Phase-locked control method, device and storage medium for single-phase power grid

Abstract

The present application provides a phase-locked control method, device and storage medium for a single-phase power grid, the phase-locked control method comprising: determining a first orthogonal voltage and a second orthogonal voltage based on a voltage signal; processing the first orthogonal voltage and the second orthogonal voltage to determine the phase information of the voltage signal; performing frequency phase-locked processing on the voltage signal, the first orthogonal voltage and the second orthogonal voltage to determine the frequency signal of the voltage signal; determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and controlling the sinusoidal signal of the inverter using the phase angle of the voltage signal. By performing frequency phase-locked processing using the voltage signal, the first orthogonal voltage and the second orthogonal voltage to determine the real-time frequency signal, the real-time tracking of the power grid frequency is realized, thereby eliminating the influence of the power grid frequency fluctuation on the phase-locked loop, and improving the accuracy of the detection of the phase and frequency of the power grid.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a phase-locked control method, device and storage medium for a single-phase power grid. Background Art

[0002] At present, green energy such as wind power, photovoltaics, and energy storage are booming. Under this general trend, distributed power generation technology has become a hot spot in today's scientific and technological development. Residential electricity is generally single-phase power grid. At present, the installation volume of household photovoltaic systems and household energy storage systems has shown explosive growth. The control technology of single-phase photovoltaic inverters and single-phase energy storage converters has become one of the research focuses in the field of new energy. For single-phase power grid systems, the most core technology involved is the phase-locked technology of single-phase power grid voltage.

[0003] At present, the phase locking of single-phase power grid is usually controlled by phase detector, low-pass filter and voltage-controlled oscillator. However, this method will lead to a narrow frequency recognition range of the power grid, slow dynamic recognition speed and a greater impact of harmonics on the phase locking accuracy, resulting in errors in the phase and frequency detection of the power grid. Therefore, how to improve the accuracy of power grid phase locking control has become a technical issue that cannot be underestimated. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a phase-locked control method, device and storage medium for a single-phase power grid. By utilizing a voltage signal, a first orthogonal voltage and a second orthogonal voltage to perform frequency phase-locked processing, a real-time frequency signal is determined, and real-time tracking of the power grid frequency is achieved, thereby eliminating the impact of power grid frequency fluctuations on the phase-locked loop and improving the accuracy of power grid phase and frequency detection.

[0005] The present application provides a phase-locked control method for a single-phase power grid, the phase-locked control method comprising:

[0006] Acquire a voltage signal of a single-phase power grid, and determine a first quadrature voltage and a second quadrature voltage based on the voltage signal;

[0007] Processing the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal;

[0008] Performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine a frequency signal of the voltage signal;

[0009] Based on the frequency signal of the voltage signal and the phase information of the voltage signal, the phase angle of the voltage signal is determined, and the phase angle of the voltage signal is used to control the sinusoidal signal of the inverter connected to the single-phase power grid.

[0010] In a possible implementation manner, determining the first quadrature voltage and the second quadrature voltage based on the voltage signal includes:

[0011] The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

[0012] In a possible implementation manner, the first quadrature voltage and the second quadrature voltage are processed, and the phase information of the voltage signal includes:

[0013] Performing park transformation processing on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal;

[0014] The quadrature-axis region signal is subjected to PI processing to determine the phase information of the voltage signal.

[0015] In a possible implementation manner, performing park transformation on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal includes:

[0016] Obtaining a preset sine wave angle, and determining a cosine value of the sine wave angle and a sine value of the sine wave angle;

[0017] Determine a target matrix composed of the cosine value of the sine wave angle and the sine value of the sine wave angle;

[0018] determining a target vector formed by the first orthogonal voltage and the second orthogonal voltage;

[0019] The direct-axis region signal and the quadrature-axis region signal are determined according to the product of the target matrix and the target vector.

