Positive and negative sequence component detection method, system and equipment of power grid signal and medium

Abstract

The invention discloses a positive and negative sequence component detection method, system and device for a power grid signal, and a medium. The method comprises the following steps: converting an obtained power grid signal into an orthogonal signal; a first orthogonal signal obtained after first fundamental wave tracking is conducted on the orthogonal signal and a second orthogonal signal obtained after second fundamental wave tracking is conducted on the orthogonal signal are obtained; performing amplitude compensation on the first orthogonal signal and the second orthogonal signal to obtain a third orthogonal signal and a fourth orthogonal signal; performing orthogonal transformation by combining the third orthogonal signal and the fourth orthogonal signal to obtain fundamental wave positive and negative sequence signals; and obtaining harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal so as to improve the accuracy of positive and negative sequence component detection of the power grid signal.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method, system, device and medium for detecting positive and negative sequence components of power grid signals. Background Art

[0002] With the development of science and technology and the dependence of daily life on electricity, fault detection of power grids to ensure safe, stable and efficient operation of power grids has become an important research direction of power systems. At present, the positive and negative sequence components in power grid signals are often used as important components of power grid synchronization detection for ground fault identification, power quality monitoring and compensation, etc.

[0003] However, with the access of a high proportion of distributed renewable energy and the complexity of the power system, non-ideal operating conditions such as three-phase imbalance, harmonic distortion and frequency fluctuation often occur in the power grid. The existing detection methods for extracting positive and negative sequence components of power grid signals are unable to accurately identify and detect positive and negative sequence components under the influence of the above non-ideal conditions, which in turn affects the subsequent detection of the power grid. Summary of the invention

[0004] In order to solve the above technical problems, the present invention discloses a method, system, device and medium for detecting positive and negative sequence components of power grid signals, which are used to improve the accuracy of positive and negative sequence component detection of power grid signals.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention discloses a method for detecting positive and negative sequence components of a power grid signal, comprising:

[0006] Convert the acquired power grid signal into an orthogonal signal;

[0007] Acquire a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal;

[0008] Performing amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal;

[0009] Combining the third orthogonal signal with the fourth orthogonal signal to perform orthogonal transformation to obtain fundamental wave positive and negative sequence signals;

[0010] Harmonic positive and negative sequence signals are obtained according to the fundamental positive and negative sequence signals and the power grid signal.

[0011] The present invention discloses a method for detecting positive and negative sequence components of a power grid signal. First, the acquired power grid signal is converted into a two-phase orthogonal signal to eliminate the unbalanced component in the power grid signal and realize the detection of the positive sequence component. Then, the first orthogonal signal and the second orthogonal signal corresponding to different fundamental wave tracking of the orthogonal signal are obtained to improve the accuracy of subsequent detection of positive and negative sequence components of the fundamental wave through the fundamental wave tracking. Furthermore, in order to compensate for the amplitude error of the signal generated during the fundamental wave tracking process, the first orthogonal signal and the second orthogonal signal are amplitude compensated respectively, so as to perform frequency adaptive adjustment on the output third orthogonal signal and the fourth orthogonal signal, thereby improving the accuracy of subsequent extraction of fundamental positive and negative sequence signals and harmonic positive and negative sequence signals, and then accurately detecting the positive and negative sequence components of the acquired power grid signal.

[0012] As a preferred example, it is characterized in that the converting the acquired power grid signal into an orthogonal signal comprises:

[0013] The acquired three-phase power grid signal is transformed into a coordinate system to obtain a two-phase orthogonal signal.

[0014] The present invention obtains a three-phase grid signal to extract positive and negative sequence components that can be used for grid detection from the three-phase grid signal, and converts the three-phase grid signal into a two-phase orthogonal signal to eliminate the unbalanced component caused by non-ideal grid conditions, thereby improving the accuracy of subsequent positive and negative sequence component detection.

[0015] As a preferred example, the step of obtaining a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal includes:

[0016] The two-phase orthogonal signal is input into a pre-built second-order generalized integrator to output a first two-phase orthogonal signal through a first filter function preset in the second-order generalized integrator; wherein the amplitude of the first two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the first two-phase orthogonal signal is consistent with the phase of the two-phase orthogonal signal; the first filter function is:

[0017]

[0018] Wherein, s represents a variable in the frequency domain; v i (s) is the input two-phase orthogonal signal; the v 0 (s) is the first two-phase orthogonal signal output; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

[0019] The present invention utilizes a second-order generalized integrator with frequency selection characteristics to eliminate harmonic signals caused by non-ideal working conditions while completing zero-static tracking of fundamental signals in converted orthogonal signals, so as to avoid harmonic disturbances caused by the non-ideal working conditions.

[0020] As a preferred example, the step of acquiring a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal includes:

[0021] The two-phase orthogonal signal is input into a pre-built second-order generalized integrator to output a second two-phase orthogonal signal through a second filter function preset in the second-order generalized integrator; wherein the amplitude of the second two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the second two-phase orthogonal signal differs from the phase of the two-phase orthogonal signal by several cycles; the second filter function is:

[0022]

[0023] Among them, the v i (s) is the input two-phase orthogonal signal; the qv 0 (s) is the output second two-phase orthogonal signal; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

[0024] The present invention sets different transfer functions in the second-order generalized integrator to perform fundamental wave tracking and harmonic elimination to different degrees, which can not only improve the accuracy of the generalized integrator in performing fundamental wave tracking and harmonic elimination, but also use orthogonal signals with consistent amplitudes but different phases to solve the three-phase imbalance caused by non-ideal working conditions, so as to improve the accuracy of positive and negative sequence component detection.

