverter.

[0039] The additional reactive current is determined according to the additional reactive current flag.

[0040] Optionally, determine whether the module is specifically used for:

[0041] If the terminal voltage of the new energy inverter exceeds a preset first voltage threshold, and the duration of the terminal voltage of the new energy inverter exceeding the first voltage threshold exceeds a preset delay, the additional reactive current flag is set to 1.

[0042] If the terminal voltage of the new energy inverter does not exceed the preset second voltage threshold, the additional reactive current flag is set to 0.

[0043] The second voltage threshold is smaller than the first voltage threshold.

[0044] Furthermore, the module is specifically used to:

[0045] If the additional reactive current flag is 1, the additional reactive current is gradually reduced according to the preset rate of change of the additional reactive current. If the additional reactive current flag is 0, it is determined that the additional reactive current remains unchanged.

[0046] The additional reactive current is limited according to an upper limit of the additional reactive current and a lower limit of the additional reactive current.

[0047] Exemplarily, the additional reactive current satisfies:

[0048]

[0049] Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

[0050] Optionally, determine whether the module is specifically used for:

[0051] If the additional reactive current is greater than the upper limit of the additional reactive current, the additional reactive current is set to the upper limit of the additional reactive current.

[0052] If the additional reactive current is less than the lower limit of the additional reactive current, the additional reactive current is set to the lower limit of the additional reactive current.

[0053] In some further possible implementations, the computing module is specifically used for:

[0054] The additional reactive current is superimposed on the preset second reactive current reference value to obtain the first reactive current reference value.

[0055] In some other possible implementations, the suppression module is specifically used to:

[0056] The first reactive current reference value is inverted to obtain a q-axis current reference value.

[0057] The q-axis current component of the new energy inverter is current controlled according to the q-axis current reference value of the new energy inverter to obtain the q-axis modulation voltage component.

[0058] The d-axis current component of the new energy inverter is controlled according to the d-axis current reference value of the new energy inverter to obtain the d-axis modulation voltage component.

[0059] The q-axis modulation voltage component and the d-axis modulation voltage component are subjected to Park transformation to obtain the three-phase modulation voltage of the new energy inverter.

[0060] The three-phase modulation voltage is modulated to obtain a driving signal.

[0061] The power frequency overvoltage is suppressed according to the driving signal.

[0062] On the other hand, the present application also provides a computer device, including: one or more processors.

[0063] A processor is used to execute one or more programs.

[0064] When one or more programs are executed by one or more processors, the suppression method as described above is implemented.

[0065] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the above-mentioned suppression method is implemented.

[0066] Compared with the prior art, the beneficial effects of this application are:

[0067] In the method for suppressing power frequency overvoltage of a new energy inverter provided in the present application, the additional reactive current of the new energy inverter is determined according to the terminal voltage of the new energy inverter, the first reactive current reference value of the new energy inverter is calculated according to the additional reactive current, and the power frequency overvoltage is suppressed according to the first current reference value. It can be seen that the present application combines the additional reactive current of the new energy inverter, and the first reactive current reference value can be reduced by the additional reactive current, thereby suppressing the power frequency overvoltage of the new energy inverter according to the first current reference value, and the suppression reliability is high.

[0068] The present application can significantly reduce the terminal voltage of the new energy inverter by absorbing additional reactive current, has a good effect in suppressing power frequency overvoltage, avoids the new energy inverter from being disconnected from the grid, and ensures the reliable operation of the new energy inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0070] Figure 1 A schematic flow chart of a method for suppressing power frequency overvoltage of a new energy inverter in an embodiment of the present application;

[0071] Figure 2Another schematic flow chart of a method for suppressing power frequency overvoltage of a new energy inverter in an embodiment of the present application;

[0072] Figure 3 It is a schematic diagram of the terminal voltage, active current and reactive current waveforms of the new energy inverter when no additional reactive current is absorbed in the related art;

[0073] Figure 4 This is a schematic diagram of the terminal voltage, active current and reactive current waveforms of the new energy inverter after absorbing the additional reactive current in the embodiment of the present application;

[0074] Figure 5 This is a schematic structural diagram of a device for suppressing power frequency overvoltage of a new energy inverter in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0076] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device 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 devices.

[0077] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0078] Embodiment 1:

[0079] The present application embodiment provides a method for suppressing power frequency overvoltage of a new energy inverter. Figure 1 The suppression method 100 comprises the following steps:

[0080] Step S1: According to the terminal voltage of the new energy inverter (which can be expressed as u term Indicates that through Figure 2 Three-phase terminal voltage u of new energy inverter ta 、u tb 、u tc Calculated), determine the additional reactive current of the new energy inverter.