[0020] In a possible implementation manner, performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine the frequency signal of the voltage signal includes:

[0021] Get the phase-locked control period;

[0022] determining a first voltage difference based on a difference between the voltage signal and the first quadrature voltage;

[0023] A frequency signal of a voltage signal is determined based on the product of the first voltage difference, the second orthogonal voltage and the phase-locked control period.

[0024] In a possible implementation manner, determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal includes:

[0025] The frequency signal of the voltage signal and the phase information of the voltage signal are input into a voltage-controlled oscillator, and the frequency signal of the voltage signal and the phase information of the voltage signal are processed to determine the phase angle of the voltage signal.

[0026] The embodiment of the present application also provides a phase-locked control device for a single-phase power grid, the phase-locked control device comprising:

[0027] A determination module, configured to obtain a voltage signal of a single-phase power grid, and determine a first orthogonal voltage and a second orthogonal voltage based on the voltage signal;

[0028] A transformation module, configured to process the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal;

[0029] A frequency phase-locking module, used for performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage and the second orthogonal voltage to determine a frequency signal of the voltage signal;

[0030] The phase angle calculation module is used to determine the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and use the phase angle of the voltage signal to control the sinusoidal signal of the inverter connected to the single-phase power grid.

[0031] In a possible implementation manner, when the determination module is used to determine the first quadrature voltage and the second quadrature voltage based on the voltage signal, the determination module is specifically used to:

[0032] The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

[0033] An embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the phase-locked control method of the single-phase power grid as described above are performed.

[0034] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the phase-locked control method for a single-phase power grid as described above are executed.

[0035] The embodiment of the present application provides a phase-locked control method, device and storage medium for a single-phase power grid, the phase-locked control method comprising: obtaining a voltage signal of the single-phase power grid, determining a first quadrature voltage and a second quadrature voltage based on the voltage signal; processing the first quadrature voltage and the second quadrature voltage to determine the phase information of the voltage signal; performing frequency phase-locking processing on the voltage signal, the first quadrature voltage and the second quadrature voltage to determine the frequency signal of the voltage signal; determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and using the phase angle of the voltage signal to control the sinusoidal signal of the inverter. By performing frequency phase-locking processing on the voltage signal, the first quadrature voltage and the second quadrature voltage to determine the real-time frequency signal, the real-time tracking of the power grid frequency is realized, thereby eliminating the influence of the power grid frequency fluctuation on the phase-locked loop, and improving the accuracy of the detection of the phase and frequency of the power grid.

[0036] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A flow chart of a phase-locked control method for a single-phase power grid provided in an embodiment of the present application;

[0039] Figure 2 This is the FFT analysis result diagram after a multi-stage second-order generalized integrator;

[0040] Figure 3 This is the FFT analysis result diagram after a single-stage second-order generalized integrator;

[0041] Figure 4 It is a waveform diagram without frequency adaptive phase locking;

[0042] Figure 5 A schematic diagram of a waveform with frequency adaptive phase locking provided in an embodiment of the present application;

[0043] Figure 6 A schematic diagram of a phase-locked control method for a single-phase power grid provided in an embodiment of the present application;

[0044] Figure 7A schematic diagram of the structure of a phase-locked control device for a single-phase power grid provided in an embodiment of the present application;

[0045] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0047] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0048] In order to enable those skilled in the art to use the contents of this application, the following implementation method is given in combination with the specific application scenario of "phase-locked control of the power grid". For those skilled in the art, the general principles defined here can be applied to other embodiments and application scenarios without departing from the spirit and scope of this application.

[0049] The following methods, devices, electronic devices or computer-readable storage media of the embodiments of the present application can be applied to any scenario where phase-locked control of a power grid is required. The embodiments of the present application are not limited to specific application scenarios. Any scheme using a phase-locked control method, device and storage medium for a single-phase power grid provided by the embodiments of the present application is within the scope of protection of the present application.

[0050] First, the application scenarios to which the present application is applicable are introduced. The present application can be applied in the field of electronic power technology.

