A Capacitive Voltage Transformer Used in Transient Overvoltage Monitoring System

Abstract

A capacitive voltage mutual inductor (2) for a transient over-voltage monitoring system comprises a first capacitor (C1), a second capacitor (C2), a third capacitor (C3), an intermediate transformer (T), a transient over-voltage monitoring unit (M), a grounding switch (K), a compensation reactor (L) and a first lightning arrester (BL1). One end of the first capacitor (C1) is connected to a power grid (1), and the other end is respectively connected to one end of the second capacitor (C2) and one end of a primary winding in the intermediate transformer (T). The other end of the second capacitor (C2) is respectively connected to one end of the transient over-voltage monitoring unit (M) and one end of the compensation reactor (L). The other end of the primary winding of the intermediate transformer (T) is respectively connected to the other end of the compensation reactor (L) and one end of the first lightning arrester (BL1). The other end of the transient over-voltage monitoring unit (M) and the other end of the first lightning arrester (BL1) are both grounded. The grounding switch (K) is connected in parallel at the two ends of the transient over-voltage monitoring unit (M). One end of the third capacitor (C3) is connected to the other end of the second capacitor (C2), and the other end of the third capacitor (C3) is grounded. A voltage bearable by the first capacitor (C1) is greater than a voltage bearable by the second capacitor (C2), and the voltage bearable by the second capacitor (C2) is greater than a voltage bearable by the third capacitor (C3).

Description

technical field [0001] The invention relates to the field of electrical engineering, in particular to a capacitive voltage transformer used in a transient overvoltage monitoring system. Background technique [0002] The transient process of the power grid is an important indicator of the operating state of the power grid. At present, there is still a lack of effective measurement or monitoring methods for transient overvoltages (lightning waves, operating wave overvoltages) in the power grid at home and abroad. For newly-built equipment, only some power units in China test the operating overvoltage of the 500kV system before it is officially put into operation. Generally, they conduct transient measurements when switching no-load lines, main transformers, low-voltage reactors or capacitors, as a test Live assessment of new equipment. There are reports of using optical fiber technology for monitoring in foreign countries. [0003] For operating equipment, currently installe...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the total capacity of the system, the sampling frequency of the equipment will not be too high. In addition, due to the frequency response characteristics of the sampling equipment, the current dispatch monitoring system and other system monitoring systems cannot effectively monitor the transient process of the power system. Therefore, it is impossible to comprehensively monitor the operating status of the power system.

Images