Design and Implementation of 6 kW Three-Phase T-Type Inverter for Microgrid Application

Abstract

This paper proposes the design and implementation of a digital controlled three-phase three-level inverter using T-type topology. The advantages of this topology are reducing components usage, minimizing the devices stress, and resulting lower output voltage Total Harmonic Distortion (THD). This design employs a high-performance TMS320F28335 Digital Signal Processor (DSP) from Texas Instruments. The chip is powered with Floating Point Unit (FPU) feature for processing three-phase controlled algorithm. The proposed modulation strategy is Carrier-Based Pulse Width Modulation (CBPWM) that can be implemented with a very simple algorithm and fast processing time. In addition, it can generate the highest modulation index up to 1.154 that is feasible under linear modulation, such as Space Vector Modulation (SVM). Finally, a 6 kW three-phase T-type inverter is verified by simulation and experimental result. It can reach 99% efficiency in the full-load condition.