[0051] According to research, at present, the phase lock of single-phase power grid is usually controlled by phase detector, low-pass filter and voltage-controlled oscillator. However, this method will lead to a narrow frequency recognition range of the power grid, slow dynamic recognition speed and a greater impact of harmonics on the phase lock accuracy, resulting in errors in the phase and frequency detection of the power grid. Therefore, how to improve the accuracy of power grid phase lock control has become a technical issue that cannot be underestimated.

[0052] Based on this, an embodiment of the present application provides a phase-locked control method for a single-phase power grid. By utilizing a voltage signal, a first orthogonal voltage, and a second orthogonal voltage to perform frequency phase-locked processing, a real-time frequency signal is determined, and real-time tracking of the power grid frequency is achieved, thereby eliminating the impact of power grid frequency fluctuations on the phase-locked loop and improving the accuracy of power grid phase and frequency detection.

[0053] See also Figure 1 , Figure 1 The following is a flow chart of a phase-locked control method for a single-phase power grid provided in an embodiment of the present application. Figure 1 As shown in , the phase-locked control method provided by the embodiment of the present application includes:

[0054] S101: Acquire a voltage signal of a single-phase power grid, and determine a first orthogonal voltage and a second orthogonal voltage based on the voltage signal.

[0055] In this step, a voltage signal of the single-phase power grid is acquired, and a first orthogonal voltage and a second orthogonal voltage are determined according to the voltage signal.

[0056] In a possible implementation manner, determining the first quadrature voltage and the second quadrature voltage based on the voltage signal includes:

[0057] The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

[0058] Here, the voltage signal is subjected to two-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage. Thus, the voltage signal of the single-phase power grid is processed by multi-stage second-order generalized integration to obtain the first orthogonal voltage Vα and the second orthogonal voltage Vβ. On the one hand, the anti-interference energy of the power grid inverter of the single-phase inverter can be improved. On the other hand, more importantly, the harmonic interference in the single-phase power grid signal is eliminated, thereby eliminating the influence of the harmonics in the power grid inverter signal of the single-phase inverter on the accuracy of the phase-locked loop. In addition, the harmonic anti-interference ability of the multi-stage second-order generalized integration processing is stronger than that of the single-stage processing.

[0059] For further information, see Figure 2 , Figure 3 , Figure 2 This is the FFT analysis result diagram after the multi-stage second-order generalized integrator. Figure 3 This is the FFT analysis result diagram after a single-stage second-order generalized integrator. Figure 2 and Figure 3 As shown, through test comparison, it is found that the harmonic anti-interference ability of multi-stage processing is stronger than that of single-stage harmonic anti-interference ability.

[0060] Generally, when a single-phase inverter is connected to the power grid, attention should be paid to the following: First, the grid connection point should be equipped with a disconnecting device that is easy to operate, lockable, has a clear disconnection point, has a grounding function, and can disconnect the fault current. Second, the inverter should comply with relevant industry technical standards and have high / low voltage lockout and automatic grid connection functions for voltage detection (automatic grid connection for voltage detection of 85% UN). Third, when the distributed power source is connected by a dedicated line, the dedicated line may not be equipped with or disable the reclosing switch. Fourth, when the public power grid line is put into automatic reclosing, it is advisable to add the reclosing switch to detect no pressure; when the conditions are not met, it should be checked whether the reclosing time is coordinated with the distributed power source and the off-grid control time (the reclosing time should be set to 2+δt seconds, δt is the protection coordination differential time). Fifth, the power factor of the distributed power source should be adjustable within the range of 0.95 (leading) to 0.95 (lagging). Inverter type Distributed power source access to 220 / 380 volt distribution network technical requirements.

[0061] S102: Process the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal.

[0062] In this step, the first orthogonal voltage and the second orthogonal voltage are processed to determine the phase information of the voltage signal.

