×

System for monitoring the insulation quality of step graded insulated high voltage apparatus

  • US 5,471,144 A
  • Filed: 09/27/1993
  • Issued: 11/28/1995
  • Est. Priority Date: 09/27/1993
  • Status: Expired due to Term
First Claim
Patent Images

1. An insulation monitoring system for measuring a charging current through an insulation system between a high voltage conductor and earth ground, said insulation monitoring system comprising:

  • a. an AC current sensor for measuring said charging current and for converting said charging current to a first voltage signal proportional to said charging current;

    b. a transmission network;

    c. a transmitter coupled between said AC current sensor and said transmission network, said transmitter having electronic circuit means for converting said first voltage signal to a DC current and modulating a first current signal by said DC current for transmission over said transmission network, said modulated first current signal proportional to said charging current;

    d. a controller for generating said first current signal and coupled to said transmitter by said transmission network to receive said modulated first current signal, said controller for demodulating said modulated first current signal to extract said DC current, converting said DC current to a voltage proportionally to said charging current, comparing said proportional voltage with a preset voltage level, and generating an alarm signal when said proportional voltage exceeds said preset voltage level; and

    e. wherein said insulation monitoring system continuously monitors said insulation system.

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