Coordination Control of Synchronous Condenser and Reactive Power Compensation Equipment in UHVDC Converter Station

In order to promote the transmission capacity and to increase the reliability of ultra-high voltage direct current (UHVDC) transmission, a new generation synchronous condenser was developed and installed in both the sending-end and receiving-end converter stations. The synchronous condenser has excellent dynamic characteristics of fast response and overload capacity, which can provide dynamic reactive power reserve to support the system voltage and reduce the possibility of DC commutation failure when there is a system fault. To make further use of the synchronous condenser during normal operation, a study was carried out to coordinate the condenser with other reactive compensation equipment in the converter station, which not only can make smooth switchover of the filter or the capacitor by utilizing the reactive power reserve of the synchronous condenser, but can also reduce the number of operations of the on-load tap changer (OLTC), thus extending its service life.