A Low Power Photovoltaic Generation Systems

Shortage of energy sources and pollution of environment are becoming more and more serious in modern world. Human awareness of the importance of protecting the global environment is growing. Scientists are expected to search for new energy sources that can substitute conventional ones. Photovoltaic source is renewable energy, which is pollution-free and inexhaustible. Photovoltaic generation has made great strides in all sorts of technologies of utilizing solar energy. This paper presents the boost circuit and the inverter circuit of a low power PV system.The first part of the work is designing a DC-DC circuit. Experiments are conducted for the isolation type and the non-isolated type circuits. Considering the high voltage ratio, the small cubage advantage of non-isolated type is not incarnated. Therefore, we choose the isolation type circuit. Build boost circuit on foundation of the push-pull forward inverter based on high-frequency link technology , wrap the high-frequency transformer, the control signal is produced by SG3525. The second part is a single-phase full bridge inverter circuit (DC-AC), this part is controlled by DSP TMS320LF2407, the modulation mode is sinusoidal pulse width modulation (SPWM), a PI method is used to control the output voltage. The hardware work is based on the exploring of TMS320LF2407, then design a isolation and driving circuits with 6N137 and IR2110. For the software design, using the compare register of DSP to produce the SPWM signal with dead time. PI control algorithm is used to keep the output voltage according to the feedback voltage.Final, an experimental board is produced successfully, and the experimental waveforms are obtained by Tektronix oscilloscope. The results prove the correction and applicability of the schemes.