A method and system for measuring time difference of variable displacement of isogenous switch of power system

Abstract

The application discloses a kind of power system homologous switch quantity variable position time difference measurement method and system, it is related to the technical field of power system automation, including: respectively obtaining the fault recording file of protection device and intelligent recording device and homologous switch quantity variable absolute time;Respectively calculate the fault component value of fault recording file in homologous ac voltage channel, and determine fault component point position;Respectively in homologous ac voltage channel, find the zero-crossing time corresponding to the nearest zero-crossing point from fault component point position;In fault recording file intercepts fault section waveform;With the sampling rate of intelligent recording device, first fault section waveform is resampled;Calculate phase angle difference;Calculate the homologous switch variable position time difference of protection device and intelligent recording device.The application alleviates the technical problem that existing technology cannot accurately measure the homologous switch quantity variable position time difference of protection device and intelligent recording device when not connected to external public clock or external time service fails.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power system automation, in particular to a method and system for measuring time difference of switch quantity displacement of power system homologous. BACKGROUND

[0002] The development of self-diagnosis technology of power system automation device lays a foundation for intelligent operation and inspection of substation. The intelligent wave recorder has high sampling rate and records various electrical quantity changes in the whole process before, during and after the fault of the system. When the power system fails, the A and B set protection devices and the intelligent wave recorder will record the primary system electrical quantity, protection action signal and circuit breaker position signal before and after the fault. The waveforms recorded by the three devices are asynchronous sampling data. When no external public clock is connected or external timing fails, the A and B set protection devices and the intelligent wave recorder are in self-keeping time state. The time difference of displacement of the protection action signal and the circuit breaker position signal recorded by the A and B set protection devices and the intelligent wave recorder cannot be accurately measured by comparing the fault waveforms recorded by the three devices. SUMMARY

[0003] The present application relates to the field of power system automation, in particular to a method and system for measuring time difference of switch quantity displacement of power system homologous.

[0004] In a first aspect, an embodiment of the present application provides a method for measuring time difference of same-origin switching variable displacement, applied to a target power system; the target power system comprises a protection device and an intelligent recording device; the method comprises: obtaining a first fault recording file generated by the protection device when the protection device acts, and a first same-origin switching variable displacement absolute time; obtaining a second fault recording file generated by the intelligent recording device when a circuit breaker is displaced, and a second same-origin switching variable displacement absolute time; calculating fault component values of the first fault recording file and the second fault recording file in a same-origin alternating voltage channel respectively, and determining respective fault component point positions based on the fault component values; finding a first zero-crossing time and a second zero-crossing time corresponding to the nearest zero-crossing point to the fault component point position in the same-origin alternating voltage channel of the first fault recording file and the second fault recording file respectively; intercepting a first fault segment waveform from the first fault recording file based on the first zero-crossing time, and intercepting a second fault segment waveform from the second fault recording file based on the second zero-crossing time; resampling the first fault segment waveform at a sampling rate of the intelligent recording device to obtain a third fault segment waveform; calculating a phase angle difference based on phase angle values of a fundamental wave vector at a plurality of sampling points in the same-origin alternating voltage channel of the second fault segment waveform and the third fault segment waveform; and calculating a same-origin switching displacement time difference of the protection device and the intelligent recording device based on the phase angle difference, the first same-origin switching variable displacement absolute time, the second same-origin switching variable displacement absolute time, the first zero-crossing time, and the second zero-crossing time.

[0005] Further, the fault component value comprises:

[0006]

[0007] In the formula, Δu(k) is a fault component value at a kth sampling time, u(k) is a sampling value of a same-origin alternating voltage channel at the kth sampling time; u(k-N) is a sampling value of a same-origin alternating voltage channel at a previous half cycle of the kth sampling time; u(k-N) is a sampling value of a same-origin alternating voltage channel at a previous cycle of the kth sampling time; and N is a number of sampling points per cycle.

[0008] Further, determining respective fault component point positions based on fault component values comprises: determining, as the fault component point position, a position at which the fault component values of the first fault recording file and the second fault recording file at corresponding sampling times are both greater than a preset threshold.

