Abstract
The major purpose of this thesis is to develop a prototype photovoltaic system interconnected with the power grid. The major contributions are three folds. First, a new implementation of maximum power point tracking (MPPT) controller is proposed. The method not only can achieve instantaneous response instead of using the traditional perturbation and observation method with slow response but also can be operated without the temperature effect. Second, rather ideal soft- switching circuits are adopted in the converter and the inverter of the proposed system respectively to reduce the switching loss, electric stress and EMI. Finally, a prototype with a bi-directional power flow inverter is implemented and tested. Some experimental results are presented in the thesis.