[0025] As a preferred example, the amplitude compensation is performed on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal, including:

[0026] The first orthogonal signal and the second orthogonal signal are input into a preset amplitude compensation calculation formula to output the third orthogonal signal and the fourth orthogonal signal through the amplitude compensation calculation formula; wherein the amplitude compensation calculation formula is:

[0027]

[0028]

[0029]

[0030]

[0031] Among them, the ω g is the grid voltage frequency; the v αo and the v β0 is the orthogonal signal in the first orthogonal signal; the qv αo And the qv β0 is an orthogonal signal in the second orthogonal signal; and stated is an orthogonal signal in the third orthogonal signal; and stated is the orthogonal signal in the fourth orthogonal signal.

[0032] The present invention performs amplitude compensation on the signal output after fundamental wave tracking, thereby eliminating the amplitude error of the signal caused by the fundamental wave tracking process, offsetting the frequency fluctuation caused by non-ideal working conditions, and further improving the accuracy of positive and negative sequence component detection.

[0033] As a preferred example, the combining the third orthogonal signal and the fourth orthogonal signal to perform orthogonal transformation to obtain fundamental wave positive and negative sequence signals includes:

[0034] An orthogonal transformation is performed on each of the third orthogonal signal and the fourth orthogonal signal to obtain a positive-sequence orthogonal signal and a negative-sequence orthogonal signal; wherein the calculation formula of the orthogonal transformation is:

[0035]

[0036] Among them, the is the positive-sequence orthogonal signal; is the negative-sequence orthogonal signal;

[0037] The positive-sequence quadrature signal and the negative-sequence quadrature signal are respectively subjected to coordinate system inverse transformation to obtain a fundamental positive-sequence three-phase signal and a fundamental negative-sequence three-phase signal.

[0038] After amplitude compensation, the present invention can calculate the positive and negative sequence components of the asymmetric power grid signal based on the coordinate system of the orthogonal signal through orthogonal transformation, thereby avoiding the acquisition of zero sequence components and improving the accuracy of positive and negative sequence component detection.

[0039] As a preferred example, obtaining harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal includes:

[0040] Subtracting the fundamental positive-sequence three-phase signal from the power grid signal to obtain a harmonic positive-sequence three-phase signal;

[0041] The fundamental negative-sequence three-phase signal is subtracted from the grid signal to obtain a harmonic negative-sequence three-phase signal.

[0042] The present invention subtracts the fundamental positive-sequence three-phase signal and the fundamental negative-sequence three-phase signal obtained after inverse conversion of the coordinate system from the acquired power grid signal to obtain a positive-sequence harmonic signal and a negative-sequence harmonic signal, thereby completing the positive and negative sequence component detection under non-ideal power grid conditions and improving the detection accuracy.

[0043] In a second aspect, the present invention discloses a positive and negative sequence component detection system for a power grid signal, including a signal conversion module, a fundamental wave tracking module, an amplitude compensation module, a fundamental wave detection module and a harmonic detection module;

[0044] The signal conversion module is used to convert the acquired power grid signal into an orthogonal signal;

[0045] The fundamental wave tracking module is used to obtain a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal;

[0046] The amplitude compensation module is used to perform amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal;

[0047] The fundamental wave detection module is used to perform orthogonal transformation on the third orthogonal signal and the fourth orthogonal signal to obtain fundamental wave positive and negative sequence signals;

[0048] The harmonic detection module is used to obtain harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal.

[0049] The present invention discloses a positive and negative sequence component detection system for a power grid signal, which first converts the acquired power grid signal into a two-phase orthogonal signal to eliminate the unbalanced component in the power grid signal and realize the detection of the positive sequence component. Then, the first orthogonal signal and the second orthogonal signal corresponding to different fundamental wave tracking of the orthogonal signal are obtained, so as to improve the accuracy of subsequent fundamental wave positive and negative sequence component detection through the fundamental wave tracking. Furthermore, in order to compensate for the amplitude error of the signal generated during the fundamental wave tracking process, the first orthogonal signal and the second orthogonal signal are amplitude compensated respectively, so as to perform frequency adaptive adjustment on the output third orthogonal signal and the fourth orthogonal signal, so as to improve the accuracy of subsequent extraction of fundamental wave positive and negative sequence signals and harmonic positive and negative sequence signals, and then accurately detect the positive and negative sequence components of the acquired power grid signal.

[0050] In a third aspect, the present invention discloses an electronic device, comprising: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute a method for detecting positive and negative sequence components of a power grid signal as described in the first aspect.

[0051] In a fourth aspect, the present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute a method for detecting positive and negative sequence components of a power grid signal as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 : A schematic diagram of a flow chart of a method for detecting positive and negative sequence components of a power grid signal disclosed in an embodiment of the present invention;

[0053] Figure 2 : is a structural schematic diagram of a positive and negative sequence component detection system of a power grid signal disclosed in an embodiment of the present invention;

[0054] Figure 3 : A schematic flow chart of a method for detecting positive and negative sequence components of a power grid signal disclosed in another embodiment of the present invention;

[0055] Figure 4 : A schematic diagram of an amplitude compensation structure disclosed in another embodiment of the present invention;

[0056] Figure 5 : A schematic diagram of a multi-stage filtering structure disclosed in another embodiment of the present invention;

[0057] Figure 6 : A schematic diagram of a positive and negative sequence component detection process disclosed in another embodiment of the present invention.

