UBC Theses and Dissertations
A compact, flexible controller for PWM inverters Mauch, Konrad
A flexible, low cost inverter controller for use in variable speed AC motor drives has been designed. Originally designed for use in a submersible thruster drive, the controller has been found to have potential for use in other drives as well. Low cost and small size are made possible by the use of large scale integrated circuits. Flexibility in a variety of motor drive applications is achieved by using a microcomputer as the heart of the controller. In comparison to other controllers for PWM inverters, this controller has the following distinctive features: i) The controller can operate the inverter to output frequencies of 400 Hz or more as opposed to maximum frequency limits of 120 Hz to 200 Hz for other controllers. ii) The controller is programmed in the C high level programming language instead of the assembly language used in other microcomputer based controllers. This allows the controller to be adapted more rapidly to new applications, iii) The controller is smaller and has a lower component count than most other controllers. As a result the controller should be more reliable, easier to package, and less expensive. After a review of AC drive technology, the objectives and the basic alternatives in the design of the controller are presented. The circuit design and software design of the controller are discussed. Two applications of the inverter controller are presented and the success of the design in these two applications is evaluated. Conclusions are presented on the overall success of the design and suggestions are made for improvements and further work.
Item Citations and Data