Design And Realization Of High-Power Hybrid Wind And Photovoltaic Generation Independent Power System

Energy crisis and environmental pollution becomes more and more serious after entering 21 Century. Wind energy and solar energy, which has many properties such as pollution-free, radiation-free, clean, safe and sustainable developmental, are natural and green. Effective utilization of new energy has become hot research subject of the whole world. The area which far away from power grid, such as farmers and herders settlements, communication base station, frontier sentry, expressway monitor station, forest fireproof monitor station, and field research station, they all need standalone power systems. It is worth noting that there are rich wind and solar energy in those areas. With increasing of the policy and fund support and wind and solar power generation technology, generation cost has continuously decreased. Hybrid wind and photovoltaic generation stand-alone power system can provide low cost and high reliable power supply for those remote and undeveloped areas, so it has become the optimal selection of power supply problem in those areas.Hybrid wind and photovoltaic generation stand-alone power system,which use the complementarities of wind and solar energy, provide stable power through the intelligent control system. Hybrid wind and photovoltaic generation stand-alone power system consists of independent wind turbines, solar panels square, battery, intelligent control system and inverter. Intelligent control system needs to convert wind and solar energy to a stable DC battery charging, control battery to supply the load, and supply the intelligent protection of every parts of the system. Immaturity of intelligent control technologies is the biggest obstacle of hybrid wind and photovoltaic generation stand-alone power system. In this paper, a method of designing and realizing the system is provided, which focus on intelligent controller design and implementation. There are three main contents in the paper:1) Design intelligent controller of wind and solar hybrid generation system in accordance with the requirement of modular structure. Accord to the function of controller, It is comprised of four key modules, including rectifier and filter module, DC-DC converter module, intelligent control center module and the auxiliary and status display module. This thesis introduces design of modules and choosing of key components. The same as controller, the design of controller software also follows modular structure, which makes the generation system easy to maintain and expand, also extends the system's application. This thesis also provides the main Experimental results.2) This thesis presents a three-phase dual-voltage rectifier technology, based on the analysis of the existing three-phase full-bridge and two-phase dual-voltage rectifier technology. Compared with the existing rectifier technology in the situation that wind turbine supply the same output, it reduces the rectifier and filter output DC voltage fluctuations and the same time improves the utilization wind turbines effectively.3) This thesis presents an intelligent current sharing technology based on MCU, which estimates battery charging status by detecting the charging voltage and each DC-DC module charging current by the A/D port of the MCU, then, adjusts the duty cycle of the PWM of each module to realize current sharing and charge control based on the average current theory, according the analysis of parallel redundancy DC-DC converters and three-stage battery charging simultaneously. The method, which makes the hardware circuits simple and low system cost, can meet the requirements of the parallel redundancy DC-DC converters and three-stage battery charging simultaneously, and can effectively improve system reliability and extend battery life.