Power factor correction for thyristor equipment in the glass industry

Thyristor power controllers are now widely used in the glass industry for controlling furnace temperature. While offering a number of operational advantages, they operate at lagging power factors, which require correction for minimum power cost. Harmonic resonances with the utility feed, however, complicate the use of capacitor banks. The nature of harmonic problems is described and the use of inductors to tune capacitor banks below any possible harmonic frequency is demonstrated. An example design procedure is covered