Silicon (Si) insulated-gate bipolar transistors are widely used in railway traction converters. In the near future, silicon carbide (SiC) technology will push limits of switching devices three directions: higher blocking voltage, operating temperature, and speeds. The first MOSFET modules available on market look promising. Although they still limited breakdown these wide-bandgap components should improve traction-chain efficiency. Particularly, a significant reduction losses is expected...

This paper highlights the potential of medium-voltage dc electrification for railway traction. A method is proposed determining voltage level in order to guarantee, terms traffic, equivalent performances an ac-electrified line. Railroad type transport service, and network topology being given, analysis takes into account following constraints: at pantograph, heating overhead line rail-to-ground voltage. Once chosen, system compared with a standard 25-kV ac case French high-speed from Paris...

Silicon (Si) insulated-gate bipolar transistors (IGBTs) are widely used in power converters. carbide (SiC) technology will push the limits of switching devices three directions: higher blocking voltage, operating temperature, and speed. The first SiC-metal-oxide-semiconductor field-effect transistor (MOSFET) half-bridge modules (SiC HBM) now commercially available look promising. Although they still limited breakdown these components should, for instance, improve traction-chain efficiencies....

The test and the characterization of medium or high-power electronic converters, under nominal operating conditions, are made difficult by requirement electrical source load. In addition, energy lost during may be very significant. opposition method, which consists an association two identical converters supplied same source, one as a generator, other receptor, can better way to do these test. Another advantage is possibility realize accurate measurements different losses in first part this...

In today's voltage source converter HVDC solutions, insulated-gate bipolar transistors (IGBTs) are used exclusively, generally in module form where the modular multilevel is concerned; this entails a number of protective measures that increase complexity and cost. As we move to higher transmitted powers, use integrated gate-commutated thyristors (IGCTs) would allow both voltages currents while simultaneously reducing losses, failure rates, costs, as paper tries demonstrate by comparing...

Today, in electric railways, the old dc supply systems are reaching their limits. To improve efficiency and increase railroad traffic, a new electrification has recently been proposed at 9 kV. It is now necessary to prepare migration of infrastructure rolling stock, using power electronic transformers (PETs), for adaptation this voltage level. For application, high reduced volume essential. This article clearly demonstrates that it possible achieve compact, high-power, isolated dc-dc...

Today, dc arc furnaces are supplied by thyristor rectifiers. Because of the phase control strategy on rectifiers, voltage swings induce large reactive power variations network and a static VAr compensator (SVC) or synchronous (STATCOM) is always added to avoid flicker effect. In this paper, authors present new which suppresses effect increases furnace productivity. To supply furnace, ac/dc converter based diode rectifiers choppers with constant strategy. Consequently, can operate without...

Silicon (Si) IGBTs are widely used in railway traction converters. In the near future, Carbide (SiC) technology will push limits of switching devices three directions: higher blocking voltage, operating temperature and speed. The first SiC MOSFET modules available on market look promising. Although they still limited breakdown these wideband-gap components should improve traction-chain efficiency. Particularly, a significant reduction losses is expected which lead to improvements...

High-voltage direct current (HVDC) is more and often implemented for long distance electrical energy transmission, especially off-shore wind farms. In this study, a full DC farm, which requires high-power high-voltage DC/DC converter, considered. order to reduce the size of trend increase operating frequency. Silicon carbide (SiC) metal–oxide–semiconductor field-effect transistors (MOSFETs) are becoming industrially available give scope realisation high-performance converters based on...

In this paper, the authors show how high power static converters contribute to voltage quality in railways. The first part of paper gives an overview electronics solutions currently used by French National Railways and Swiss Federal such as frequency converter for 15 kV/16.7 Hz system line booster or unbalance compensator 25 kV/50 system. Operating results devices are presented. second is dedicated future trends railway supply. Innovative concerning DC AC systems proposed. each case,...

In AC rail networks, the new locomotives using four-quadrant rectifiers are responsible for low frequency disturbances on overhead line voltage. recent years, around world, interactions between and power supply have been observed. some sectors of 25kV-50Hz French network, serious affected system operation while flicker was observed upstream electrical network. To prevent such dysfunctions, an analysis method is proposed. Any locomotive or multiple-unit train characterized as admittance...

