Strategy of reactive power control in Yunnan-Guangdong ±800 kV DC system

In ultra high voltage direct current(UHVDC) transmission system, in order to realize the function of the reactive power control to mitigate the harms of the harmonics produced by the converters to the system and the primary equipments, then to balance the reactive power exchanged between the AC and DC systems. Taking Yunnan-Guangdong ±800 kV UHVDC transmission project as an example, the voltage control, reactive power control and harmonic performance control for the DC filter groups switching was analyzed, and certain strategies to optimize the control logic of the DC filter groups were presented: pole control system for the station control system of the reference voltage was changed to the current voltage, at the same time increase a logic judgement that used to determine each pole whether effective unlocked, in order to eliminate filter group reactive power values and avoid excessive input filter system. This optimization strategy can fully solve the problems of station control in Yunnan-Guangdong project and have good reference value for the following UHVDC transmission project.