[0058] Figure 7 : is a schematic diagram of a waveform of a three-phase grid voltage obtained under a working condition disclosed in another embodiment of the present invention;

[0059] Figure 8 : A waveform diagram of detection of a positive sequence component of a fundamental wave of a power grid corresponding to a working condition disclosed in another embodiment of the present invention;

[0060] Fig. 9 : A waveform diagram of detection of a negative sequence component of a fundamental wave of a power grid corresponding to a working condition disclosed in another embodiment of the present invention;

[0061] Fig.10 : A waveform diagram of detection of a harmonic positive sequence component of a power grid corresponding to a working condition disclosed in another embodiment of the present invention;

[0062] Fig.11 : A waveform diagram of detection of harmonic negative sequence components of a power grid corresponding to a working condition disclosed in another embodiment of the present invention;

[0063] Fig.12 : is a schematic diagram of a waveform of a three-phase grid voltage obtained under another working condition disclosed in yet another embodiment of the present invention;

[0064] Fig.13 : A waveform diagram of detection of a fundamental positive sequence component of a power grid corresponding to another working condition disclosed in yet another embodiment of the present invention;

[0065] Fig.14 : A waveform diagram of detection of a negative sequence component of a fundamental wave of a power grid corresponding to another working condition disclosed in yet another embodiment of the present invention;

[0066] Fig.15 : A waveform diagram of detection of a harmonic positive sequence component of a power grid corresponding to another working condition disclosed in yet another embodiment of the present invention;

[0067] Fig.16 : It is a waveform diagram of the detection of the negative sequence component of harmonics in the power grid corresponding to another working condition disclosed in another embodiment of the present invention. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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.

[0069] Embodiment 1

[0070] In order to ensure that the positive and negative sequence components in the power grid signal can be accurately obtained even under non-ideal power grid conditions, in certain implementations of this embodiment, a positive and negative sequence component detection method for a power grid signal is provided. The specific implementation process can be referred to Figure 1 , mainly including steps 101 to 105, wherein the steps are mainly:

[0071] Step 101: Convert the acquired power grid signal into an orthogonal signal.

[0072] In this embodiment, this step mainly includes: performing coordinate system conversion on the acquired three-phase power grid signal to obtain a two-phase orthogonal signal.

[0073] In this embodiment, the step 101 obtains a three-phase grid signal to extract positive and negative sequence components that can be used for grid detection from the three-phase grid signal, and converts the three-phase grid signal into a two-phase orthogonal signal to eliminate the unbalanced component caused by non-ideal grid conditions, thereby improving the accuracy of subsequent positive and negative sequence component detection.

[0074] Step 102: Acquire a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal.

[0075] In this embodiment, this step mainly includes: inputting the two-phase orthogonal signal into a pre-built second-order generalized integrator to output a first two-phase orthogonal signal through a first filter function preset in the second-order generalized integrator; wherein the amplitude of the first two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the first two-phase orthogonal signal is consistent with the phase of the two-phase orthogonal signal; the first filter function is:

[0076]

[0077] Wherein, s represents a variable in the frequency domain; v i (s) is the input two-phase orthogonal signal; the v 0 (s) is the first two-phase orthogonal signal output; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

[0078] Further, the two-phase orthogonal signal is input into a pre-constructed second-order generalized integrator to output a second two-phase orthogonal signal through a second filter function preset in the second-order generalized integrator; wherein the amplitude of the second two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the second two-phase orthogonal signal differs from the phase of the two-phase orthogonal signal by several cycles; the second filter function is:

[0079]

[0080] Among them, the v i (s) is the input two-phase orthogonal signal; the qv 0 (s) is the output second two-phase orthogonal signal; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

[0081] In this embodiment, this step utilizes a second-order generalized integrator with a frequency-selective characteristic to complete the zero-static error tracking of the fundamental signal in the converted orthogonal signal while eliminating the harmonic signal caused by the non-ideal working condition, so as to avoid the harmonic disturbance caused by the non-ideal working condition. At the same time, different transfer functions are set in the second-order generalized integrator to perform fundamental tracking and harmonic elimination to different degrees, which can not only improve the accuracy of the generalized integrator in performing fundamental tracking and harmonic elimination, but also use the orthogonal signal with the same amplitude but different phase to solve the three-phase imbalance caused by the non-ideal working condition, so as to improve the accuracy of the positive and negative sequence component detection.

[0082] Step 103: Perform amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal.

[0083] In this embodiment, this step mainly includes: inputting the first orthogonal signal and the second orthogonal signal into a preset amplitude compensation calculation formula to output the third orthogonal signal and the fourth orthogonal signal through the amplitude compensation calculation formula; wherein the amplitude compensation calculation formula is:

[0084]

[0085]

[0086]

[0087]

[0088] Among them, the ω g is the grid voltage frequency; the v αo and the v β0 is the orthogonal signal in the first orthogonal signal; the qv αo And the qv β0 is an orthogonal signal in the second orthogonal signal; and stated is an orthogonal signal in the third orthogonal signal; and stated is the orthogonal signal in the fourth orthogonal signal.

[0089] In this embodiment, this step performs amplitude compensation on the signal output after fundamental wave tracking, thereby eliminating the amplitude error of the signal caused by the fundamental wave tracking process, offsetting the frequency fluctuation caused by non-ideal working conditions, and thus improving the accuracy of positive and negative sequence component detection.

[0090] Step 104: performing orthogonal transformation on the third orthogonal signal and the fourth orthogonal signal to obtain fundamental wave positive and negative sequence signals.

[0091] In this embodiment, the step mainly includes: performing an orthogonal transformation on each of the third orthogonal signal and the fourth orthogonal signal to obtain a positive-sequence orthogonal signal and a negative-sequence orthogonal signal; wherein the calculation formula of the orthogonal transformation is:

[0092]

[0093] Among them, the is the positive-sequence orthogonal signal; is the negative-sequence orthogonal signal;

[0094] The positive-sequence quadrature signal and the negative-sequence quadrature signal are respectively subjected to coordinate system inverse transformation to obtain a fundamental positive-sequence three-phase signal and a fundamental negative-sequence three-phase signal.