[0081] Step S2: Calculate the first reactive current reference value of the new energy inverter according to the additional reactive current (which can be calculated using i Qref1 express).

[0082] Step S3: suppressing the power frequency overvoltage according to the first current reference value.

[0083] In some possible implementations, determining the additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter in step S1 includes:

[0084] According to the terminal voltage u of the new energy inverter term Set the additional reactive current flag Flag_I Qad .

[0085] According to the additional reactive current flag Flag_I Qad Determine the additional reactive current.

[0086] Furthermore, according to the terminal voltage u of the new energy inverter term Set the additional reactive current flag Flag_I Qad ,include:

[0087] If the terminal voltage u of the new energy inverter term Exceeds the preset first voltage threshold (can be used u HVpf1 represents), that is, satisfying u term >u HVpf1 , and the terminal voltage of the new energy inverter exceeds the first voltage threshold for a duration exceeding a preset delay (which can be expressed as T HVpf Indicates), the reactive current flag Flag_I is added Qad Set to 1.

[0088] If the terminal voltage of the new energy inverter does not exceed the preset second voltage threshold (which can be HVpf2 represents), that is, satisfying u term ≤u HVpf2 , add the reactive current flag Flag_I Qad Set to 0.

[0089] The second voltage threshold is smaller than the first voltage threshold. The second voltage threshold can be 1.05 pu, and the first voltage threshold can be 1.1 pu.

[0090] Optionally, according to the additional reactive current flag Flag_I Qad Determine the additional reactive current, including:

[0091] If the additional reactive current flag is 1, according to the preset additional reactive current change rate K ad Gradually reduce the additional reactive current. If the additional reactive current flag is 0, it is determined that the additional reactive current remains unchanged.

[0092] According to the upper limit of additional reactive current I Qadmax and the lower limit of the additional reactive current I Qadmin Limit the additional reactive current.

[0093] Exemplarily, the additional reactive current satisfies:

[0094]

[0095] Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

[0096] Optional, according to the upper limit of additional reactive current I Qadmax and the lower limit of the additional reactive current I Qadmin Limit the additional reactive current, including:

[0097] If the additional reactive current i Qad_k+1 Greater than the upper limit of additional reactive current I Qadmax , the additional reactive current i Qad_k+1 Set as the upper limit of the additional reactive current I Qadmax .

[0098] If the additional reactive current i Qad_k+1 Less than the lower limit of additional reactive current I Qadmin , the additional reactive current i Qad_k+1 Set as the lower limit of the additional reactive current I Qadmin .

[0099] In some further possible implementations, calculating the first reactive current reference value of the new energy inverter according to the additional reactive current in step S2 includes:

[0100] The additional reactive current iQad_k+1 and the preset second reactive current reference value (which can be Qref2 The first reactive current reference value (which can be represented by i Qref1 express).

[0101] In some other possible implementations, such as Figure 2 As shown, in step S3, the power frequency overvoltage of the new energy inverter is suppressed according to the q-axis current reference value, including:

[0102] The first reactive current reference value i Qref1 Take the inverse value and get the q-axis current reference value (which can be used with i qref express).

[0103] According to the q-axis current reference value i qref For the q-axis current component of the new energy inverter (which can be represented by i q Indicates that the terminal current i of the new energy inverter a 、i b 、i c Perform Park transformation to obtain) to perform current control and obtain the q-axis modulation voltage component (which can be obtained by u mq In other words, the q-axis current reference value i qref and the q-axis current component i of the new energy inverter q Input current controller, the current controller can output q-axis modulation voltage component u mq . Figure 2 In, G i (s) represents the current controller, H i Represents the current feedback coefficient.

[0104] According to the d-axis current reference value of the new energy inverter (which can be used dref Represents) the d-axis current component of the new energy inverter (can be represented by i d To express) current control, the d-axis modulation voltage component is obtained (which can be expressed as u md In other words, the d-axis current reference value i of the new energy inverter is dref and the d-axis current component i of the new energy inverter d Input current controller, the current controller can output d-axis modulation voltage component u md .

[0105] According to the phase θ of the new energy inverter, the q-axis modulation voltage component u mq and the d-axis modulation voltage component u md Perform Park transformation to obtain the three-phase modulation voltage of the new energy inverter (which can be expressed as u ma 、u mb 、umc express).

