AVC control strategy and system of converter station with phase modifier

Abstract

The invention discloses an AVC control strategy and system of a converter station with a phase modifier. According to the method, coordinative control of the phase modifier and a filter of the converter station is utilized to achieve the AVC control strategy of the converter station, the phase modifier implements a control target issued by AVC through reactive power output, and the control targetcan be busbar voltage of the converter station or the reactive power exchanged by the converter station and an alternating current system; when the converter station senses that the reactive power output by the phase modifier exceeds a setting range and the filter satisfies a free switching condition, the converter station emits a filter switching command to make the phase modifier run within a setting range in a reactive power mode; when the filter of the converter station does not satisfy the free switching condition, the phase modifier achieves the AVC control target as possible as it can,and the converter station no longer cooperates with the filter for switching; during reactive power adjustment of the phase modifier, attention should be paid in real time to ensure that the busbar voltage and output reactive power of the converter station do not exceed the setting range. By adopting the strategy and system, the output reactive power of the phase modifier during steady-state operation can be controlled within a reasonable range.

Description

technical field [0001] The invention relates to the technical field of power system control, in particular to an AVC (automatic voltage control) control strategy and system of a converter station with a regulator. Background technique [0002] In order to improve the resistance to continuous commutation failure of the DC system, the installation of condensers in UHV converter stations has become an important means. While improving the continuous commutation failure resistance of the DC system, the condenser can also be used as an important reactive voltage regulation device to improve the voltage controllability of the main network. In the traditional DC converter station, only the reactive power output by the converter station is generally controlled, and since the filters can only be switched in groups, the reactive power output by the converter station cannot be continuously adjusted. After the condenser is added to the converter station, in conjunction with the switchin...

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Problems solved by technology

[0003] The Chinese patent "Reactive Power Coordinated Control Method of AC Filter and Regulator of DC Converter Station" with application number 201710307415.7 proposes a coordinated control method of reactive power control and regulator of converter station, which does not take into account at all The original reactive power control logic in the converter station only treats the filter in the station as a switchable capacitor, which is not practical

The first function of the filter in the converter station is to filter out the harmonics generated by the converter station, and then it can be used as a reactive power compensation device. In order to ensure the reliable operation of the DC system, a certain filter must be used in the converter station to operate. Failure to meet the requirements for the input quantity of the filter may lead to the outage of the DC system

In addition, as a rotating device, the condenser is a rotating device. During system disturbance, the output reactive power will inevitably oscillate. If the steady-state reactive power of the condenser is within the critical range mentioned in this method, the system disturbance will cause the condenser to After the reactive power output oscillates, it will cause the filter in the converter station to oscillate and switch back and forth

[0004] The document "High Voltage DC Digital Display Engineering Technology" (China Electric Power Publishing House, second edition, page 177) proposes the use of a condenser as a continuous adjustment reactive power compensation device, but does not specifically describe how to implement related technologies

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