直驱风机HVRT两种直流侧卸荷方法对比仿真研究

Comparative simulation analysis of PMSG HVRT on two different choppers

近年来,国内外学者对风电机组低电压穿越进行了研究,但对于并网风电机组高电压穿越研究较少。为提高直驱风电机组高电压穿越能力,以2. 5 MW直驱风电机组为研究对象。首先对比分析了国内外的风电机组高电压穿越标准,然后提出对网侧变流器采用稳态时单位功率因数控制、暂态时提供无功的控制策略。最后,在Matlab/Simulink中分别建立了斩波电路和超级电容储能系统两种直流侧卸荷电路模型,在相同工况下,仿真分析了两种卸荷电路对机组暂态特性的影响。研究结果表明:两种卸荷方式均能实现直驱风电机组高电压穿越,相比斩波电路,超级电容储能系统不仅能够提升风电机组的高电压穿越能力,而且能够改善机组故障穿越结束后机组稳定运行特性。

In recent years, domestic and foreign scholars have studied the low-voltage ride through of wind turbines, while few have studied the high-voltage ride through of grid-connected wind turbines. In order to improve the high voltage ride through （HVRT） capability of permanent magnet synchronous generator （ PMSG）, the 2.5 MW direct drive wind turbine was studied. In this paper, the overseas high voltage ride through standards of wind turbines are compared and analyzed, and then, a control strategy is put forward to control the grid side converter with unit power factor control in steady state and reactive power in transient state. Based on the voltage swell transient characteristic of PMSG, the model of chopper and super capacitor energy storage system were set up in Matlab/Simulink. The two different transient characteristic were simulated and compared. The result shown that, the two different circuits can be implemented when grid voltage swell occurs, compared with the chopper circuit, the super capacitor energy storage system can not only enhance the HVRT capability of PMSG , but also improve the operation stability after HVRT.