Study on coordinate control strategy for photovoltaic generation and hybrid energy storage system

A novel coordinate control scheme for battery and super-capacitor energy storage device used in the stand-alone photovoltaic (PV) power generation system is presented in this paper. The stand-alone PV power generation system is composed of PV arrays, battery charging and discharging circuit, super capacitor charging and discharging circuit. PV arrays provide energy for the load, excess and insufficient energy is dynamically adjusted through controlling the charge and discharge of the energy storage device. The super-capacitors absorb the high-frequency components of the PV output power and can quickly provide the instantaneous power under abrupt load variation. The key of the system energy management is to control the inverter and bidirectional DC-DC converter working in the suitable mode according to analyzing droop characteristic of DC bus voltage and Real-time charging and discharging power. Simulation and experiment results show the validity and effectiveness of the proposed energy management control strategy.