Extending the operating range of the neuro-computing vector classification space vector modulation algorithm of three-level inverters into overmodulation region

Three-level voltage source pulse width-modulated (PWM) inverters are used in high power industrial drive applications. Operating the converter in the undermodulation range of PWM technique restricts the drive operation in constant torque region. Therefore, an overmodulation strategy to extend the modulation region is essential. This paper is an extension to the operating range of the classification algorithm for the implementation of overmodulation schemes for SVM in three-level converters. Two schemes, depending upon the output voltage level, are developed to continuously increase the output voltage, in a controllable manner, up to the maximum attainable value. The technique requires less computational time, when compared with conventional SVM methods. The mathematical analysis is verified by means of simulation results.