CN103454517B - Capacitance type potential transformer on-line monitoring method - Google Patents

Abstract

A kind of capacitance type potential transformer on-line monitoring method, comprises step: the secondary voltage data of obtaining the capacitance type potential transformer of each transformer station in monitored area based on EMS; The converting equipment information that described secondary voltage data are corresponding with each transformer station is carried out associated; Judge the fault status information of described capacitance type potential transformer according to described secondary voltage data; Monitor the running status of the capacitance type potential transformer of the converting equipment of each transformer station in described monitored area according to described fault status information. Above-mentioned capacitance type potential transformer on-line monitoring method, without increasing hardware device, realize the real time on-line monitoring to capacitance type potential transformer running status, monitoring cost is low, and do not affect the operation of power system safety and stability, suitable in power system wide popularization and application.

Description

Online Monitoring Method of Capacitive Voltage Transformer

technical field

The invention relates to the technical field of electric power engineering, in particular to an online monitoring method of a capacitive voltage transformer.

Background technique

Capacitive voltage transformer (CapacitorVoltageTransformer, CVT) is widely used in power system, it is a power equipment for voltage measurement, power measurement and control, automatic control, relay protection and also used as power line carrier capacitor. With the advantages of small size, light weight, reliable damping of ferromagnetic resonance and excellent transient response characteristics in practical applications, it gradually replaces electromagnetic voltage transformers and is an indispensable device in the power grid.

During the operation of capacitive voltage transformers, there may be equipment defects such as increased dielectric loss and abnormal secondary voltage due to internal moisture, aging, and breakdown of internal capacitive elements. In severe cases, explosions may occur, causing serious consequences. Therefore, it is necessary to monitor the capacitor voltage transformer. Through monitoring, the operation status of the capacitor voltage transformer can be grasped, the fault of the capacitor voltage transformer can be found in time, and the fault can be eliminated early, so as to minimize the damage of the fault.

At present, there are also some online monitoring systems and methods for capacitive voltage transformers in the power system, but these methods are based on measuring the current flowing through the insulating medium under the phase voltage, mainly through the capacitance of the capacitive voltage transformer. Monitor and dielectric loss value, and calculate with related algorithms, such as unbalance compensation method, bridge method, zero-crossing comparison method or digital waveform method, etc., and obtain monitoring results through signal detection and calculation.

Since this method needs to be based on capacitance and dielectric loss values of capacitive voltage transformers that are difficult to measure accurately, the accuracy and sensitivity of capacitive voltage transformer monitoring cannot be effectively guaranteed. Hardware transformation, complex construction process, high cost, and hardware transformation will bring problems such as maintenance difficulties, which will easily affect the operation safety of the power system. Therefore, it is difficult to widely popularize and apply it in the power system.

Contents of the invention

Based on this, it is necessary to provide an on-line monitoring method for capacitive voltage transformers for the problems of high cost and easy influence on safe and stable operation in the prior art.

An on-line monitoring method for a capacitive voltage transformer, comprising the steps of:

Based on the energy management system, obtain the secondary voltage data of the capacitive voltage transformers of each substation in the monitoring area;

Associating the secondary voltage data with the substation equipment information corresponding to each substation;

judging fault state information of the capacitive voltage transformer according to the secondary voltage data;

The operating status of the capacitive voltage transformers of the substations in the monitoring area is monitored according to the fault status information.

The above online monitoring method for capacitive voltage transformers is based on the secondary voltage data obtained by the energy management system, correlating the secondary voltage data with the information of the substation equipment corresponding to each substation, and judging the capacitive voltage according to the obtained secondary voltage data. The fault state information of the transformer, so as to realize the monitoring of the operation state of the capacitor voltage transformer. Without adding hardware equipment, real-time online monitoring of the operation status of the capacitive voltage transformer is realized, the monitoring cost is low, and the safe and stable operation of the power system is not affected, and it is suitable for widespread application in the power system.

