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It is very important for railway vehicles to have a good braking performance to avoid the phenomenon of idling and skidding, which can be implemented by looking for and keeping an optimal slip ratio. The optimal slip ratio is a value existing in the creep zone of functions between friction coefficient and slip ratio corresponding to the maximum adhesion. Controller based on the sliding mode control...
This paper investigates the utilization of two different six-leg configurations of single-phase to three-phase converters. One of the topologies is transformerless and the other is transformer-based. The drive systems provide both bidirectional power flow and power factor control. Pulsewidth modulation techniques for the converter control are discussed. Simulation and experimental results are provided...
Due to the increasing popularity of renewable energies, a significant share of the power generation in future microgrids is expected to originate from converter-interfaced Distributed Energy Resources (DERs). Traditionally, idealized device models are used to conduct grid stability studies. For instance, a DER interfaced via a Voltage-Source Converter (VSC) would be modeled as an ideal current or...
In this paper the Z-source converter is introduced to power factor correction (PFC) applications. The concept is demonstrated through a wireless power transfer (WPT) system for electric vehicle battery charging, namely Z-source resonant converter (ZSRC). Due to the Z-source network (ZSN), the ZSRC inherently performs PFC and regulate the system output voltage simultaneously, without adding extra semiconductor...
A novel multiple pulse generation of DAB (dual active bridge) converter is proposed based on the auxiliary circuit for realization of complete soft-switching. The proposed auxiliary circuit enables multiple pulse width modulation (MPWM) with soft-switching. MPWM can transfer more power to the secondary side with the less peak inductor current when the output voltage ratio is very different from the...
In order to increase the conversion efficiency in photovoltaic (PV) systems, different configurations and topologies were developed. Depending on the application, the converters used for grid connection are built using one or two conversion stages. The advantages of the converters with a DC-stage are mainly the distributed maximum power point tracking algorithm per PV string, a wider range of operation,...
This paper presents two topologies of three-phase semi-controlled rectifiers suitable to open-end configured ac power sources. The rectifiers are composed by a combination of two-level three-phase bridges (controlled, semi-controlled ou uncontrolled), and three single-phase floating capacitor H-bridges. These topologies generate two powered dc-links, each one belonging to a three-phase bridge. They...
Torque ripple and acoustic noise are two major drawbacks to switched reluctance motors. The abrupt change of phase current is main cause of acoustic noise, while both commutation and current wave shape are two major factors contributing to high torque ripple. In order to simultaneously reduce torque ripple and noise, a specific current modulation based on real inductance profile can be employed to...
The analysis of an isolated single-stage three-phase ac-dc converter with high power factor, based on the modularity of dc-dc SEPIC converters operating in discontinuous conduction mode is presented in this paper. The ac input is star-connected while the output of the modules are series connected. Doing so, the converter can provide a high step-up ratio and, consequently, besides high output voltage,...
In this paper, a new power electronics interface topology for Direct Drive Wind Turbines (DDWTs) to improve the system reliability and with a potential to decrease the size of the Permanent Magnet (PM) generator is presented. In the proposed topology the grid-side Voltage Source Converter in a traditional DDWT is replaced by a three-phase single-stage boost inverter. This enables the use of a low-voltage...
Models of converters based on averaging have been used widely with numerous benefits. Multifrequency averaging (MFA) model can predict both the fundamental and switching behavior of converters and has the faster simulation run times associated with average-value models. Third harmonic injection is commonly used in the modulation signal for three-phase inverters to increase the inverter maximum output...
An improved two-half-bridge cascaded three-level (TL) DC-DC converter with reduced circulating current is proposed in this paper. The converter contains two transformers but without clamping diodes or flying capacitors. The rectifier stage is composed of four diodes and four windings of the two transformers. Because of the proper sequence of the windings, the circulating currents on the primary side...
This paper introduces an isolated step-down impedance control network (ICN) resonant dc-dc converter that utilizes enhanced inverter and rectifier phase-shifts to achieve both soft-switching and output voltage regulation. Compared to previously presented ICN converters, which utilize burst-mode control to achieve output voltage regulation, this ICN converter with the proposed enhanced phase-shift...
This paper evaluates the SuperJunction MOSFET in cascode configuration with a low-voltage silicon MOSFET. The structure combines the good switching performance provided by the cascode configuration with advantages of the silicon technology as the robustness, the maturity and the low-cost. The objective of this paper is to elucidate and to demonstrate the reduction of switching losses of SuperJunction...
This paper compares three possible linear motor topologies for an electromagnetic launch system to assist civil aircraft take-off. Assisted launch of civil aircraft has the potential of reducing the required runway length, reducing noise and emissions near airports and improving overall aircraft efficiency through reducing engine thrust requirements. A comparison is made of practical designs of a...
This paper presents the modeling, performance analysis, and design of an undersea storage system (USS). The USS can be employed for conditioning the output power of wave energy converters (WECs) and floating wind turbines (FWTs) at sea or ocean cites. A mathematical model is developed to describe the governing equations of the USS operation. Next, based on the developed model, a storage system is...
This paper developed models for DM electromagnetic interference (EMI) input filters in AC-DC converters. The models are developed based on the circuit structures and control configurations. The models are developed for feedback, feedforward, feedforward-feedback and feedback-feedforward configurations. The closed loop gains are derived respectively. Based on the closed loop gain models, the open loop...
With increasing demand for higher efficiency, engineers are looking for an alternative solution to replace induction motors (IMs) in many applications. One of the very promising topologies is the permanent magnet (PM) motor with a squirrel cage on the rotor, which is referred to as the cage rotor PM motor in this paper. Based on the literature survey, the cage rotor PM motors have been studied and...
This paper proposes an interleaved hybrid boost converter (IHBC) with simultaneous AC and DC outputs for microsource applications. The proposed IHBC is realized by interleaving two boost converters and replacing the control switch of one of the boost converters with H-bridge voltage source inverter network. The IHBC gives DC and AC output simultaneously from a single DC input and has the property...
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