A method, device and equipment for real-time estimation of instantaneous phase angle of power supply voltage

Abstract

The present invention discloses a method, device, and apparatus for real-time estimation of the instantaneous phase angle of a power supply voltage. This method first collects real-time power supply voltage samples and then uses an analytical signal model and an extended Kalman filter to estimate the instantaneous phase angle of the power supply voltage in real time. Compared to existing technologies, this method offers simpler calculations, stronger anti-interference capabilities, higher accuracy, and greater real-time performance, effectively improving the accuracy of calculating the initial phase angle of the power supply voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of power data measurement, and in particular to a method for estimating the instantaneous phase angle of a power supply voltage. Background Art

[0002] The phase angle is called "phase angle", also known as "phase", "cycle phase" and "phase". The expression of AC voltage is: u = u m sin(ωt+φ), the voltage at different times is determined by the value of (ωt+φ), (ωt+φ) is called the phase. When t=0, φ is called the initial phase angle.

[0003] A generator has three windings, each generating a voltage, forming a three-phase voltage. Because the three windings are positioned equally across a circle, with an angle difference of 360 / 3 = 120 degrees, the amplitudes of the three-phase voltages do not vary uniformly. Instead, there is an internal delay equal to the time it takes to rotate 1 / 3 of a circle, or 120 degrees. This angular difference is called the phase difference. While the phase angle is a relative value, the phase difference is the difference between two phase angles.

[0004] Because the frequency of the power grid is unstable, and in industrial environments, the influence of a large number of capacitive and inductive loads, as well as diode and transistor rectifier loads, can cause certain distortions in the grid waveform. This results in simple inverse trigonometric calculations being unable to accurately calculate the grid phase angle and frequency. Existing methods for calculating the instantaneous phase angle of the grid voltage are often complex, with long response times and a large amount of computation, making them difficult to implement. Furthermore, the calculated instantaneous phase angle of the grid voltage often deviates from the actual instantaneous phase angle. Summary of the Invention

[0005] Based on this, the present invention provides a real-time estimation method, device and equipment for the instantaneous phase angle of power supply voltage. Compared with the existing technology, this method is simple to calculate, has stronger anti-interference ability, higher accuracy and real-time performance, and effectively improves the calculation accuracy of the initial phase angle of power supply voltage.

[0006] According to a first aspect of some embodiments of the present application, a method for real-time estimation of an instantaneous phase angle of a power supply voltage is provided, the method comprising the following steps:

[0007] Step 1: Obtain the instantaneous measurement value of the power supply voltage;

[0008] Step 2: Preset an oscillation model of the power supply voltage and perform Hilbert transform on the oscillation model to obtain an analytical model of the power supply voltage;

[0009] Step 3: Establishing an extended Kalman filter measurement equation based on the known voltage amplitude and angular frequency, calculating the error rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model using the extended Kalman filter measurement equation, and setting the error rate to zero;

[0010] Step 4: Using the extended Kalman filter, the initial phase angle is estimated in real time, and the instantaneous phase angle of the power supply voltage is obtained based on the obtained initial phase angle.

[0011] Optionally, step 2 specifically includes the following steps:

[0012] Assume that the power supply voltage oscillation model is: v(t) = Acos(ωt+φ);

[0013] Performing Hilbert transform on the power supply voltage oscillation model, the analytical model of the power supply voltage is obtained as follows:

[0014] V(t)=Ae j(ωt+φ)

[0015] Where: t is time, v(t) is the amplitude of the power supply voltage at time t, A is the voltage amplitude, ω is the voltage angular frequency, φ is the initial voltage phase angle, and V(t) is the Hilbert transform of the instantaneous value of the power supply voltage.

