The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, a method to limit fault current from DC side short-circuit condition in AC-DC power converters is presented. This approach is based on using Normally-ON SiC-JFETs in series with the DC capacitors as Current Limiting Diodes (CLDs). In this configuration, the gate and source contacts of the JFETs are connected together to make two-terminal devices (Vgs=0). Under a fault condition, the...
Single-phase traction loads generate negative sequence currents, reactive current and harmonics to the power grid. Modular multilevel converter (MMC) is a better alternative to implement railway power conditioner (RPC), which is connected to 25 kV supply system. A MMC with delta configuration is fit for controlling negative-sequence current because circulating currents across delta-connected clusters...
The use of multilevel inverters in Photovoltaic (PV) applications have attracted major attentions in both industry and academic research. This paper presents a PV system based on a single-phase Quasi-Z-Source (QZS) multilevel inverter with a great reduction in number of switches. The introduced inverter is based on a Multilevel DC link (MLDCL) structure and an H-bridge inverter. The MLDCL consists...
This paper presents two new pulse-width modulation (PWM) methods for a high frequency ac-link (HF-link) inverter commutation which uses a form of four-step switching scheme for safe commutation. A HF-link inverter topology enables galvanic isolation and voltage step-up, with a reduced-size transformer, but eliminates the secondary-side rectification so it has less power conversion stages than other...
In this paper, the zero sequence circulating current in open winding (OW) permanent magnet synchronous machine (OW-PMSM) drives with common DC bus is systematically analysed for the first time. It is revealed that the zero sequence circulating current is affected by zero sequence back electromotive force (EMF), cross coupling voltages in zero sequence, from the machine side, pulse width modulation...
This paper presents a triple-rotor axial-flux spoke-array vernier permanent magnet (TR-AFSAVPM) machine to enhance the performance of vernier machines. By cooperating spoke-array rotor and coil-wounded winding, power factor and torque density of the proposed machines are much improved and their copper utilization is reduced as well comparing with conventional vernier machines. Firstly, the machine...
Due to the simplicity and flexibility of the structure of the Second-Order Generalized Integrator based Quadrature Signal Generator (SOGI-QSG), it has been widely used over the past decade for many applications such as frequency estimation, grid synchronization, and harmonic extraction. However, the SOGI-QSG will produce errors when its input signal contains a dc component or harmonic components with...
A new current-fed topology for wireless inductive power transfer (IPT) application using half-bridge circuit is proposed and analyzed. Conventional IPT circuits employ parallel L-C resonant tank/compensation network to transfer power effectively through air-gap. However, in medium power application, this topology suffers from a major drawback that the voltage stress across the inverter switches are...
Insulated Gate Bipolar Transistors (IGBTs) will soon be replaced by wide band gap devices (SiC and GaN) as the choice for power semi-conductor switch in Voltage Source Inverters. These devices have extremely fast rise time and fall time compared to IGBT devices. The high dv/dt of PWM outputs create excessive voltage stress in the insulation system of AC motors due to voltage reflection issues associated...
Unbalanced voltage has adverse effects on power electronic interfacing converters (IFCs) operation such as output power oscillations, DC link voltage oscillations and peak current increase. These adverse effects can be aggregated in parallel IFCs with common DC and AC link, which are commonly used to connect AC and DC subsystems in hybrid AC/DC microgrid or to interface high-power distributed generations/storage...
This paper presents a novel digital deadbeat + repetitive control (DBRC) strategy for output voltage regulation of pulsed power resonant converters used in high energy physics applications. The proposed converter contains three individual series resonant parallel loaded (SRPL) converter arms, which effectively mitigate the influence of resonant tank unbalances on the converter operation. The deadbeat...
In this paper, a new generator-converter system for direct drive wind turbines in order to decrease the capital cost and improve the system reliability is presented. The grid-side Voltage Source Inverter (VSI) is replaced by a single-stage boost inverter. This provides flexibility to design a low-voltage generator and thus decreasing the number poles required in the generator. A 1.5MW generator for...
This paper proposes a new general space vector pulse-width modulation (SVPWM) scheme for multilevel inverters with any voltage levels. The proposed SVPWM scheme calculates the duty cycles and switching states based on the modulation triangle quickly identified through a simple coordinate transformation; no prestored memory-consuming lookup table or time-consuming iterative calculation is required...
Transformer-less PV inverters are gaining widespread applications with lower cost, reduced footprint, and improved efficiency. This paper proposes a topology that can eliminate the common mode leakage current which is a major challenge in transformer-less PV inverters. In addition, an active power decoupling strategy is implemented in this topology instead of using large energy storage element for...
With the increasing penetration of nonlinear loads into distribution system, stable operation of power distribution system suffers challenge by harmonic voltage propagation and resonance amplification which is also known as whack-a-mole phenomenon. However, until now this phenomenon has not been well investigated and discussed. This paper starts from theoretical analysis of harmonic propagation and...
Hybrid Excitation Synchronous Machines allow broad flux regulation, and therefore a very wide Constant Power Speed Range. Literature shows that it is possible to build them both with a Single-Axis and with a Bi-Axial excitation. This paper presents a unified approach for the analysis, comparison and performance prediction of the two structures. Finite element simulation and experimental tests are...
The matrix converter rectifier is an AC-to-DC converter that can be considered for emerging applications, related to smart grids and renewable energy production. The most attractive characteristics of this converter are the simultaneous control of the input power factor and the output voltage, and the small volume of the input capacitors. In this paper, after a small review of the modulation techniques,...
In this paper, modularity concept using standard three-leg converters is addressed. Three-phase cascade converters composed by standard three-leg converters are investigated. They are composed of three, nine, twenty-one or n three-leg converters. It permits to reduce levels of currents and voltages on switches compared to conventional three-phase module or cascaded H-bridge converter. Other advantages...
This paper presents a multilevel universal active power filter (UAPF) topology with nine legs. The proposed system is a combination of two series and one shunt active power filters with a connection series-shunt-series. It is suitable to improve the harmonic distortion in the grid currents and a voltage compensation. The filter is composed of three three-phase converters resulting in nine legs sharing...
Three phase ac drives using a dc link typically feature a significant amount of dc energy storage to maintain a stiff dc bus. This paper examines the concept of reducing the size of the dc link capacitor dramatically, to store just enough energy to provide one high frequency switching cycle of output power. The dc bus is no longer stiff and hence the classical sinusoidal pulse width modulation cannot...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.