[0009] Further, the first fault segment waveform is intercepted based on the first zero-crossing time in the first fault recording file, including: taking the first zero-crossing time as a starting point in the first fault recording file, and intercepting the entire fault segment waveform backward to obtain the first fault segment waveform; the second fault segment waveform is intercepted based on the second zero-crossing time in the second fault recording file, including: taking the second zero-crossing time as a starting point in the second fault recording file, and intercepting the entire fault segment waveform backward to obtain the second fault segment waveform.

[0010] Further, the first fault segment waveform is resampled at a sampling rate of the intelligent recording device, including: taking the highest sampling rate of the intelligent recording device as a sampling pace, and resampling by using a parabolic interpolation formula.

[0011] Further, the phase angle difference includes:

[0012]

[0013] In the formula, [θ1, θ2, …, θn] is a phase angle value of a fundamental wave vector of the second fault segment waveform at consecutive n sampling points of a homologous alternating voltage channel, n is a phase angle value of a fundamental wave vector of the third fault segment waveform at consecutive n sampling points of a homologous alternating voltage channel, and Δθ is the phase angle difference.

[0014] Further, the homologous switch position time difference includes:

[0015] ΔT di = T di1 -T di2 + Δt + t 01 -t 02

[0016] wherein, T di1 and T di2 are the first homologous switch quantity position absolute time and the second homologous switch quantity position absolute time, respectively, t 01 and t 02 are the first zero-crossing time and the second zero-crossing time, respectively, Δt is a time difference corresponding to the phase angle difference, and ΔT di is the homologous switch position time difference.

[0017] ​In a second aspect, the embodiment of the present application further provides an isochronous switch quantity variable position time difference measurement system of a power system, which is applied to a target power system; the target power system comprises a protection device and an intelligent recording device; and the isochronous switch quantity variable position time difference measurement system comprises an acquisition module, a first calculation module, a searching module, an intercepting module, a resampling module, a second calculation module and a third calculation module; wherein the acquisition module is configured to acquire a first fault recording file generated by the protection device when the protection device acts, first isochronous switch quantity variable position absolute time, and acquire a second fault recording file generated by the intelligent recording device when a circuit breaker is in a variable position, second isochronous switch quantity variable position absolute time; the first calculation module is configured to calculate fault component values in isochronous AC voltage channels of the first fault recording file and the second fault recording file respectively, and determine respective fault component point positions based on the fault component values; the searching module is configured to search for first zero-crossing time and second zero-crossing time corresponding to the nearest zero-crossing point to the fault component point positions in the isochronous AC voltage channels of the first fault recording file and the second fault recording file respectively; the intercepting module is configured to intercept a first fault segment waveform from the first fault recording file based on the first zero-crossing time, and intercept a second fault segment waveform from the second fault recording file based on the second zero-crossing time; the resampling module is configured to resample the first fault segment waveform at a sampling rate of the intelligent recording device to obtain a third fault segment waveform; the second calculation module is configured to calculate a phase angle difference based on phase angle values of fundamental wave vectors of a plurality of sampling points in the isochronous AC voltage channels of the second fault segment waveform and the third fault segment waveform; and the third calculation module is configured to calculate an isochronous switch variable position time difference of the protection device and the intelligent recording device based on the phase angle difference, the first isochronous switch quantity variable position absolute time, the second isochronous switch quantity variable position absolute time, the first zero-crossing time and the second zero-crossing time.

[0018] In a third aspect, the embodiment of the present application further provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the method provided by the embodiment of the present application when executing the computer program.

[0019] In a fourth aspect, the embodiment of the present application further provides a computer readable storage medium, which stores computer instructions, and the computer instructions implement the method provided by the embodiment of the present application when executed by a processor.

[0020] The application provides a power system homologous switch quantity displacement time difference measurement method and system. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 A flowchart of a power system homologous switch quantity displacement time difference measurement method provided by the embodiment of the present application;

[0023] Figure 2 A schematic diagram of a power system homologous switch quantity displacement time difference measurement system provided by the embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0025] Embodiment one

[0026] Figure 1 A flowchart of a power system homologous switch quantity displacement time difference measurement method provided by the embodiment of the present application, the method is applied to a target power system; wherein the target power system includes a protection device and an intelligent recording device. As shown in the figure, the method specifically includes the following steps: Figure 1

[0027] ​In step S102, the first fault recording file generated by the protection device during the protection action, the first absolute time of the same-origin switching quantity displacement, and the second fault recording file generated by the intelligent fault recording device during the circuit breaker displacement, and the second absolute time of the same-origin switching quantity displacement are obtained.

