Title:
INSULATION LEVEL MONITOR AND TEST METHOD THEREOF
Document Type and Number:
Japanese Patent JP2020115095
Kind Code:
A
Abstract:
To determine, regardless of the direction of a leakage current in a field, whether an insulation level monitor operates correctly from a measurement value obtained by flowing a test current in any field.SOLUTION: An insulation level monitor of a fundamental wave effective component method comprises a test device. The test device includes a test current generation unit, an output direction switching unit, an effective leakage current calculation unit, a measurement storage unit, and a determination processing unit. The test current generation unit generates a test current having a same phase on the basis of a voltage signal. The output direction switching unit switches a polarity of the test current and supplies the test currents in a forward direction and a reverse direction to a zero-phase current transformer. The effective leakage current calculation unit acquires a fundamental wave effective leakage current based on a leakage current taken from the zero-phase current transformer and the voltage signal, and sets the fundamental wave effective leakage current as an initial value. The measurement storage unit stores measurement values of leakage currents when the test currents in the forward direction and the reverse direction are supplied to the zero-phase current transformer. The determination processing unit selects a larger measurement value among the measurement values of leakage currents when the forward and reverse test currents are supplied to the zero-phase current transformer, and determines whether the insulation level monitor is good or not based on the measurement value, the test current value, and the initial value.SELECTED DRAWING: Figure 1
Inventors:
SATO KOJI
MINAGAWA HARUKI
MINAGAWA HARUKI
Application Number:
JP2019006333A
Publication Date:
July 30, 2020
Filing Date:
January 17, 2019
Export Citation:
Assignee:
HITACHI INDUSTRY EQUIPMENT SYSTEMS CO LTD
International Classes:
G01R31/50
Domestic Patent References:
| JPH06138154A | 1994-05-20 | |||
| JP2007285790A | 2007-11-01 |
Attorney, Agent or Firm:
Aoritsu patent business corporation