A Modulation Technique to Reduce Switching Losses in Matrix Converters
ABSTRACT This paper presents a modulation technique based on the generalized pulsewidth-modulation strategy for matrix converters. The proposed technique uses a discontinuous modulation to clamp each output leg of the converter during 120deg of the output voltage period, achieving a reduced number of switchings compared with the traditional modulation techniques. Aside from that, the major attraction of the proposed technique is an additional algorithm that lags the clamping of each output leg of the converter to synchronize it with the peak of the corresponding output current (load current), avoiding high switching losses (switching at high currents). Therefore, this technique reduces the number of switchings as well as guarantees only medium and low current switchings. Simulation and experimental results show the efficiency of the proposed technique.
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ABSTRACT: This study presents an input filter resonance mitigation method for an AC-DC matrix converter. This method combines the advantages of the one-cycle control strategy and the active damping technique. Unnecessary sensors are removed, and system cost is reduced by employing the grid-side input currents as feedback to damp out LC resonance. A model that includes the proposed method and the input filter is established with consideration of the delay caused by the actual controller. A zero-pole map is employed to analyze model stability and to investigate virtual resistor parameter design principles. Based on a double closed-loop control scheme, the one-cycle control strategy does not require any complex modulation index control. Thus, this strategy can be more easily implemented than traditional space vector-based methods. Experimental results demonstrate the veracity of theoretical analysis and the feasibility of the proposed approach.Journal of power electronics 07/2014; 14(4):778-787. DOI:10.6113/JPE.2014.14.4.778 · 0.75 Impact Factor
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ABSTRACT: This paper presents a novel topology for a direct ac–ac power converter, called as the "three-to-k" phase matrix converter. The input to the proposed matrix converter configura-tion is a three-phase fixed voltage and a fixed frequency supply from the grid. The output is a variable voltage and variable frequency ac supply of any number of phases (k phase). However, the discussion is limited here for a k that is equal to odd number of phases. As an example, a "three-to-five" phase matrix converter is utilized for discussion and analysis. This paper also proposes two pulsewidth modulation (PWM) control techniques for the general topology of the "three-to-k" phase matrix converter. This is based on the so-called direct duty ratio PWM (DPWM). In one presented technique, the output voltage is limited to one half of the input volt-age. For the other proposed scheme, the output voltage is enhanced to 78.86% of the input voltage. The proposed control algorithm is validated using simulation and an experimental approach. Index Terms—AC–AC power conversion, direct duty ratio, multiphase, pulsewidth modulation (PWM).IEEE Transactions on Industrial Electronics 01/2011; 58. DOI:10.1109/TIE.2010.2098373 · 6.50 Impact Factor
Conference Paper: Matrix Converter Applied to Energy Saving for Street Lighting Systems[Show abstract] [Hide abstract]
ABSTRACT: This work presents a three-phase AC-AC converter, with independent phase control, based on matrix-converter structure. This converter is applied to electrical energy saving on the public lighting systems by means of regulation and control of the voltage applied to the lamps. The developed converter represents a technological improvement with respect to the traditional systems based on an autotransformer: it reduces system cost and volume, and increases lamps lifetime.MELECON 2010 - 2010 15th IEEE Mediterranean Electrotechnical Conference; 05/2010