电压源换相高压直流输电改善异步发电机风电场暂态电压稳定性的研究

基于普通异步发电机的恒速风电机组并网风电场会引起本地电网的电压稳定性问题.为此本文分析了并网风电场的电压稳定问题和电压源换相高压直流输电(VSC-HVDC)的风电场并网方式的技术特点,研究了VSC-HVDC的数学模型和控制方式.基于国际大电网会议(CIGRE)B4-39工作组标准模型,应用PSCAD/EMTDC仿真软件建立了大规模风电场并网系统模型,研究了VSC- HVDC输电改善异步发电机风电场暂态电压稳定性的贡献.研究表明VSC-HVDC不仅能够有效实现恒速风电机组在电网发生大扰动故障后的快速电压恢复能力,而且可以避免在电压恢复过程中由风电机组输入输出功率不平衡引起的发电机超速及电压失稳,确保风电机组的连续运行及电网的安全稳定.

Transient Voltage Stability Enhancement of Induction Generator-Based Wind Farm by VSC-HVDC

The large integrated wind farm composed of the constant speed wind turbines equipped with induction generator may cause the voltage stability problem in local grid. So the voltage stability of the integrated wind farm and the technical advantages of the integrated wind farm based on DC transmission using voltage source converters (VSC-HVDC) are presented in the paper, and then the VSC-HVDC mathematic model and its control modes are studied. Finally based on the benchmark of international council on large electric systems (CIGRE) working group B4-39, the integrated wind farm models are implemented in the power system simulation program PSCAD/EMTDC. The contribution of VS-HVDC to the transient voltage stability is verified by power system simulation. From the simulation results, it can be illustrated that VSC-HVDC can assist the induction generator restoring the voltage rapidly in the duration of power system large disturbance, prevent the wind turbines from over-speeding and transient voltage instability ensure the continuous operation of wind turbines and the security and stability of the power network.