Thyristor battery chargers with improved control system

摘要

A battery charging device has a supply voltage 1 reduced by a transformer 2. The reduced voltage is rectified using a thyristor controlled rectifier 3. The rectified voltage is then smoothed using an inductor 4 and a capacitor 5. The charger output, output voltage and output current are indicated at 6,7, and 8 respectively. A feedback control 9 generates a demand control signal 10 which is fed into linearizer 11. The linearizer generates a corrected demand control signal 12 which is supplied to the thyristor controlled rectifier 3. The corrected signal acts to control the thyristor and therefore produces an output voltage from the rectifier that is linear with respect to the firing angle [Figures 2 and 4]. The linear relationship between the firing angle and the rectifier output acts to produce a constant gain in the control system for all firing angles allowing the battery charger to operate over a wider range of input and output voltages including single and multiple phase input voltages.