Synchronous switching-on phase angle difference calculation method and system, storage medium and equipment

Abstract

The invention relates to the technical field of power distribution and utilization, and discloses a synchronous switching-on phase angle difference calculation method and system, a storage medium and equipment, and the method comprises the following steps: obtaining two voltage signals at the same time at the two sides of switch equipment, and detecting and repairing an abnormal point; carrying out IIR mean filtering on the signal; judging whether the signal frequency is between 40Hz and 60Hz or not; carrying out direct current removal processing on the signal; judging whether the effective values of the signals are greater than 80% of a standard effective value or not; and calculating a signal phase angle difference and outputting a result. The method is simple and effective, when the sampling frequency of the feeder terminal device is low, the accuracy of a phase angle difference calculation result is improved through a designed algorithm, so that synchronous closing is controlled more accurately, and the method has very high engineering practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution and utilization, and particularly to a method, system, storage medium and device for calculating the phase angle difference of synchronous closing. Background Art

[0002] The synchronous closing of switchgear in a power system needs to meet three conditions: (1) the amplitudes of the power supply voltages on both sides of the switch are equal; (2) the frequencies of the voltages on both sides of the switch are equal; (3) the phases of the voltages on both sides of the switch are equal, that is, the phase angle difference is zero.

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

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

[0005] In view of the deficiencies and defects existing in the prior art, the present invention provides a method, system, storage medium and device for calculating the phase angle difference of synchronous closing, which can obtain a relatively accurate calculation result of the phase angle difference even when the hardware sampling frequency is low, so as to realize precise control of synchronous closing.

[0006] The object of the present invention can be achieved by the following technical solutions:

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

[0008] S1: Obtain the voltage signals at the same moment collected by the voltage transformers on both sides of the switchgear and , detect and repair and the abnormal points in.

[0009] S2: Perform IIR mean filtering on and to eliminate the influence of noise and harmonics.

[0010] S3: Judge whether the frequencies of and are both between 40 Hz and 60 Hz: if so, continue to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated.

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

[0012] S5: Determine and Whether the effective values of both are greater than 80% of the standard effective value: If yes, proceed to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated.

[0013] S6: Calculate and The phase angle difference between them and output the result.

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

[0015] Preferably, in the step S1, the abnormal point repair method is: replace the abnormal point with the value of the closest normal point.

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

[0017] .

[0018] In the formula, , , , , Are respectively the (m - 2)th, (m - 1)th, mth, (m + 1)th, and (m + 2)th instantaneous values of the voltage signal; m ∈ [ 3 , N s − 2 ] , is the total length of the voltage signal.

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

[0020] .

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

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

[0023] .

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

[0025] In the step S5, the calculation formula for the effective value rms of the signal is as follows.

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

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

[0028] .

[0029] In the formula, , are respectively the first positive zero-crossing points after removing the DC component of the signals , , is the value of at the point , is the value of at the point , is the value of at the point , is the value of at the point , is the number of points in one cycle of the signal. The positive zero-crossing point refers to the time point when the signal changes from negative to positive on the time axis.

[0030] A synchronous closing phase angle difference calculation system, based on the synchronous closing phase angle difference calculation method as described above, further includes the following modules.

[0031] A signal detection and repair module, used to obtain the voltage signals and collected by the voltage transformers on both sides of the grid connection switch at the same moment, detect and repair the abnormal points in and .

[0032] A filtering module, used to perform IIR mean filtering on and to eliminate the influence of noise and harmonics.

[0033] A frequency judgment module, used to judge whether the frequencies of and are both between 40Hz and 60Hz: if yes, continue to the next step; otherwise, it does not meet the calculation conditions, and the execution of the above calculation process is terminated.

[0034] A DC removal module, used to perform DC removal on and Perform DC removal processing.

[0035] The effective value judgment module is used to judge and whether the effective values of both are greater than 80% of the standard effective value: if so, continue to the next step; otherwise, the calculation condition is not met, and the execution of the above calculation process is terminated.

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

[0037] A computer device includes a memory and a processor.