[0028] In step S104, the fault component values of the first fault recording file and the second fault recording file in the same-origin alternating voltage channel are calculated respectively, and the fault component point positions are determined based on the fault component values.

[0029] In step S106, the first zero-crossing time and the second zero-crossing time corresponding to the zero-crossing points closest to the fault component point positions are searched in the same-origin alternating voltage channel of the first fault recording file and the second fault recording file respectively.

[0030] In step S108, the first fault segment waveform is intercepted from the first fault recording file based on the first zero-crossing time, and the second fault segment waveform is intercepted from the second fault recording file based on the second zero-crossing time.

[0031] In step S110, the first fault segment waveform is resampled at the sampling rate of the intelligent fault recording device to obtain a third fault segment waveform.

[0032] In step S112, the phase angle difference is calculated based on the phase angle values of the fundamental wave vectors at multiple sampling points in the same-origin alternating voltage channel of the second fault segment waveform and the third fault segment waveform.

[0033] In step S114, the time difference of the same-origin switching displacement of the protection device and the intelligent fault recording device is calculated based on the phase angle difference, the first absolute time of the same-origin switching quantity displacement, the second absolute time of the same-origin switching quantity displacement, the first zero-crossing time, and the second zero-crossing time.

[0034] Specifically, the fault component value includes:

[0035]

[0036] In the formula, Δu(k) is the fault component value at the kth sampling time, u(k) is the sampling value of the same-origin alternating voltage channel at the kth sampling time; u(k-N) is the sampling value of the same-origin alternating voltage channel at the kth sampling time; N is the number of sampling points per cycle.

[0037] Specifically, step S104 further includes: determining the positions where the fault component values of the first fault recording file and the second fault recording file at the corresponding sampling times are both greater than a preset threshold as the fault component point positions.

[0038] In an optional implementation provided by an embodiment of the present invention, the first fault recording file and the second fault recording file are first opened, the AC voltage channel of the fault interval is selected, and then the AC voltage channel of the fault interval is scanned according to the above-mentioned fault component value calculation formula, and the fault component value Δu(k) is calculated point by point, and the fault component value Δu(k) is found to be greater than the preset threshold ΔU set The sampling point is the location of the fault component point.

[0039] Specifically, step S108 includes the following steps:

[0040] Step S1081, starting from the first zero-crossing moment in the first fault recording file, intercepting the entire fault segment waveform backward to obtain the first fault segment waveform;

[0041] Step S1082: In the second fault recording file, the entire fault segment waveform is intercepted backwards with the second zero-crossing moment as the starting point to obtain the second fault segment waveform.

[0042] Specifically, step S110 also includes: using the highest sampling rate of the intelligent recording device as the sampling beat, resampling using a parabolic interpolation formula, and converting the low sampling rate waveform of the protection device into a waveform with a high sampling rate of the intelligent recording device.

[0043] Specifically, the parabola difference formula includes:

[0044]

[0045] Where (x0, y0), (x1, y1), and (x2, y2) are three consecutive sampling points on the recorded waveform, x is the interpolation position in the interval [x1, x2], and L2(x) is the parabolic interpolation at x.

[0046] Preferably, the phase angle difference comprises:

[0047]

[0048] Where, [θ1, θ2···θ n ] is the phase angle value of the fundamental wave vector of the second fault segment waveform at n consecutive sampling points in the homologous AC voltage channel, is the phase angle value of the fundamental wave vector of the third fault segment waveform at n consecutive sampling points in the same source AC voltage channel. Preferably, n is 5; Δθ is the phase angle difference.

[0049] Specifically, the time difference of the homologous switch position change in step S114 includes:

[0050] ΔT di =T di1 -T di2 +Δt+t 01 -t02

[0051] Wherein, T di1 and T di2 are the first and second homologous switch variable displacement absolute time, respectively, t 01 and t 02 are the first and second zero-crossing time, respectively, Δt is the time difference corresponding to the phase difference, and ΔTdi is the homologous switch variable displacement time difference.

[0052] Specifically, The unit of Δθ is degree, and the unit of Δt is microsecond.

[0053] The power system homologous switch variable displacement time difference measurement method provided by the application realizes accurate measurement and comparison analysis of the homologous switch variable displacement time difference through the fault component point, zero-crossing point and phase difference of the homologous analog quantity, the measurement error is not greater than 50 microseconds, the measurement accuracy is improved, the basic data for realizing the comparison analysis of the homologous switch variable displacement time difference is provided, and the efficiency of the intelligent operation and maintenance of the substation is improved.

