CN101988941A - A method, device and system for monitoring power quality - Google Patents

Abstract

The present invention is applicable to the field of electric power technology, and provides a method, device and system for monitoring power quality. The method includes: obtaining a transient event at a designated monitoring point; obtaining the occurrence time _T of the transient event at the designated monitoring point. Before the time, the time interval between the occurrence of the transient event and the first related event of the system setting time ΔT; obtain all monitoring points in the database before and after the occurrence time _T of the transient event, and the occurrence of the transient event The time interval is the second relevant event of the system setting time ΔT; the obtained first relevant event and the second relevant event are analyzed to generate a power quality monitoring report. The invention improves the efficiency and accuracy of power quality monitoring, provides beneficial technical references for electric power safety production and stable operation, and produces significant economic and social benefits.

Description

A method, device and system for monitoring power quality

technical field

The invention belongs to the field of electric power technology, and in particular relates to a power quality monitoring method, device and system.

Background technique

With the continuous development of power technology, users have also put forward high requirements for power quality monitoring.

Among them, the power quality monitoring and analysis system should have two basic functions: monitoring function and analysis function.

The monitoring function is mainly to provide simple and real-time display of power quality characteristics, such as harmonic spectrum diagram, vector diagram, real-time alarm, etc., so that users can understand the real-time status of power quality. The monitoring function is relatively easy to realize, and it can be realized without complicated data processing.

The analysis function is mainly to conduct in-depth processing on the change trend of power quality, whether it is qualified, the reason, and the scope of influence, etc., allowing users to conduct in-depth analysis on specific power quality events.

Analysis functions are more complex functions. The realization of the analysis function is to consider that for a certain monitoring point, there is a certain physical relationship between the various electrical quantities at a certain moment, and due to the characteristics of the grid interconnection, the electrical quantities of different monitoring points will also be have a certain impact. This mutual influence between electrical quantities makes it possible to conduct an in-depth analysis of specific power quality phenomena, but it also makes this analysis very complicated, requiring the analysis of a large amount of data in the database, which affects the monitoring efficiency.

Moreover, power quality monitoring and analysis systems basically focus on the discrete analysis of a single power quality parameter, without taking into account the mutual influence between power quality parameters, nor the propagation of power quality parameters between different monitoring points. As a result, the power quality monitoring and analysis systems on the market are not enough in terms of advanced analysis functions such as cause analysis and impact range analysis for specific power quality events (especially transient power quality events), especially in terms of accuracy, which cannot satisfy users. Increasing demand for analytical capabilities.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a power quality monitoring method that improves power quality monitoring efficiency and accuracy.

The embodiment of the present invention is achieved in this way, a method for monitoring power quality, the method includes the following steps:

Get the transient events of the specified monitoring point;

Obtain the first relevant event whose time interval from the occurrence of the transient event is the system setting time ΔT before the transient event occurrence time _T0 of the specified monitoring point;

Obtain all monitoring points in the database before and after the transient event occurrence time T ₀ , and the second related event whose time interval from the transient event occurrence is the system setting time ΔT;

Analyzing the obtained first relevant event and the second relevant event to generate a power quality monitoring report.

Another object of the embodiments of the present invention is to provide a power quality monitoring device, the device comprising:

The specified monitoring point transient event acquisition module is used to obtain the transient event of the specified monitoring point;

Appointed monitoring point related event acquisition module, used to obtain the transient event occurrence time T ₀ moment of the specified monitoring point, and the first related event with the transient event occurrence time interval as the system setting time ΔT;

All monitoring point related event acquisition modules are used to obtain all monitoring points in the database before and after the transient event occurrence time T ₀ , and the second related event with the transient event occurrence time interval as the system setting time ΔT;

The monitoring report generating module is configured to analyze the obtained first related event and the second related event, and generate a power quality monitoring report.

Another object of the embodiments of the present invention is to provide a power quality monitoring system, the system including the power quality monitoring device provided by the embodiments of the present invention.

