초록 ▼

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

대표청구항 ▼

A reactive power compensating system for a three phase induction machine comprising an array of switchable capacitors connected to a power line of each phase, means for measuring the reactive power drawn by said induction machine, logic decision means responsive to said measuring means for selecting

A reactive power compensating system for a three phase induction machine comprising an array of switchable capacitors connected to a power line of each phase, means for measuring the reactive power drawn by said induction machine, logic decision means responsive to said measuring means for selecting the capacitors of each array required to compensate for the said reactive power drawn by said induction machine, and means responsive to said logic decision means for switching the said selected capacitors of each array onto the power line associated with the array wherein said reactive power measuring means is comprised of means for sensing the current through a power line of only one phase, means for converting the current sensed into a proportional voltage signal, and means for sampling and holding for at least a half cycle said proportional voltage signal when the voltage of said one phase crosses zero.