Variable Step Size Adaptive Control for Solar PV-Diesel Generated Based Standalone System

This work presents the control of the synchronous diesel generator (DG) set integrated with the solar PV power plant (SPVP) during the variation in solar insolation and the nonlinear load. In this work, the DG set power factor is controlled at unity by controlling the SPVP's reactive power equal to the load's reactive power. Moreover, the SPVP is controlled to supply the negative sequence currents and harmonic currents at the point of common coupling (PCC) so that the DG set currents remain balanced if any nonlinear or unbalanced currents are drawn by the loads. The DC link voltage remains constant throughout the system's operation irrespective of solar insolation and load variations. In this work, an improved variable step-size (VSS) normalized least mean square (NLMS) adaptive filter is used to estimate the fundamental component of the nonlinear load currents. To extract optimum power from the SPV array, the VSS perturb and observe (P&O) algorithm is utilized. A detailed simulation study is conducted to present the work's effectiveness.