[0016] Optionally, step three specifically includes the following steps:

[0017] Let the state variable x in the extended Kalman filter be the initial phase angle φ. Since the initial phase angle is a constant and does not change with time, the extended Kalman filter system equation is:

[0018] x k+1 =x k

[0019] Among them, x k It is the estimated value of the state variable x at the kth moment, that is, the estimated value of the initial phase angle at the kth moment. Since the initial phase angle is a constant, the value at the kth moment is consistent with the k+1 moment;

[0020] The extended Kalman filter measurement equation is:

[0021]

[0022] The final expression of the measurement equation is:

[0023]

[0024] Where: x k is the estimated value of the initial phase angle at time k; x k+1is the estimated value of the initial phase angle at time k+1; y k+1 is the error rate between the instantaneous measured value and the estimated value of the power supply voltage, h(x k+1 ) is the measurement equation of the extended Kalman filter. Since the error change rate is zero when the estimated value of the initial phase angle is consistent with the true value, the result of the measurement equation is set to zero; H(v k+1 ) is the Hilbert transform of the instantaneous measurement value of the power supply voltage at time k+1, is the value of the voltage analytical model at time k+1, v k+1 is the instantaneous measured value of the power supply voltage at time k+1.

[0025] Optionally, step 4 specifically includes the following steps:

[0026]

[0027] One-step prediction: k = 0, that is, at time zero, there is no information about the initial phase angle. A value between 0 and 360° is assigned to x0, and then the one-step prediction is obtained according to the above formula, where: Represents the state vector of the initial phase angle estimated from time k to time k+1, represents the state vector estimated at the initial phase angle at time k, F k represents the system matrix at time k;

[0028]

[0029] One-step prediction variance matrix, since k = 0, that is, at zero time, there is no information about the initial phase angle, so it is believed that the initial assignment error is large, so P0 is given a large value, indicating that the estimation error of x0 is very large, and the one-step prediction variance matrix is obtained, where P k+1 / k It represents the minimum prediction mean square error matrix of the initial phase angle from time k to time k+1, P k Represents the minimum prediction mean square error matrix at the initial phase angle k;

[0030]

[0031] The gain matrix K is obtained from the one-step prediction variance matrix, where K k+1 represents the gain matrix of the initial phase angle at time k+1, represents the state vector estimated at the initial phase angle at time k+1, H k+1 Represents the state observation matrix at time k+1;

[0032]

[0033] The measurement error is amplified or reduced by the gain matrix K, that is, the difference between y and the measurement function value, and added to the one-step estimate as the estimate at time k+1, where Represents the output value of the measurement equation when the initial phase angle is the one-step estimated value at time k;

[0034] P k+1 =(IK k+1 H k+1 )P k+1 / k

[0035] At the same time, the variance matrix of the state value at time k+1 is updated to evaluate the accuracy of the initial phase angle estimation at time k+1, where I represents the unit matrix and P k+1 Represents the minimum prediction mean square error matrix at the initial phase angle k+1;

[0036] If P k+1 If the value of x is less than a preset threshold, or the number of estimations k increases to a certain threshold, the estimation is stopped and the current x is k+1 As the final initial phase angle estimate;

[0037] Where: y k+1 =0, F k =1, R k+1 =γ,γ∈R + ; These formulas need to be brought into the above 5 Kalman filter equations to iteratively solve the initial phase angle. For example, y k+1 =0 into F k =1 into And so on. Among them, R k+1 =γ,γ∈R + The γ in γ needs to be selected according to the measurement noise level. If the measurement data (measured voltage data) has large noise, a larger value is selected. This parameter is an empirical parameter.

[0038] Among them, R k+1 is the noise matrix, which is used to measure the noise level in the measurement data;

[0039] After the initial phase angle φ is estimated, the instantaneous phase angle of the power supply voltage is obtained by the following formula:

[0040] Φ=ωt+φ。

[0041] Optionally, step one specifically includes the following steps:

[0042] The instantaneous measurement value of the power supply voltage is obtained by detecting with a voltage sensor.

