The Research For Photovoltaic Water Pumping System Based On DSP

Facing the increasingly severe energy problem, the development of new energy for achieving sustainable economy, has become the consensus of all the countries. In northwest China the sun is ample, but the groundwater resources is not fully utilized, which seriously affected the quality of life for the people of the region.The development and use of photovoltaic water-pump is an effective way of utilizing light energy,and can also help the people of the region overcome the problem of drinking water. The bottleneck of photovoltaic water pump systems application is too low efficiency, so related research is necessary to improve the control strategy for the efficiency of photovoltaic pumping system. Based on this, the portable low-power photovoltaic water-pump control system with maximum power tracking (MPPT) and variable voltage variable frequency (VVVF) function is discussed on this paper.This paper introduces the high-frequency boost full-bridge rectifier circuit, IPM inverter circuit; the drive circuit with the IR2100S as the core;and control circuit with TMS320F2812as the master chip.The perfect running and fully-digital controlling of three phase asynchronous motor are achieved by (VVVF) control method based on SVPWM. The main content in this paper is:1. The structure of the photovoltaic water pump system is analysed and compared. The structure of the main circuit of the PV water pump is designed.2. Hardware design of photovoltaic water pumping control system is in detail and component parameters are selected.3. The principle and algorithm of SVPWM and the principle of VVVF control is in-depth studyed. VVVF is mainly used for speed control to make the water pump run at high efficiency and make the water pump get more energy.4. The solar cell output characteristic is in-depth studyed. Several commonly used MPPT algorithm is analysed and compared. Combined with its advantages and disadvantages of MPPT algorithm, an improved MPPT algorithm with fixed step size is introduced, which makes maximum power output of the PV array and make the pump motor get more energy.5. The experiment model machine with180W is designed and completed and the experimental waveforms are given.The experimental results show that the system can meet the design requirements.