Seamless Operation and Control of Single-Phase Hybrid PV-BES-Utility Synchronized System

This paper presents the control of a single-phase photovoltaic (PV) battery energy storage (BES) based hybrid system with seamless transfer and power quality (PQ) improvement features. The PV-BES based single-phase system provides uninterruptable power to the dedicated nonlinear loads even under utility outage by transferring smoothly to the islanding. Therefore, the smooth transfer from the grid integrated operation to the islanding and vice versa provides high reliability of the system than the conventional system. To control the proposed synchronized system in the grid integrated mode, a learning quantization (LQ) based current control with PV feed-forward (PVFF) loop is used. The LQ current control extracts the net active component of load current. Moreover, PVFF is included in the LQ control to reflect the PV power contribution in the utility, which also improved the fast tracking ability of the proposed control under variable climate conditions. In islanding operation, the load voltage is regulated by the voltage control. The effectiveness of the LQ-based current control for a single-phase PV-BES-utility synchronized system is demonstrated through the simulated as well as experimental results.