[0054] Embodiment two

[0055] Figure 2 is a schematic diagram of a power system homologous switch variable displacement time difference measurement system provided by the application, which is applied to a target power system; the target power system includes a protection device and an intelligent recording device. As Figure 2 shown, the measurement system provided by the application includes an acquisition module 10, a first calculation module 20, a search module 30, an interception module 40, a resampling module 50, a second calculation module 60 and a third calculation module 70.

[0056] Specifically, the acquisition module 10 is used to acquire the first fault recording file generated by the protection device when the protection device acts, the first homologous switch variable displacement absolute time, and the second fault recording file generated by the intelligent recording device when the circuit breaker is displaced, and the second homologous switch variable displacement absolute time.

[0057] The first calculation module 20 is used to calculate the fault component values of the first fault recording file and the second fault recording file in the homologous alternating current voltage channel respectively, and determine the respective fault component point positions based on the fault component values.

[0058] The search module 30 is used to search for the first zero-crossing time and the second zero-crossing time corresponding to the zero-crossing point closest to the fault component point position in the homologous alternating current voltage channel of the first fault recording file and the second fault recording file, respectively.

[0059] The intercepting module 40 is used for intercepting a first fault segment waveform in the first fault recording file based on the first zero-crossing moment and intercepting a second fault segment waveform in the second fault recording file based on the second zero-crossing moment.

[0060] The resampling module 50 is used for resampling the first fault segment waveform at a sampling rate of the intelligent recording device to obtain a third fault segment waveform.

[0061] The second calculating module 60 is used for calculating a phase angle difference based on phase angle values of fundamental wave vectors at a plurality of sampling points of the homologous AC voltage channel of the second fault segment waveform and the third fault segment waveform.

[0062] The third calculating module 70 is used for calculating a homologous switching displacement time difference between the protection device and the intelligent recording device based on the phase angle difference, the first homologous switching displacement absolute time, the second homologous switching displacement absolute time, the first zero-crossing moment and the second zero-crossing moment.

[0063] Specifically, the first calculating module 20 is further used for determining, as a fault component point position, a position at which fault component values of the first fault recording file and the second fault recording file at a corresponding sampling moment are both greater than a preset threshold.

[0064] Specifically, the intercepting module 40 is further used for:

[0065] intercepting the entire fault segment waveform backward in the first fault recording file with the first zero-crossing moment as a starting point to obtain the first fault segment waveform;

[0066] intercepting the entire fault segment waveform backward in the second fault recording file with the second zero-crossing moment as a starting point to obtain the second fault segment waveform.

[0067] Specifically, the resampling module 50 is further used for resampling at a highest sampling rate of the intelligent recording device as a sampling beat and using a parabolic interpolation formula.

[0068] The embodiment of the application further provides an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the method in the above embodiment one when executing the computer program.

[0069] The embodiment of the application further provides a computer readable storage medium, the computer readable storage medium stores computer instructions, and the computer instructions are executed by the processor to implement the method in the above embodiment one.

[0070] It will be obvious to a person skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims to the identity of the reference signs therein.

[0071] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for measuring the time difference of the switching value of the same source in the power system, characterized in that: Application to target power system; The target power system includes a protection device and an intelligent recording device; the method includes: Obtaining a first fault recording file and a first homologous switch value change absolute time generated by the protection device when the protection action is taken, and obtaining a second fault recording file and a second homologous switch value change absolute time generated by the intelligent recording device when the circuit breaker changes position; respectively calculating the fault component values ​​of the first fault recording file and the second fault recording file in the same source AC voltage channel, and determining the respective fault component point locations based on the fault component values; Searching for a first zero-crossing moment and a second zero-crossing moment corresponding to a zero-crossing point closest to the fault component point in the same-source AC voltage channel of the first fault recording file and the second fault recording file respectively; intercepting a first fault segment waveform from the first fault recording file based on the first zero-crossing moment, and intercepting a second fault segment waveform from the second fault recording file based on the second zero-crossing moment; Resampling the first fault segment waveform at the sampling rate of the intelligent recording device to obtain a third fault segment waveform; Calculating a phase angle difference based on phase angle values ​​of fundamental wave vectors of the second fault segment waveform and the third fault segment waveform at multiple sampling points of the same source AC voltage channel; Based on the phase angle difference, the absolute time of the first homologous switch quantity change, the absolute time of the second homologous switch quantity change, the first zero-crossing moment and the second zero-crossing moment, the homologous switch change time difference between the protection device and the intelligent recording device is calculated.

