Operation Control Strategy of Soft Open Point Based on Unified Virtual Electric Machinery Technology

Abstract

Soft open point (SOP) mostly adopts “rigid” control strategy, which is insufficient with inertia and damping. It leads to the lack of flexibility in feeder power flow control and cannot actively participate in power adjustment of the distribution network. In addition, SOP mostly relies on feeder power to stabilize the DC bus voltage, which greatly limits the flexibility and operational reliability of feeder power flow control in distribution network. In this paper, a self-energy storage soft open point (SES-SOP) operation control strategy is proposed to solve the aforementioned problems. The AC and DC ports of the SESSOP are integrated with a unified virtual motor control, and the operating characteristics of the rotating electric machinery are simulated simultaneously on both ports, and there is no need to switch control strategies during multi-mode operation. The DC port exhibits flexible characteristics, suppresses the impulsion of the feeder exchange power to the DC bus voltage, and enhances the inertia and stability of the DC bus voltage. At the same time, the active and reactive power of the port can be adjusted actively to support the frequency and voltage of the distribution network. The simulation results demonstrate the correctness and effectiveness of the proposed operation control method.