Control Strategies for 3L-T-Type Inverter in Islanded and Grid-Tied Modes Using Controller-Hardware in the Loop

This paper presents the closed-loop control of a three-level T-type (3L-TNPC) inverter in both islanded and gridtied modes, with a focus on optimizing control strategies using a digital signal processor (DSP) microcontroller in conjunction with controller-hardware in the loop (C-HIL) through space vector pulse width modulation (SVPWM). The study leverages C-HIL to validate control algorithms in a realistic environment. It progresses to a comprehensive simulation phase in MATLAB/Simulink, utilizing proportional-integral (PI) control mechanisms to regulate the converter's operations. Furthermore, a 67 kVA power-rated inverter is evaluated through a C-HIL experimental setup in Typhoon HIL, an advanced real-time simulation platform. The performance of these methodologies is validated across various load types, both linear and nonlinear. The model is also tested in grid-tied mode, delivering 67 kVA of power to the grid at unity power factor (UPF). Additionally, total harmonic distortion (THD) is observed for both modes.