Design and Simulation of Digitally Controlled High Current Thyristor Rectifier for Nuclear Research

The paper presents design considerations and circuit simulation of digitally controlled high current, six pulse thyristor rectifier system. The rectifier system is utilized for powering Fuel Rod Cluster Simulator of thermal hydraulic experimental R&D facilities for simulating temperature and power transients expected in nuclear reactor. To maintain the desired amount of nuclear fission heat flux across Fuel Rod Cluster Simulator, suitably scaled rectifier system is necessary. A 5300 Amp thyristor controlled rectifier system is designed to cater the requirement of 600 kW power for experimental R&D facilities. The digital control philosophy has been designed for generating pulses for triggering thyristors. Design calculations for the configuration of six pulse hexa-phase thyristor rectifier system with inter phase transformer has been presented. The simulation of power circuit configuration including closed loop feedback control mechanism has been performed utilizing circuit simulation software. The simulation results including harmonic spectrum have been highlighted in the paper.