[0038] The memory stores a computer program.

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

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

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

[0042] The beneficial technical effects of the present invention: The method is simple and effective. When the sampling frequency of the feeder terminal unit is low, the accuracy of the phase angle difference calculation result is improved through the designed algorithm, so as to more accurately control synchronous closing, and it has strong engineering practicability. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0044] Figure 2 is the original voltage waveform diagram corresponding to the embodiment of the present invention.

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

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

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

[0048] Figure 6 is the schematic diagram of the first positive zero crossing point after DC removal of the signal corresponding to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0050] Embodiment: In combination with the attached Figure 1 , a method for calculating the synchronous closing phase angle difference includes the following steps.

[0051] S1: Obtain the voltage signals at the same moment collected by the voltage transformers on both sides of the switchgear and . As Figure 2 shown, it is detected that contains abnormal points, and the difference between its value and the previous point exceeds 20% of the standard value of 10 kV. Repair it, and the waveform after repair is as Figure 3 shown.

[0052] The method for repairing abnormal points is: replace the abnormal points with the values of the closest normal points.

[0053] S2: Perform IIR mean filtering on and to eliminate the influence of noise and harmonics. The waveform after filtering is as Figure 4 shown.

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

[0055] .

[0056] Wherein, , , , , are respectively the (m - 2)th, (m - 1)th, mth, (m + 1)th, and (m + 2)th instantaneous values of the voltage signal; m ∈ [ 3 , N s − 2 ] , is the total length of the voltage signal.

[0057] S3: Respectively obtain the number of points in one cycle of the voltage signals and , both of which are 100 points. Combining with the sampling frequency of the device, 5 kHz, it can be obtained that and have a frequency of 50 Hz, which is between 40 Hz and 60 Hz, meeting the phase angle difference calculation conditions.

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

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

[0060] S4: For and perform DC removal processing, and the waveform after DC removal is as Figure 5 shown.

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

[0062] .

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

[0064] S5: Calculate that and the effective values are 9.98 kV and 10.03 kV respectively, both of which are greater than 80% of the voltage standard effective value of 10 kV, meeting the phase angle difference calculation condition.

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

[0066] S6: Obtain and the first positive zero crossing after DC removal and , which are the 101st point and the 117th point respectively, with a difference of 16 points between them. At the value is -94.23, and at the value is 1110. At the value is -556.44, and at the value is 313.16. The calculated phase angle difference between the two is 59.62°. The calculation formula for the phase angle difference angle is as follows.

[0067] .

[0068] Furthermore, this embodiment also provides a synchronous closing phase angle difference calculation, including:

[0069] A signal detection and repair module, used to obtain the voltage signals collected by the voltage transformers on both sides of the grid connection switch at the same moment and , detect and repair and the abnormal points in

[0070] A filtering module, used to perform IIR mean filtering on and to eliminate the influence of noise and harmonics.

[0071] A frequency judgment module, used to judge whether the frequencies of and are both between 40Hz and 60Hz: if so, continue to the next step; otherwise, it does not meet the calculation conditions, and the execution of the above calculation process is terminated.

[0072] A DC removal module, used to perform DC removal processing on and

[0073] An effective value judgment module, used to judge whether the effective values of and are both greater than 80% of the standard effective value: if so, continue to the next step; otherwise, it does not meet the calculation conditions, and the execution of the above calculation process is terminated.

[0074] A phase angle difference calculation and output module, used to calculate the phase angle difference between and and output the result.

[0075] Furthermore, this example also provides a computer device, applicable to the situation of synchronous closing phase angle difference calculation, 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 synchronous closing phase angle difference calculation method proposed in the above embodiment.

[0076] This computer device can be a terminal. This computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of this computer device is used to provide computing and control capabilities. The memory of this computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of this computer device is used to communicate with an external terminal in a wired or wireless manner. The wireless manner can be achieved through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. The display screen of this computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of this computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad set on the computer device housing, or an external keyboard, touchpad, or mouse, etc.

[0077] This example also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the synchronous closing phase angle difference calculation method proposed in the above-mentioned embodiment.

