基于电容能量的海上风电柔性直流快速功率控制

Fast active power regulation of offshore wind power integrated by modular multilevel converter based high voltage direct current based on energy of capacitors

经过柔性直流输电并网的海上风电会对电力系统的稳定性产生显著影响,按照GB 38755-2019《电力系统安全稳定导则》要求,海上风电厂需要具备快速调节有功功率的能力。研究并提出了一种利用柔性直流换流器分布式电容存储的能量来实现海上风电并网点有功功率紧急调节的控制方法。通过设计特定的电容电压变化曲线,实现交流功率按照预定的目标曲线变化,而且在调节过程中不会对直流侧有功功率和直流电压产生扰动,可避免影响直流侧系统的运行。在此基础上,通过开展电磁暂态仿真,验证了该控制方法的有效性。研究成果可为经柔性直流输电并网的海上风电提供一种无需加装额外设备、对直流侧无扰动的有功功率快速调节途径,并能有效提高海上风电的并网性能指标。

The grid-connecting of offshore wind power by modular multilevel converter based high voltage direct current(MMC-HVDC)places notable influence on stability of a power system.Required by GB 38755-2019 Code on security and stability for power system,offshore wind power plant should be able to quickly adjust the active power if necessary.This paper proposed a fast active power regulation method for offshore wind power by utilizing the energy stored in the distributed capacitors of MMC.By designing a specific capacitance voltage change curve,the AC power can be changed according to the predetermined target curve,and no disturbance is implemented on the DC side active power and DC voltage in the adjustment process,which can avoid affecting the operation of the DC side system.The effectiveness of the proposed control method was verified by electromagnetic transient simulation.The research results can provide a fast active power regulation method for offshore wind power grid-connecting by MMC-HVDC without additional equipment and without disturbance to the DC side,which can effectively improve the grid-connected performance index of offshore wind power.