[0043] According to a second aspect of some embodiments of the present application, a device for real-time estimation of the instantaneous phase angle of a power supply voltage is provided, comprising:

[0044] An instantaneous measurement value acquisition module, used for acquiring an instantaneous measurement value of the power supply voltage;

[0045] An analytical model building module is used to preset an oscillation model of the power supply voltage and perform Hilbert transform on the oscillation model to obtain an analytical model of the power supply voltage;

[0046] a measurement equation establishment module, configured to establish an extended Kalman filter measurement equation based on the known voltage amplitude and angular frequency, calculate the error change rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model using the extended Kalman filter measurement equation, and set the error change rate to zero;

[0047] The estimation module is used to use the extended Kalman filter to estimate the initial phase angle in real time, and obtain the instantaneous phase angle of the power supply voltage based on the obtained initial phase angle.

[0048] According to a third aspect of some embodiments of the present application, a device for real-time estimation of an instantaneous phase angle of a power supply voltage is provided, comprising:

[0049] at least one memory and at least one processor;

[0050] The memory is used to store one or more programs;

[0051] When the one or more programs are executed by the at least one processor, the at least one processor implements the steps of a method for real-time estimation of the instantaneous phase angle of a power supply voltage as described in the first aspect of the present application.

[0052] This application provides a real-time method for estimating the instantaneous phase angle of a power supply voltage. This method first collects real-time power supply voltage samples and then uses an analytical signal model and an extended Kalman filter to estimate the instantaneous phase angle of the power supply voltage in real time. Compared to existing technologies, this method offers simpler calculations, stronger anti-interference capabilities, higher accuracy, and greater real-time performance, effectively improving the accuracy of calculating the initial power supply voltage phase angle.

[0053] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the steps of a method for real-time estimation of the instantaneous phase angle of a power supply voltage provided by the present invention;

[0055] Figure 2 A schematic diagram of instantaneous measurement values of a power supply voltage measured in one embodiment of the present invention;

[0056] Figure 3 Schematic diagram of a curve showing the estimated instantaneous voltage phase angle and the actual instantaneous voltage phase angle in one embodiment of the present invention;

[0057] Figure 4 This is a structural schematic diagram of a real-time estimation device for the instantaneous phase angle of a power supply voltage provided by the present invention. DETAILED DESCRIPTION

[0058] In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

[0059] It should be clear that the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the embodiments of the present application.

[0060] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the embodiments of the present application. The singular forms "a," "the," and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0061] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar human bodies, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0062] In addition, in this application, unless otherwise specified, "plurality" refers to two or more. "And / or" describes the relationship between related entities, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the related entities are in an "or" relationship.

[0063] See also Figure 1 , Figure 1 The present invention provides a method for real-time estimation of the instantaneous phase angle of a power supply voltage, comprising the following steps:

[0064] S101: Obtaining an instantaneous measurement value of the power supply voltage.

[0065] like Figure 2 As shown, Figure 2 The diagram is a schematic diagram of the instantaneous measurement value of the power supply voltage in an example. Optionally, the instantaneous measurement value of the power supply voltage is obtained in real time by means of detection by a voltage sensor. The voltage sensor may be a voltage transformer or other voltage detection device.

[0066] S102 presets an oscillation model of the power supply voltage, and performs Hilbert transform on the oscillation model to obtain an analytical model of the power supply voltage.

[0067] Optionally, the power supply voltage oscillation model is assumed to be: v(t) = Acos(ωt+φ);

[0068] The Hilbert transform of the power supply voltage oscillation model is performed to obtain the analytical model of the power supply voltage: V(t) = Ae j(ωt+φ) ;

[0069] Where t is time, v(t) is the amplitude of the power supply voltage at time t, A is the voltage amplitude, ω is the voltage angular frequency, φ is the initial voltage phase angle, and V(t) is the instantaneous Hilbert transform of the power supply voltage. This model assumes that the voltage amplitude A is known (e.g., 110V or 220V) and the voltage angular frequency ω is known (e.g., 60Hz or 50Hz). Once the initial phase angle φ is determined, the voltage phase angle at any time can be calculated using the following formula: Φ = ωt + φ.

[0070] Step 3: Based on the known voltage amplitude and angular frequency, an extended Kalman filter measurement equation is established. The extended Kalman filter measurement equation is used to calculate the error change rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model, and the error change rate is set to zero.

