JPH0816687B2 - Resistance measuring device for electric wire connection - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wire connection part resistance measuring device, and more particularly, to a wire connection part that is installed in an environment where an electromagnetic field is generated and in which an induced current is generated. The present invention relates to an electric wire connecting portion resistance measuring device that measures the resistance of an electric wire connecting portion in order to know in advance that electric resistance increases and heat is generated due to deterioration over time.

[Prior Art] For example, in a transmission line having two lines, the connection of the transmission line in a steel tower portion is usually performed by a compression clamp, and the connection portion tends to increase in electric resistance due to aging. As a result, abnormal heat is generated, and in the worst case, the electric wire may come off. As a means to deal with such a situation, if only one side line of the transmission line is operated and the other side line is stopped and the resistance of the wire connection part is measured by the conventional measuring instrument by the four-terminal measurement method, the wire connection The resistance of the part is much smaller than the resistance of the measuring cord, and the measuring current for the measurement by the measuring instrument is also small, and the induced current is generated in the measuring cord due to the effect of the electromagnetic field generated by the hot wire. Therefore, the induced current is superposed on the measured current and has a large influence, and as a result, judgment based on the measured value becomes impossible or an error occurs.

On the other hand, as a means for detecting the state of the electric wire connecting portion, there is an image processing device called an aviometer, and normally, this device detects deterioration of the electric wire connecting portion. This device is for observing the temperature of an object from a distant point.When the power line is hot in a live state, the temperature of the wire and the wire connection part are detected and compared, and the wire connection is performed. If the temperature of the part is considerably high, it is estimated that the part is deteriorated, and the deterioration is not quantitatively and obviously detected. Furthermore, when using this device,
It requires a considerable amount of know-how for its handling and judgment.

Furthermore, in the case of using an avometer, there is a problem that the transmission current is considerably large and the determination cannot be made unless the heat generation state occurs.

[Problems to be Solved by the Invention] Conventionally, as described above, a clear measurement result cannot be obtained even when the measurement is performed by the four-terminal measurement method, and the measured part is a special part such as a transmission line. There is a problem that there is no suitable measuring device that can be taken to the site, and that the work of attaching the measurement terminal is extremely dangerous and difficult. Has a problem in that it cannot be detected until abnormal heat is generated, and therefore deterioration cannot be detected in advance.

The present invention has been made to solve the above-mentioned problems, and a one-sided line is on a steel tower in a live state, that is, a state where an induced current is normally generated in an electromagnetic field environment. It is an object of the present invention to provide an electric wire connection part resistance measuring device capable of accurately measuring the electric resistance of an electric wire connection part even with the electric wire connection part.

[Means for Solving the Problems] The electric wire connection portion resistance measuring device according to the present invention applies a measuring current to both sides of the electric wire connection portion of the electric wire by means of an attached power source, and makes the electric wire connection portion close to both sides of the electric wire connection portion. Measuring the voltage at the position, and a measuring device for measuring the voltage drop between both sides of the electric wire connecting portion, the measuring device, the current applying portion,
The voltage measuring unit, and a connecting wire between the measuring device and the current applying unit, the voltage measuring unit, a shield for blocking an electromagnetic field that generates an induced current in each of the units, the measuring device is normal. It has a function of removing both mode noise and common mode noise.

[Operation] Since the electric wire connection portion resistance measuring device of the present invention is configured as described above, the current applying part, the voltage measuring part, the connecting wire, and the measuring device are all shielded. In addition, no induced current is generated inside them, so that only the measurement current flows and no noise is generated, and the measuring device has a function of removing both normal mode noise and common mode noise. Therefore, pure resistance measurement can be performed by the measurement result by the four-terminal measurement method, and the change in resistance can be accurately captured.

[Embodiment] The present invention will be described below with reference to the drawings showing an embodiment thereof. However, the case of a transmission line in a steel tower part connected by a compression clamp as an electric wire and an electric wire connecting portion in which an induced current is generated in an electromagnetic field will be described.

In FIG. 1, reference numeral (1) is a steel tower, (2) is an insulator fixed to the steel tower (1), (3) For example, (3a) (3
b) is a compression clamp which is an electric wire connection part retained by the insulator (2), and (4) is, for example, (4a) (4b) is an electric wire compressed and fixed to one end of the compression clamps (3a) (3b). Transmission line, (4c) is a jumper wire that is an electric wire compressed and fixed to the other end of the compression clamps (3a) and (3b), and (5) and (6) are close to both sides of the compression clamp (3a). Voltage measurement terminals attached to the transmission line (4a) and jumper line (4c), (7) and (8) are attached to the transmission line (4a) and jumper line (4c) apart from the compression clamp (3a) The current applying terminal for applying the measurement current of (9) is a ground terminal, and the voltage measuring terminals (5) and (6), the current applying terminals (7) and (8), and the ground terminal (9) are It is connected via 10) to the measuring device (11). Further, (12) is a portable power source which is connected to the measuring device (11) and supplies a direct current to the current application terminals (7) and (8). Although not shown, the voltage measuring terminals (5) and (6), the current applying terminals (7) and (8), and the connecting wire (1
0), the measuring device (11) and the power supply (12) have the above-mentioned electromagnetic fields in order to avoid an induced current from being generated by an electromagnetic field generated by a live line near the electromagnetic field or an influence of the electromagnetic field itself. Has a shield to block.
Further, the measuring device (11) has a removing function for removing both normal mode noise and common mode noise. Furthermore, the power transmission lines (4a) and (4b) are one-sided lines whose power transmission is stopped for measurement of the two-line power transmission line, and the other-side lines are live lines although not shown.

