三相电压不对称且畸变情况下无功电流检测研究

Research on detection of reactive current while three-phase voltage asymmetry and distortion

对于配电网中无功电流的准确检测,是静止同步补偿器(STATCOM)最核心的部分。基于瞬时无功功率的ip-iq法和p-q法是目前STATCOM应用最为广泛的无功电流检测法。在配电网电压未发生畸变时,这两种方法皆能对无功电流进行准确检测。当电压发生畸变且不对称时,p-q法测量误差大,而ip-iq法无法分离出无功分量并受到锁相环(PLL)的影响。本文在ip-iq法和p-q法的基础上,提出一种无锁相环并适合于电压畸变且不对称情况下的无功电流检测法。经过理论分析和仿真验证,该方法具有准确性和可行性。

The accurate detection of reactive current in the power distribution network is the core part of static synchronous compensator（STATCOM）.The most frequently applied reactive current tests of STATCOM are ip-iq method and p-q method based on instantaneous reactive power.When the distribution network voltage distortion does not occur,the two methods both can carry out accurate detection for reactive current.When the voltage distortion and asymmetry happen,p-q method has much error in the measurement,and ip-iq method cannot isolate reactive component and is affected by the phase lock loop（PLL）.Based on ip-iq method and p-q method,the reactive current detection method without phase locked loop was proposed,which is suitable when the voltage distortion and asymmetry occur.This method has the accuracy and feasibility through theory analysis and simulation verification.