Author(s)

A. I. MASWOOD, S. ANJUM

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The paper discusses the application of PWM delta modulation with PI controller as an alternative to the standard PWM techniques for providing gating signals to the voltage source inverters. Its inherent characteristics of constant volts/Hertz control without feedback complexity and boosting of the fundamental voltage makes it an excellent choice for motor drive applications. This paper discusses the comparison between a basic delta modulation, the advanced Delta modulation with PI controller and an optimized DMPI. It is shown that in addition to the aforementioned advantages, VSI with optimized DMPI produces superior load current/voltage waveforms compared to simple DMPI, when IGBT is employed as a switching device for the inverter. Since the tacho feedback or other traditional speed sensing means is not permissible in sealed motor or the pump, a novel method is used to monitor the motor speed from the terminal quantities like voltage, current, and motor input power factor.

Delta Modulation, PI Controller, Voltage Source Inverter, Constant v/f Control

A. MASWOOD and S. ANJUM, "Delta Modulation with PI Controller—A Comparative Study," Journal of Electromagnetic Analysis and Applications, Vol. 1 No. 3, 2009, pp. 145-151. doi: 10.4236/jemaa.2009.13023.