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

Abstract

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.

Three‐phase three‐level one‐cycle controlled bidirectional ac–dc neutral‐point‐clamped converter without having voltage sensors

“…A survey of various control strategies for three-level NPC ac-dc converters indicates that elimination of sensors in three-level NPC ac-dc converter offers the same potential advantages as that obtained in the case of two-level ac-dc converters such as more overall reliability, reduction in system cost, reduction in requirement for isolation between control board and power circuit and better shielding against noise and electromagnetic interference. The sensorless control algorithms for three-level NPC ac-dc converters can be broadly classified into Direct Power Control [13][14][15] and Voltage Oriented Control [15,16] and they are inspired from their counterparts for two-level ac-dc converters, the major difference being the additional functionality to control the neutral point potential.…”

“…By substituting K in (16) and considering the switching time interval to be small, (16) can be approximated as…”

DC‐link current estimation for load‐side converter of brushless doubly‐fed generator in the current feed‐forward control

“…Moreover, the load‐side converter (LSC) controls the DC‐link voltage [4, 5]. The LSC is a three‐phase AC–DC boost converter which usually adopts the double‐loop control strategy with outer voltage loop and inner current loop [6, 7]. In the case of the load disturbance and reference change, the fast response is most important for the stand‐alone BDFG system.…”