Microprocessor Control of Double Output Induction Generator, Part I: Inverter Firing Circuit

This paper investigates the design and implementation of a firing scheme using the INTEL 8086 microprocessor to control the inverter firing angle of the Variable Speed Constant Frequency Double Output Induction Generator (VSCF-DOIG). The INTEL 8086 microprocessor is used to control the firing angle of the DC-linked inverter of the VSCF-DOIG. In this system, the microprocessor computes the voltage signals from a reference voltage pot and then outputs the calculated firing angle shifting time (as opposed to deriving it from a table look-up method) to the interface timer. This gives full range control of the firing angle between 0° and 180°, and updates the phase shifting timer in each cycle based on the values of the past three cycles. The control circuit is designed for multi-tasked purpose. The hardware, software, interface, I/O, and experimental results are presented in this paper.