Solar energy is one of the widely used renewable energy at the moment. Solar photovoltaic (PV) modules are usually used to harvest and convert solar energy into direct current (DC) electricity. In order to supply standard alternating current (AC) electrical appliances, a DCAC electrical power conversion stage is needed. A single PV module usually generates low output DC voltage. Conventionally, the DC output voltage of the PV module is firstly inverted to AC voltage using a H-bridge inverter before it is filtered and stepped up to AC mains level using a power transformer. However, the need of the AC mains power transformer makes such conversion stage rather bulky and costly to build. Another approach is to boost the PV module output DC voltage up to 380 V before it is inverted toAC mains level voltage using an H-bridge inverter. While a power transformer is not needed, a DC-DC converter with high voltage conversion gain is required in the second approach. To achieve a high voltage conversion gain, a conventional boost converter must be operated at high duty cycle. However, the performance of conventional boost converter operating at high duty cycle is likely to be degraded due to the parasitic effects in the circuit. In this thesis, an alternative boost conversion topology based on voltage lifting technique is employed to provide the high voltage conversion gain. The output DC voltage of the proposed boost converter is inverted to AC voltage using a H-bridge inverter. A LC filter is then used to filter the higher order harmonics of the H-bridge's output voltage so that a sinusoidal AC output voltage is produced. The performance of the single-phase DCAC conversion stage employing the proposed boost converter has been modelled and evaluated using PSIM software. Simulation results show that the single-phase DC-AC conversion stage is able to produce an AC output voltage of240 VRMS without requiring a power transformer. A prototype which consists of the proposed Re-Lift Luo converter, a sinusoidal pulse width modulation (SPWM) controlled H-bridge and a LC filter has been developed and tested. The experimental results show that the DC-AC conversion prototype is able to produce near to sinusoidal AC output voltage waveform.