In the embodiment of the present invention, by obtaining the first relevant event of the transient event at the specified monitoring point within the ΔT time before the occurrence time T ₀ , and obtaining the second relevant event of all monitoring points within the ΔT time before and after the T ₀ time, combined with the first The first related event and the second related event analyze the transient event at the designated monitoring point and generate a power quality monitoring report, which improves the efficiency and accuracy of power quality monitoring and provides useful technical reference for safe production and stable operation of power. Produce significant economic and social benefits.

Description of drawings

Fig. 1 is the flowchart of the power quality monitoring method provided by the embodiment of the present invention;

Fig. 2 is a structural diagram of a power quality monitoring device provided by an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 shows the flow of a method for monitoring power quality provided by an embodiment of the present invention.

In step S101, the power quality monitoring data is saved to a database.

In the specific implementation process, the relevant SOE event records and original data of the transient events recorded in the system are read and saved in the database. Among them, the content of the SOE event record includes the event occurrence time, event priority, event cause and characteristic values of related parameters, event result and characteristic values of related parameters.

The SOE record is the sequence of events record. When the remote signal displacement of the power equipment occurs, such as the switch displacement, the power protection device or the intelligent power meter will automatically record the displacement time, the cause of the displacement, and the corresponding remote measurement value when the switch trips (such as Corresponding three-phase current, active power, etc.) to form SOE records for subsequent analysis.

In step S102, a transient event at a specified monitoring point is obtained.

In step S103, the first relevant event that is separated from the occurrence of the transient event by the system setting time ΔT before the transient event occurrence time _T0 of the specified monitoring point is acquired.

In step S104, all the monitoring points in the database are acquired around the transient event occurrence time T ₀ and the second related events whose time interval from the transient event occurrence is the system setting time ΔT.

Of course, T ₀ time and T are unified time scales of the entire power network, which are used to identify a certain moment when the transient time occurs, and the time range from the T ₀ time interval to ΔT;

Analyzing the obtained first relevant event and the second relevant event to generate a power quality monitoring report.

This step specifically includes:

analyzing the cause of the transient event at the specified monitoring point according to the first relevant event;

According to the second related event, analyze the initial location and influence range of the transient event at the designated monitoring point; for a selected transient event, the program recursively forwards or backwards in time order to find out the According to the SOE events of all monitoring points in a period of events before and after the transient event, according to the sequence of events, find out the loop that may cause the problem and the loop that may be affected;

Generate a power quality monitoring report based on the above analysis results.

Preferably, the power quality monitoring report is in text or report form.

The embodiment of the present invention screens and mines the data through the power quality analysis program, and collects the parameters of all monitoring points with unqualified power quality, fault waveforms, power supply circuits that may cause the problem, power supply circuits that may be affected by the problem, and the main components involved. The wiring diagram and other information form a power quality report that can be saved, displayed and printed out, which provides an effective auxiliary analysis method for quickly finding out the reasons for unqualified power quality, and provides the possibility for power quality failure trend analysis and predictive maintenance. Make the power quality monitoring and analysis get rid of the traditional simple data collection and statistics, thereby effectively improving the power quality analysis and management automation level, providing useful technical references for power safety production and stable operation, and producing significant economic and social benefits.

The embodiment of the present invention uses data mining technology to automatically find data related to power quality transient events from massive databases, without requiring users to search for data aimlessly for analysis, thereby greatly improving power quality analysis. Improve the work efficiency of system users and realize intuitive and systematic power quality analysis.

Embodiments of the present invention are based on SOE event records, which can help users qualitatively and quantitatively understand the related events and waveforms of the monitoring point and related monitoring points during and before and after the occurrence of power quality events, thereby helping to find the cause, scope and scope of power quality. The dynamic process can carry out targeted governance or improvement for the weak links of the power grid, and provide the necessary basis for maintaining power lines and reducing failure losses.

Fig. 2 shows the structure of the power quality monitoring device provided by the embodiment of the present invention.

Wherein, the power quality monitoring data saving module 21 is used for saving the power quality monitoring data to the database.

