Research On Control Strategy Of Grid-connected Inverter Of UPS And PV Hybrid System

Because of its inexhuaustible and environmental protection, photovoltaic power generation become the main trend. with the development of science and technology, variety of advanced electronic products has penetrated into society, because of its high-quality power supply for the electrical equipment, double conversion UPS has been widely applied.But both have short comings. for example:photovoltaic have low utilition rate,because its only during good weather conditions can work. The new double conversion UPS can improve the current harmonics and power factor. But its former PWM rectifier has not been fully utilized;Other, the support time of UPS is its insurmountable disadvantages.For the lack of both,base on analysis of their respective topology, working principle and control strategy, by sharing a network-side converter fuse the two together to build a new power supply system. This system have photovoltaic and double conversion UPS two functions, improve the equipment utilization; it is possible to extend the operating time of UPS when power outage; cost savings by eliminates an inverter.The topic of the working principle of the new system were analyzed,focus on the research of the network side PWM converter control strategy and the PV array maximum power point tracking algorithm. Network side PWM converter uses double-loop structure. Outer voltage uses feedforward compensation and output voltage feedback PI control.Current inner uses sliding mode control. Using an improved fuzzy control algorithm for the traditional fuzzy control MPPT does not condider changes in the pulse width of the PWM inverter. And do the appropriate research of battery management system, hardware and software of core components design and other technical.Finally,do simulation for three-phase voltage-type PWM converter system and photovoltaic MPPT algorithm by Matlab7.1. By model building, waveform analysis to validate the PWM inverter control strategy can stabilize the DC voltage and the AC side with unity power factor operation. The improved fuzzy control algorithm can track MPPT more quickly and enhance the stability of the system.