| Abstract |
The design of a 5-kVA transistorized PWM inverter for the variable-frequency supply of a three-phase induction motor (127 VLL, 22.7 A) is presented. A detailed description is given of various design aspects, including determination of the converter structure, development of the base drive circuits and the related auxiliary switching power supply, and real-time implementation of symmetrical-pulse PWM strategy on a 8031 microcontroller. A three-phase PWM signal from 3.1 to 64.1 Hz is computed under real-time operating conditions with a carrier frequency of 1 to 2. 5 kHz and a minimum modulation ratio of 39. The inverter performance is illustrated by experimental results. |
