基于谐波分量系数控制的低电压穿越策略研究

Based on the Control of Harmonic Component Coefficien Low Voltaget Through the Strategy Research

本文研究了双馈感应发电机(DFIG)在电网电压骤降中的电磁特性,推导出了定子满电流的表达式。提出了一种控制策略,通过控制转子侧激励电压并使谐波分量系数为零来消除瞬态过程中谐波分量的影响。对电压降深度和电流,有功功率和无功功率的分析表明,DFIG可以将无功功率保持在电网中,同时在该控制策略下保持非离网运行。仿真结果证明了理论分析的正确性,同时表明,该控制策略消除了电压跌落过渡过程中的定、转子侧谐波电流,实现了并网转换器保护的目的,可以有效提高DFIG的低电压穿越能力。

When grid voltage drop, analyzed the expression of the electromagnetic properties of DFIG and stator current, by controlling the rotor excitation voltage side of the harmonic component coefficient is zero, in order to eliminate the transient process of the harmonic component. On the depth of the voltage drop and current, active power and reactive power analysis showed that the DFIG under this control strategy can keep net running off at the same time also to the power grid reactive power injection. Simulation results prove the validity of the theoretical analysis and show that the control strategy to eliminate the voltage drop in the process of transition, the rotor side harmonic current, attaining the aim of the grid converter protection, effectively improve the low voltage through capacity of the DFIG.