northeast grid of china
Currently, the overvoltage of UHVDC transmission sending system caused by disturbances such as blocking has become the main constraint to the UHVDC transfer capacity and new energy consumption. Based on the ±800kV Lugu UHVDC weak transmission sending system in combination with the condenser project of Zarut station and the system protection construction of northeast power grid, this thesis puts forward the overvoltage suppressing strategy through coordinating converter station filter (capacitor), condenser, and the synchronous unit near the converter station. On the one hand, during the steady-state of power grid, the condenser and the synchronous unit are fully utilized to compensate the reactive power consumed by the valve group, and reduce the input of filters (capacitors), thus reducing the transient overvoltage caused by the lagging removal of filters (capacitors).On the other hand, the increase of the reactive power of the condenser and the synchronous unit provides sufficient fall-back reactive power reserve for suppressing steady-state overvoltage caused by large-scale power retreat. Finally, the effectiveness of the strategy is verified based on the Lugu UHVDC transmission sending system.
YUE Han,SHAO Guanghui,XIA Deming,et al.Reactive Power Control Strategy for UHVDC Weak Sending-end System Considering Overvoltage Suppression[J/OL].Automation of Electric Power Systems,http://doi.org/10.7500/AEPS20200304004.