Methods, systems, storage media and equipment for calculating phase angle difference during synchronous closing.

Abstract

This invention relates to the field of power distribution technology, and discloses a method, system, storage medium, and device for calculating the phase angle difference of synchronous closing. The method includes the following steps: acquiring two voltage signals from both sides of the switching equipment at the same time, detecting and repairing abnormal points; performing IIR mean filtering on the signals; determining whether the signal frequencies are all between 40Hz and 60Hz; performing DC removal processing on the signals; determining whether the effective values ​​of the signals are all greater than 80% of the standard effective value; calculating the signal phase angle difference and outputting the result. This invention is simple and effective. When the sampling frequency of the feeder terminal device is low, the designed algorithm improves the accuracy of the phase angle difference calculation result, thereby more accurately controlling synchronous closing, and has strong engineering practicality.

Description

Technical Field

[0001] This invention relates to the field of power distribution technology, and in particular to a method, system, storage medium, and device for calculating the phase angle difference of synchronous closing. Background Technology

[0002] Synchronous closing of switching equipment in a power system requires three conditions to be met: (1) the voltage amplitudes on both sides of the switch are equal; (2) the voltage frequencies on both sides of the switch are equal; and (3) the voltage phases on both sides of the switch are equal, i.e., the phase angle difference is zero.

[0003] The feeder terminal unit has functions such as remote control, telemetry, remote signaling, and fault detection. It can communicate with the distribution automation master station, provide various parameters for the operation of the distribution system, and execute commands issued by the distribution master station to regulate and control the distribution equipment. It can collect the voltage on both sides of the switch to detect whether the voltage amplitude, frequency, and phase meet the conditions for synchronous closing, thereby achieving automatic synchronous closing.

[0004] Currently, calculating voltage amplitude and frequency is relatively easy, but the calculation error for phase angle difference is large, especially when the sampling frequency of the feeder terminal device is not high. This problem urgently needs to be improved. Summary of the Invention

[0005] This invention addresses the shortcomings and defects of existing technologies by providing a method, system, storage medium, and device for calculating the phase angle difference of synchronous closing. Even with a low hardware sampling frequency, it can obtain a high-precision phase angle difference calculation result, thereby achieving precise control of synchronous closing.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for calculating the phase angle difference during synchronous closing includes the following steps.

[0008] S1: Acquire the simultaneous voltage signals collected by the voltage transformers on both sides of the switching equipment. and Detect and repair and Anomalies in the data.

[0009] S2: Yes and IIR mean filtering is performed to eliminate the effects of noise and harmonics.

[0010] S3: Judgment and Are all frequencies between 40Hz and 60Hz? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated.

[0011] S4: Yes and Perform DC removal processing.

[0012] S5: Judgment and Are all valid values ​​greater than 80% of the standard valid value? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated.

[0013] S6: Calculation and The phase angle difference is calculated and the result is output.

[0014] Preferably, the outlier detection method in step S1 is to compare the difference between two adjacent points sequentially. If the difference is greater than 20% of the standard effective value, the next point is considered an outlier.

[0015] Preferably, the abnormal point repair method in step S1 is to replace the abnormal point with the nearest normal point value.

[0016] Preferably, the IIR mean filtering formula in step S2 is as follows.

[0017] .

[0018] In the formula, , , , , These are the (m-2), (m-1), (m), (m+1), and (m+2)th instantaneous values ​​of the voltage signal, respectively. m ∈ [ 3 , N s − 2 ] , This represents the total length of the voltage signal.

[0019] Preferably, the formula for calculating the signal frequency in step S3 is as follows.

[0020] .

[0021] In the formula, f is the signal frequency; The signal sampling frequency; The number of points in one cycle of the signal.

[0022] Preferably, the calculation formula for DC removal processing of the signal in step S4 is as follows.

[0023] .

[0024] In the formula, and These are the magnitudes of the nth and kth instantaneous values ​​of the signal, respectively. n ∈ [ 1 , N s ] ; This is the total length of the voltage signal; The number of points in one cycle of the signal.

[0025] The formula for calculating the effective value rms of the signal in step S5 is as follows.

[0026] rms = ∑ k = 1 N c [ U ( k ) ] 2 N c .

[0027] Preferably, the formula for calculating the phase angle difference angle in step S6 is as follows.

[0028] .

[0029] In the formula, , Signals , The first positive zero crossing after removing DC. for At point The value at that location, for At point The value at that location, for At point The value at that location, for At point The value at that location, It represents the number of points in one cycle of the signal. A positive zero crossing point refers to the time point in time during which the signal changes from a negative value to a positive value on the time axis.

[0030] A system for calculating the phase angle difference of synchronous closing, based on the aforementioned method for calculating the phase angle difference of synchronous closing, further includes the following modules.

[0031] The signal detection and repair module is used to acquire the simultaneous voltage signals collected by the voltage transformers on both sides of the grid-connected switch. and Detect and repair and Anomalies in the data.

