Design of High Frequency PWM Inverter as a Part of 100kVA Solid State Transformer


The emergence of high power converters establishes the existed power grid much more dynamic, vibrant than it was ever before. One of the scorching research directions in power electronics field is a Solid State Transformer (SST) which aims at replacing the existing broadly used conventional Line Frequency (50/60Hz) Transformers (LFT).

This research dissertation deliberates a high frequency PWM inverter design for 11kV/ 381V, 100kVA solid-state transformer for a power distribution system application. Half Bridge topology strategy, incorporating less number of switches with reduced losses as compared to full bridge configuration is implemented. This design outpaces and alleviates the predecessors in terms of efficiency and THD measurements. The mathematical analysis and computer simulations are carried out to design the proposed converter. This anticipated design has been premeditated in MATLAB/SIMULINK environment for effectiveness of study and performance measures. The use of medium frequency transformer has contributed in efficiency rise of the proposed converter in comparison with its predecessors. The input DC voltage is shared firstly by two capacitors in this arrangement; leading to the reduction of cost. Apart from SST applications, the proposed inverter topology can be used in a number of industrial applications with small modifications.

A radical structure for fabrication of three phase 15KV high frequency PWM inverter, incorporating high voltage capacitors, IGBTs and medium frequency isolation transformer in half bridge topology perspective for 100 KVA three phase SSTs in energy distribution system has been anticipated. It is also apprehended in hardware laboratory for a half-bridge configuration in downscaled values, where it revealed that these experimental results are consistent and demonstrate good agreement, covenant with the simulation fallouts and confirm the reliability of the inverter. From the measurement, the efficiency of the proposed inverter is found to be at 98% average with reduced THD.

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