[0063] Here, the phase information of the voltage signal is determined through two steps. First, the first orthogonal voltage and the second orthogonal voltage are park transformed to obtain the direct axis area signal V for detecting the single-phase power grid. D and quadrature axis signal V Q Then the quadrature axis signal V Q Input into the PI controller to obtain the phase information of the voltage signal.

[0064] In a possible implementation manner, the first quadrature voltage and the second quadrature voltage are processed, and the phase information of the voltage signal includes:

[0065] A: Perform park transformation processing on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal.

[0066] Here, the first orthogonal voltage and the second orthogonal voltage are subjected to park transformation processing to determine a direct-axis region signal and a quadrature-axis region signal.

[0067] Among them, the Park transformation is to convert the projection of the ia, ib, ic currents on the α and β axes to the d and q axes, and convert the currents on the stator to the direct and quadrature axes. For the steady state, after such an equivalent, iq and id are just constants. This makes the coefficient matrix a constant matrix when establishing the differential equation of the electromagnetic relationship of the rotor loop, rather than a coefficient matrix that changes with time and space. This greatly simplifies the differential equation for analyzing the electromagnetic relationship of the generator and motor.

[0068] In a possible implementation manner, performing park transformation on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal includes:

[0069] (1): Obtain a preset sine wave angle, and determine the cosine value of the sine wave angle and the sine value of the sine wave angle.

[0070] Here, a preset sine wave angle is obtained, and the cosine value of the sine wave angle and the sine value of the sine wave angle are determined.

[0071] The sine wave angle is set to 0-2π.

[0072] (2): Determine a target matrix composed of the cosine value of the sine wave angle and the sine value of the sine wave angle.

[0073] Here, a target matrix composed of the cosine value of the sine wave angle and the sine value of the sine wave angle is determined based on the cosine value of the sine wave angle and the sine value of the sine wave angle.

[0074] The target matrix is:

[0075]

[0076] Where θ is the angle of the sine wave, ranging from 0 to 2π.

[0077] (3): Determine a target vector formed by the first orthogonal voltage and the second orthogonal voltage.

[0078] Here, a target vector consisting of an orthogonal voltage and the second orthogonal voltage is determined.

[0079] The target vector is:

[0080]

[0081] Among them, the first orthogonal voltage is V α , the second quadrature voltage is V β .

[0082] (4): Determine the direct axis region signal and the cross axis region signal according to the product of the target matrix and the target vector.

[0083] Here, the direct-axis region signal and the quadrature-axis region signal are determined according to the product of a target matrix consisting of cosine values ​​of the sine wave angle and sine values ​​of the sine wave angle and a target vector consisting of the first orthogonal voltage and the second orthogonal voltage.

[0084] Among them, the determination formula of the direct axis area signal and the quadrature axis area signal is:

[0085]

[0086] Among them, the first orthogonal voltage is V α , the second quadrature voltage is V β , θ is the sine wave angle, V D is the direct axis area signal, V Q It is the cross-axis area signal.

[0087] In a specific embodiment, a preset sine wave angle is obtained, the cosine value and the sine value of the sine wave angle are determined, and a target matrix composed of the cosine value and the sine value of the sine wave angle is determined according to the cosine value and the sine value of the sine wave angle. A target vector composed of an orthogonal voltage and the second orthogonal voltage is determined, and a direct axis region signal and a quadrature axis region signal are determined according to the product of the target vector and the target matrix.

[0088] B: Perform PI processing on the quadrature-axis region signal to determine the phase information of the voltage signal.

[0089] Here, the quadrature-axis region signal is input into a PI controller for PI processing to determine the phase information of the voltage signal.

[0090] S103: performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine a frequency signal of the voltage signal.

[0091] In this step, the voltage signal, the first orthogonal voltage and the second orthogonal voltage are subjected to frequency phase-locking processing to determine the frequency signal of the voltage signal.

[0092] In a possible implementation manner, performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine the frequency signal of the voltage signal includes:

[0093] a: Get the phase-locked control period.

[0094] Here, the phase lock control period is obtained.