The designated monitoring point transient event acquisition module 22 is used to obtain the transient event of the designated monitoring point;

Designated monitoring point related event acquisition module 23 is used to obtain the first related event of the system setting time ΔT with the transient event occurrence time interval before the transient event occurrence time T ₀ moment of the designated monitoring point;

All monitoring point related event acquisition modules 24 are used to obtain all monitoring points in the database before and after the transient event occurrence time T ₀ moment, and the second related event with the transient event occurrence time interval as the system setting time ΔT;

The monitoring report generating module 25 is configured to analyze the obtained first relevant event and the second relevant event, and generate a power quality monitoring report.

Preferably, the monitoring report generating module 25 specifically includes:

A designated monitoring point related event analysis module 251, configured to analyze the cause of the transient event at the designated monitoring point according to the first related event;

All monitoring point-related event analysis module 252, configured to analyze the initial location and influence range of the transient event at the designated monitoring point according to the second related event;

The power quality monitoring report generation module 253 is configured to generate a power quality monitoring report according to the analysis results of the specified monitoring point-related event analysis module 251 and all monitoring point-related event analysis modules 252 .

Preferably, the power quality monitoring report is in text or report form.

An embodiment of the present invention also provides a power quality monitoring system, which includes the above-mentioned power quality monitoring device. Since the power quality monitoring device has been described in detail above, details will not be repeated here.

In the embodiment of the present invention, by obtaining the first relevant event of the transient event at the specified monitoring point within the ΔT time before the occurrence time T ₀ , and obtaining the second relevant event of all monitoring points within the ΔT time before and after the T ₀ time, combined with the first The first related event and the second related event analyze the transient event at the designated monitoring point and generate a power quality monitoring report, which improves the efficiency and accuracy of power quality monitoring and provides useful technical reference for safe production and stable operation of power. Produce significant economic and social benefits.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (9)

1. A method for monitoring power quality, characterized in that the method comprises the following steps: Get the transient events of the specified monitoring point; Obtain the first relevant event whose time interval from the occurrence of the transient event is the system setting time ΔT before the occurrence time _T0 of the transient event at the designated monitoring point; Obtain all monitoring points in the database after the transient event occurrence time T ₀ moment, and the second related event whose time interval from the transient event occurrence is the system setting time ΔT; Analyzing the obtained first relevant event and the second relevant event to generate a power quality monitoring report. 2. The power quality monitoring method according to claim 1, wherein the step of analyzing the acquired first related event and the second related event and generating a power quality monitoring report specifically includes: analyzing the cause of the transient event at the specified monitoring point according to the first relevant event; analyzing the initial location and influence range of the transient event at the designated monitoring point according to the second relevant event; Generate a power quality monitoring report based on the above analysis results. 3. The power quality monitoring method as claimed in claim 1, wherein, before the step of obtaining the transient event of the specified monitoring point, the method also includes: Save the power quality monitoring data to the database. 4. The power quality monitoring method according to claim 1, wherein the power quality monitoring report is in text or report form. 5. A power quality monitoring device, characterized in that the device comprises: The specified monitoring point transient event acquisition module is used to obtain the transient event of the specified monitoring point; Designated monitoring point related event acquisition module, used to obtain the first related event of the system setting time ΔT with the transient event occurrence time interval before the time of occurrence T ₀ of the transient event of the designated monitoring point; All monitoring point related event acquisition modules are used to obtain all monitoring points in the database before and after the transient event occurrence time T ₀ , and the second related event with the transient event occurrence time interval as the system setting time ΔT; The monitoring report generating module is configured to analyze the obtained first related event and the second related event, and generate a power quality monitoring report. 6. The power quality monitoring device according to claim 5, wherein the monitoring report generating module specifically includes: A designated monitoring point-related event analysis module, configured to analyze the cause of the transient event at the designated monitoring point according to the first related event; An event analysis module related to all monitoring points, configured to analyze the initial location and scope of influence of the transient event at the designated monitoring point according to the second related event; The power quality monitoring report generating module is used to generate a power quality monitoring report according to the above analysis results. 7. The power quality monitoring device according to claim 5, wherein the device further comprises: The power quality monitoring data saving module is used for saving the power quality monitoring data to a database. 8. The power quality monitoring device according to claim 5, wherein the power quality monitoring report is in a text or report form. 9. A power quality monitoring system, characterized in that the system comprises the power quality monitoring device according to any one of claims 5 to 8.

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