Residential photovoltaic energy storage system

TLDR

The study presents a residential photovoltaic energy storage system that couples a DC‑DC converter with a small battery storage unit and introduces a novel maximum‑power‑point tracking control technique. The system operates by following a daily pattern that balances homeowner load, PV generation, and utility demand, using a state‑averaged model of the converter and PV array to select cost‑effective modes, while the DC‑DC converter and battery are coordinated for power conditioning and active filtering. Experimental results from a 600‑W prototype confirm that the discrete MPPT controller achieves zero‑slope regulation and current‑mode control, demonstrating the system’s effectiveness.

Abstract

This paper introduces a residential photovoltaic (PV) energy storage system, in which the PV power is controlled by a DC-DC power converter and transferred to a small battery energy storage system (BESS). For managing the power, a pattern of daily operation considering the load characteristic of the homeowner, the generation characteristic of the PV power, and the power-leveling demand of the electric utility is prescribed. The system looks up the pattern to select the operation mode, so that powers from the PV array, the batteries and the utility are utilized in a cost-effective manner. As for the control of the system, a novel control technique for the maximum power-point tracking (MPPT) of the PV array is proposed, in which the state-averaged model of the DC-DC power converter, including the dynamic model of the PV array, is derived. Accordingly, a high-performance discrete MPPT controller that tracks the maximum power point with zero-slope regulation and current-mode control is presented. With proposed arrangements on the control of the BESS and the current-to-power scaling factor setting, the DC-DC power converter is capable of combining with the BESS for performing the functions of power conditioning and active power filtering. An experimental 600 W system is implemented, and some simulation and experimental results are provided to demonstrate the effectiveness of the proposed system.