[0095] b: Determine a first voltage difference based on a difference between the voltage signal and the first orthogonal voltage.

[0096] Here, the difference between the voltage signal and the first orthogonal voltage is determined as the first voltage difference. If the voltage signal is less than the first orthogonal voltage, the absolute value of the difference between the voltage signal and the first orthogonal voltage is determined as the first voltage difference.

[0097] c: Determine a frequency signal of the voltage signal based on the product of the first voltage difference, the second orthogonal voltage and the phase-locked control period.

[0098] Here, the frequency signal of the voltage signal is determined according to the product of the first voltage difference, the second orthogonal voltage and the phase-locked control period.

[0099] Here, the determination formula is as follows:

[0100] Wt=(Vgrid-Vα)*Vβ*T;

[0101] Wherein, Wt is a frequency signal, Vgrid is a voltage signal, Vα is a first orthogonal voltage, Vβ is a second orthogonal voltage, and T is a phase-locked control period.

[0102] In a specific embodiment, the phase-locked control period is obtained, and the first voltage difference is determined according to the difference between the voltage signal and the first orthogonal voltage; the frequency signal of the voltage signal is determined according to the product of the first voltage difference, the second orthogonal voltage and the phase-locked control period.

[0103] S104: Determine a phase angle of the voltage signal based on a frequency signal of the voltage signal and phase information of the voltage signal, and use the phase angle of the voltage signal to control a sinusoidal signal of an inverter connected to the single-phase power grid.

[0104] In this step, the phase angle of the voltage signal is determined according to the frequency signal of the voltage signal and the phase information of the voltage signal, and the phase angle of the voltage signal is used to control the sinusoidal signal of the inverter, so that the sinusoidal signal is used to control the devices in the inverter connected to the single-phase power grid.

[0105] In a possible implementation manner, determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal includes:

[0106] The frequency signal of the voltage signal and the phase information of the voltage signal are input into a voltage-controlled oscillator, and the frequency signal of the voltage signal and the phase information of the voltage signal are processed to determine the phase angle of the voltage signal.

[0107] Here, the frequency signal of the voltage signal and the phase information of the voltage signal are input into the voltage-controlled oscillator, the frequency signal of the voltage signal and the phase information of the voltage signal are processed, and the phase angle of the voltage signal is determined.

[0108] The voltage controlled oscillator is a digital oscillator. The frequency signal of the voltage signal and the phase information of the voltage signal are input into the voltage controlled oscillator, so that the phase angle of the voltage signal can be quickly determined.

[0109] In a specific embodiment, after the voltage signal Vgrid is subjected to multi-stage second-order generalized integration processing, a pair of orthogonal voltage signals, a first orthogonal voltage Vα and a second orthogonal voltage Vβ, are obtained. The first orthogonal voltage and the second orthogonal voltage are subjected to Park transformation to obtain a direct axis region signal and a quadrature axis region signal. The quadrature axis region signal is input into a PI controller and then adjusted to obtain the phase information of the voltage signal. The voltage signal, the first orthogonal voltage and the second orthogonal voltage are subjected to frequency phase-locking processing to determine the frequency signal of the voltage signal. The frequency signal of the voltage signal and the phase information of the voltage signal are input into a voltage-controlled oscillator to determine the phase angle of the voltage signal, and the phase angle of the voltage signal is used to control the sinusoidal signal of the inverter. By using the voltage signal, the first orthogonal voltage and the second orthogonal voltage for frequency phase-locking processing, a real-time frequency signal is determined, and real-time tracking of the frequency of the power grid inverter is achieved, thereby eliminating the influence of the power grid frequency fluctuation on the phase-locked loop, and improving the accuracy of the detection of the phase and frequency of the power grid inverter.

