An Active Power Management to Prevent Reverse Power Flow and ITOAGI-PLL Control to Enhance Power Quality in SyRG DG-PV Standalone System

Abstract

An active power management strategy for preventing reverse power flows and DC link overshoots/undershoots for a diesel engine driven synchronous reluctance generator (SyRG) and solar photovoltaic array (SPVA) based standalone system is presented in this paper. The SPVA is controlled via a conditional derated perturb and observe (CDP&O) maximum power point tracking (MPPT) algorithm. The load is categorized into emergency and auxiliary loads. The DC link voltage is maintained constant, and the system remains operational and feeds power to the loads in extreme conditions. To enhance the power quality of the standalone system in presence of nonlinear loads, this paper also presents an improved third order adaptive generalized integrator (ITOAGI) with a phase-locked loop (PLL) based control algorithm. The control makes the system adaptive to the frequency of the DG voltages during sudden frequency due to changes in loading conditions. The control utilizes the voltage source converter (VSC) of the SPVA to compensate for the unbalanced and harmonic current components to maintain the SyRG DG set currents linear and distortion-free as per the IEEE std. 519. The system Simulink model is used to simulate the performance of the standalone system in steady-state and various dynamic conditions during day and night time.