[0032] The filtering module is used to filter... and IIR mean filtering is performed to eliminate the effects of noise and harmonics.

[0033] Frequency determination module, used to determine and Are all frequencies between 40Hz and 60Hz? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the above calculation process is terminated.

[0034] DC-DC converter module, used for... and Perform DC removal processing.

[0035] The valid value determination module is used to determine... and Are all valid values ​​greater than 80% of the standard valid value? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the above calculation process is terminated.

[0036] The phase angle difference calculation and output module is used to calculate... and The phase angle difference is calculated and the result is output.

[0037] A computer device, including memory and processor.

[0038] The memory stores computer programs.

[0039] When the processor executes the computer program, it implements the steps of the synchronous closing phase angle difference calculation method as described above.

[0040] A computer-readable storage medium having a computer program stored thereon.

[0041] When the computer program is executed by the processor, it implements the steps of the synchronous closing phase angle difference calculation method as described above.

[0042] The beneficial technical effects of this invention are: the method is simple and effective. When the sampling frequency of the feeder terminal device is low, the accuracy of the phase angle difference calculation result is improved by the designed algorithm, thereby controlling the synchronous closing more accurately, which has strong engineering applicability. Attached Figure Description

[0043] Figure 1 This is the overall flowchart of the present invention.

[0044] Figure 2 This is the original voltage waveform diagram corresponding to the embodiment described in this invention.

[0045] Figure 3 This is a voltage waveform diagram after repairing the abnormal point corresponding to the embodiment of the present invention.

[0046] Figure 4 This is a voltage waveform diagram after IIR mean filtering corresponding to the embodiment of the present invention.

[0047] Figure 5 This is a voltage waveform diagram after DC removal corresponding to the embodiment of the present invention.

[0048] Figure 6 This is a schematic diagram of the first positive zero-crossing point of the signal after DC removal in the embodiment of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and do not limit the scope of the invention.

[0050] Example: Combined with Appendix Figure 1 A method for calculating the phase angle difference during synchronous closing includes the following steps.

[0051] S1: Acquire the simultaneous voltage signals collected by the voltage transformers on both sides of the switching equipment. and ,like Figure 2 As shown, the detection revealed An outlier was found whose value differed from the previous value by more than 20% of the standard value of 10kV. This outlier was repaired, and the waveform after repair is shown below. Figure 3 As shown.

[0052] The method for repairing outliers is to replace the outlier with the value of the nearest normal point.

[0053] S2: Yes and IIR mean filtering is performed to eliminate the effects of noise and harmonics. The filtered waveform is as follows: Figure 4 As shown.

[0054] The formula for IIR mean filtering is as follows.

[0055] .

[0056] in, , , , , These are the (m-2), (m-1), (m), (m+1), and (m+2)th instantaneous values ​​of the voltage signal, respectively. m ∈ [ 3 , N s − 2 ] , This represents the total length of the voltage signal.

[0057] S3: Acquire voltage signals respectively and One cycle consists of 100 points, which, combined with the device's sampling frequency of 5kHz, yields... and The frequencies are all 50Hz, which is between 40Hz and 60Hz, satisfying the phase angle difference calculation conditions.

[0058] The formula for calculating signal frequency is: .

[0059] Where f is the signal frequency; The signal sampling frequency; The number of points in one cycle of the signal.

[0060] S4: Yes and The DC removal process is performed, and the waveform after DC removal is as follows: Figure 5 As shown.

[0061] The calculation formula for DC removal is as follows.

[0062] .

[0063] in, and These are the magnitudes of the nth and kth instantaneous values ​​of the signal, respectively. n ∈ [ 1 , N s ] ; This is the total length of the voltage signal; The number of points in one cycle of the signal.

[0064] S5: Calculation and The effective values ​​are 9.98kV and 10.03kV, respectively, both of which are greater than 80% of the standard effective value of 10kV, thus satisfying the phase angle difference calculation conditions.

[0065] The formula for calculating the effective value (RMS) is: rms = ∑ k = 1 N c [ U ( k ) ] 2 N c .

[0066] S6: Acquire and The first positive zero crossing after DC removal and The points are 101 and 117 respectively, a difference of 16 points. exist value at It is -94.23, at value at It is 1110. exist value at The value is -556.44. value at The value is 313.16, and the phase angle difference between the two is calculated to be 59.62°. The formula for calculating the phase angle difference is as follows.

[0067] .

[0068] Furthermore, this embodiment also provides a method for calculating the phase angle difference during synchronous closing, including:

[0069] The signal detection and repair module is used to acquire the simultaneous voltage signals collected by the voltage transformers on both sides of the grid-connected switch. and Detect and repair and Anomalies in the data.

[0070] The filtering module is used to filter... and IIR mean filtering is performed to eliminate the effects of noise and harmonics.

[0071] Frequency determination module, used to determine and Are all frequencies between 40Hz and 60Hz? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the above calculation process is terminated.

[0072] DC-DC converter module, used for... and Perform DC removal processing.

