Comparison of thyristor vs. chopper rectifiers in a common application

This paper compares the electrical parameters of two large DC power supplies operating in the same plant operation. Each of the supplies is rated at 13.2 kV input and 35000 Amp 156-Volt output and both are powering graphite furnaces. The installation of a chopper power supply in replacement of a thyristor supply will enable a comparison of all the features of both topologies while operating side by side in the same operating plant environment. Key parameters that will be compared are power factor, harmonics, efficiencies, response to input transients and to load changes, total power consumption and operating cost per unit production. A "constant output power" regulation mode is used and the effect on "system flicker" and furnace operation are compared.