Design of Three Phase Solid State Transformer Deployed within Multi-Stage Power Switching Converters

Abstract

This paper presents a symmetrical topology for the design of solid-state transformer; made up of power switching converters; to replace conventional bulky transformers. The proposed circuitry not only reduces the overall size but also provides power flow control with the ability to be interfaced with renewable energy resources (RESs) to fulfill the future grid requirements at consumer end. The proposed solid-state transformer provides bidirectional power flow with variable voltage and frequency operation and has the ability to maintain unity power factor; and total harmonic distortion (THD) of current for any type of load within defined limits of Institute of Electrical and Electronics Engineers (IEEE) standard. Solid state transformer offers much smaller size compared to the conventional iron core transformer. MATLAB/Simulink platform is adopted to test the validity of the proposed circuit for different scenarios by providing the simulation results evaluated at 25 kHz switching frequency.

Keywords

• decoupled controller
• ferrite material
• proportional integral (PI)
• solid state transformer (SST)
• space vector pulse width modulation (SVPWM)
• voltage source converter (VSC)
• voltage source inverter (VSI)