[0095] In this embodiment, after amplitude compensation is performed in this step, according to the coordinate system of the orthogonal signal, the positive and negative sequence components of the asymmetric power grid signal can be calculated by orthogonal transformation of the components of the coordinate system, thereby avoiding the acquisition of zero sequence components and improving the accuracy of positive and negative sequence component detection.

[0096] Step 105: Obtain harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal.

[0097] In this embodiment, the steps mainly include: subtracting the fundamental positive-sequence three-phase signal from the grid signal to obtain a harmonic positive-sequence three-phase signal; and subtracting the fundamental negative-sequence three-phase signal from the grid signal to obtain a harmonic negative-sequence three-phase signal.

[0098] In this embodiment, this step subtracts the fundamental positive-sequence three-phase signal and the fundamental negative-sequence three-phase signal obtained after the inverse conversion of the coordinate system from the acquired grid signal to obtain a positive-sequence harmonic signal and a negative-sequence harmonic signal, thereby completing the positive and negative sequence component detection under non-ideal grid conditions and improving the detection accuracy.

[0099] On the other hand, this embodiment also discloses a positive and negative sequence component detection system of a power grid signal. Specifically, the specific structure of the detection system is shown in FIG. Figure 2 , including a signal conversion module 201, a fundamental wave tracking module 202, an amplitude compensation module 203, a fundamental wave detection module 204 and a harmonic detection module 205.

[0100] The signal conversion module 201 is used to convert the acquired power grid signal into an orthogonal signal.

[0101] The fundamental wave tracking module 202 is used to obtain a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal.

[0102] The amplitude compensation module 203 is used to perform amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal.

[0103] The fundamental wave detection module 204 is used to perform orthogonal transformation on the third orthogonal signal and the fourth orthogonal signal to obtain fundamental wave positive and negative sequence signals.

[0104] The harmonic detection module 205 is used to obtain harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal.

[0105] According to Figure 1 A method for detecting positive and negative sequence components of a power grid signal is shown. Accordingly, this embodiment provides an electronic device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the following is implemented Figure 1The positive and negative sequence component detection method of the power grid signal shown in the figure. Wherein, the processor can be a central processing unit (CPU), or other general 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. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The processor is the control center of the terminal, and various interfaces and lines are used to connect the various parts of the entire terminal. The memory can be used to store the computer program, and the processor realizes various functions of the terminal by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0106] Furthermore, this embodiment also provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the following Figure 1 The positive and negative sequence components of the grid signal are detected.

[0107] Among them, Figure 2If the positive and negative sequence component detection system of the power grid signal shown 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, all or part of the processes in the above-mentioned embodiment method can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0108] Compared with the prior art, the positive and negative sequence component detection method, system, device and medium of the power grid signal provided by this embodiment have the following beneficial effects:

[0109] The present embodiment discloses a method, system, device and medium for detecting positive and negative sequence components of a power grid signal. First, the acquired power grid signal is converted into a two-phase orthogonal signal to eliminate the unbalanced component in the power grid signal and realize the detection of the positive sequence component. Then, the first orthogonal signal and the second orthogonal signal corresponding to the orthogonal signal after different fundamental wave tracking are obtained, so as to improve the accuracy of subsequent detection of positive and negative sequence components of the fundamental wave through the fundamental wave tracking. Furthermore, in order to compensate for the amplitude error of the signal generated in the fundamental wave tracking process, the first orthogonal signal and the second orthogonal signal are amplitude compensated respectively, so as to perform frequency adaptive adjustment on the output third orthogonal signal and the fourth orthogonal signal, so as to improve the accuracy of subsequent extraction of fundamental positive and negative sequence signals and harmonic positive and negative sequence signals, and then accurately detect the positive and negative sequence components of the acquired power grid signal.

[0110] Embodiment 2

[0111] In order to solve the interference caused by three-phase imbalance, harmonic distortion and frequency fluctuation in the detection of positive and negative sequence components under non-ideal power grid conditions, the existing technology often uses filtering methods and calculation methods to eliminate disturbance signals in the process of positive and negative sequence component detection. For example, there is an existing technology that uses a filter with a notch characteristic, such as combining a moving average filter (MAF) and a delay single cancellation (DSC) to eliminate specific harmonics of the power grid. The above method ensures the detection accuracy under harmonic distortion or frequency fluctuation conditions by connecting multiple filters with the same parameters in series and introducing a negative feedback compensation method. However, the above detection method requires cumbersome parameter design in the filter to solve complex harmonic signals, and when the power grid harmonic frequency changes, the overall filter structure needs to be redesigned, which is not universal for non-ideal power grid detection.

[0112] In addition, in the prior art, a filter with frequency selection characteristics is selected to achieve tracking of fundamental frequency components and elimination of harmonic components, thereby realizing detection of positive and negative sequence components of the power grid. Among them, such as reduced-order generalized integrators, second-order generalized integrators, and third-order generalized integrators. Under frequency fluctuation conditions, the above-mentioned prior art achieves output adjustment by adding a frequency feedback branch, but it is easy to cause nonlinearity and instability. At the same time, due to the limitation of the frequency selection characteristics of the generalized integrator, the filtering effect of low-order harmonics is poor, and the low-order harmonic content in the power grid is often high, which affects the detection accuracy.