[0071] Optionally, step three specifically includes the following steps:

[0072] Since the initial phase φ is the only physical quantity that needs to be estimated in the voltage analysis model, the state variable x in the extended Kalman filter is set to the initial phase angle φ. Since the initial phase angle is a constant, it does not change with time, so the extended Kalman filter system equation is:

[0073] x k+1 =x k

[0074] Among them, x k It is the estimated value of the state variable x at the kth moment, that is, the estimated value of the initial phase angle at the kth moment. Since the initial phase angle is a constant, the value at the kth moment is consistent with the k+1 moment;

[0075] The idea behind the measurement equation is to use the voltage analytical model to describe the actual voltage measurement value, that is, the estimated initial phase angle is required to minimize the difference between the voltage analytical model and the actual measurement value at any time. The mathematical description here is the value of the voltage analytical model at time k+1. Subtract the Hilbert transform v of the voltage measurement value at time k+1 k+1 +jH(v k+1 ), the energy of the difference (i.e., 2-norm) calculates the partial derivative with respect to the initial phase angle φ and takes the corresponding φ value at the minimum.

[0076] The extended Kalman filter measurement equation is:

[0077]

[0078] The final expression of the measurement equation is:

[0079]

[0080] Where: x k is the estimated value of the initial phase angle at time k; x k+1 is the estimated value of the initial phase angle at time k+1; y k+1 is the error rate between the instantaneous measured value and the estimated value of the power supply voltage, h(x k+1 ) is the measurement equation of the extended Kalman filter. Since the error change rate is zero when the estimated value of the initial phase angle is consistent with the true value, the result of the measurement equation is set to zero; H(v k+1 ) is the Hilbert transform of the instantaneous measurement value of the power supply voltage at time k+1, is the value of the voltage analytical model at time k+1, v k+1 is the instantaneous measured value of the power supply voltage at time k+1.

[0081] Step 4: Use the extended Kalman filter to estimate the initial phase angle in real time.

[0082] Optionally, step 4 specifically includes the following steps:

[0083]

[0084] One-step prediction, k = 0, that is, at time zero, there is no information about the initial phase angle, so you can choose any value between 0-360° and assign it to x0, and then get the one-step prediction according to the above formula, where Represents the state vector of the initial phase angle estimated from time k to time k+1, represents the state vector estimated at the initial phase angle at time k, F k represents the system matrix at time k;

[0085]

[0086] One-step prediction variance matrix, since k = 0, that is, at zero time, there is no information about the initial phase angle, so it is believed that the initial assignment error is large, so P0 is given a large value, indicating that the estimation error of x0 is very large, so the one-step prediction variance matrix can be obtained, where P k+1 / k It represents the minimum prediction mean square error matrix of the initial phase angle from time k to time k+1, P k Represents the minimum prediction mean square error matrix at the initial phase angle k;

[0087]

[0088] The gain matrix K can be obtained from the one-step prediction variance matrix, where K k+1 represents the gain matrix of the initial phase angle at time k+1, represents the state vector estimated at the initial phase angle at time k+1, H k+1 Represents the state observation matrix at time k+1;

[0089]

[0090] The measurement error is amplified or reduced by the gain matrix K, that is, the difference between y and the measurement function value, and added to the one-step estimate as the estimate at time k+1, where Represents the output value of the measurement equation when the initial phase angle is the one-step estimated value at time k;

[0091] P k+1 =(IK k+1 H k+1 )P k+1 / k

[0092] At the same time, the variance matrix of the state value at time k+1 is updated to evaluate the accuracy of the initial phase angle estimation at time k+1, where I represents the unit matrix and P k+1Represents the minimum prediction mean square error matrix at the initial phase angle k+1;

[0093] If P k+1 If the value of x is less than a preset threshold, or the number of estimations k increases to a certain threshold, the estimation is stopped and the current x is k+1 As the final initial phase angle estimate;

[0094] Where: y k+1 =0, F k =1, R k+1 =γ,γ∈R + ;

[0095] Among them, R k+1 is the noise matrix, which is used to measure the noise level in the measurement data. In the above iterative process, these formulas need to be brought into the above five Kalman filter equations to iteratively solve the initial phase angle. For example, y k+1 =0 into F k =1 into And so on. Among them, R k+1 =γ,γ∈R + The γ in γ needs to be selected according to the measurement noise level. If the measurement data (measured voltage data) has large noise, a larger value is selected. This parameter is an empirical parameter.

