C. Papadopoulos, Th. Antonakopoulos, S. Pressas and V. Makios:

A  Variable Frequency Controller for Three Phase DC/AC Inverters

The IEEE International Symposium on Industrial Electronics, Athens, Greece, July 1995, pp. 227-231.

Abstract: In this paper a multiprocessing system for variable amplitude/frequency control of three phase DC/AC power inverters is presented. The controller consists of four microcontrollers connected in a master-slave configuration. A single microcontroller is used for generating the PWM pulses of each phase and a master microcontroller for determining the system operational parameters. Each phase microcontroller operates as a state machine with analog feedback capabilities and uses an internal look-up table for specifying the duration of the open-loop PWM pulses. Variable frequency is achieved by controlling the clock of the phase microcontrollers, while the modulation depth is determined by the master controller, using an unidirectional high speed synchronous link. The modulator can be used for generating sinewaves in a large frequency range (from 6.25 Hz up to 100 Hz), has very good resolution (0.2% up to 0.4%) and is transient free in amplitude/frequency changes.

If you need additional information concerning this paper, please contact either one of the authors or send an e-mail to: comes-sup@ee.upatras.gr