Design and Implementation of 500W Remote Controlled Transformer-Less Solar System

Abstract

Over 70% of the inverter systems are designed with transformers which are galvanic isolations. However, such inverters are big, heavy and expensive with low efficiency. In this work, a transformer-less PV system is introduced. It is smaller, lighter, and cheaper with higher efficiency as compared to the transformer of the same rating. The proposed inverter employs push pull circuit, an H bridge circuit, the oscillating circuit, an automatic changeover dual battery bank and an RF remote control circuit unit. The switching technique of the proposed inverter consists of a pulse width modulation system along with grid synchronization condition. As the suggested method is entirely transformer-less, there is a reduction in transformer loss which tremendously reduces the total harmonic distortion (THD) to even less than1% with an assumption of; inductor is ideal without any internal resistance, the switches and diodes are ideal with the dead line between the switches are neglected. A filtering capacitor provides a nearly constant output current which stabilizes the system rapidly and reduces harmonics generated by the switching circuit. Overall performance of the proposed inverter was simulated with PROTEUS and validated with MATLAB which produced a pure sinusoidal waveform as the output voltage. The proposed inverter minimizes size and increases the inverter efficiency to 90% which can be used in our homes, offices and schools for lightening and charging.