[0110] For further information, see Figure 4 , Figure 5 , Figure 4 Schematic diagram of waveform without frequency adaptive phase locking. Figure 5 This is a waveform diagram of frequency adaptive phase locking provided in the embodiment of the present application. Figure 5 As shown, the voltage signal, the first orthogonal voltage and the second orthogonal voltage are subjected to frequency phase-locked processing to determine the frequency signal of the voltage signal, so that real-time tracking of the frequency can be achieved, thereby eliminating the influence of frequency fluctuation on the accuracy of the phase-locked loop. Figure 5 By using frequency adaptive phase locking, the frequency jumps from 50 Hz to 52 Hz at 0.5 seconds, and the phase error is adjusted to 0 after one cycle. Figure 4 Without frequency adaptive phase locking, the phase error is 1.4% after the frequency jumps from 50 Hz to 52 Hz at 0.5 seconds.

[0111] For further information, see Figure 6 , Figure 6 A schematic diagram of a phase-locked control method for a single-phase power grid provided in an embodiment of the present application. Figure 6As shown, it includes a multi-stage second-order generalized integration module, a frequency phase-locked module, a park converter, a PI controller, and a voltage-controlled oscillator. After the voltage signal Vgrid is processed by a multi-stage second-order generalized integration, a pair of orthogonal voltage signals, a first orthogonal voltage Vα and a second orthogonal voltage Vβ, are obtained. The first orthogonal voltage and the second orthogonal voltage are subjected to Park transformation to obtain a direct-axis region signal D and a quadrature-axis region signal Q. The quadrature-axis region signal is input into the PI controller and adjusted to obtain the phase information of the voltage signal. The voltage signal, the first orthogonal voltage, and the second orthogonal voltage are subjected to frequency phase-locked processing to determine the frequency signal of the voltage signal. The frequency signal of the voltage signal and the phase information of the voltage signal are input into the voltage-controlled oscillator to determine the phase angle of the voltage signal, and the phase angle of the voltage signal is used to control the sinusoidal signal of the inverter. By using the voltage signal, the first orthogonal voltage and the second orthogonal voltage to perform frequency phase-locked processing, a real-time frequency signal is determined, and real-time tracking of the grid inverter frequency is achieved, thereby eliminating the impact of grid frequency fluctuations on the phase-locked loop and improving the accuracy of phase and frequency detection of the grid inverter.

[0112] The embodiment of the present application provides a phase-locked control method for a single-phase power grid, the phase-locked control method comprising: obtaining a voltage signal of the single-phase power grid, determining a first quadrature voltage and a second quadrature voltage based on the voltage signal; processing the first quadrature voltage and the second quadrature voltage to determine the phase information of the voltage signal; performing frequency phase-locking processing on the voltage signal, the first quadrature voltage and the second quadrature voltage to determine the frequency signal of the voltage signal; determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and controlling the sinusoidal signal of the inverter using the phase angle of the voltage signal. By performing frequency phase-locking processing using the voltage signal, the first quadrature voltage and the second quadrature voltage to determine the real-time frequency signal, the real-time tracking of the frequency of the power grid inverter is realized, thereby eliminating the influence of the power grid frequency fluctuation on the phase-locked loop, and improving the accuracy of the detection of the phase and frequency of the power grid inverter.

[0113] See also Figure 7 , Figure 7 This is a schematic diagram of the structure of a phase-locked control device for a single-phase power grid provided in an embodiment of the present application. Figure 7 As shown in , the phase-locked control device 700 of the single-phase power grid includes:

[0114] A determination module 710 is used to obtain a voltage signal of a single-phase power grid, and determine a first orthogonal voltage and a second orthogonal voltage based on the voltage signal;

[0115] A transformation module 720, configured to process the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal;

[0116] A frequency phase locking module 730, configured to perform frequency phase locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine a frequency signal of the voltage signal;

[0117] The phase angle calculation module 740 is used to determine the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and use the phase angle of the voltage signal to control the sinusoidal signal of the inverter.