[0113] In order to solve the above technical problems, this embodiment discloses a method for detecting positive and negative sequence components of power grid signals, which realizes the detection of positive and negative sequence components in power grid signals through coordinate transformation, and performs fundamental wave tracking, harmonic elimination and amplitude compensation on the converted signal to resist the harmonic interference and frequency fluctuation caused by different non-ideal working conditions to the detection of positive and negative sequence components. Then, a positive and negative sequence detection calculation method is used to accurately extract the positive and negative sequence components. Specifically, the specific implementation process of the positive and negative sequence component detection method can be referred to Figure 3 , mainly including steps 301 to 305, wherein the steps are mainly:

[0114] Step 301: Convert the acquired three-phase grid signal into a two-phase orthogonal signal.

[0115] Specifically, in this embodiment, in order to detect the positive and negative sequence components from the acquired power grid signal, the detection of the positive and negative sequence components is performed by constructing an orthogonal signal corresponding to the power grid signal, thereby realizing the detection of the positive and negative sequence components.

[0116] In some implementations of this embodiment, the acquired three-phase signal is first converted into a two-phase signal to eliminate the unbalanced signal in the power grid signal. The acquired three-phase power grid signal can be converted into a two-phase orthogonal signal by means of coordinate system conversion, such as Clark transformation, Park transformation, etc.

[0117] Specifically, taking the Clark transformation as an example, the acquired three-phase voltage signal (v a 、v b 、v c ) is converted into a two-phase quadrature signal v αi and v βi The process is:

[0118]

[0119] Wherein, α and β are the coordinate systems in the Clark transformation; v α represents the orthogonal signal of the three-phase voltage signal on the α coordinate axis; the v β Represents the orthogonal signal of the three-phase voltage signal on the β coordinate axis.

[0120] Step 302: Input the two-phase quadrature signal into a pre-built second-order generalized integrator to output a first two-phase quadrature signal and a second two-phase quadrature signal through the second-order generalized integrator.

[0121] Specifically, in this embodiment, based on the frequency selection characteristics and filtering characteristics of the second-order generalized integrator, the tracking of the fundamental signal in the power grid signal and the elimination of the harmonic signal can be achieved, thereby inputting the two-phase orthogonal signal into the second-order generalized integrator to resist the harmonic interference caused by non-ideal working conditions. Furthermore, the filtering effect of the existing second-order generalized integrator on low-order harmonics is poor. In some implementations of this embodiment, different transfer functions are set in the second-order generalized integrator to output two-phase orthogonal signals with the same amplitude but different phases through different transfer functions, thereby improving the filtering effect on low-order harmonics through the difference in the phase.

[0122] In some implementations of this embodiment, the transformed two-phase signal is input into the second-order generalized integrator, and the frequency selection characteristics and filtering characteristics of the second-order generalized integrator are used to complete the tracking of the grid fundamental signal and the elimination of the harmonic signal. The output of the second-order generalized integrator is two signals, one of which is a signal with the same amplitude and phase as the input, and the other is a signal with the same amplitude but a phase difference of 1 / 4 cycle.

[0123] Specifically, the quadrature signal v in the input two-phase quadrature signal αi and v βi After the generalized integrator D SOGI(s) and Q SOGI (s), output v αo 、v βo , v qαo and v qβo Specifically, the transfer function between the output signal and the input signal in the second-order generalized integrator is:

[0124]

[0125]

[0126] Wherein, s represents a variable in the frequency domain; v i (s) is the input signal; the v 0 (s),qv 0 (s) are the first two-phase orthogonal signal and the second two-phase orthogonal signal output respectively; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator. Specifically, the output amplitudes of the first two-phase quadrature signal and the second two-phase quadrature signal are equal and the phases differ by several cycles. Further, in order to ensure the filtering effect, the phase difference is set to 1 / 4 cycle, that is, 90°. At the same time, the resonant frequency is set to the grid fundamental angular frequency 100π.

[0127] Step 303: Perform amplitude compensation on the first two-phase quadrature signal and the second two-phase quadrature signal respectively to obtain a third two-phase quadrature signal and a fourth two-phase quadrature signal.

[0128] Specifically, in this embodiment, amplitude compensation calculation is performed on the output first two-phase orthogonal signal and the second two-phase orthogonal signal to compensate for the amplitude error generated by tracking the baseband signal when the frequency fluctuates, thereby completing frequency adaptive adjustment of the output orthogonal signal.

[0129] In some implementations of this embodiment, a frequency-adaptive amplitude compensation structure is provided, and the first two-phase orthogonal signal and the second two-phase orthogonal signal are input into the amplitude compensation structure for amplitude compensation. Specifically, the amplitude compensation structure can refer to Figure 4 .

[0130] like Figure 4 As shown, the orthogonal signals output by the generalized integrator are respectively input into each adder in the amplitude compensation structure, so that each of the input orthogonal signals is added by the adder to generate an amplitude compensated orthogonal signal. Specifically, referring to Figure 4 , the first two-phase quadrature signal v αo is input to the first adder-subtractor, and the first two-phase quadrature signal v β0The first processor K1 processes the orthogonal signal after processing, and the first processor K1 sends the processed orthogonal signal to the first adder-subtractor to be processed by the v αo Add together to generate the v αo Orthogonal signal after amplitude compensation Similarly, the first two-phase quadrature signal v β0 is input to the second adder-subtractor, and the second two-phase quadrature signal v αo The first processor K1 sends the processed orthogonal signal to the second adder to be processed by the v β0 Subtract, and then generate the v β0 Orthogonal signal after amplitude compensation Similarly, the second two-phase quadrature signal v qαo is input to the second processor K2, and the second two-phase quadrature signal v qβ0 The orthogonal signals output by the second processor K2 and the third processor K3 are simultaneously sent to the third adder-subtractor for addition, thereby generating the v qαo Orthogonal signal after amplitude compensation Similarly, the second two-phase quadrature signal v qβ0 is input to the second processor K2, and the second two-phase quadrature signal v qαo The orthogonal signals output by the second processor K2 and the third processor K3 are simultaneously sent to the third adder-subtractor for subtraction, thereby generating the v qβ0 Orthogonal signal after amplitude compensation

