500kV system air-closing band high-resistance line DC bias suppression method

Abstract

The invention discloses a 500kV system air-closing band high-resistance line DC bias suppression method. The method comprises the following steps: step 1, detecting a circuit breaker closing trigger signal; step 2, judging whether a circuit breaker closing trigger signal is received or not, and if not, continuing to execute the operation in the step 1; step 3, if so, further judging whether the circuit breaker closing trigger signal belongs to an air closing line operation or not; if not, enabling the circuit breaker to execute a three-phase quick closing action; and step 4, if so, enabling the circuit breaker to execute a three-phase delay closing action according to the set A-phase target closing time delay, B-phase target closing time delay and C-phase target closing time delay, so as to suppress the direct current bias of the air closing band high-resistance line. According to the invention, the zero-bias time of the air charging current can be significantly reduced, the occurrenceof arc reignition or failure in normal breaking during opening of the circuit breaker in the air charging process is effectively prevented, and the safe and stable operation of a power system is ensured.

Description

Technical field: [0001] The invention belongs to the field of power transmission, and in particular relates to a method for suppressing the direct current bias of a 500kV system air-closing belt high-resistance line. Background technique: [0002] For the 500kV ultra-high voltage line running with high resistance, there will be a current DC bias phenomenon when the line is air-closed, that is, the empty charging current flowing through the circuit breaker contains a large DC component and decays slowly, making the current unstable for a long time At the zero crossing point, if the circuit breaker needs to be opened due to a fault at this time, it may cause the circuit breaker to fail to extinguish the arc or the arc will re-ignite multiple times, which is not conducive to the safe and stable operation of the power system. Therefore, for 500kV lines with high The DC bias problem is very important during the charging process. [0003] Research institutes at home and abroad ha...

AI Technical Summary

Problems solved by technology

[0004] The above research work covers the generation mechanism, influencing factors and suppression methods of the DC bias phenomenon of the air-to-air circuit, which is of great significance for reducing the zero bias time and reducing the risk of circuit breaker re-breakdown. However, there are still certain limitations, especially in the suppression In terms of method research: In the case of excessive compensation, the closing resistance of the circuit breaker has limited suppression effect on the DC component, and the configuration of the closing resistance of the circuit breaker will increase the failure rate of the circuit breaker itself; the phase control closing technology is carried out In the research, the phase-by-phase closing technology of zero-crossing detection is adopted. Due to the need for matching detection devices, it is difficult to realize, the cost is high, and there are few practical applications.

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