[0078] The above-mentioned embodiment is an illustration of the specific implementation manner of the present invention, rather than a limitation thereof. Those skilled in the relevant technical field can also make various transformations 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 of synchronous closing, characterized in that, Including the following steps: S1: Obtain the voltage signals collected by the voltage transformers on both sides of the switchgear at the same moment and , detect and repair and the abnormal points in; S2: For and perform IIR mean filtering to eliminate the influence of noise and harmonics; S3: Determine and whether the frequencies of both are between 40 Hz and 60 Hz: If yes, proceed to the next step; otherwise, the calculation conditions are not met, and the execution of this process is terminated. S4: Perform DC removal on and ; S5: Determine and whether the valid values of both are greater than 80% of the standard valid value: if yes, proceed to the next step; otherwise, the calculation conditions are not met and the execution of this process is terminated; S6: Calculate and phase angle difference and output the result.

2. The synchronous closing phase angle difference calculation method according to claim 1, wherein In the abnormal point detection method in step S1, the differences between adjacent points are compared in sequence. If the difference is greater than 20% of the standard effective value, the latter point is considered an abnormal point.

3. A method for calculating the in-phase closing phase angle difference according to claim 1, characterized in that In the abnormal point repair method in step S1, the abnormal point is replaced with the value of the closest normal point.

4. The synchronous closing phase angle difference calculation method according to claim 1, wherein The IIR mean filtering formula in step S2 is as follows: ； Wherein, , , , , are respectively the (m-2)th, (m-1)th, mth, (m+1)th, and (m+2)th instantaneous values of the voltage signal; , is the total length of the voltage signal.

5. A method for calculating the synchronous closing phase angle difference according to claim 1, characterized in that, The calculation formula for the signal frequency in step S3 is as follows: ； where f is the signal frequency; is the signal sampling frequency; is the number of points in one cycle of the signal.

6. The synchronous closing phase angle difference calculation method according to claim 1, wherein The calculation formula for removing the DC component from the signal in step S4 is as follows: ； Wherein, and are respectively the magnitudes of the n-th and k-th instantaneous values of the signal; ; is the total length of the voltage signal; is the number of points in one cycle of the signal; The calculation formula for the root mean square (rms) value of the signal in step S5 is as follows: 。 7. A method for calculating the in-phase closing phase angle difference according to claim 1, characterized in that The calculation formula for the phase angle difference angle in step S6 is as follows: ； Wherein, and are respectively the first positive zero-crossing points after removing the DC component of signals and ; is the value of at the point ; is the value of at the point ; is the value of at the point ; is the value of at the point ; is the number of points in one cycle of the signal, and the positive zero-crossing point refers to the time point when the signal changes from negative to positive on the time axis.​​​​​ 8. A synchronous closing phase angle difference calculation system, characterized in that, Based on the synchronous closing phase angle difference calculation method according to any one of claims 1 to 7, it further includes: A signal detection and repair module, which is used to obtain voltage signals at the same moment collected by voltage transformers on both sides of the grid-connected switch and , detect and repair and the abnormal points in; Filter module, used to and perform IIR mean filtering to eliminate the influence of noise and harmonics; A frequency judgment module for judging and whether the frequencies of both are between 40 Hz and 60 Hz: if so, proceed to the next step; otherwise, the calculation condition is not met, and the execution of the above calculation process is terminated; DC removal module, used to perform DC removal processing on and ; The valid value judgment module is used to judge and whether the valid values of both are greater than 80% of the standard valid value: if so, proceed to the next step; otherwise, the calculation condition is not met, and the execution of the above calculation process is terminated; Phase angle difference calculation and output module, used to calculate and phase angle difference and output the result.

9. A computer device, characterized in that, Including a memory and a processor; The memory stores a computer program; When the processor executes the computer program, it implements the steps of the synchronous closing phase angle difference calculation method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, On which a computer program is stored; When the computer program is executed by the processor, it implements the steps of the synchronous closing phase angle difference calculation method according to any one of claims 1 to 7.

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