[0106] For three-phase modulation voltage u ma 、u mb 、u mc Modulation is performed (which may be sinusoidal pulse width modulation, ie, SPWM) to obtain a driving signal DS.

[0107] The power frequency overvoltage is suppressed according to the driving signal DS. It is conceivable that the inverter bridge of the new energy inverter is controlled according to the driving signal DS, and the semiconductor devices of the bridge arm in the inverter bridge will act accordingly to reduce the reactive current of the new energy inverter, thereby achieving the suppression of the power frequency overvoltage.

[0108] refer to Figure 2 The new energy inverter in the embodiment of the present application may include an inverter bridge 1 and a filter module 2. The filter module 2 may include an inductor L1, an inductor L2 and a capacitor C. Figure 2 in, u s Indicates the voltage of the power grid, L s Represents the impedance of the power grid.

[0109] The suppression effect of the method for suppressing power frequency overvoltage of the new energy inverter provided in the embodiment of the present application is verified below. Figure 3 The terminal voltage u of the new energy inverter is shown when no additional reactive current is absorbed. term , active current i P and reactive current i Q Waveform. Figure 3 In the figure, the horizontal axis represents time t. Figure 3 It can be seen that after the fault is cleared, the terminal voltage of the new energy inverter can only drop to about 1.15pu and cannot return to below 1.1pu. The new energy inverter still has the risk of overvoltage and disconnection from the grid after long-term operation. Figure 4 The terminal voltage u of the new energy inverter after absorbing the additional reactive current is shown. term , active current i P and reactive current i Q Waveform. Figure 4 In the figure, the horizontal axis represents time t. Figure 4 It can be seen that the peak voltage of the terminal voltage can reach 1.32pu. When the power frequency overvoltage lasts for more than 1s, Flag_I Qad Set to 1 to start absorbing additional reactive current (I Qad The reactive current of the new energy inverter begins to decrease (such as Figure 4 The terminal voltage of the new energy inverter also decreases slowly. When the terminal voltage of the new energy inverter is lower than 1.05pu, Flag_I QadSet to 0, the reactive current of the new energy inverter will no longer decrease (such as Figure 4 By comparing Figure 3 and Figure 4 It can be found that absorbing additional reactive current can significantly reduce the terminal voltage of the new energy inverter and has a good inhibitory effect on power frequency overvoltage.

[0110] Embodiment 2:

[0111] Based on the same inventive concept, the embodiment of the present application also provides a device for suppressing power frequency overvoltage of a new energy inverter. Figure 5 As shown, the suppression device 200 comprises:

[0112] Determining module 21, used for determining the terminal voltage of the new energy inverter (which can be term Indicates that through Figure 2 Three-phase terminal voltage u of new energy inverter ta 、u tb 、u tc Calculated) to determine the additional reactive current of the new energy inverter.

[0113] The calculation module 22 is used to calculate the first reactive current reference value of the new energy inverter according to the additional reactive current (which can be calculated using I Qref1 express).

[0114] The suppression module 23 is used to suppress the power frequency overvoltage according to the q-axis current reference value.

[0115] In some possible implementations, the determination module 21 is specifically configured to:

[0116] According to the terminal voltage u of the new energy inverter term Set the additional reactive current flag Flag_I Qad .

[0117] According to the additional reactive current flag Flag_I Qad Determine the additional reactive current.

[0118] Optionally, determine whether the module is specifically used for:

[0119] If the terminal voltage u of the new energy inverter term Exceeds the preset first voltage threshold (can be used u HVpf1 represents), that is, satisfying u term >u HVpf1 , and the terminal voltage u of the new energy inverter term Exceeding the first voltage threshold u HVpf1 The duration exceeds the preset delay (which can be expressed as T HVpf Indicates), the reactive current flag Flag_I is added QadSet to 1.

[0120] If the terminal voltage u of the new energy inverter term Does not exceed the preset second voltage threshold (can be used u HVpf2 represents), that is, satisfying u term ≤u HVpf2 , add the reactive current flag Flag_I Qad Set to 0.

[0121] The second voltage threshold is smaller than the first voltage threshold. The second voltage threshold can be 1.05 pu, and the first voltage threshold can be 1.1 pu.

[0122] Furthermore, the determination module 21 is specifically used for:

[0123] If the reactive current flag u is added term is 1, according to the preset rate of change of additional reactive current K ad Gradually reduce the additional reactive current. If the additional reactive current flag is u term is 0, ensuring that the additional reactive current remains unchanged.

