Simulation and Construction of a High Frequency Transformer-Based Inverter for Photovoltaic System Applications

Aims: To simulate and construct a single phase, pure sine wave inverter using a high frequency transformer.

Study Design: Experimental design through simulation studies using pulse width modulation and proportional integral controller.

Place and Duration of Study: Department of Physics, Nasarawa State University Keffi, Nigeria, between July 2021 and March 2022.

Methodology: Secondary data from Shenzhen EMPTEK EP1100 PRO manufacturer’s datasheets website was utilized for modelling and simulation of the inverter schematic using PSIM version 12.0.3 software. The system consists of DC source-Link, DC-DC converter, VS full bridge with MOSFET driver, LCL filter, HF transformer, and PI controller. The circuit was constructed at a rated power of 1kW and analysis of the inverter output was carried out over a range of steady state loading conditions.

Results: A fairly good steady state dynamic response was obtained by the system with an output voltage range of 220V to 224V, output current range of 5.02A to 5.51A; all recorded over a range of loading conditions. The highest inverter efficiency was found to be 97.47% at a load of 0.036Ω, while the power delivered by the inverter at this load was 1049.18W. The lowest value of the efficiency, which was 91.79%, occurred at the lowest load of 0.029Ω, and the output power delivered by the inverter at this load was 1172.53W.

Conclusion: The circuit combines the advantage of galvanic isolation and high conversion efficiency which reduces harmonic disturbance resulting from non-linear circuit behavior. The disadvantage of weaker load capacity and impact resistance is greatly improved using the PI controller. It can serve as a good source of alternative power supply for domestic and commercial users especially in Nigeria where the power supply is unstable and unreliable.