[0131] Preferably, the calculation formula for the processor and the adder to perform amplitude compensation on the orthogonal signal is:

[0132]

[0133]

[0134]

[0135]

[0136] Among them, the ω g is the grid voltage frequency; the v αo and the v β0 is the orthogonal signal in the first orthogonal signal; the v qαo and the v qβ0 is an orthogonal signal in the second orthogonal signal; and stated is an orthogonal signal in the third orthogonal signal; and stated is the orthogonal signal in the fourth orthogonal signal.

[0137] Specifically, based on the above compensation calculation formula, according to the angular frequency of the grid voltage, when ω n =ω g That is, when the grid frequency does not fluctuate, the error term of the amplitude compensation calculation is 0, and the filter output remains unchanged; when ω n ≠ω g That is, when the grid frequency fluctuates, the error term of the amplitude compensation calculation is calculated based on algebraic operations to calculate the fundamental amplitude error caused by the frequency fluctuation that needs to be compensated, thereby realizing the frequency adaptive adjustment of the output amplitude of the filter module.

[0138] It should be noted that the use of the second-order generalized integrator to perform harmonic elimination on the orthogonal signal and the amplitude compensation on the signal output by the second-order generalized integrator is not performed only once. In fact, based on the different actual grid conditions, the requirements for the degree of suppression of grid harmonics and DC components of the acquired grid signal are also different. Therefore, in some implementations of this embodiment, the second-order generalized integrator and the amplitude compensation can be placed in a functional module, and then the harmonic elimination and amplitude compensation are achieved through the functional module, and then the third two-phase orthogonal signal and the fourth two-phase orthogonal signal are output.

[0139] Further, assuming that the overall functional module formed by the generalized integrator and the amplitude compensation is a single-stage FSOGI filter module, the FSOGI filter module can accurately detect the grid fundamental signal under frequency fluctuation and harmonic disturbance conditions.

[0140] Furthermore, based on the actual grid conditions, multiple single-stage FSOGI modules can be connected in series to form a multi-stage series adaptive filtering structure. The multi-stage series adaptive filtering structure uses the channel with the same amplitude and phase angle as the input of the next stage FSOGI output by the single-stage FSOGI to form a multi-stage series FSOGI filtering module, whose output is 2 groups of signals. and is a set of orthogonal signals output by the first multi-stage cascade FSOGI. and is a set of orthogonal signals output by the second multi-stage series FSOGI, and and It is also an orthogonal signal. The structure formed is as follows Figure 5 The suppression capabilities of grid harmonics and DC components under different series are shown in the following table. The series series can be selected according to the actual grid conditions.

[0141] In some implementations of this embodiment, experiments show that the proportion of harmonics and DC components in the orthogonal signals output by the FSOGIs connected in series at different levels are different. Specifically, the proportions of FSOGI filter modules at different levels after processing harmonics of different orders are shown in the following table:

[0142]

[0143] Step 304: performing orthogonal transformation on the third two-phase orthogonal signal and the fourth two-phase orthogonal signal respectively to obtain a positive-sequence orthogonal signal and a negative-sequence orthogonal signal.

[0144] Specifically, in this embodiment, the FCSOGI module of a single pole or multiple poles is used to output the third orthogonal signal and the fourth orthogonal signal After that, based on the coordinate system corresponding to the Clark transformation, in the αβ coordinate system, the positive and negative sequence components of the asymmetric voltage can be calculated by orthogonal transformation of the αβ components, and there is no zero sequence component, as shown in the following formula:

[0145]

[0146] Among them, the is the positive-sequence orthogonal signal; is the negative-sequence quadrature signal.

[0147] Step 305: performing an inverse coordinate transformation on the positive-sequence quadrature signal and the negative-sequence quadrature signal to obtain fundamental wave positive and negative sequence signals and harmonic positive and negative sequence signals.

[0148] Specifically, in this embodiment, each group of positive-sequence and negative-sequence orthogonal signals is subjected to Clark inverse transformation to obtain a fundamental positive-sequence three-phase signal And fundamental negative sequence three-phase signal And subtract it from the grid signal to get the positive sequence harmonic signal and negative sequence harmonic signals Complete the positive and negative sequence component detection of non-ideal power grid.