[0124] According to the upper limit of additional reactive current I Qadmax and the lower limit of the additional reactive current I Qadmin Limit the additional reactive current.

[0125] Exemplarily, the additional reactive current satisfies:

[0126]

[0127] Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

[0128] Optionally, the determination module 21 is specifically configured to:

[0129] If the additional reactive current i Qad_k+1 Greater than the upper limit of additional reactive current I Qadmax , the additional reactive current i Qad_k+1 Set as the upper limit of the additional reactive current I Qadmax .

[0130] If the additional reactive current i Qad_k+1 Less than the lower limit of additional reactive current I Qadmin , the additional reactive current i Qad_k+1Set as the lower limit of the additional reactive current I Qadmin .

[0131] In some possible implementations, the calculation module 22 is specifically configured to:

[0132] The additional reactive current i Qad_k+1 and the preset second reactive current reference value (which can be Qref2 The first reactive current reference value i is obtained by superposition. Qref1 .

[0133] In some other possible implementations, refer to Figure 2 , the suppression module 23 is specifically used for:

[0134] The first reactive current reference value i Qref1 Take the inverse value and get the q-axis current reference value (which can be used with i qref express).

[0135] According to the q-axis current reference value i qref For the q-axis current component of the new energy inverter (which can be represented by i q To express) current control, the q-axis modulation voltage component is obtained (which can be expressed as u mq express).

[0136] According to the d-axis current reference value of the new energy inverter (which can be used dref Represents) the d-axis current component of the new energy inverter (can be represented by i d To express) current control, the d-axis modulation voltage component is obtained (which can be expressed as u md express).

[0137] The q-axis modulation voltage component u mq and the d-axis modulation voltage component u md Perform Park transformation to obtain the three-phase modulation voltage of the new energy inverter (which can be expressed as u ma 、u mb 、u mc express).

[0138] For three-phase modulation voltage u ma 、u mb 、u mc Modulation (which may be pulse width modulation, namely PWM) is performed to obtain a driving signal DS.

[0139] The power frequency overvoltage is suppressed according to the driving signal DS. It is conceivable that the inverter bridge of the new energy inverter is controlled according to the driving signal DS, and the semiconductor devices of the bridge arm in the inverter bridge will act accordingly to reduce the reactive current of the new energy inverter, thereby achieving the suppression of the power frequency overvoltage.

[0140] Embodiment 3:

[0141] Based on the same inventive concept, the embodiment of the present application also provides a computer device, which includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the suppression method provided in the above embodiment.

[0142] Embodiment 4:

[0143] Based on the same inventive concept, the embodiment of the present application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the suppression method provided in the above embodiment.

[0144] Those skilled in the art will appreciate that the embodiments of the application may be provided as methods, systems, or computer program products. Therefore, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0145] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A method for suppressing power frequency overvoltage of a new energy inverter, characterized in that: include: Determining an additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter; Calculating a first reactive current reference value of the new energy inverter according to the additional reactive current; The power frequency overvoltage is suppressed according to the first current reference value.

2. The suppression method according to claim 1, characterized in that: The step of determining the additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter comprises: Setting an additional reactive current flag according to the terminal voltage of the new energy inverter; The additional reactive current is determined according to the additional reactive current flag.

3. The suppression method according to claim 2, characterized in that: The additional reactive current flag is set according to the terminal voltage of the new energy inverter, including: If the terminal voltage of the new energy inverter exceeds a preset first voltage threshold, and the duration of the terminal voltage of the new energy inverter exceeding the first voltage threshold exceeds a preset delay, the additional reactive current flag is set to 1; If the terminal voltage of the new energy inverter does not exceed the preset second voltage threshold, the additional reactive current flag is set to 0; The second voltage threshold is smaller than the first voltage threshold.

4. The suppression method according to claim 2, characterized in that: The determining the additional reactive current according to the additional reactive current flag bit includes: If the additional reactive current flag is 1, the additional reactive current is gradually reduced according to a preset rate of change of the additional reactive current; if the additional reactive current flag is 0, it is determined that the additional reactive current remains unchanged; The additional reactive current is limited according to an upper limit of the additional reactive current and a lower limit of the additional reactive current.