[0096] After the initial phase angle φ is estimated, the instantaneous phase angle of the power supply voltage can be obtained using the following formula:

[0097] Φ=ωt+φ。

[0098] like Figure 3 As shown, Figure 3 A schematic diagram of a curve showing the estimated instantaneous voltage phase angle and the true instantaneous voltage phase angle according to an embodiment of the present invention, wherein the solid line is the true instantaneous voltage phase angle and the dotted line is the estimated instantaneous voltage phase angle.

[0099] Corresponding to the above-mentioned method for estimating the instantaneous phase angle of a power supply voltage in real time, the embodiment of the present application further provides a device for estimating the instantaneous phase angle of a power supply voltage in real time, such as Figure 4 As shown, the apparatus 400 includes:

[0100] An instantaneous measurement value acquisition module 410 is used to obtain an instantaneous measurement value of the power supply voltage;

[0101] An analytical model building module 420 is used to preset an oscillation model of the power supply voltage and perform a Hilbert transform on the oscillation model to obtain an analytical model of the power supply voltage;

[0102] a measurement equation establishing module 430 for establishing an extended Kalman filter measurement equation based on the known voltage amplitude and angular frequency, calculating the error change rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model using the extended Kalman filter measurement equation, and setting the error change rate to zero;

[0103] The estimation module 440 is configured to use the extended Kalman filter to perform real-time estimation of the initial phase angle.

[0104] Corresponding to the above-mentioned method for real-time estimation of the instantaneous phase angle of a power supply voltage, an embodiment of the present application further provides a device for real-time estimation of the instantaneous phase angle of a power supply voltage, comprising:

[0105] at least one memory and at least one processor;

[0106] The memory is used to store one or more programs;

[0107] When the one or more programs are executed by the at least one processor, the at least one processor implements the steps of the method for real-time estimation of the instantaneous phase angle of the power supply voltage as described in any of the above embodiments.

[0108] This application provides a method and device for real-time estimation of the instantaneous phase angle of a power supply voltage. This method first collects real-time power supply voltage samples and then uses an analytical signal model and an extended Kalman filter to estimate the instantaneous phase angle of the power supply voltage in real time. Compared to existing technologies, this method offers simpler calculations, stronger anti-interference capabilities, higher accuracy, and greater real-time performance, effectively improving the accuracy of calculating the initial phase angle of the power supply voltage.

[0109] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is limited only by the appended claims.

[0110] The above-described embodiments merely represent several implementation methods of the embodiments of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the concept of the embodiments of the present application, and these modifications and improvements fall within the scope of protection of the embodiments of the present application.

