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

Abstract

A three-phase three-level bidirectional ac-dc neutral-point-clamped converter (3 L-NPC) based on one-cycle control (OCC) is proposed in this study. It ensures that the 3 L-NPC converter operates stably during inverting mode of operation. A neutral point potential regulator is also presented which adds a dc offset to the three-phase modulating signals to nullify the deviation in the neutral point potential. First, a one-cycle controlled (OCC) 3 L-NPC converter which requires the sensing of instantaneous phase voltages of the utility is presented. Subsequently, a modified version of the OCC-based 3 L-NPC converter which does not requires sensing of the instantaneous phase voltages is proposed. The modified OCC-based 3 L-NPC estimates instantaneous phase voltages of the source from the pulse width modulation (PWM) switching sequence of the converter. The viability of the schemes is confirmed through a detailed simulation and experimental studies.

Finite‐state model predictive power control of three‐phase bidirectional AC/DC converter under unbalanced grid faults with current harmonic reduction and power compensation

“…In recent years, the use of traditional fossil energy has caused severe environmental pollution. Microgrids are an effective means to connect the power grid and distributed generation [1][2][3][4], which has been widely concerned with improving the efficiency of clean energy. As the key equipment to control power conversion in hybrid microgrids, the reliable and stable work of a three-phase bidirectional AC/DC converter is essential [5][6][7][8][9][10].…”

Hybrid three‐level PWM and resonant converter

“…Introduction: Three-level pulse-width modulation (PWM) techniques [1,2] have been researched for high voltage converters. The main advantages of three-level converters are low switching losses and voltage stresses on power semiconductors.…”