双馈风电场柔性高压直流输电并网控制策略

A new control design for grid integration of DFIG wind farm with VSC-HVDC

针对双馈风力发电机风电场VSC-HVDC的系统接入方式提出了一个控制方案,保障电力系统在波动的风电穿透率下的安全和稳定运行,对整个系统的动态模型分别进行了描述,基于矢量控制系统和虚拟电压坐标定向,对WFVSC稳态的电压控制模块和引入了d-q电流的交叉乘积项的暂态电压控制模块分别进行了设计,用来控制风电场电压的相应部分,同时,考虑交流侧和直流侧的参数变化以及外部扰动,提出了基于Lyapunov稳定性判据的GSVSC改进backstepping控制方案,这两个控制方案构成了本研究所提出的新的控制设计,此外,为验证所提控制方案的性能,假设了3种不同的仿真案例,包含交流和直流侧的参数变化,外部扰动如本地负荷的切入切出,电网电压谐波,通过MATLAB/Simulink软件模拟1台200MW机组VSC-HVDC并网运行验证,证明了该方案能够提高系统性能,并在文中做了进一步说明。

This paper proposes a control scheme for a doubly-fed induction generator（DFIG）wind farm with VSC-HVDC grid integration to ensure secure and reliable operation of power system with fluctuated wind power penetration.The whole system dynamic models are respectively described.Based on vector control system with a virtual voltage orientation,a steady-state voltage control block and a dynamic voltage control block with a cross-product term of d-q currents are separately designed for WFVSC to control the corresponding parts of the wind farm voltage.Meanwhile,with the consideration of AC and DC side parameter variation and external disturbance,an improved backstepping control scheme with Lyapunov stability provement is also proposed for the GSVSC.The combination of the two schemes makes up the new control design of this study.Besides,to verify the performance of the proposed new control design,three different cases are suggested which contain the AC and DC side parameter variation and external disturbance such as local load cut off-in,grid voltage harmonics.Finally,numerical simulations using MATLAB/Simulink are presented for a 200 MW DFIG wind farm with VSC-HVDC grid integration to validate the proposed control scheme and demonstrate the improved system operation performance.Moreover,the corresponding discussions are also presented for further illustrations.