[0118] In a possible implementation manner, when the determination module 710 is used to determine the first quadrature voltage and the second quadrature voltage based on the voltage signal, the determination module 710 is specifically used to:

[0119] The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

[0120] In a possible implementation manner, when the transformation module 720 is used to process the first quadrature voltage and the second quadrature voltage and obtain the phase information of the voltage signal, the transformation module 420 is specifically used to:

[0121] Performing park transformation processing on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal;

[0122] The quadrature-axis region signal is subjected to PI processing to determine the phase information of the voltage signal.

[0123] In a possible implementation manner, when the transformation module 720 is used to perform park transformation processing on the first orthogonal voltage and the second orthogonal voltage to determine the direct-axis region signal and the quadrature-axis region signal, the transformation module 720 is specifically used to:

[0124] Obtaining a preset sine wave angle, and determining a cosine value of the sine wave angle and a sine value of the sine wave angle;

[0125] Determine a target matrix composed of the cosine value of the sine wave angle and the sine value of the sine wave angle;

[0126] determining a target vector formed by the first orthogonal voltage and the second orthogonal voltage;

[0127] The direct-axis region signal and the quadrature-axis region signal are determined according to the product of the target matrix and the target vector.

[0128] In a possible implementation manner, when the frequency phase locking module 730 is used to perform frequency phase locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine the frequency signal of the voltage signal, the frequency phase locking module 730 is specifically used to:

[0129] Get the phase-locked control period;

[0130] determining a first voltage difference based on a difference between the voltage signal and the first quadrature voltage;

[0131] A frequency signal of a voltage signal is determined based on the product of the first voltage difference, the second orthogonal voltage and the phase-locked control period.

[0132] In a possible implementation manner, when the phase angle calculation module 740 is used to determine the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, the phase angle calculation module 740 is specifically used to:

[0133] The frequency signal of the voltage signal and the phase information of the voltage signal are input into a voltage-controlled oscillator, and the frequency signal of the voltage signal and the phase information of the voltage signal are processed to determine the phase angle of the voltage signal.

[0134] The embodiment of the present application provides a phase-locked control device for a single-phase power grid, the phase-locked control device comprising: a determination module for acquiring a voltage signal of the single-phase power grid, and determining a first orthogonal voltage and a second orthogonal voltage based on the voltage signal; a conversion module for processing the first orthogonal voltage and the second orthogonal voltage to determine the phase information of the voltage signal; a frequency phase-locked module for performing frequency phase-locked processing on the voltage signal, the first orthogonal voltage and the second orthogonal voltage to determine the frequency signal of the voltage signal; a phase angle calculation module for determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and using the phase angle of the voltage signal to control the sinusoidal signal of the inverter. By performing frequency phase-locked processing using the voltage signal, the first orthogonal voltage and the second orthogonal voltage, a real-time frequency signal is determined, and real-time tracking of the frequency of the power grid inverter is achieved, thereby eliminating the influence of the power grid frequency fluctuation on the phase-locked loop, and improving the accuracy of the detection of the phase and frequency of the power grid inverter.

[0135] See also Figure 8 , Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 8 As shown in , the electronic device 800 includes a processor 810 , a memory 820 and a bus 830 .

[0136] The memory 820 stores machine-readable instructions executable by the processor 810. When the electronic device 800 is running, the processor 810 communicates with the memory 820 via the bus 830. When the machine-readable instructions are executed by the processor 810, the above-mentioned Figure 1 The steps of the phase-locked control method for a single-phase power grid in the method embodiment shown and the specific implementation thereof can be referred to the method embodiment, which will not be described in detail here.

[0137] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 The steps of the phase-locked control method for a single-phase power grid in the method embodiment shown and the specific implementation thereof can be referred to the method embodiment, which will not be described in detail here.

