Design Consideration for IGBT-Based PWM Inverter-Fed Induction Motors

Abstract

: Pulse width modulated (PWM) inverter has applications in many areas as it offers control of voltage, frequency, and harmonic in one power stage. In the practical design of three-phase inverter circuits, a proper understanding of the operations and peculiarities of the specific model to be built is necessary. Most often, perhaps due to different models and configurations; these details are often omitted or assumed to be obvious. An IGBT-based PWM inverter for a 0.5hp induction motor was designed and implemented. Though the implementation posed a challenge to realize, the experience obtained during the process informed the design consideration presented in this paper. The power supply requirements, gate drive requirements, driver protection and dv/dt protections are necessary considerations for successful implementation. This paper presents detailed specific requirements when designing a PWM inverter with IGBT as a driver for induction motor application. The focus is on the theoretical analysis and important design considerations during the practical implementation of an inverter. Different stages involved are analyzed and discussed from the input stage to the output load section. The model used involved single-phase ac input which is rectified to dc. At the output of the rectifier is a large filter capacitor to maintain a constant dc link voltage. The insulated gate bipolar transistor was used as a switching device to drive the 0.5hp induction motor. The analysis simplified inverter design, especially for beginners.