An Adaptive Phase-Locked Oscillator Control Method

Abstract

The invention discloses an adaptive phase-locked oscillator control method. The technical solution adopted by the present invention includes: Step 1, judging whether the system is in a large disturbance state according to the commutation voltage on the AC side; Step 2, calculating the phase correction amount according to the current commutation voltage and the output of the phase-locked oscillator; Step 3, phase After the correction amount passes through the PI controller, the latest phase output is obtained, and the parameters of the PI controller are determined according to the system state determined in step one. The invention ensures the small disturbance stability of the system during normal operation, and improves the ability of the phase-locked oscillator to capture the voltage phase during the fault recovery period of the DC system. The invention has an obvious inhibitory effect on preventing the subsequent phase commutation failure caused by the output error of the phase-locked oscillator during the restoration of the DC fault.

Description

Technical field[0001]The present invention belongs to the technical field of power system, and more particularly to an adaptive phase lock oscillator control method for increasing DC transmission exchange failure recovery capabilities.Background technique[0002]In actual operation, the DC mixed system has occurred from multiple DC continuous commutation failures due to AC system failure. Displacement failure faults generate DC power transmission interrupts, exchange valve overheating, transformer gag magnet, relay protection malfunction, etc. At the same time, according to the current high-voltage DC control strategy, it may be possible when continuous multi-phase failure Causes DC lock. If multi-high power DC is lost, the system frequency crashed risk is present, which may cause large-scale power outages to adversely affect social stability and economic development.[0003]DC transmission systems have been transported to a multi-DC blocking accident, and the recovery control of DC sys...

AI Technical Summary

Problems solved by technology

Commutation failure failures will cause problems such as interruption of DC power transmission, overheating of converter valves, transformer bias, and relay protection malfunctions; at the same time, according to the current UHV DC control and protection strategy, when multiple consecutive commutation failures occur cause DC blocking

If multiple high-power DCs are lost at the same time, there is a risk of system frequency collapse in the receiving system, which may cause large-scale power outages and adversely affect social stability and economic development.

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