A three‐phase inverter circuit using half‐bridge cells and T‐NPC for medium‐voltage applications

This paper presents an original method of power loss validation in medium-voltage SiC MOSFET (metal–oxide–semiconductor field-effect transistor) modules of a three-phase inverter. The base of this method is a correct description of the on-state performance of the diodes and the transistors in a PWM (pulse width modulation)-controlled inverter phase leg. Combined electro-thermal calculations are applied to precisely estimate the losses in the power devices and then, to find the suitable circuit parameters of a test circuit to emulate these conditions. A simple square-wave-controlled half-bridge with an inductive load enables the electrical and thermal stresses comparable to these in the inverter, and moreover, provided equations that confirmed the possibility of balancing the load between the diodes and the transistors. The circuit with 3.3 kV SiC MOSFETs was tested to verify the impact of selected parameters on power losses with the main focus on duty ratio. The same module was applied, in addition to an inductive load (3 × 112 μH) and two sets of DC-link capacitors (750 μF), to validate a phase leg of a 220 kVA inverter. In spite of a significantly apparent power, the active power delivered from the DC supply settled around 1 kW, which was enough to emulate 390 W of losses in two transistors and diodes.

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Power Loss Analysis Model of a Dc-Dc Buck-Boost Converter with an Interfaced Three Phase Inverter for Medium Voltage Application

Journal of Asian Scientific Research ◽

10.18488/journal.2.2019.98.100.115 ◽

2019 ◽

Vol 9 (8) ◽

pp. 100-115

Author(s):

Crescent Onyebuchi Omeje

Keyword(s):

Power Loss ◽

Boost Converter ◽

Analysis Model ◽

Phase Inverter ◽

Medium Voltage ◽

Loss Analysis ◽

Three Phase ◽

Voltage Application ◽

Three Phase Inverter

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Three-phase inverter circuit PWM controller which is based on CPLD

2011 Second International Conference on Mechanic Automation and Control Engineering ◽

10.1109/mace.2011.5988049 ◽

2011 ◽

Author(s):

Qiong Wu ◽

Liyu Tao ◽

Ming Zhang

Keyword(s):

Phase Inverter ◽

Three Phase ◽

Inverter Circuit ◽

Three Phase Inverter

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Multi-Mode Voltage Sag/Swell Generator Based on Three-Phase Inverter Circuit

Energies ◽

10.3390/en14206520 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6520

Author(s):

Qiguo Han ◽

Xing Wang ◽

Pengfei Hu ◽

Maolin Wang ◽

Xu Luo ◽

...

Keyword(s):

Low Voltage ◽

Power Grid ◽

Thermal Power ◽

Voltage Sag ◽

Phase Inverter ◽

Grid Voltage ◽

Three Phase ◽

Inverter Circuit ◽

Three Phase Inverter ◽

Multi Mode

The voltage ride through capability of the major auxiliary variable-frequency drive (VFD) in large thermal power plants is the key technical issue of power grid and source coordination. In order to test the high voltage ride through (HVRT) and low voltage ride through (LVRT) capability of the auxiliary VFD, it is necessary to develop a power supply to simulate different grid voltage sag and swell accurately. In this paper, a generator (VSSG) based on the common three-phase inverter circuit that can simulate multi-mode voltage sag/swell is proposed. The designed main circuit consisting of transformer, rectifier, DC split capacitors, three-phase inverter, and LC-filter can generate single-phase and three-phase voltage sag, swell, and phase angle jumping flexibly. The developed control strategies composed of the double closed-loop control and the neutral voltage balance control achieve accurate output, fast dynamic response, and step-less adjustment. Simulation and experiment results verify the multi-mode voltage simulation performances of the proposed VSSG, which can be effectively used to emulate power grid voltage sag and swell phenomena under the IEEE 1159 and IEC standards.

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