Synthesis and performance investigation of a digitally controlled three-phase neutral-point clamped bidirectional rectifier

In this study, parameter plane synthesis of a three-phase neutral-point clamped bidirectional rectifier has been performed. The converter involves one outer-loop PI voltage controller and two inner-loop proportional-integral (PI) current controllers for closed-loop control. A D-partition technique has been employed for precise design of the current controllers. The performance of the converter has been evaluated using MATLAB/Simulink software. An experimental prototype of the converter has been developed and the experimental investigation of the converter performance in closed loop has been carried out. DSP -DS1104- of digital signal processing and control engineering (dSPACE) has been used for real-time implementation of the designed controllers. The converter gives a very good performance in steady-state and dynamic state (for rectification as well as inversion modes of operation) using the designed controller parameters.