Description of drawings

Fig. 1 is a flowchart of an online monitoring method for a capacitive voltage transformer according to an embodiment.

detailed description

The specific implementation of the capacitive voltage transformer online monitoring method of the present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, Fig. 1 is a flow chart of an embodiment of a capacitive voltage transformer online monitoring method, including the following steps;

S1: Obtain the secondary voltage data of the capacitive voltage transformers of each substation in the monitoring area based on the energy management system (EMS).

In one embodiment, the process of acquiring secondary voltage data in step S1 includes the following steps:

S101. Collect the secondary voltage by using the signal sensors installed on the capacitive voltage transformers of each substation in the monitoring area.

The function of the signal sensor is to collect the secondary voltage data of the capacitive voltage transformer operated on site. Preferably, the accuracy of the signal sensor used can be 0.2, that is, the error between the measured value and the real value is less than 0.2%. Since the fault detection accuracy of the capacitive voltage transformer set by the energy management system is 1%, the above-mentioned The accuracy of the signal sensor can meet the requirements of the energy management system.

S102. The energy management system periodically polls and collects the signal sensors of each substation to obtain secondary voltage data and saves it in the database.

This step is mainly to collect and transmit the signal of the sensor. The amount of data obtained through periodic polling is relatively complete. The signal collection time interval is at the ms level, that is, hundreds of data are taken per second, which can meet the requirements of energy management. The system's demand for data volume enables real-time acquisition of the secondary voltage data of the capacitive voltage transformer.

S2: Associating the secondary voltage data with the information of the substation equipment corresponding to each substation.

In one embodiment, the associated process in S2 includes the following steps:

S201. Draw a wiring topology diagram of the capacitive voltage transformers of each substation in the monitoring area.

S202. According to the capacitor voltage transformer of the wiring topology diagram, the information of the substation equipment corresponding to each substation is obtained from the equipment ledger system.

S203. Associate the secondary voltage data of each capacitive voltage transformer with the information of the power transformation equipment.

Since there is no capacitive voltage transformer in the primary wiring diagram of the energy management system, the collected secondary voltage data of the capacitive voltage transformer can be associated with its specific equipment. First draw the topology diagram of the primary wiring of capacitive voltage transformers in all substations in the monitoring area, and then combine the equipment ledger system to realize the association between the secondary voltage data of capacitive voltage transformers in the database of the energy management system and the corresponding substation equipment, Get the topological diagram of the capacitive voltage transformer.

By establishing the association between the secondary voltage data of the capacitor voltage transformer in the wiring topology diagram and the information of the corresponding substation equipment, it provides a basis for real-time monitoring of the operating status of each capacitor voltage transformer, making the capacitor voltage transformer The fault state information can be correctly judged.

S3: Judging fault state information of the capacitor voltage transformer according to the secondary voltage data.

In this step, the purpose of fault discrimination is mainly achieved by utilizing the secondary voltage data stored in the database for judgment processing.

In one embodiment, the step of judging the fault state information of the capacitive voltage transformer in step S3 specifically includes:

Obtain secondary voltage data of capacitor voltage transformers in each substation.

Obtain the capacitive voltage transformer of the same type as the capacitive voltage transformer to be tested; preferably, first determine the type of the capacitive voltage transformer to be tested, and then find the same type of capacitive voltage transformer from the topological map of the capacitive voltage transformer A capacitor voltage transformer of the same type as the capacitor voltage transformer to be tested.

Comparing the secondary voltage of the capacitor voltage transformer to be tested with the secondary voltage of the capacitor voltage transformer of the same type.

If the secondary voltage and voltage deviations between the capacitive voltage transformer to be tested and the same type of capacitive voltage transformers are greater than the set threshold value, and the capacitor voltage transformer is different from the secondary voltage of the previous set time period If the secondary voltage deviation value is greater than the set threshold value, it is determined that the capacitor voltage transformer is in a fault state.

