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EPE Journal Volume 21-1 - Papers
- Built-in EMC for Integrated Power Electronics Systems
- A New Soft-switching Technique for CCM Synchronous Buck Converter
- An asymmetric cascaded H-Bridge inverters for generating 12-sided polygonal space vector diagrams for Motor drives
- Current Balancing Strategy for Interleaved Voltage Source Inverters
- Switching Strategies for DTC on Asymmetric Converters Driving Induction Motors
- Active Filtering of DFIG Stator and Rotor Current Harmonics Caused by Distorted Stator Voltages
EPE Journal Volume 21-1 - Editorial
By Pat Wheeler, Phil Mawby and Colin Oates
It is our pleasure to invite the whole of the Power Electronics Community to the 14th Conference on Power Electronics and Applications, EPE’11, in Birmingham, UK, from the 30th August to the 1st September 2011.
EPE Journal Volume 21-1 - Papers
By Jean-Luc Schanen; James Roudet
Power electronics is today the most common way for electrical power conversion. However, a set of new problems, linked to ElectroMagnetic Compatibility (EMC) arises from the generalization of this very attractive technology: high frequency disturbances, generated from power switching, must be mitigated to avoid the disturbance of the device itself, or its environment. This paper proposes an investigation of several available solutions to reduce the ElectroMagnetic Interferences (EMI) of power electronics devices (power modules and associated interconnections), by using cost free solutions, lying on a proper choice of layout and on the exploitation of some technological properties of the module. Both internal and external EMC will be considered.
By Do Hyun-Lark
A new soft-switching technique for synchronous buck converter is proposed. It utilizes an auxiliary winding of the filter inductor and an auxiliary capacitor to provide zero-voltage-switching (ZVS) of the power switches and maintain a continuous filter inductor current. The reverse recovery problem of the anti-parallel body diode of the synchronous switch is solved. Moreover, it provides a simple structure and shows a higher efficiency compared to the conventional synchronous buck converter. Theoretical analysis of the proposed buck converter and the experimental results obtained on 230 W prototype are discussed.
By K Mathew; Chintan Patel; K Gopakumar; Anandarup Das; Rijil Ramchand
A new topology of asymmetric cascaded H-Bridge inverter is presented in this paper. It consists of two cascaded H-bridge cells per phase. They are fed from isolated dc sources having a dc bus ratio of 1:0.366. Out of many space vectors possible from this circuit, only those are chosen that lie on 12-sided polygons. Thus, the overall space vector diagram produced by this circuit consists of multiple numbers of 12-sided polygons. With a proper PWM timing calculations based on these selected space vectors, it is possible to eliminate all the 6n ± 1, (n = odd) harmonics from the phase voltage under all operating conditions. The switching frequency of individual H-Bridge cells is also substantially low. Extensive experimental results have been presented in this paper to validate the proposed concept.
By Josep Pou; Jordi Zaragoza; Gabriel Capella; Igor Gabiola; Salvador Ceballos; Eider Robles
The parallel connection of inverter legs is a way to increase the output currents and thus, the converter rated power. The connection is made by inductors and a critical issue is to achieve balanced currents among the legs. Circulating currents produce additional losses and stress to the power devices of the converter. Therefore, they should be controlled and minimized. An efficient technique to achieve such balance is presented in this paper. The proposed strategy does not include proportional-integral (PI) controllers and parameter tuning is not required. The exact control action to achieve current balance is straightforward calculated and applied. Simulation and experimental results are shown in this paper to verify the efficiency of the proposed balancing method.
By José A. Restrepo; José M. Aller; Julio C. Viola; Alexander Bueno; Víctor M. Guzmán; María I. Giménez
In this work, the possibilities offered by the additional switching states present in an asymmetric three phase converter (compared with the existing states in the conventional three phase inverter) are studied in order to improve the performance of Direct Torque Control induction motor drives. The proposed algorithms make use of these additional switching states sets in order to increase the operational range of the asymmetric converter and to reduce the ripple in the system variables. Simulated and experimental results obtained for different switching sets are presented and compared.
By Carlos Ramos; António Martins; Adriano Carvalho
Power quality requirements related to renewable energy systems and distributed generation are becoming more restrictive, especially in the total harmonic distortion of the injected grid current. The doubly-fed induction generator is particularly appropriate to be used in wind power generation systems. However, in weak grids its stator connection to unbalanced or distorted voltages not only causes harmonic currents in the stator but also imposes low frequency and high amplitude rotor current harmonics. Also, the grid-side converter must deal with the same voltage conditions. The paper addresses the first issue presenting a voltage harmonics controller in the d-q reference frame to be included in the high dynamics rotor current controller. Simulation and experimental results demonstrate the performance of the proposed controller imposing a sinusoidal input current.