考虑谐波电压下双馈异步发电机控制技术

Control technique of DFIG considering distorted voltage conditions

为提高双馈感应发电机(DFIG)在谐波电网下的运行性能,提出了DFIG运行于谐波电网电压下包含5个目标的谐波优化控制策略。在建立考虑5次谐波电网电压下DFIG瞬时有功和无功功率数学模型基础上,讨论不同控制目标下DFIG基波和谐波电流指令计算原则,并设计了基频、5倍频同步旋转坐标下的多PI电流控制方案,进而分别实现定、转子电流无谐波,定子输出有功功率、无功功率或电磁转矩无波动等5个控制目标。分析结果表明,所提控制策略能够优化DFIG在谐波电网下的运行性能,从而确保DFIG的稳定可靠安全运行。实验结果验证了该控制策略的可行性和有效性。

To improve the operation performance of doubly-fed induction generator（DFIG） under harmon- ic distorted grid voltage conditions, based on the instantaneous active and reactive power mathematic model of DFIG under the 5th harmonically distorted grid voltage, five different control strategies were pro- posed to eliminate the stator or rotor current harmonic components, active or reactive power ripple, or torque ripple, in which the current reference of the fundamental frequency and the harmonic frequency for the different control targets was deduced. Furthermore, based on the fundamental frequency and harmon- ic frequency synchronous rotating reference frames of the grid voltage, a multiple PI current control scheme was proposed to implement the accurate control of the fundamental frequency and harmonic fre- quency current. The availability of the proposed control strategy was validated by experimental studies on a DFIG experiment system.