A control method of active power filter where system voltage contains negative-phase-sequence component or zero-phase-sequence component

The usual instantaneous reactive power q has been defined by using α, β components of the voltage and current. The current from the power source contains higher harmonic components when q is used for the control method of an active power filter in an unsymmetrical three phase system. The higher harmonic current components are bad for telecommunication and so on. Therefore, the authors have defined a new instantaneous reactive power whose mean value is equal to the three phase reactive power. By the use of this value. The authors have clarified a new calculation method for compensating current command which solves the defects of the conventional pq method