Measuring and reconstruction algorithm based on improved second‐order generalised integrator configured as a quadrature signal generator and phase locked loop for the three‐phase AC signals of independent power generation systems

Abstract

In an independent power generation system, the amplitude and frequency of the power generation voltage are easily affected by the fluctuation of the external load and harmonic pollution. The power quality may also be reduced by relatively imprecise measurements. In this regard, a measuring and reconstruction algorithm based on an improved second-order generalised integrator configured as a quadrature signal generator (SOGI-QSG) and phase locked loop (PLL) for three-phase alternating current signals has been proposed in this study. The amplitudes and direct current components of the measured signals are obtained from three SOGI-QSGs. The inverse function of sine is introduced to optimise the phase error that has been used to quickly acquire fundamental frequency and phase of the measured signals. Moreover, the phase sequence of the measured signals is determined by the sign function. Compared with a traditional dual second order generalised integrator PLL, quick responses and reconstruction performances of the proposed algorithm are validated by experiments.