Phase Converters, Their Application and Current Demand

Phase converters may employ autotransformers to step up voltage in conjunction ´ ith series capacitors. Their use permits relaxation of many limitations on capacitor-only phase-converter applications. The phase converters now available, as described in the paper, have numerous advantages, the chief of which are listed here: 1) their circuits provide balanced 3-phase currents to 3-phase induction motors from single-phase lines; 2) the starting kilovoltamperes required are much less than the amount required for single-or 3-phase motors on balanced 3-phase lines; 3) power factors are improved throughout the motors´ operating range; 4) starting torques compare favorably with those of single-phase motors; 5) startirg kilovoltamperes per foot pound are less than for any single-or 3-phase motor; 6) the cost of autotransformer-phase converters and 3-phase motors is competitive with the cost of single-phase motors; 7) the simplicity of 3-phase motors reduces maintenance; 8) where 3-phase power may eventually become available, 3-phase motors can be used immediately from a single-phase line through converters at about 82-percent efficiency, which surpasses that of many single-phase motors; and 9) converter units of given horsepower ratings may be used with motors smaller than these ratings.