Claims

1. A method for real-time estimation of the instantaneous phase angle of a power supply voltage, characterized in that: The method comprises the following steps: Step 1: Obtain the instantaneous measurement value of the power supply voltage; Step 2: Preset an oscillation model of the power supply voltage and perform Hilbert transform on the oscillation model to obtain an analytical model of the power supply voltage; Specifically, the power supply voltage oscillation model is assumed to be: v(t) = Acos(ωt+φ); Performing Hilbert transform on the power supply voltage oscillation model, the analytical model of the power supply voltage is obtained as follows: V(t)=Ae j(ωt+φ) Where: t is time, v(t) is the amplitude of the power supply voltage at time t, A is the voltage amplitude, ω is the voltage angular frequency, φ is the initial voltage phase angle, and V(t) is the Hilbert transform of the instantaneous value of the power supply voltage; Step 3: Establishing an extended Kalman filter measurement equation based on the known voltage amplitude and angular frequency, calculating the error rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model using the extended Kalman filter measurement equation, and setting the error rate to zero; Specifically, let the state variable x in the extended Kalman filter be the initial phase angle φ. Since the initial phase angle is a constant and does not change with time, the extended Kalman filter system equation is: x k+1 =x k Among them, x k It is the estimated value of the state variable x at the kth moment, that is, the estimated value of the initial phase angle at the kth moment. Since the initial phase angle is a constant, the value at the kth moment is consistent with the k+1 moment; The extended Kalman filter measurement equation is: The final expression of the measurement equation is: Where: x k is the estimated value of the initial phase angle at time k; x k+1 is the estimated value of the initial phase angle at time k+1; y k+1 is the error rate between the instantaneous measured value and the estimated value of the power supply voltage, h(x k+1 ) is the measurement equation of the extended Kalman filter. Since the error change rate is zero when the estimated value of the initial phase angle is consistent with the true value, the result of the measurement equation is set to zero; H(v k+1 ) is the Hilbert transform of the instantaneous measurement value of the power supply voltage at time k+1, is the value of the voltage analytical model at time k+1, v k+1 is the instantaneous measured value of the power supply voltage at time k+1; Step 4: Using the extended Kalman filter, the initial phase angle is estimated in real time, and the instantaneous phase angle of the power supply voltage is obtained based on the obtained initial phase angle; One-step prediction: k = 0, that is, at time zero, there is no information about the initial phase angle. A value between 0 and 360° is assigned to x0, and then the one-step prediction is obtained according to the above formula, where: Represents the state vector of the initial phase angle estimated from time k to time k+1, represents the state vector estimated at the initial phase angle at time k, F k represents the system matrix at time k; One-step prediction variance matrix, since k = 0, that is, at zero time, there is no information about the initial phase angle, so it is believed that the initial assignment error is large, so P0 is given a large value, indicating that the estimation error of x0 is very large, and the one-step prediction variance matrix is obtained, where P k+1 / k It represents the minimum prediction mean square error matrix of the initial phase angle from time k to time k+1, P k Represents the minimum prediction mean square error matrix at the initial phase angle k; The gain matrix K is obtained from the one-step prediction variance matrix, where K k+1 represents the gain matrix of the initial phase angle at time k+1, represents the state vector estimated at the initial phase angle at time k+1, H k+1 Represents the state observation matrix at time k+1; The measurement error is amplified or reduced by the gain matrix K, that is, the difference between y and the measurement function value, and added to the one-step estimate as the estimate at time k+1, where Represents the output value of the measurement equation when the initial phase angle is the one-step estimated value at time k; P k+1 =(I-K k+1 H k+1 )P k+1 / k At the same time, the variance matrix of the state value at time k+1 is updated to evaluate the accuracy of the initial phase angle estimation at time k+1, where I represents the unit matrix and P k+1 Represents the minimum prediction mean square error matrix at the initial phase angle k+1; If P k+1 If the value of x is less than a preset threshold, or the number of estimations k increases to a certain threshold, the estimation is stopped and the current x is k+1 As the final initial phase angle estimate; Among them: y k+1 =0,F k =1, R k+1 =γ,γ∈R + ; Among them, R k+1 is the noise matrix, which is used to measure the noise level in the measurement data; After the initial phase angle φ is estimated, the instantaneous phase angle of the power supply voltage is obtained by the following formula: Φ = ωt + φ.

2. A method for real-time estimation of the instantaneous phase angle of power supply voltage according to claim 1, characterized in that: Step 1 specifically includes the following steps: The instantaneous measurement value of the power supply voltage is obtained by detecting with a voltage sensor.