Due to the different requirements of power system operation, the installation methods of capacitor voltage transformers in substations will be different. Generally, capacitor voltage transformers will be installed on the three phases of the busbar in the substation. For the 500kV busbar, each outgoing line Capacitive voltage transformers will be installed on the three phases of the bus, and for the 220kV and below busbars, the outgoing line usually only installs capacitor voltage transformers on a single phase. Therefore, in view of the above situation, judge the fault state of the capacitor voltage transformer Information can be included in the following two ways:

(1) Obtain the secondary voltage data of a single capacitor voltage transformer of the same type on the outgoing line of the substation bus; compare the secondary voltage of the capacitor voltage transformer to be tested with the secondary voltage of the capacitor voltage transformer of the same type Comparison; within the set time period, if the secondary voltage voltage deviation between the capacitive voltage transformer and the same type of capacitive voltage transformer on the same phase is greater than the set threshold, and the capacitive voltage transformer If the deviation value of the secondary voltage from itself within the previously set time period is greater than the set threshold value, it is determined that the capacitive voltage transformer is in a fault state.

For example, if a capacitive voltage transformer is installed on a single-phase line for the bus bar and outgoing line of a 220kV substation, then the secondary voltage of the capacitive voltage transformer is compared with that of the capacitor voltage transformer on the same phase as the corresponding bus bar. If the secondary voltage The deviation value exceeds the set threshold value, and compares the secondary voltage value with the secondary voltage value in the previous setting period. If the secondary voltage deviation value also exceeds the set threshold value, it is judged that the capacitive The voltage transformer has failed.

(2) Obtain the secondary voltage data of each phase capacitor voltage transformer on the outgoing line of the substation bus; compare the secondary voltage of the capacitor voltage transformer to be tested with the secondary voltage of the capacitor voltage transformer of the same type; If the secondary voltage deviation between the capacitor voltage transformer and the capacitor voltage transformer on the same phase is greater than the set threshold value, and the capacitor voltage transformer and its secondary voltage within the previously set time period If the voltage deviation value is greater than the set threshold value, it is determined that the capacitor voltage transformer is in a fault state.

For example, if there are multiple capacitive voltage transformers installed on the busbar and outgoing line of a 500kV substation, the secondary voltages of the same type of capacitive voltage transformers among these capacitive voltage transformers will be compared in real time. The secondary voltage deviation value (voltage difference/secondary voltage value) of the capacitor voltage transformer and other capacitor voltage transformers exceeds the set threshold within the set time, and the secondary voltage value is compared with its own Compared with the secondary voltage value in the previously set period, if the secondary voltage deviation value also exceeds the set threshold value, it is judged that the capacitor voltage transformer has failed.

In this embodiment, according to the requirements of the operation of the capacitor voltage transformer, a secondary voltage deviation value (for example, 0.5%) that can reflect the fault of the capacitor voltage transformer of each secondary voltage level is selected as the threshold value, through multiple capacitors The fault state information of the capacitor voltage transformer is judged by combining the real-time mutual comparison of the secondary voltage of the capacitor voltage transformer and the mutual comparison of the secondary voltage of the single capacitor voltage transformer in different time periods.

S4: Monitor the operation status of the capacitive voltage transformers of the substation equipment in the monitoring area according to the fault status information.

In this step, the operation state of the whole process of the capacitive voltage transformer is recorded, and the fault state information of the previous steps is judged to monitor in real time the operation state of the capacitive voltage transformer of the substation equipment in each substation in the monitoring area. Provide technical support for failure analysis and troubleshooting.

Further, for the fault state obtained by the above judgment, the faulty capacitor voltage transformer is displayed on the capacitor voltage transformer topology diagram. The capacitive voltage transformers of the substation equipment in the monitoring area can be displayed through the capacitive voltage transformer topology diagram, and the faulty capacitive voltage transformers can be displayed through indicator lights or highlighted displays.

In addition, when it is judged that a capacitive voltage transformer is in a fault state, a corresponding alarm is executed to realize a fast early warning function.

The on-line monitoring method of the capacitive voltage transformer in the above embodiment uses the hardware equipment of the energy management system, based on the secondary voltage data of the capacitive voltage transformer running in the energy management system, and monitors without increasing the monitoring hardware. The capacitive voltage transformers of each substation in the region are monitored in real time, and the secondary voltage data of the capacitive voltage transformers are used as the fault characteristic quantities of the capacitive voltage transformers, and a fault judgment model is established. The real-time comparison of the secondary voltage of the capacitor voltage transformer and the comparison of the data of the secondary voltage of a single capacitor voltage transformer at different times can judge the fault state of the capacitor voltage transformer, which is easy to maintain and low in cost, and avoids affecting the safety and stability of the power system. The impact of operation improves the accuracy and sensitivity of online monitoring.