[0149] Reference Figures 4 to 5 The amplitude compensation structure and multi-stage filtering structure provided by the present embodiment can be used as follows to detect the positive and negative sequence components of the power grid signal: Figure 6 See Figure 6, through coordinate transformation such as Clark transformation, a set of two-phase orthogonal signals corresponding to the three-phase power grid signal is constructed, and the multi-stage filtering module constructed based on the generalized integrator is used to eliminate the harmonics of the two-phase orthogonal signal. Then, according to the relationship between the output and input signals under frequency changes, an amplitude compensation structure is designed, which can realize the zero-static error tracking of the fundamental component of the power grid and the elimination of harmonic components under frequency fluctuations; further, by using the medium-amplitude and in-phase input and output channels in the filtering module, the designed adaptive filtering module is connected in series in multiple stages, thereby improving the insufficient suppression ability of low-order harmonics and DC components; finally, the two sets of orthogonal signals are output, and the positive and negative sequence detection calculation method is used to extract the positive and negative sequence components. Based on such as Figure 6 The positive and negative sequence component detection method shown can stably detect positive and negative sequence fundamental and harmonic signals under non-ideal grid conditions such as harmonic disturbance, unbalanced component disturbance and frequency conversion, and the designed method is experimentally verified in an inverter control device. Among them, in a specific embodiment, the effect of the method provided by this embodiment in two complex working conditions is verified. Specifically, in working condition 1, that is, when the grid voltage has three-phase imbalance and harmonic distortion and the system frequency is increased to 55Hz, the waveform of the three-phase grid voltage first obtained is as follows: Figure 7 As shown, Figure 7 The waveform curves in represent the A phase voltage, the B phase voltage and the C phase voltage respectively. Among them, the B phase voltage amplitude is the lowest, the C phase voltage amplitude is higher than the B phase voltage amplitude, and the A phase voltage amplitude is the highest. Figure 7 The three-phase voltage shown in FIG. 1 is detected by the positive and negative sequence component detection method provided in this embodiment, and the grid fundamental positive sequence component detection waveform, grid fundamental negative sequence component detection waveform, grid harmonic positive sequence component detection waveform and grid harmonic negative sequence component detection waveform are respectively as shown in FIG. Figures 8 to 11 See Figure 8 It can be seen that in the detection waveform of the power grid fundamental positive sequence component obtained by the detection method provided by this embodiment, the three-phase positive sequence component waveform is symmetrical and has high waveform quality, which effectively suppresses the influence of the three-phase power grid voltage disturbance component and meets the requirements for power grid positive sequence component detection. Fig. 9 It can be seen that in the detection waveform of the fundamental negative sequence component of the power grid obtained by the detection method provided by this embodiment, the three-phase negative sequence component waveform is symmetrical and the waveform distortion rate is low, which effectively suppresses the influence of the three-phase power grid voltage disturbance component and meets the requirements for the detection of the negative sequence component of the power grid. Fig.10 It can be seen that the detection waveform of the power grid harmonic positive sequence component obtained by the detection method provided by this embodiment can stably detect the positive sequence harmonic signals of each phase generated by the three-phase unbalanced working condition. Fig.11It can be seen that the power grid harmonic negative-sequence component detection waveform obtained by the detection method provided by this embodiment can stably detect the negative-sequence harmonic signals of each phase generated by the three-phase unbalanced working condition.

[0150] Furthermore, in the second working condition, that is, when one phase of the grid voltage is disconnected and there is a phenomenon of harmonic distortion and the system frequency is reduced to 45 Hz, the waveform of the three-phase grid voltage obtained first is as follows: Fig.12 As shown, Fig.12 The waveform curves in represent the voltage of phase A, phase B and phase C respectively. The voltage of phase A and phase C have the same amplitude, which is 311V, and the two-phase voltage waveform distortion rates are different. Phase B is a disconnected phase, and the voltage value is 0V. Fig.12 The three-phase voltage shown in FIG. 1 is detected by the positive and negative sequence component detection method provided in this embodiment, and the grid fundamental positive sequence component detection waveform, grid fundamental negative sequence component detection waveform, grid harmonic positive sequence component detection waveform and grid harmonic negative sequence component detection waveform are respectively as shown in FIG. Figures 13 to 16 See Fig.13 It can be seen that in the detection waveform of the power grid fundamental positive sequence component obtained by the detection method provided by this embodiment, the three-phase positive sequence component waveform is symmetrical and has high waveform quality, which effectively suppresses the influence of the three-phase power grid voltage disturbance component and meets the requirements for power grid positive sequence component detection. Fig.14 It can be seen that in the detection waveform of the fundamental negative sequence component of the power grid obtained by the detection method provided by this embodiment, the three-phase negative sequence component waveform is symmetrical and the waveform distortion rate is low, which effectively suppresses the influence of the three-phase power grid voltage disturbance component and meets the requirements for the detection of the negative sequence component of the power grid. Fig.15 It can be seen that the positive sequence harmonic component detection waveform of the power grid obtained by the detection method provided by this embodiment can effectively detect the positive sequence harmonic components of phase A and phase C, and the positive sequence harmonic component of phase B is 0, which meets the detection accuracy under the condition of line failure. Fig.16 It can be seen that the negative-sequence harmonic component detection waveform of the power grid obtained by the detection method provided by this embodiment can effectively detect the negative-sequence harmonic components of phase A and phase C, and the positive-sequence harmonic component of phase B is 0, which meets the detection accuracy under the disconnection fault condition. The experimental results of the above two working conditions show that the positive and negative sequence component detection method designed under non-ideal power grid working conditions can stably detect the positive and negative sequence components of the power grid under complex component disturbances, the detected fundamental positive and negative sequence components are of high quality, contain almost no harmonic components, and maintain stable detection capabilities under frequency fluctuation conditions, which can provide stable signals for asymmetric fault diagnosis, power quality compensation and system control of new power systems.

[0151] Compared with the prior art, the method provided in this embodiment has the following beneficial effects:

[0152] The present embodiment provides a method for detecting positive and negative sequence components of power grid signals. Through coordinate transformation, a group of power grid orthogonal signals are constructed. Based on the filtering characteristics and frequency selection characteristics of the generalized integrator, according to the relationship between the output and input signals under frequency changes, an amplitude compensation structure is designed, which can realize the zero-static tracking of the fundamental wave component of the power grid under frequency fluctuations and the elimination of harmonic components; further, by using the input and output channels of the medium amplitude and the same phase in the filtering module, the designed adaptive filtering module is connected in multiple stages in series, which improves the insufficient ability to suppress low-order harmonics and DC components; finally, the two groups of orthogonal signals are output, and the positive and negative sequence detection calculation method is used to extract the positive and negative sequence components. The designed method can be universal under non-ideal power grid conditions of frequency fluctuations, complex harmonic disturbances and unbalanced component disturbances, and can stably detect the positive sequence fundamental and harmonic components of the power grid, providing electrical parameter support for ground fault identification, power quality detection, control system compensation and other aspects, and ensuring the safe, stable and efficient operation of the power grid.

