Abstract

A pair of clamping parts clamp a conductor to be measured and biased in closing directions. A pair of gripping parts are provided to be able to change a distance between the respective clamping parts according to a distance therebetween. Magnetoelectric conversion element(s) for current measurement is/are provided on either one or both of the respective clamping parts. A distance measurement unit is provided to be able to measure a physical quantity corresponding to the distance between the respective gripping parts as a physical quantity corresponding to the distance between the respective clamping parts. A current calculation device is provided to obtain a current flowing in the conductor to be measured on the basis of a magnetic field detected by the magnetoelectric conversion element(s) for current measurement and the physical quantity measured by the distance measurement unit when the conductor to be measured is clamped by the respective clamping parts.

IPC Classes  ?

• G01R 19/165 - Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
• G01R 1/22 - Tong testers acting as secondary windings of current transformers
• G01R 15/20 - Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices
• G01R 19/00 - Arrangements for measuring currents or voltages or for indicating presence or sign thereof
• G01R 33/07 - Hall-effect devices

Abstract

[Problem] To provide a current measurement apparatus that is capable of reducing or removing the necessity of the work of pulling out a conductor in which measurement is to be performed, from a wiring duct or the like, and facilitating current measurement. [Solution] A pair of pinching parts 11a are provided so as to pinch a conductor 1 in which measurement is to be performed, and are biased in a closing direction. A pair of griping parts 11b are provided so as to be able to change, according to the distance therebetween, the distance between the pinching parts 11a. A current measurement magneto-electric conversion element 12 is provided to one or both of the pinching parts 11a. A distance measurement unit 13 is provided so as to be able to measure a physical amount corresponding to the distance between the griping parts 11b as a physical amount corresponding to the distance between the pinching parts 11a. A current calculation means 15 is provided so as to calculate the current flowing through the conductor 1 on the basis of a magnetic field detected by the current measurement magneto-electric conversion element 12 and the physical amount measured by the distance measurement unit 13 when the conductor 1 is pinched by the pinching parts 11a.

IPC Classes  ?

• G01R 1/22 - Tong testers acting as secondary windings of current transformers
• G01R 15/20 - Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices

Abstract

A multipoint simultaneous measurement method and a multipoint simultaneous measurement system in an electric power station and an internal clock used therefor, capable of performing measurement at the correct time even at a place in the electric power station where GPS radio waves cannot be received, and of securing simultaneity with high accuracy and with ease without connecting a plurality of measurement points via a cable and the like.

IPC Classes  ?

• G04G 5/00 - Setting, i.e. correcting or changing, the time-indication
• G04R 20/02 - Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
• G04R 40/06 - Correcting the clock frequency by computing the time value implied by the radio signal
• G04R 20/28 - Tuning or receivingCircuits therefor
• G04R 20/30 - Decoding time dataCircuits therefor
• H04Q 9/04 - Arrangements for synchronous operation

Abstract

[Problem] Provided are a multiple-point simultaneous-measurement method, a multiple-point simultaneous-measurement system and internal clocks used therein for an electric power station whereby measurements at accurate times can be achieved even at places, where no GPS radio waves can be received, in the electric power station and whereby simultaneity can easily be obtained with high precision even without interconnecting multiple measurement points by use of a cable or the like. [Solution] Each of a plurality of measurement devices (12) comprises: an internal clock (21) with a time correcting means (21b); and a measuring means (22). The time correcting means (21b) corrects the internal clock (21) by determining the difference between an actually counted number of pulses generated by an oscillator (21a) in a predetermined time of period and the product of an oscillation frequency of the oscillator (21a) and the predetermined time of period, and further adding the difference to that product each that predetermined time of period. A master unit (11) wirelessly transmits a measurement time to each of the measurement devices (12). When it is the measurement time by the internal clock (21), each of the measurement devices (12) uses the measuring means (22) to perform measurements, and then wirelessly transmits the data of those measurements to the master unit (11).

IPC Classes  ?

• G04G 5/00 - Setting, i.e. correcting or changing, the time-indication
• G08C 15/06 - Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path successively, i.e. using time division