A 24-hour operational single-phase quasi-Z-source photovoltaic power system

Battery energy stored single-phase quasi-Z-source inverter photovoltaic (BES-qZSI-PV) power system shows many advantages in comparison with other tri-port inverter-based PV power systems. However, the existing BES-qZSI-PV power system does not work at night or cloudy day because of its circuit limitation. This paper proposes a 24-h operational BES-qZS-PV system by the following approaches: (1) the main power circuit is proposed for the day and night operation; (2) the detailed circuit models including the DC model and the second-harmonics ripple model are built by considering scenarios of day and night operations; (3) the design method of quasi-Z-source network parameters is proposed to meet the requirement of day and night operations; and (4) the control strategy is proposed to achieve the high-performance system operation all the time and seamless transition between day and night operation. After theoretical modeling and analysis, the built models are verified by comparing their calculation results with the circuit-based simulation and experimental results. The proposed single-phase BES-qZSI-PV power system is tested; experimental and simulation results are captured when the system operates in day, night, and transition to validate the proposed 24-h operational BES-qZSI-PV system.