Investigation And Design Of Appliance Singe-Phase Photovoltaic Inverter System

Recently, as the fossil fuel exhaustion and environmental pollutions are intensified, a kind of new and promising renewable energy, photovoltaic(PV) sources is abundant all over the world, don’t generate environmental pollution and very economic. so the needs for solar energy have grown and used in many fields. The PV power generation systems produce electric power by PV batteries transforming solar radiations into electricity. In order to investigate a set of photovoltaic inverter system suitable for miniwatt household appliances, spreading photovoltaic technology over the domestic life and fully realize a well-off society.This system uses a STM32F103VC signal-chip microcomputer as a core processor, its’ inverter’s topology-loop structure implement a hybrid of DC-AC-DC-AC topologies. This photovoltaic inverter system is a multiple-stage boost inverter which consists of pre-stage full H-bridge converter, a small size transformer which operates at high frequency, H-bridge rectifier filter, the last stage H-bridge converter. But new alternatives differ from classical topologies control ways, the power switches of former full H-bridge converter are controlled so that produce half sinusoidal wave, then the last stage H-bridge converter switch at the50Hz rate to unfold the waveform to flip one half of it to negative.This photovoltaic inverter system is based on stm32f103VC, while it takes the12V DC from the solar panels and converts it to220V/50HZ singe-phase AC which is the power that most of household appliance use. So carry out the main works as follow.(1) Deeply presents the main topologies of solar inverter, fully comparative introduce the working principle and performance of three converter topology which are push-pull converter, Full-bridge converter and Half-bridge converter. This paper propose to use the Full-bridge converter.(2) Detailed analyze the various control strategy of SPWM technique to produce SPWM waves, takes out main principle and mathematics model of regular sampling, irregular sampling, average symmetry sampling SPWM method. According to the design requirements and highly efficiency energy, this paper suggest to use a old technique which is look-up table procedure.(3) Tell about the solar inverter’s hardware and software main portion design and method. High voltage section of the inverter tends to produce a large number of interference signal, then string into the low voltage control circuit affects signal processing, so the hardware is divided into two printed circuit board. The low voltage board is the inverter control board, the high voltage board is the inverter power board. In order to use solar energy effectively and improve the efficiency of the system, software part adopts the maximum power point tracking technology to make solar panels working in the maximum power range.(4) This design is given to test the research by industrial site and discuss the problem appeared on the experiment.