张北柔性直流电网试验示范工程直流控制保护设计原则与验证

Design Principle and Verification of Control and Protection System for Zhangbei VSC-HVDC Grid Demonstration Project

张北柔性直流电网试验示范工程(简称张北工程)将建成世界上首个直流电网,该工程4个换流站采用手拉手环网结构,具有多回路冗余特性,可以实现新能源孤岛接入、多电源供电、多能互补,形成了真正意义上的直流电网。针对张北工程直流电网特点,确定了控制保护系统的难点与主要设计原则,提出了针对直流电网的多换流站协调控制、换流器自适应控制等关键控制策略以及直流保护配置,最后通过硬件闭环实时仿真验证了控制保护系统设计的合理性。

The Zhangbei VSC-HVDC gird demonstration(Zhangbei project for short)will be the first HVDC grid in the world.Four MMC converter stations will be connected in a ring circuit.In this manner,through multiloop redundancy,the grid can provide renewable energy with isolated island access,realize multi-energy supplement,and form a true HVDC grid.Based on the characteristics of the project,the difficulties and major design principle of the control and protection system were proposed.The control strategies for the structure were studied,e.g.,coordination control at the grid level and adaptive control in each converter.Then,a protection configuration was proposed for each station.Finally,the rationality of the control and protection design was verified by performing the closed-loop simulation of real-time control and protection systems using the RTDS simulator.