Limitations of cross vector generalized p-q theory

This paper investigates the limitations of Generalized Instantaneous Reactive Power p-q Theory introduced by Peng et al, which is referred to as the Cross Vector p-q Theory. The theory, which applies to four wire systems, is shown to contain mostly the same limitations as the original instantaneous reactive power theory, namely that the instantaneous active current is not the lowest rms current in all circuit conditions and could contain higher levels of harmonic distortion than the supply voltage. Also, most recommended compensation strategies based on the theory require the supply voltage to be approximately sinusoidal and symmetrical to avoid erroneous compensation. Under these conditions, the compensation strategies produce the desired results. However, they require calculation of average power which is not instantaneous, and energy storage is necessary if the oscillating component of instantaneous power is compensated.