5. The suppression method according to claim 4, characterized in that: The additional reactive current satisfies: Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

6. The suppression method according to claim 4, characterized in that: The step of limiting the additional reactive current according to the upper limit of the additional reactive current and the lower limit of the additional reactive current comprises: If the additional reactive current is greater than the upper limit of the additional reactive current, setting the additional reactive current to the upper limit of the additional reactive current; If the additional reactive current is less than the lower limit of the additional reactive current, the additional reactive current is set to the lower limit of the additional reactive current.

7. The suppression method according to claim 1, characterized in that: The calculating the first reactive current reference value of the new energy inverter according to the additional reactive current includes: The additional reactive current is superimposed on a preset second reactive current reference value to obtain the first reactive current reference value.

8. The suppression method according to claim 1, characterized in that: The suppressing the power frequency overvoltage of the new energy inverter according to the first current reference value includes: Reversing the first reactive current reference value to obtain a q-axis current reference value; Performing current control on the q-axis current component of the new energy inverter according to the q-axis current reference value of the new energy inverter to obtain a q-axis modulation voltage component; Performing current control on the d-axis current component of the new energy inverter according to the d-axis current reference value of the new energy inverter to obtain a d-axis modulation voltage component; Performing Park transformation on the q-axis modulation voltage component and the d-axis modulation voltage component to obtain a three-phase modulation voltage of the new energy inverter; Modulating the three-phase modulation voltage to obtain a driving signal; The power frequency overvoltage is suppressed according to the driving signal.

9. A device for suppressing power frequency overvoltage of a new energy inverter, characterized in that: include: A determination module, used to determine the additional reactive current of the new energy inverter according to the terminal voltage of the new energy inverter; A calculation module, used for calculating a first reactive current reference value of the new energy inverter according to the additional reactive current; A suppression module is used to suppress the power frequency overvoltage according to the first current reference value.

10. The suppression device according to claim 1, characterized in that The determination module is specifically used for: Setting an additional reactive current flag according to the terminal voltage of the new energy inverter; The additional reactive current is determined according to the additional reactive current flag.

11. The suppression device according to claim 10, characterized in that The determination module is specifically used for: If the terminal voltage of the new energy inverter exceeds a preset first voltage threshold, and the duration of the terminal voltage of the new energy inverter exceeding the first voltage threshold exceeds a preset delay, the additional reactive current flag is set to 1; If the terminal voltage of the new energy inverter does not exceed the preset second voltage threshold, the additional reactive current flag is set to 0; The second voltage threshold is smaller than the first voltage threshold.

12. The suppression device according to claim 10, characterized in that The determination module is specifically used for: If the additional reactive current flag is 1, the additional reactive current is gradually reduced according to a preset rate of change of the additional reactive current; if the additional reactive current flag is 0, it is determined that the additional reactive current remains unchanged; The additional reactive current is limited according to an upper limit of the additional reactive current and a lower limit of the additional reactive current.

13. The suppression device according to claim 12, characterized in that The additional reactive current satisfies: Among them, i Qad_k+1 represents the additional reactive current of the k+1th control cycle, i Qad_k represents the additional reactive current of the kth control cycle, K ad Indicates the rate of change of the additional reactive current, dt indicates the time differential, Flag_I Qad Indicates the additional reactive current flag.

14. The suppression device according to claim 12, characterized in that The determination module is specifically used for: If the additional reactive current is greater than the upper limit of the additional reactive current, setting the additional reactive current to the upper limit of the additional reactive current; If the additional reactive current is less than the lower limit of the additional reactive current, the additional reactive current is set to the lower limit of the additional reactive current.

15. The suppression device according to claim 9, characterized in that The calculation module is specifically used for: The additional reactive current is superimposed on a preset second reactive current reference value to obtain the first reactive current reference value.

16. The suppression device according to claim 9, characterized in that The suppression module is specifically used for: Reversing the first reactive current reference value to obtain a q-axis current reference value; Performing current control on the q-axis current component of the new energy inverter according to the q-axis current reference value of the new energy inverter to obtain a q-axis modulation voltage component; Performing current control on the d-axis current component of the new energy inverter according to the d-axis current reference value of the new energy inverter to obtain a d-axis modulation voltage component; Performing Park transformation on the q-axis modulation voltage component and the d-axis modulation voltage component to obtain a three-phase modulation voltage of the new energy inverter; Modulating the three-phase modulation voltage to obtain a driving signal; The power frequency overvoltage is suppressed according to the driving signal.

17. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the suppression method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the suppression method according to any one of claims 1 to 8 is implemented.

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