Skip to Main Content
A firing scheme based on a microprocessor to control an antiparallel-connected three-phase thyristor dual converter is presented. Using table-look-up algorithm to speed up the response, it gives a full range control of the firing angle between 0Â° and 180Â° for both positive and negative current control. The maximum time delay required to correct the firing angle is one-sixth period of the ac power source. The firing angle between 120Â° and 180Â° is used for the regeneration braking to achieve the required dynamic performance in four quadrants. Built with all digital circuits with no further adjustment, this system is more reliable and has lower cost.