3. A real-time estimation device for the instantaneous phase angle of a power supply voltage, characterized in that: include: instantaneous A measurement value acquisition module, used for acquiring an instantaneous measurement value of the power supply voltage; The analytical model building module is used to preset the oscillation model of the power supply voltage and perform Hilbert transform on the oscillation model to obtain the analytical model of the power supply voltage; specifically, the power supply voltage oscillation model is set to: v(t) = Acos(ωt+φ); the power supply voltage oscillation model is performed Hilbert transform to obtain the analytical model of the power supply voltage: V(t) = Ae j(ωt+φ) ; Where: t is time, v(t) is the amplitude of the power supply voltage at time t, A is the voltage amplitude, ω is the voltage angular frequency, φ is the initial voltage phase angle, and V(t) is the Hilbert transform of the instantaneous value of the power supply voltage; The measurement equation establishment module is used to establish an extended Kalman filter measurement equation based on the known voltage amplitude and angular frequency, calculate the error change rate between the instantaneous measurement value of the power supply voltage and the estimated value obtained by the analytical model through the extended Kalman filter measurement equation, and set the error change rate to zero; specifically, let the state variable x in the extended Kalman filter be the initial phase angle φ. Since the initial phase angle is a constant and does not change with time, the extended Kalman filter system equation is: x k+1 =x k , where x k is the estimated value of the state variable x at the kth moment, that is, the estimated value of the initial phase angle at the kth moment. Since the initial phase angle is a constant, the value at the kth moment is consistent with the k+1th moment. The measurement equation of the extended Kalman filter is: The final expression of the measurement equation is: Where: x k is the estimated value of the initial phase angle at time k; x k+1 is the estimated value of the initial phase angle at time k+1; y k+1 is the error rate between the instantaneous measured value and the estimated value of the power supply voltage, h(x k+1 ) is the measurement equation of the extended Kalman filter. Since the error change rate is zero when the estimated value of the initial phase angle is consistent with the true value, the result of the measurement equation is set to zero; H(v k+1 ) is the Hilbert transform of the instantaneous measurement value of the power supply voltage at time k+1, is the value of the voltage analytical model at time k+1, v k+1 is the instantaneous measured value of the power supply voltage at time k+1; An estimation module is used to use the extended Kalman filter to estimate the initial phase angle in real time, and obtain the instantaneous phase angle of the power supply voltage based on the obtained initial phase angle; One-step prediction: k = 0, that is, at time zero, there is no information about the initial phase angle. A value between 0 and 360° is assigned to x0, and then the one-step prediction is obtained according to the above formula, where: Represents the state vector of the initial phase angle estimated from time k to time k+1, represents the state vector estimated at the initial phase angle at time k, F k represents the system matrix at time k; One-step prediction variance matrix, since k = 0, that is, at zero time, there is no information about the initial phase angle, so it is believed that the initial assignment error is large, so P0 is given a large value, indicating that the estimation error of x0 is very large, and the one-step prediction variance matrix is obtained, where P k+1 / k It represents the minimum prediction mean square error matrix of the initial phase angle from time k to time k+1, P k Represents the minimum prediction mean square error matrix at the initial phase angle k; The gain matrix K is obtained from the one-step prediction variance matrix, where K k+1 represents the gain matrix of the initial phase angle at time k+1, represents the state vector estimated at the initial phase angle at time k+1, H k+1 Represents the state observation matrix at time k+1; The measurement error is amplified or reduced by the gain matrix K, that is, the difference between y and the measurement function value, and added to the one-step estimate as the estimate at time k+1, where Represents the output value of the measurement equation when the initial phase angle is the one-step estimated value at time k; P k+1 =(I-K k+1 H k+1 )P k+1 / k At the same time, the variance matrix of the state value at time k+1 is updated to evaluate the accuracy of the initial phase angle estimation at time k+1, where I represents the unit matrix and P k+1 Represents the minimum prediction mean square error matrix at the initial phase angle k+1; If P k+1 If the value of x is less than a preset threshold, or the number of estimations k increases to a certain threshold, the estimation is stopped and the current x is k+1 As the final initial phase angle estimate; Among them: y k+1 =0,F k =1, R k+1 =γ,γ∈R + ; Among them, R k+1 is the noise matrix, which is used to measure the noise level in the measurement data; After the initial phase angle φ is estimated, the instantaneous phase angle of the power supply voltage is obtained by the following formula: Φ = ωt + φ.

4. A real-time estimation device for instantaneous phase angle of power supply voltage, characterized in that: include: at least one memory and at least one processor; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the at least one processor implements the steps of the method for real-time estimation of the instantaneous phase angle of power supply voltage as claimed in claim 1 or 2.

Images