三相四线制系统谐波检测p-q-0法的研究

以瞬时无功功率理论为基础,介绍了针对三线四线制系统谐波电流检测和无功补偿所提出的p-q-0法,分析了瞬时无功功率理论在三线四线制电力系统下的物理意义,并给出了该系统下谐波和无功电流的检测控制算法原理图,详细讨论了三相负载不平衡时的补偿效果。通过理论分析,在M atlab环境下对三相不平衡负载电路仿真证明,当电网电流发生严重畸变时,p-q-0法不仅能准确、实时地消除三相四线制系统中的谐波电流,对中线电流抑制及无功功率补偿也有较好的效果,并且补偿后的电源瞬时三相功率为定值。

Three-phase four-wire system harmonics detection by the p-q-0 method

The p-q-0 method which is applied in three-phase four-wire harmonic current detecting and reactive power compensation is introduced based on the instantaneous reactive power theory.The physical meaning of instantaneous reactive power theory is analyzed in the three-phase four-wire system,and the control strategy block diagram of harmonics and reactive power currents detection is given.The effect on compensating the unbalanced load harmonic and reactive power currents are researched in detail.Through theoretical analysis and simulation,it testifies that the p-q-0 theory can not only eliminate harmonic currents precisely in real-time,but also compensate the instantaneous reactive power and eliminate the neutral-line current as well,and the source instantaneous three-phase power becomes into a constant value after active power filter turning on.