ASIC control strategies for cycloconverter induction motor drives

The authors have examined the logic and control strategy used in a microprocessor controlled cycloconverter drive and compare this with an updated ASIC-only design. After the introduction of the ASICs used in the microprocessor controlled cycloconverter drive a closer investigation into the function of the microprocessor was initiated. This investigation led to the development of a control strategy which allows the removal of the microprocessor from the control system and replaces its function with a total digital ASIC controller (TDAC). This has the effect of reducing the size of the control system still further and allows a much faster response to input speed changes. The authors describe the design and development of the two ASICs using Mentor Graphics Computer Aided Design (CAD) packages for design, simulation and layout. Fabrication was then carried out by Micro Circuit Engineering (MCE). An ASIC controlled cycloconverter-induction motor drive has been achieved without a dedicated microprocessor