[0138] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0139] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0140] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0141] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0142] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0143] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A phase-locked control method for a single-phase power grid, characterized in that: The phase-locked control method comprises: Acquire a voltage signal of a single-phase power grid, and determine a first quadrature voltage and a second quadrature voltage based on the voltage signal; Processing the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal; Performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine a frequency signal of the voltage signal; Determine the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and use the phase angle of the voltage signal to control the sinusoidal signal of the inverter connected to the single-phase power grid; The step of performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine the frequency signal of the voltage signal includes: Get the phase-locked control period; determining a first voltage difference based on a difference between the voltage signal and the first quadrature voltage; Determine a frequency signal of a voltage signal based on a product of the first voltage difference, the second orthogonal voltage, and the phase-locked control period; The frequency signal is determined by the following formula: Wt=(Vgrid-Vα)*Vβ*T; Wherein, Wt is a frequency signal, Vgrid is a voltage signal, Vα is a first orthogonal voltage, Vβ is a second orthogonal voltage, and T is a phase-locked control period.

2. The phase-locked control method according to claim 1, characterized in that: The determining of the first quadrature voltage and the second quadrature voltage based on the voltage signal comprises: The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

3. The phase-locked control method according to claim 1, characterized in that: The first quadrature voltage and the second quadrature voltage are processed, and the phase information of the voltage signal includes: Performing park transformation processing on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal; The quadrature-axis region signal is subjected to PI processing to determine the phase information of the voltage signal.

4. The phase-locked control method according to claim 3, characterized in that: The performing park transformation on the first orthogonal voltage and the second orthogonal voltage to determine a direct-axis region signal and a quadrature-axis region signal includes: Obtaining a preset sine wave angle, and determining a cosine value of the sine wave angle and a sine value of the sine wave angle; Determine a target matrix composed of the cosine value of the sine wave angle and the sine value of the sine wave angle; determining a target vector formed by the first orthogonal voltage and the second orthogonal voltage; The direct-axis region signal and the quadrature-axis region signal are determined according to the product of the target matrix and the target vector.

5. The phase-locked control method according to claim 1, characterized in that: Determining the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal includes: The frequency signal of the voltage signal and the phase information of the voltage signal are input into a voltage-controlled oscillator, and the frequency signal of the voltage signal and the phase information of the voltage signal are processed to determine the phase angle of the voltage signal.

6. A phase-locked control device for a single-phase power grid, characterized in that: The phase-locked control device comprises: A determination module, configured to obtain a voltage signal of a single-phase power grid, and determine a first orthogonal voltage and a second orthogonal voltage based on the voltage signal; A transformation module, configured to process the first quadrature voltage and the second quadrature voltage to determine phase information of the voltage signal; A frequency phase-locking module, used for performing frequency phase-locking processing on the voltage signal, the first orthogonal voltage and the second orthogonal voltage to determine a frequency signal of the voltage signal; a phase angle calculation module, configured to determine the phase angle of the voltage signal based on the frequency signal of the voltage signal and the phase information of the voltage signal, and to control the sinusoidal signal of the inverter connected to the single-phase power grid using the phase angle of the voltage signal; When the frequency phase locking module is used to perform frequency phase locking processing on the voltage signal, the first orthogonal voltage, and the second orthogonal voltage to determine the frequency signal of the voltage signal, the frequency phase locking module is specifically used to: Get the phase-locked control period; determining a first voltage difference based on a difference between the voltage signal and the first quadrature voltage; Determine a frequency signal of a voltage signal based on a product of the first voltage difference, the second orthogonal voltage, and the phase-locked control period; The frequency signal is determined by the following formula: Wt=(Vgrid-Vα)*Vβ*T; Wherein, Wt is a frequency signal, Vgrid is a voltage signal, Vα is a first orthogonal voltage, Vβ is a second orthogonal voltage, and T is a phase-locked control period.

7. The phase-locked control device according to claim 6, characterized in that: When the determination module is used to determine the first quadrature voltage and the second quadrature voltage based on the voltage signal, the determination module is specifically used to: The voltage signal is subjected to multi-stage second-order generalized integration processing to determine the first orthogonal voltage and the second orthogonal voltage.

8. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the phase-locked control method for a single-phase power grid as described in any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the phase-locked control method for a single-phase power grid as claimed in any one of claims 1 to 5 are executed.

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