Real-time performance evaluation of two-quadrant z-source DC-DC converter for DC drive

Abstract

This paper contributes to real-time performance evaluation of two-quadrant z-source DC-DC converter drive for industrial application. Regulating the switching duty ratio of the converter produces the desired output voltage level. Z-source DC-DC converter has additional qualities over a traditional buck-boost converter such as higher boost factor at low switching duty ratio, more reliable, inherent short circuit protection and impedance network that behaves as a second-order filter. Z-source converter-fed separately excited DC-drive model is developed in MATLAB/Simulink and executed in field programmable gate array (FPGA)-based real-time digital simulator (RTDS) at fixed-time step of 10 μs and the constant switching frequency is 5 KHz. The real-time simulation results present the real-time performance of the z-source converter-fed DC-drive system during motoring and regenerative braking mode. Small signal analysis is done using state space averaging approach to design a suitable controller for closed-loop drive system. A laboratory-based low voltage hardware prototype of z-source DC-DC converter system is developed utilising a real-time digital simulator (OP5600) as a rapid control prototype.