2. The method according to claim 1, wherein: The fault component values ​​include: Where Δu(k) is the fault component value at the kth sampling moment, and u(k) is the sampling value of the homologous AC voltage channel at the kth sampling moment; is the sampling value of the half cycle before the k-th sampling moment of the homologous AC voltage channel; u(kN) is the sampling value of the one cycle before the k-th sampling moment of the homologous AC voltage channel; N is the number of sampling points per cycle.

3. The method according to claim 1, wherein: Determining respective fault component point locations based on fault component values ​​includes: determining the locations where the fault component values ​​of the first fault recording file and the second fault recording file at corresponding sampling moments are both greater than a preset threshold as the fault component point locations.

4. The method according to claim 1, wherein: Intercepting a first fault segment waveform from the first fault recording file based on the first zero-crossing moment includes: Taking the first zero-crossing moment as the starting point in the first fault recording file, intercepting the entire fault segment waveform backward to obtain the first fault segment waveform; Intercepting a second fault segment waveform from the second fault recording file based on the second zero-crossing moment includes: In the second fault recording file, the second zero-crossing moment is used as the starting point, and the entire fault segment waveform is intercepted backward to obtain the second fault segment waveform.

5. The method according to claim 1, wherein: The first fault segment waveform is resampled at the sampling rate of the intelligent recording device, including: taking the highest sampling rate of the intelligent recording device as the sampling beat and resampling using a parabolic interpolation formula.

6. The method according to claim 1, wherein: The phase angle difference includes: Where, [θ1, θ2···θ n ] is the phase angle value of the fundamental wave vector of the second fault segment waveform at n consecutive sampling points in the homologous AC voltage channel, is the phase angle value of the fundamental wave vector of the third fault segment waveform at n consecutive sampling points in the same source AC voltage channel, and Δθ is the phase angle difference.

7. The method according to claim 1, wherein: The homologous switch position change time difference includes: ΔT di =T di1 -T di2 +Δt+t 01 -t 02 Among them, T di1 and T di2 The absolute time of the first homologous switch value changing and the absolute time of the second homologous switch value changing are respectively, t 01 and t 02 are the first zero-crossing moment and the second zero-crossing moment respectively, Δt is the time difference corresponding to the phase angle difference, △T di is the time difference of the homologous switch displacement.

8. A power system homologous switch variable time difference measurement system, characterized in that: Application to target power system; The target power system includes a protection device and an intelligent recording device; including: an acquisition module, a first calculation module, a search module, an interception module, a resampling module, a second calculation module and a third calculation module; wherein, The acquisition module is used to acquire a first fault recording file and a first homologous switch value change absolute time generated by the protection device when the protection action is taken, and to acquire a second fault recording file and a second homologous switch value change absolute time generated by the intelligent recording device when the circuit breaker changes position; The first calculation module is used to calculate the fault component values ​​of the first fault recording file and the second fault recording file in the same source AC voltage channel respectively, and determine the respective fault component point locations based on the fault component values; The search module is used to search for a first zero-crossing moment and a second zero-crossing moment corresponding to a zero-crossing point closest to the fault component point in the same source AC voltage channel of the first fault recording file and the second fault recording file respectively; The interception module is configured to intercept a first fault segment waveform in the first fault recording file based on the first zero-crossing moment, and intercept a second fault segment waveform in the second fault recording file based on the second zero-crossing moment; The resampling module is configured to resample the first fault segment waveform at the sampling rate of the intelligent recording device to obtain a third fault segment waveform; The second calculation module is configured to calculate a phase angle difference based on phase angle values ​​of fundamental wave vectors of the second fault segment waveform and the third fault segment waveform at multiple sampling points of the same source AC voltage channel; The third calculation module is used to calculate the time difference of the homologous switch change of the protection device and the intelligent recording device based on the phase angle difference, the absolute time of the first homologous switch change, the absolute time of the second homologous switch change, the first zero-crossing time and the second zero-crossing time.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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