Capacitive voltage transformer dielectric loss and capacitance on-line monitoring method and monitoring system

A voltage transformer and capacitive technology, which is applied in the field of on-line monitoring methods and monitoring systems for capacitance voltage transformer dielectric loss and capacitance, can solve problems such as inaccurate measurement, inaccurate fault location, and heavy measurement workload, and achieve The effect of accurate measurement results, reduced workload, and clear physical meaning

CN106771645BActive Publication Date: 2019-06-25STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2019-06-25

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Abstract

The invention discloses a method and a system for online monitoring of dielectric loss and capacitance of a capacitor voltage transformer. According to the method, a voltage / current monitoring device is used for obtaining secondary voltage of a busbar PT, secondary voltage of the capacitor voltage transformer, piezoelectric capacitance current in the capacitor voltage transformer and primary current of an intermediate transformer of the voltage transformer and sending the obtained data to a data processing device for calculation. The method and the system have the advantages that automatic online monitoring of the dielectric loss and the capacitance of the capacitor voltage transformer is achieved, definite physical significance and accurate measurement results are obtained, and fault positions of the capacitor voltage transformer can be judged and positioned accurately; assembly and disassembly of a high-voltage primary lead wire of the capacitor voltage transformer are avoided, onsite measurement workload is reduced, and all test operations can be conducted without powering off, so that normal power supply of an electrical power system is unaffected.
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Description

technical field

[0001] The invention relates to the technical field of power equipment performance monitoring, in particular to a method and a monitoring system for on-line monitoring of dielectric loss and capacitance of capacitive voltage transformers. Background technique

[0002] Potential transformers and transformers are used to transform the voltage on the line. However, the purpose of the transformer to transform the voltage is to transmit electric energy, and the purpose of the voltage transformer to transform the voltage is mainly to supply power to the measuring instrument and the relay protection device. In recent years, capacitor voltage transformers (Capacitor Voltage Transformer, CVT) have been used more and more in power systems. However, the voltage division ratio caused by capacitance changes and insulation aging problems during the use of capacitor voltage transformers Changes directly affect the accuracy of measuring instruments, the stability of relay p...

Examples

Embodiment 1

[0041] Such as figure 1 as shown, figure 1 It is a block diagram of the circuit structure of the capacitance voltage transformer dielectric loss and capacitance on-line monitoring system provided by Embodiment 1 of the present invention.

[0042] Capacitive voltage transformer dielectric loss and capacitance online monitoring system, including voltage / current monitoring device, data processing device, clock synchronization device, switch and local server.

[0043] The voltage / current monitoring device is electrically connected with the bus PT and the voltage transformer, obtains the secondary voltage signal and current signal of the bus PT and the secondary voltage signal and current signal of the capacitive voltage transformer, and sends it to the data processing The device specifically includes a voltage acquisition module, a current acquisition module, a signal processing module, an A / D conversion module, a CPU and an I / O interface module. The voltage acquisition module u...

Embodiment 2

[0050] This embodiment discloses a method for on-line monitoring of dielectric loss and capacitance of a capacitive voltage transformer.

[0051] figure 2 It is a flow chart of the on-line monitoring method for dielectric loss and capacitance of a capacitive voltage transformer provided by Embodiment 2 of the present invention.

[0052] The method for on-line monitoring the dielectric loss and capacitance of a capacitive voltage transformer specifically includes the following steps:

[0053] S101. Monitoring the secondary voltage of the busbar PT, the secondary voltage of the capacitor voltage transformer, the medium voltage capacitor current of the capacitor voltage transformer, and the primary current of the intermediate transformer of the capacitor voltage transformer.

[0054] Such as image 3 as shown, image 3 It is a circuit schematic diagram of a capacitive voltage transformer provided by Embodiment 2 of the present invention.

[0055] Among them, C 1 is the capa...