1.State Grid Jibei Electric Power Research Institute, Beijing 100045, China;2.Power Dispatch and Control Center of State Grid Jibei Electric Power Co., Ltd., Beijing 100054, China;3.NR Electric Co., Ltd., Nanjing 211102, China

Deploying the distributed synchronous condenser in the renewable energy station is an effective measure to improve the voltage-supporting ability of the power supply side in the whole process. However, the existing cascade strategy of “reactive power outer loop + voltage inner loop” is adopted to integrate the synchronous condenser into the automatic voltage control system (AVC) of the station, which limits the low-frequency voltage source characteristics of the synchronous condenser. First, this paper describes the existing problems of the synchronous condenser integrated into AVC and proposes the requirement for constant voltage for the synchronous condenser throughout the whole process. Based on the topology of the renewable energy station with distributed synchronous condensers, the reactive voltage conversion coefficient and the reactive power shunt influence factor are analyzed. Then, this paper proposes a new scheme of “constant voltage + reactive power shunt suppression” for integrating the synchronous condenser into AVC. The program is developed on an equipment of domestic mainstream manufacturer, and the effectiveness of the proposed scheme is verified by the hardware-in-the-loop simulation of the dual controllers of synchronous condenser excitation and AVC at the station. Finally, the engineering application has been completed in an actual renewable energy station. The field operation results show that the proposed scheme realizes the steady-state regulation of multi-type reactive power equipment of the station, effectively reduces the voltage fluctuation amplitude at the grid-connection point of the station, fully utilizes the voltage source characteristics of the synchronous condenser in the whole process, and guarantees the voltage stability margin of the system.