Improved Control Strategy for AC-Filters Switching in UHVDC Converter Station

Abstract

The AC-filter configuration, reactive power consumption, reactive power control function, switching and replacement strategy in SHANSHAN UHVDC converter station are introduced in detail. The various types of AC filters in the converter station are evenly configured in the large groups of filters based on their quantity. And the related types of filters within a large group are usually switched preferentially. The problem of this switching strategy that may cause large impact on the AC system and long reactive power recovery time during the large group of AC filter bus lines fault are analyzed. Then an improved strategy that the needed filters with same type are equally switched on the large AC-filter group is proposed. The proposed strategy can effectively reduce the influences of AC-filter bus fault to the AC system which will give some references for the design and operation of subsequent UHVDC projects.