JPS6027864A - Magnetic field measurement for compressed gas insulated cable - Google Patents

Abstract

PURPOSE:To enable an accurate measurement of a magnetic field by providing a magnetic field measuring element at the point separated by 90 deg. from sheath bonding bars in a compressed gas insulated cable with a plurality of sheathes covering conductors connected by the sheath bonding bars. CONSTITUTION:Conductors 1-3 in three phases, A, B and C, are passed through sheathes 4-6 and connected integral with sheath bonding bars 7 and 8. Measuring holes 9 are provided through respective sheathes 4-6 in such a manner that the center lines thereof is at the right angle to the center lines of the sheath bonding bars 7 and 8. Then, A magnetic field measuring element 10 is inserted into the hole 9 and measures the intensity of magnetic field by gauging current flowing through the element 10. Such arrangement of the element 10 enables an accurate measurement of the magnetic field generated in each phase without being affected by the magnetic field generated in the sheath bonding bars.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring magnetic fields in gas-insulated equipment or pipes and aerial cables.

As shown in the figure, for example, conductors 1, 2, and 8 of three phases, ie, human phase, B phase, and C phase, are passed through a sheath 4, 5, and 6, and each of these sheaths is are connected together with a sheath bond par 7.8.

In such a conduit air cable, when current flows through each phase as shown by arrow a in FIGS. 1 and 3, a clockwise magnetic field 9 as shown by arrow υ is generated according to Faraday's law.

The strength of such a magnetic field is proportional to the strength of the current flowing through the conductors 1, 2.8 of each phase, so measuring the strength of each magnetic field will tell you the strength of the current flowing through the conductor. .

However, when current flows through the conductors 1 and 2.8 as shown in the figure, a magnetic field is also generated in the sheath pump 7.8 as shown by arrow C, and this causes the magnetic field generated in each conductor 1 and 2. influence

Therefore, if the method for measuring magnetic fields when current is passed through independent conductors is applied to an 8-phase pipe air cape JvK in which sheaths are connected by sheath bonds, measurement errors will occur.

An object of the present invention is to provide a method for accurately measuring the magnetic field created in each phase without being affected by the magnetic field generated in the sheath pumper as described above.

An embodiment of the measuring method of the present invention will be described below with reference to the accompanying drawings.

As shown in the figure, each sheath 4, 5.6 is provided with a measuring hole 9 such that its center line is perpendicular to the center line of the sheath pontoon <-r, s.

Next, an i-field measuring element 10 is inserted into this hole 9. An element that utilizes the Fraday effect is used as this element 10, and this element 10 is inserted so that it is perpendicular to the center line of the sheath pounder 7 as shown in FIG. The strength of the magnetic field can be measured by measuring the current flowing through the element 10.

By arranging the element 10 so as to be perpendicular to the center line of the pond par 7.8, for example, as shown in the figure,
When measuring the phase, the element 10 vertically receives the magnetic field generated by the current flowing through the conductor l of the human phase, so the human phase current can be measured. At this time, the magnetic field due to the current flowing through the pounder 7 is Element 1 installed on the A phase as shown below.
0, this element 10 is not affected by the current flowing through the pounder 7.

Further, the magnetic field caused by the current flowing through the conductors 2 and 8 of the other phases is also parallel to the human phase element 10, so that it is not affected.

In the end, the element 10 placed on the human body can accurately measure only the current flowing through the human body.

Further, the current flowing through the conductors 2.8 of the B phase and C phase other than the A phase can also be accurately determined by the same measuring method as described above.

In addition, in the embodiments shown in FIGS. 1 and 8, the hole 9 is formed at a position slightly shifted from the mounting position of the sheath pounder 7.
The hole 9 may be located at the same position as the bond par 7, as shown by the chain line in FIG.
A similar effect can be obtained when the C phase or B phase is at a position of 180° with respect to the above.

In the present invention, as described above, the magnetic field measuring element is arranged at a place where the sheath pond is -90'' away from the magnetic field measuring place, so that the magnetic field due to the current flowing through the sheath spar or other conductor becomes parallel to the element.

Therefore, there is an effect that the current flowing through the conductor to be measured can be accurately measured without being affected by these magnetic fields.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing the state of implementation of the present invention, FIG. 2 is a cross-sectional front view of the same, and FIG. 8 is a partially cutaway perspective view. 1.2.8...Conductor 4,5.6...
・Sheath 9...Measurement hole 10...
Magnetic field measurement element patent applicant Sumitomo Electric Industries Co., Ltd. agent Patent attorney Kazu1) Sho

Claims (2)

[Claims] (1) In a conduit aerial cable in which multiple sheaths covering a conductor are connected by a sheath pumper, the magnetic field is measured at a location 90° away from the sheath pumper, and a magnetic field measuring element is placed here to measure the magnetic field. A method for measuring a magnetic field in a conduit aerial cable. (2) A method for measuring a magnetic field in a conduit aerial cable according to claim 1, characterized in that an element utilizing the Faraday effect is used as the a-field measuring element.