[0153] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting positive and negative sequence components of a power grid signal, characterized in that: include: Convert the acquired power grid signal into an orthogonal signal; Acquire a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal; Performing amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal; Combining the third orthogonal signal with the fourth orthogonal signal to perform orthogonal transformation to obtain fundamental wave positive and negative sequence signals; Harmonic positive and negative sequence signals are obtained according to the fundamental positive and negative sequence signals and the power grid signal.

2. A method for detecting positive and negative sequence components of a power grid signal according to claim 1, characterized in that: The step of converting the acquired power grid signal into an orthogonal signal comprises: The acquired three-phase power grid signal is transformed into a coordinate system to obtain a two-phase orthogonal signal.

3. A method for detecting positive and negative sequence components of a power grid signal according to claim 2, characterized in that: The obtaining of a first orthogonal signal after performing first fundamental wave tracking on the orthogonal signal comprises: The two-phase orthogonal signal is input into a pre-built second-order generalized integrator to output a first two-phase orthogonal signal through a first filter function preset in the second-order generalized integrator; wherein the amplitude of the first two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the first two-phase orthogonal signal is consistent with the phase of the two-phase orthogonal signal; the first filter function is: Wherein, s represents a variable in the frequency domain; v i (s) is the input two-phase orthogonal signal; v0(s) is the output first two-phase orthogonal signal; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

4. The method for detecting positive and negative sequence components of a power grid signal according to claim 2, characterized in that: The obtaining of the first orthogonal signal after performing the first fundamental wave tracking on the orthogonal signal and the second orthogonal signal after performing the second fundamental wave tracking on the orthogonal signal comprises: The two-phase orthogonal signal is input into a pre-built second-order generalized integrator to output a second two-phase orthogonal signal through a second filter function preset in the second-order generalized integrator; wherein the amplitude of the second two-phase orthogonal signal is consistent with the amplitude of the two-phase orthogonal signal; the phase of the second two-phase orthogonal signal differs from the phase of the two-phase orthogonal signal by several cycles; the second filter function is: Among them, the v i (s) is the input two-phase orthogonal signal; qv0(s) is the output second two-phase orthogonal signal; k is the damping coefficient of the second-order generalized integrator; ω n is the resonant frequency of the second-order generalized integrator.

5. The method for detecting positive and negative sequence components of a power grid signal according to claim 1, characterized in that: The performing amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal comprises: The first orthogonal signal and the second orthogonal signal are input into a preset amplitude compensation calculation formula to output the third orthogonal signal and the fourth orthogonal signal through the amplitude compensation calculation formula; wherein the amplitude compensation calculation formula is: Among them, the ω g is the grid voltage frequency; the v αo and the v β0 is the orthogonal signal in the first orthogonal signal; the qv αo And the qv β0 is an orthogonal signal in the second orthogonal signal; and stated is an orthogonal signal in the third orthogonal signal; and stated is the orthogonal signal in the fourth orthogonal signal.

6. A method for detecting positive and negative sequence components of a power grid signal according to claim 5, characterized in that: The combining the third orthogonal signal and the fourth orthogonal signal to perform orthogonal transformation to obtain fundamental wave positive and negative sequence signals includes: An orthogonal transformation is performed on each of the third orthogonal signal and the fourth orthogonal signal to obtain a positive-sequence orthogonal signal and a negative-sequence orthogonal signal; wherein the calculation formula of the orthogonal transformation is: Among them, the is the positive-sequence orthogonal signal; is the negative-sequence orthogonal signal; The positive-sequence quadrature signal and the negative-sequence quadrature signal are respectively subjected to coordinate system inverse transformation to obtain a fundamental positive-sequence three-phase signal and a fundamental negative-sequence three-phase signal.

7. A method for detecting positive and negative sequence components of a power grid signal according to claim 6, characterized in that: The obtaining harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal comprises: Subtracting the fundamental positive-sequence three-phase signal from the power grid signal to obtain a harmonic positive-sequence three-phase signal; The fundamental negative-sequence three-phase signal is subtracted from the grid signal to obtain a harmonic negative-sequence three-phase signal.

8. A positive and negative sequence component detection system for power grid signals, characterized in that: It includes a signal conversion module, a fundamental wave tracking module, an amplitude compensation module, a fundamental wave detection module and a harmonic detection module; The signal conversion module is used to convert the acquired power grid signal into an orthogonal signal; The fundamental wave tracking module is used to obtain a first orthogonal signal after performing a first fundamental wave tracking on the orthogonal signal and a second orthogonal signal after performing a second fundamental wave tracking on the orthogonal signal; The amplitude compensation module is used to perform amplitude compensation on the first orthogonal signal and the second orthogonal signal respectively to obtain a third orthogonal signal and a fourth orthogonal signal; The fundamental wave detection module is used to perform orthogonal transformation on the third orthogonal signal and the fourth orthogonal signal to obtain fundamental wave positive and negative sequence signals; The harmonic detection module is used to obtain harmonic positive and negative sequence signals according to the fundamental positive and negative sequence signals and the power grid signal.

9. An electronic device, characterized in that: include: at least one processor; and a memory communicatively coupled to at least one of the processors; The memory stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute a method for detecting positive and negative sequence components of a power grid signal as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute a method for detecting positive and negative sequence components of a power grid signal according to any one of claims 1 to 7.

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