In addition, as shown in FIG. 2, in order to prevent danger during work on the tower, the voltage measuring terminals (5) and (6), the current applying terminals (7) and (8), and the ground terminal (9) are expandable insulating rods. It is provided by being attached to the tip of (13), and each of these terminal portions is configured to grip and connect an electric wire by one-touch operation.

Since this embodiment is configured as described above, in order to investigate whether or not there is an abnormality in the compression clamp (3a), first, while keeping the power transmission line on one side (not shown) in the live state, Stop the power transmission lines (4a) (4b) and jumper line (4c) that have been installed.

Next, after raising the power supply (12), the measuring device (11) and other parts to predetermined positions on the steel tower (1), place the voltage measuring terminals (5) and (6) close to both sides of the compression clamp (3a). It is attached to the power transmission line (4a) and the jumper wire (4c), and the current application terminals (7) and (8) are separated from the compression clamp (3a) and attached to the power transmission line (4a) and the jumper wire (4c).

In this state, the terminals (5) to (9), the connecting wire (10), the measuring device (11), and the power supply (12) are all in the electromagnetic field, but each device is shielded. Since the electromagnetic field is cut off, no induced current or noise is generated in each device or the connection line (10).

Next, the power supply (12) is activated to apply the measurement current between the connected transmission lines of the current application terminals (7) and (8) via the measurement device (11).

Next, the presence or absence of abnormality is detected by measuring the voltage drop between the voltage measuring terminals (5) and (6) by the measuring device (11) and comparing it with a reference value. In this case, since the measuring device (11) has the normal mode noise removal function and the common mode noise removal function, noise or the like does not occur in the measurement signal due to the shield, and therefore,
Highly accurate measurement results can be obtained.

In addition, in the said Example, although the thing which measures the electric wire connection part in a power transmission line was shown in the air, it is not restricted to this, It is applicable also to a normal electric wire.

[Effect of the Invention] According to the present invention, as in the case of abnormality, a current for measurement is applied to both sides of the wire connecting portion of the wire by an attached power source, and voltage at positions close to both sides of the wire connecting portion is applied. Between the measuring device for measuring and measuring the voltage drop between both sides of the electric wire connecting part, the measuring device, the current applying part, the voltage measuring part, and the measuring device and the current applying part, the voltage measuring part The connecting line of the above is equipped with a shield for blocking an electromagnetic field that generates an induced current in each of the above parts, and the measuring device has a function of removing both normal mode noise and common mode noise. The resistance of the connection part can be measured by high-precision measurement that does not include noise, etc. Therefore, it is possible to judge including the degree of deterioration, and maintenance is simple and highly accurate and effective. Wire connection The shunt resistance measuring device can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a measuring method by an electric wire connection portion resistance measuring device according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of the electric wire connection portion resistance measuring device of FIG. (3a) (3b) …… Wire connection (compression clamp), (5)
(6) …… Voltage measuring terminal, (7) (8) …… Current applying terminal, (10) …… Connecting wire, (11) …… Measuring device, (12)…
…Power supply.

 ─────────────────────────────────────────────────── (72) Inventor Noriaki Kanda 475 Hisamoto, Takatsu-ku, Kawasaki, Kanagawa Asahi Denki Co., Ltd. (72) Yuzo Yamamoto 475, Hisamoto, Takatsu-ku, Kawasaki, Kanagawa Asahi Electric Co., Ltd. Within

Claims (1)

[Claims] 1. An electric wire connection part resistance measuring device for measuring the resistance of an electric wire connection part of an electric wire in which an induction current is generated in an electromagnetic field environment. A measuring device for applying a current and measuring a voltage at a position close to both sides of the electric wire connecting part, and measuring a voltage drop between both sides of the electric wire connecting part, the measuring device, a current applying part, a voltage measuring Section, and a connecting wire between the measuring device and the current applying section, the voltage measuring section, and a shield for blocking an electromagnetic field that generates an induced current in each of the sections, the measuring apparatus is a normal mode noise An electric wire connection resistance measuring device characterized by having both a common mode noise removing function.