[0073] The valid value determination module is used to determine... and Are all valid values ​​greater than 80% of the standard valid value? If yes, continue to the next step; otherwise, the calculation conditions are not met, and the above calculation process is terminated.

[0074] The phase angle difference calculation and output module is used to calculate... and The phase angle difference is calculated and the result is output.

[0075] Furthermore, this example also provides a computer device suitable for calculating the phase angle difference of synchronous closing, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the method for calculating the phase angle difference of synchronous closing as proposed in the above embodiments.

[0076] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0077] This example also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the phase angle difference of synchronous closing as proposed in the above embodiments.

[0078] The above embodiments are descriptions of specific implementations of the present invention, and not limitations thereof. Those skilled in the art can make various modifications and changes without departing from the spirit and scope of the present invention to obtain corresponding equivalent technical solutions. Therefore, all equivalent technical solutions should be included in the patent protection scope of the present invention.

Claims

1. A method for calculating the phase angle difference during synchronous closing, characterized in that, Includes the following steps: S1: Acquire the simultaneous voltage signals U1 and U2 collected by the voltage transformers on both sides of the switching equipment, and detect and repair any abnormal points in U1 and U2; S2: Perform IIR mean filtering on U1 and U2 to eliminate the effects of noise and harmonics; S3: Determine if the frequencies of U1 and U2 are both between 40Hz and 60Hz: if yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated. S4: Perform DC removal processing on U1 and U2; S5: Determine whether the effective values ​​of U1 and U2 are both greater than 80% of the standard effective value: if yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated. S6: Calculate the phase angle difference between U1 and U2 and output the result; The formula for calculating the phase angle difference is as follows: In the formula, X1 and Y1 are the first positive zero-crossing points of signals U1 and U2 after DC removal, respectively. Let U1 be the value at point X1. Let U1 be the value at point X1+1. Let U2 be the value at point Y1. Let N be the value of U2 at point Y1+1. c It represents the number of points in one cycle of the signal. A positive zero crossing point refers to the time point in time during which the signal changes from a negative value to a positive value on the time axis.

2. The method for calculating the phase angle difference during synchronous closing according to claim 1, characterized in that, The outlier detection method in step S1 is to compare the difference between two adjacent points in turn. If the difference is greater than 20% of the standard effective value, the next point is considered an outlier.

3. The method for calculating the phase angle difference during synchronous closing according to claim 1, characterized in that, The abnormal point repair method in step S1 is to replace the abnormal point with the value of the nearest normal point.

4. The method for calculating the phase angle difference during synchronous closing according to claim 1, characterized in that, The IIR mean filtering formula in step S2 is as follows: IN (m) =U (m-2) +U (m-1) +U (m) +U (m+1) +U (m+2) ; In the formula, U (m-2) U (m-1) U (m) U (m+1) U (m+2) Let m and m be the (m-2), (m-1), m, (m+1), and (m+2)th instantaneous values ​​of the voltage signal, respectively; m∈[3,N]. s -2],N s This represents the total length of the voltage signal.

5. The method for calculating the phase angle difference during synchronous closing according to claim 1, characterized in that, The formula for calculating the signal frequency in step S3 is as follows: In the formula, f is the signal frequency; s N is the signal sampling frequency; c This represents the number of points in one cycle of the signal.

6. The method for calculating the phase angle difference during synchronous closing according to claim 1, characterized in that, The calculation formula for DC removal processing of the signal in step S4 is as follows: In the formula, U (n) and U (k) These represent the magnitudes of the nth and kth instantaneous values ​​of the signal, respectively; n∈[1,N] s ];N s N is the total length of the voltage signal; c The number of points in one cycle of the signal; The formula for calculating the effective value rms of the signal in step S5 is as follows:

7. A system for calculating the phase angle difference during synchronous closing, characterized in that, The method for calculating the phase angle difference of synchronous closing as described in any one of claims 1 to 6 further includes: The signal detection and repair module is used to acquire the simultaneous voltage signals U1 and U2 collected by the voltage transformers on both sides of the grid-connected switch, and to detect and repair abnormal points in U1 and U2. The filtering module is used to perform IIR mean filtering on U1 and U2 to eliminate the effects of noise and harmonics; The frequency determination module is used to determine whether the frequencies of U1 and U2 are both between 40Hz and 60Hz: if yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of the above calculation process is terminated. The DC removal module is used to remove DC from U1 and U2; The valid value judgment module is used to determine whether the valid values ​​of U1 and U2 are both greater than 80% of the standard valid value: if yes, continue to the next step; otherwise, the calculation conditions are not met, and the execution of the above calculation process is terminated. The phase angle difference calculation and output module is used to calculate the phase angle difference between U1 and U2 and output the result.

8. A computer device, characterized in that, Including memory and processor; The memory stores computer programs; When the processor executes the computer program, it implements the steps of the method for calculating the phase angle difference of synchronous closing as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, It contains computer programs; When the computer program is executed by the processor, it implements the steps of the method for calculating the phase angle difference of synchronous closing as described in any one of claims 1 to 6.

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