Nowadays, AC single phase power supply is widely used in railway electrification. To step down the input voltage, rail vehicles should board a heavy and bulky transformer. In recent years, several multilevel topologies including medium frequency transformers were proposed to replace low The objective reduce weight volume on traction drive while increasing efficiency. This paper focuses series-resonant DC/DC converter which well-known indirect structure. An opposition-method test bench allows...

Currently, in electric railways, the old dc supply systems are reaching their limits. In several European railway networks, due to line-voltage drops between substations, there sectors where traffic can no longer increase and locomotives cannot operate at nominal ratings. To improve power capacity, a medium voltage (MVdc) three-wire system with boosters based on imbricated cell multilevel choppers (ICMC) was proposed. order efficiency, authors evaluate potential of new SiC-mosfets this...

Recently, the potential of medium voltage DC (MVDC) railway electrification has been highlighted in literature. Currently, classical systems reach their limits and it is not possible to operate locomotives at nominal ratings or increase traffic. Thus, this paper proposes a strategy for changing system from 1.5 kV 9 DC. A method with an intermediate system, keeping overhead line using feed-wire proposed. In order validate proposed solution real case study on French Railway network considered....

Selective Harmonics Elimination is a high-efficiency modulation method for multilevel inverters that allows handling very high voltage applications. It eliminates the most significant harmonics and fixes desired fundamental component. The main issue of these techniques complex process to obtain appropriate switching-angles, being necessary calculate them offline, meaning if some disturbances occur, system will not be compensated. This article proposes real-time selective harmonic elimination...

This paper presents a new technique in voltage balancing for single-phase railway substations. Using the concept of chopper-controlled impedance, authors study feasibility an active Steinmetz circuit based on ac choppers. The low power losses semiconductor devices make proposed topology interesting alternative to classical solutions such as those source inverters. Design criteria are presented using information obtained from measurements carried out substation French National Railways....

The 25-kV/50-Hz ac single-phase supply is a widely used railway system in France with length of 9,698 km. Overhead lines are supplied by substations drawing power from two phases three-phase utility. They behave as nonlinear and time-varying loads represent one the most important sources voltage unbalance for electricity-transmission network. In case weak networks, operators required to install compensation systems satisfy utility regulations avoid penalties regarding reactive consumption....

To produce cleaner electrical energy, a lot of European countries have decided to develop off shore wind farms. connect these farms the grid, an HVDC link seems be best solution when distance is important. Actually, turbines generate low frequency AC voltage and they are connected line with LCCs or VSCs. The proposed in this paper consists taking out intermediate medium stage farm. For power transmission, DC directly stepped-up by insulated DC-DC converters operating at (10 kHz) order reduce...

On the base of MMC principle, this work considers different topologies sub module (or elementary converter) which make High Voltage AC/DC converter more flexible and easy suitable respect to voltage current levels. A topological study is consolidated extended on three proposed as their employment for structure treated. For each cell, topology advantages limits are discussed in terms voltage. Under SPWM modulation conditions, an analytical approach power losses evaluation used structure....

Nowadays, in railway traction, order to reduce the weight and size of input transformer, several structures using intermediate medium frequency stages are under consideration. The major problem is reach a high switching with voltage devices. In this paper, authors propose soft commutated topology based on dual structure association. losses calculated considering 6.5 kV IGBTs commutation mode.

In this study, a new topology, using AC choppers is proposed for reactive power compensation in 25 kV/50 Hz railway networks. The low losses of these converters compared to other solutions such as voltage-sourced inverters-based STATCOMs, makes approach attractive high-power, single-phase systems A possible solution based on the controlled impedance concept working boost mode and applied substation French rail network. Design method presented end simulation results which confirm performance...

Multilevel converters, like neutral-point-clamped inverters or multilevel choppers, are particularly attractive in high-power applications. Nevertheless, these structures, all switches confronted to commutation stresses caused by their turn-on and turn-off control. Furthermore, the methods balance capacitor voltages control neutral point voltage complex enough. In this paper, authors propose new converters based on series connection of zero-current-source (ZCS) inverter cells parallel...

Nowadays, the typical railway traction chain, which operates under alternative power supplies, includes a heavy and bulky transformer. In order to reduce size weight of input transformer, medium frequency topology, involves switches in soft commutation mode, is proposed. A test bench, based on one elementary stage complete structure, was built. It allows characterizing new high voltage Silicon Carbide devices switching conditions. Switching losses measurements are performed determine optimal...