The technology of the present invention, based on the EMS data-based capacitive voltage transformer online monitoring, can realize real-time online monitoring of the operating state of the capacitive voltage transformer, timely and effectively find the fault of the capacitive voltage transformer, and reduce losses. At the same time, the system can effectively understand the failure process of the capacitor voltage transformer, which is beneficial to analyze the cause of the accident, and is of great significance for improving the operation reliability of the capacitor voltage transformer.

For example, in a 500kV substation, a line carrying a 1000MW load, when C2 of the capacitive voltage transformer of this line breaks down a component, the transformation ratio changes by 2.82%, then 24 hours a day, it will be less than 3360*10*10*10 One kilowatt-hour of electricity, the economic loss can reach 1.68 million yuan a day. It can be seen that if the fault can be found one day earlier, the electricity price loss of 1.68 million yuan can be saved. The economic benefit is very huge and the promotion prospect is huge.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (5)

1. a capacitance type potential transformer on-line monitoring method, is characterized in that, comprises the steps:

Obtain the secondary of the capacitance type potential transformer of each transformer station in monitored area based on EMSVoltage data;

The converting equipment information that described secondary voltage data are corresponding with each transformer station is carried out associated; Concrete bagDraw together: the wiring topological diagram of drawing the capacitance type potential transformer of each transformer station in described monitored area; According toIt is corresponding that the capacitance type potential transformer of described wiring topological diagram obtains each transformer station from equipment account systemConverting equipment information; By the secondary voltage data of each capacitance type potential transformer and described converting equipment informationCarry out association and obtain capacitance type potential transformer topological diagram;

Judge the fault status information of described capacitance type potential transformer according to described secondary voltage data; SpecificallyComprise: the secondary voltage data of obtaining the capacitance type potential transformer of transformer station; Obtain and testing capacitance formula electricityPress transformer capacitance type potential transformer of the same type; By the secondary electricity of described testing capacitance formula voltage transformerPress with the secondary voltage of described capacitance type potential transformer of the same type and compare; If this testing capacitance formula electricityPress the secondary voltage voltage deviation value between transformer and capacitance type potential transformer of the same type to be all greater than settingThreshold values, and this capacitance type potential transformer is greater than institute with the secondary voltage deviate in setting-up time section beforeState setting threshold values, judge that this capacitance type potential transformer is in malfunction;

Monitor the electric capacity of the converting equipment of each transformer station in described monitored area according to described fault status informationThe running status of formula voltage transformer.

2. capacitance type potential transformer on-line monitoring method according to claim 1, is characterized in that,The described secondary that obtains the capacitance type potential transformer of each transformer station in monitored area based on EMSThe step of voltage data comprises:

Utilization is installed on the signal transducer pair on the capacitance type potential transformer of each transformer station in monitored areaSecondary voltage gathers;

Signal transducer by each transformer station of EMS periodic polls also gathers voltage signal and obtainsObtain secondary voltage data and be kept in database.

3. capacitance type potential transformer on-line monitoring method according to claim 1, is characterized in that,The described step of obtaining the capacitance type potential transformer of the same type with testing capacitance formula voltage transformer comprises:

Determine the type of testing capacitance formula voltage transformer;

Find with described testing capacitance formula voltage transformer same from described capacitance type potential transformer topological diagramThe capacitance type potential transformer of type.

4. capacitance type potential transformer on-line monitoring method according to claim 1, is characterized in that,Also comprise:

By the capacitance type potential transformer of described generation fault at described acquisition capacitance type potential transformer topological diagramOn show.

5. capacitance type potential transformer on-line monitoring method according to claim 1, is characterized in that,Also comprise:

In the time having determined capacitance type potential transformer in malfunction, carry out corresponding alarm.