×

Reactive power compensator

  • US 5,134,356 A
  • Filed: 03/07/1991
  • Issued: 07/28/1992
  • Est. Priority Date: 06/22/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A reactive power compensating system, comprising:

  • a. an electrical current sensor that produces a current signal corresponding to an instantaneous value of an electrical current supplied through a line to an inductive load, the electrical current generally varying periodically at a fundamental frequency;

    b. a voltage sensor that produces a potential signal corresponding to an instantaneous voltage on the line, the potential signal varying according to a generally periodic cycle at the fundamental frequency;

    c. filter means, connected to receive the current signal, for producing a filtered current signal from which any harmonics of the fundamental frequency that are present in the current signal are substantially filtered out;

    d. processor means, connected to receive the potential signal and the filtered current signal, for determining a reactive power compensation for the inductive load as a function of the filtered current signal when the potential signal is at a predefined point in its periodic cycle and operative to produce a switching signal to select that reactive power compensation;

    e. a plurality of capacitors, each selectively connectable to compensates reactance on the line; and

    f. switching means, connected to the plurality of capacitors and connected to receive the switching signal from the processor means, for selectively connecting the capacitors to provide the reactive power compensation determined by the processor means in response to the switching signal, the reactive power compensation being substantially free of errors that would otherwise be caused by the harmonics of the fundamental frequency present in the electrical current in the line.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×