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An increased research effort on the topic of unity-power-factor rectifiers has been lately noticed. In this paper two highly efficient three-phase buck-type unity power factor rectifiers are proposed to be studied: the conventional six-switch (single-stage) and its two-stage version, referred as the interleaved six-switch solution. They are in here compared in terms of efficiency and performances...
A modular multi-level converter (MMC) is composed of many sub-modules (SMs). Each SM needs a power supply to drive insulated-gate bipolar transistor (IGBT) and control power. The MMC system has a power of 100MW, a dc link voltage of 250kV, and a total of 125 SMs. This means that each SM has a rated input voltage of 2kV. This high input voltage should be converted to low load voltage by the power supply...
The impending trends in the global demand of more-electric-aircrafts with higher efficiency, high power density, and high degree of compactness has opened up numerous opportunities in front of avionic industry to develop innovative power electronic interfaces. Traditionally, passive diode-bridge based transformer rectifier units (TRU) have been used to generate a DC voltage supply from variable frequency...
In this paper, a comparison of power losses in the conventional single-phase-to-three-phase and singlephase half-bridge plus two-leg three-phase AC/DC/AC PWM converters for low power applications is presented, in which the conduction and switching losses of each semiconductor device are taken into account. Power losses of the two converters employing devices of three different manufacturers are evaluated...
With the rapid penetration of photovoltaic (PV) grid-connected system in industrial and commercial application, it is critical to improve the efficiency and enhance the utilization of PV power generation system. This paper proposes a flexible five-level topology based on cascaded multi-level inverter for PV grid-connected system. By adding a bidirectional switch to conventional multi-level inverter,...
This paper proposes a novel topology of submodule (SM) for the modular multilevel converters (MMC) applying to the high-voltage DC (HVDC) transmission systems, where the DC-fault current due to the freewheeling effect of the diode rectifier is blocked during a short-circuit fault in the DC cables. An additional insulated-gate bipolar translator (IGBT) with a low voltage rating is required to be connected...
This study presents a new Sag Swell Generator (SSG) topology to generate several power quality problems such as sag, swell and interruption. In this paper, bridge type bidirectional switch based SSG is presented to generate different fault conditions. The main contribution of proposed topology is to provide low-cost and simple solution compared to conventional transformer based SSG topologies. The...
Doubly fed induction generator (DFIG) based wind turbines have been dominating wind market in the past decade, due to the better balance between variable speed operation and the drive converter size in terms of the unique drive topology. However, the difficulties of low voltage ride through (LVRT) fulfillment are threatening this type of turbine technology, out of the limits of current and voltage...
Nowadays there are several modulation techniques to control multilevel power converters. In this paper it's shown an implementation of the nearest level modulation for a six-level modular multilevel converter. The use of this modulation is a very interesting option when the number of submodules is large because of the complex of this modulation is independent of the number of levels. The implementation...
This paper proposes a new inverter topology based on the operation of C□uk converter for single-phase transformer-less grid connected photovoltaic system. In this topology, since the grid neutral is directly connected to the negative terminal of the photovoltaic (PV) array, there is no common mode voltage variation across the parasitic capacitance of the array and the leakage current is eliminated...
The proposed Second Target Station (STS) increases the beam energy at the SNS to 1.3 GeV by adding 7 additional cryomodules (28 cavities) to the end of the existing linear accelerator. To achieve the required gradients, these cavities will be powered with up to 700 kW peak power utilizing upgraded 550 kW klystrons. To meet the additional peak power needs, an enhancement to the present High Voltage...
The preliminary results from a bipolar industrial solid-state based Marx generator, developed for the food industry, capable of delivering 25 kV/250 A positive and negative pulses with 12 kW average power, are presented and discussed. This modular topology uses only four controlled switches per cell, 27 cells in total that can be charged up to 1000V each, the two extra cells are used for droop compensation...
Fast capacitor charging is a power electronics application with unique challenges requiring both low voltage, high current operation and high voltage, low current operation from the same system at different points in the charge cycle. Such dynamically differing operating points create distinct challenges in obtaining high efficiency throughout a charge cycle. In addition, the power supply must be...
CEA is working on a solid state pulse modulator to drive an electron gun, source of an RF accelerator. The application requires square pulses in the range of 140kV (1% flat top), 10A, 150μs width, at a repetition rate of 50Hz and a reproducibility pulse-to-pulse better than 10−3. This modulator is based on a Marx topology which employs standard 1700V IGBTs and diodes to control the charge, discharge...
The paper, after an overview of the typical requirements of Power Supply (PS) systems to control MagnetoHydroDynamic (MHD) instabilities and of technological solutions adopted in some present fusion experiments, reports on the last progress in the production of SiC power devices, which features can be interesting for this type of applications. The advantages of the SiC devices with respect to the...
High performance operation of high-speed electric machine leads to a demand on high switching frequency, which results in inverter heating, short lifespan, large heat sink, etc. In this paper, high-speed permanent magnet synchronous machine drive with IGBT based three-level T-type inverter (3LT2I) and two-level inverter are investigated and the losses in the machine and inverter are compared. A 200kW...
The aim of this paper is to compare the maximum achievable output current of the Neutral Point Clamped (NPC), Active NPC (ANPC) and Neutral Point Piloted (NPP) Voltage Source Converters (VSC), in a wide range of operating points, by simulating theses converters with 4.5kV, 1.2kA IGBT modules. The maximum currents are limited by the junction temperature of the most stressed semiconductors in a defined...
This paper proposes a dc/ac converter topology where each phase leg comprises a conventional series switch valve in one arm and a series connection of half-bridge chopper cells in the other arm. Operation with trapezoidal modulation is analyzed where the half-bridge modules have a reduced footprint and silicon area compared to standard modular multilevel converter modules. Furthermore, no arm inductance...
IPT technology has been increasingly used in EV charging systems. However, fast charging using IPT technology is still a concern due to high-power high-frequency operation. This paper presents a low cost modified MOSFET-IGBT multi-level converter that is suitable for high power and high frequency IPT systems. The proposed converter with a reduced number of switches can be employed on both sides of...
This paper proposes a novel switching strategy for high efficiency of a single-phase three-level inverter. Normally, the conventional unipolar and bipolar switching methods are used in the single-phase three-level inverter. In comparison with two conventional switching methods, the proposed switching method, which keeps switching state of some switches for switching period, is advantageous in efficiency...
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