Adaptive phase-locked oscillator control method

Abstract

The invention discloses a self-adaptive phase-locked oscillator control method. According to the technical scheme, the method comprises the steps that 1, whether a system is in a large disturbance state or not is judged according to alternating-current side commutation voltage; 2, calculating a phase correction amount according to the current commutation voltage and the output of the phase-lockedoscillator; and 3, the latest phase output is obtained after the phase correction amount passes through a PI controller, wherein parameters of the PI controller are determined according to the systemstate judged in the step 1. During the normal operation period, the small interference stability of the system is ensured; during fault recovery of the direct-current system, the voltage phase capturing capability of the phase-locked oscillator is improved. The method has an obvious inhibiting effect on subsequent commutation failure caused by output errors of the phase-locked oscillator in the DCfault recovery period.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to an adaptive phase-locked oscillator control method for improving the recovery capability of DC transmission commutation failure. Background technique [0002] In actual operation, there have been many failures of single-circuit DC continuous commutation or multi-circuit simultaneous commutation failures in AC-DC hybrid systems due to AC system failures. 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 resulting in 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 adv...

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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