交直流柔性协调控制技术在华中电网的应用

Application of Flexible Coordinated AC/DC Control Technology in Central-China Power Grid

随着特高压大规模输电快速发展,交直流相互耦合愈加紧密,电网安全稳定问题凸显,安控措施量大,迫切需要适应于交直流混联大电网的安全稳定控制技术。交直流柔性协调控制技术是利用多回直流功率紧急控制,通过交流系统与直流系统相互配合,降低大容量直流故障冲击,提升系统振荡阻尼水平,替代或减少受入直流闭锁故障后电网切负荷量,该技术在华中电网得到了成功的工程应用。文中针对华中电网运行存在的实际问题,基于多直流协调控制理论和时域仿真,构建了交直流柔性协调控制系统,现场试验结论验证了该系统对于提高电网输电能力和安全稳定运行裕度的有效性。

With rapid development of UHV transmission and continuous increase of AC/DC transmission capacity, trans-region AC/DC transmission are further strengthened and power grid＇s security and stability in operation and control becomes a more challenging problem. Study of security and stability in coordinated AC/DC control technology is urgently demanded. Trans-regional flexible coordinated AC/DC control technology utilizes emergency control of multi-loop HVDC through cooperation of AC and DC systems to reduce fault impact of large capacity HVDC and enhance low-frequency oscillation damping of power system, completely or partially replacing load shedding. The technology is applied successfully in Central China Power Grid. The paper presents problems existing in operation of the Grid and the theory and time-domain simulation of coordinated multi-DC control, building a flexible coordinated AC/DC control system. Field test results verify its validity in enhancing power system security and operation efficiency.