Modulation strategies for an open-end winding induction machine fed by a two-output indirect matrix converter

This paper presents a two-output indirect matrix converter feeding an open-ended winding induction machine. The modulation strategy for the converter input stage, which provides the DC voltage for the output stages, exploits the capability of the input rectifier to produce different DC voltage levels. Moreover, this paper includes a space vector modulation strategy for the converter output stages intended to eliminate the zero sequence load voltage. Furthermore, in order to decrease commutation losses, output stage commutation will take place at reduced voltage when load voltage requirements are low. Modulation strategies and overall system operation are verified via simulation in a PSim/Matlab platform with the machine operating under an open loop V/f control strategy. Experimental results are also presented to validate the control strategies

Induction Motors

AC motors play a major role in modern industrial applications. Squirrel-cage induction motors (SCIMs) are probably the most frequently used when compared to other AC motors because of their low cost, ruggedness, and low maintenance. The material presented in this book is organized into four sections, covering the applications and structural properties of induction motors (IMs), fault detection and diagnostics, control strategies, and the more recently developed topology based on the multiphase (more than three phases) induction motors. This material should be of specific interest to engineers and researchers who are engaged in the modeling, design, and implementation of control algorithms applied to induction motors and, more generally, to readers broadly interested in nonlinear control, health condition monitoring, and fault diagnosis

Reduction of output common mode voltage using a novel SVM implementation in matrix converters for improved motor lifetime

This paper presents the study of an alternative Space Vector Modulation (SVM) implementation for Matrix Converters (MC) which reduces the output Common Mode (CM) voltage. The strategy is based on replacing the MC zero vectors by the rotating ones. In doing this, the CM voltage can be reduced which in-turn reduces the CM leakage current. By reducing the CM current, which flows inside the motor through the bearings and windings, the Induction Motor (IM) deterioration can be slowed down. The paper describes the SVM pattern and analyses the CM voltage and the leakage current paths. Simulation and experimental results based on a MC-IM drive are provided to corroborate the presented approach

Improved space vector modulation with reduced switching vectors for multi-phase matrix converter

Multi-phase converter inherits numerous advantages, namely superior fault tolerance, lower per-leg power rating and higher degree of freedom in control. With these advantages, this thesis proposes an improved space vector modulation (SVM) technique to enhance the ac-to-ac power conversion capability of the multi-phase matrix converter. The work is set to achieve two objectives. First is to improve the SVM of a three-to-seven phase single end matrix converter by reducing number of space vector combinations. Second is to use the active vector of the SVM to eliminate the common-mode voltage due to the heterogeneous switching combination of a dual three-to-five phase matrix converter. In the first part, the proposed technique utilizes only 129 out of 2,187 possible active space vectors. With the reduction, the SVM switching sequence is greatly simplified and the execution time is shortened. Despite this, no significant degradation in the output and the input waveform quality is observed from the MATLAB/Simulink simulation and the hardware prototype. The results show that the output voltage can reach up to 76.93% of the input voltage, which is the maximum physical limit of a three-to-seven phase matrix converter. In addition, the total harmonics distortion (THD) for the output voltage is measured to be below 5% over the operating frequency range of 0.1 Hz to 300 Hz. For the second part, the common-mode voltage elimination is based on the cancellation of the resultant vectors (that causes the common-mode to be formed), using a specially derived active vectors of the dual matrix converter. The elimination strategy is coupled with the ability to control the input power factor to unity. The proposed concept is verified by the MATLAB/Simulink simulation and is validated using a 5 kW three-to-five phase matrix converter prototype. The SVM switching algorithm itself is implemented on a dSPACE-1006 digital signal processor platform. The results prove that the common-mode voltage is successfully eliminated from the five-phase induction motor winding. Furthermore, the output phase voltage is boosted up to 150% of the input voltage in linear modulation range