Effect of supply voltage asymmetry on IRP p-q-based switching compensator control

Results of a study on how the supply voltage asymmetry affects the reference signal for switching compensator control, in a situation when this signal is generated using the instantaneous reactive power (IRP) p-q theory are presented. According to the IRP p-q approach, the compensator should compensate IRP and the alternating component of the instantaneous active power of the load. However, that in the presence of the supply voltage asymmetry, even an ideal, unity power factor load has an instantaneous active power with a non-zero alternating component is demonstrated. According to IRP p-q theory-based approach, it should be compensated and this requires that a distorted current be injected into the distribution system. It means that in the presence of the supply voltage asymmetry, the algorithms based on the IRP p-q theory generate a non-sinusoidal reference signal for the compensator control, even when voltages and currents in the system are sinusoidal.