Current cable and measurement method

Abstract

To provide a current cable that simplifies operations in measurement performed by a penetration type current sensor.SOLUTION: A current cable comprises: an input part that is provided with a first input terminal and a second input terminal; a relay part that is provided with a first relay terminal and a second relay terminal; an output part that is configured to be removably attached to the relay part, and is provided with a first connection terminal connected to the first relay terminal and a second connection terminal connected to the second relay terminal when attached to the relay part and a first output terminal in conduction with the first connection terminal and a second output terminal in conduction with the second connection terminal; a first forward cable that connects the first input terminal and the first relay terminal to each other; a second forward cable that connects the second input terminal and the second relay terminal to each other; and a first loopback cable that connects the first output terminal and the second forward cable to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a current cable and a measurement method. [Background technology]

[0002] When measuring current using a through-type current sensor, it is necessary to disconnect the current path to be measured, pass one end through the through-hole of the through-type current sensor, and then reconnect the current path.

[0003] To amplify the output voltage per unit current, which is the sensitivity of a current sensor, the severed current path may be passed through a through-hole, wound an integer number of times, and then reconnected. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Fundamentals of Current Probes and Measurement (Tektronix Edition)," [online], KTECH, [Accessed April 28, 2022], Internet <URL: http: / / www.ktek.jp / probe-va-frm2011-11 / tek-current-probe-tech-note.pdf> [Overview of the project] [Problems that the invention aims to solve]

[0005] However, to properly adjust the sensitivity of the current sensor, it is necessary to repeatedly increase or decrease the number of windings around the current sensor and check the output voltage of the current sensor. This involves disconnecting the current path, increasing or decreasing the number of windings, and then reconnecting the disconnected current path. This process becomes increasingly complicated and time-consuming, especially as the number of windings increases.

[0006] Furthermore, in order to change the current path being measured, it is necessary to remove the current sensor from the current path. However, as the number of windings increases, the process of removing the current sensor becomes more complicated and time-consuming. The object of the present invention is to provide a current cable that solves the above-mentioned problems. [Means for solving the problem]

[0007] One aspect of the present invention is a current cable comprising: an input section provided with a first input terminal and a second input terminal; a relay section provided with a first relay terminal and a second relay terminal; an output section detachably configured to be attached to the relay section and provided with a first connection terminal that contacts the first relay terminal and a second connection terminal that contacts the second relay terminal when attached to the relay section, as well as a first output terminal that is conductive with the first connection terminal and a second output terminal that is conductive with the second connection terminal; a first forward cable connecting the first input terminal and the first relay terminal; a second forward cable connecting the second input terminal and the second relay terminal; and a first loopback cable connecting the first output terminal and the second forward cable.

[0008] One aspect of the present invention is a current cable comprising: an input section having a plurality of input terminals from a first input terminal to an nth input terminal (where n is an integer of 2 or more); a relay section having a plurality of relay terminals from a first relay terminal to an nth relay terminal; an output section detachably configured to attach to the relay section and provided with a first connection terminal to an nth connection terminal that sequentially contacts the first relay terminal to the nth relay terminal when attached to the relay section, and a first output terminal to an nth output terminal that sequentially conducts with the first connection terminal to the nth connection terminal; and n forward cables, each forward cable sequentially connecting the first input terminal to the nth input terminal and the first relay terminal to the nth relay terminal; and a kth loopback cable connecting the kth output terminal (1≦k≦n-1) to the (k+1) forward cable.

[0009] One aspect of the present invention relates to a first input terminal to the nth input terminal. xInput terminals (1 ≦ x ≦ m, where m is an integer greater than or equal to 2, and n x are each integers greater than or equal to 2), an input section having input terminals up to the input terminals, a relay section having a plurality of relay terminals from the first relay terminal to the n x th relay terminal, and a first connection terminal to the nth connection terminal that is detachably configured to the relay section and that contacts the first relay terminal to the nth relay terminal in order when attached to the relay section. x connection terminals, and an output section provided with first output terminals to n x output terminals that are respectively electrically connected to the first connection terminal to the n x th connection terminals in order, n x forward cables, a forward cable that connects the first input terminal to the n x th input terminal and the first relay terminal to the n x th relay terminal in order, and a kth loop-back cable that connects the kth output terminal (1 ≦ k ≦ n x - 1) and the (k + 1)th forward cable. The current cable includes m cable modules, and a module-to-module cable that connects the n x th output terminal of the output section of the xth cable module other than the mth cable module and the first forward cable of the (x + 1)th cable module.

Advantages of the Invention

[0010] According to the present invention, the sensitivity of the through-type current sensor can be easily amplified by an arbitrary integer multiple.

Brief Description of the Drawings

[0011] [Figure 1] It is a diagram showing the configuration of the current cable 1 according to the first embodiment when n = 3. [Figure 2] It is a diagram showing an example of use of the current cable 1 according to the first embodiment when n = 3. [Figure 3] It is a flowchart showing a measurement method using the current cable 1. [Figure 4]This figure shows the current cable 1 according to the second embodiment when m=2, n1=3, and n2=3. [Modes for carrying out the invention]

[0012] (First Embodiment) Embodiments of the present invention will be described in detail below. The current cable 1 according to the first embodiment comprises an input section 2, a relay section 4, an output section 5, a forward cable 40, and a loopback cable 50. The input section 2 comprises a plurality of input terminals 20 from the first input terminal 20-1 to the nth input terminal 20-n (where n is an integer of 2 or more). The relay section 4 comprises n relay terminals 41 from the first relay terminal 41-1 to the nth relay terminal 41-n. The first relay terminals 41-1 to the nth relay terminals 41-n are connected to the first input terminals 20-1 to the nth input terminals 20-n in order by the first forward cable 40-1 to the nth forward cable 40-n, respectively. That is, the kth forward cable 40-k connects the kth relay terminal 41-k and the kth input terminal 20-k.

[0013] The output unit 5 is equipped with n connection terminals 51, from the first connection terminal 51-1 to the nth connection terminal 51-n. The output unit 5 is also equipped with n output terminals 30, from the first output terminal 30-1 to the nth output terminal 30-n. The output unit 5 is configured to be detachable from the relay unit 4. When the output unit 5 is attached to the relay unit 4, the n relay terminals 41, from the first relay terminal 41-1 to the nth relay terminal 41-n, are connected sequentially to the n connection terminals 51, from the first connection terminal 51-1 to the nth connection terminal 51-n. In addition, the n output terminals 30, from the first output terminal 30-1 to the nth output terminal 30-n, are electrically connected sequentially to the n connection terminals 51, from the first connection terminal 51-1 to the nth connection terminal 51-n.

[0014] For example, the relay terminal 41 and the connection terminal 51 are configured so that their corresponding connection terminals are mated together, and the first relay terminal 41-1 to the nth relay terminal 41-n are connected sequentially to the first connection terminal 51-1 to the nth connection terminal 51-1.

[0015] Further, the k-th output terminal 30-k (1 ≦ k ≦ n-1) is connected to the (k+1)-th forward cable 40-(k+1) by the k-th loopback cable 50-k.

[0016] The procedure for using the current cable 1 will be described. First, disconnect the relay unit 4 and the output unit 5. Then, pass the forward cable 40 through the through-hole 11 of the through-current sensor 10. The loopback cable 50 is routed outside the through-current sensor 10 and not passed through the through-hole 11. Then, connect the relay unit 4 and the output unit 5.

[0017] After that, a current is passed between any input terminal 20 of the input unit 2 and the n-th output terminal 30-n of the output unit 5, and the measured value by the through-current sensor 10 is obtained. By changing the input terminal 20 through which the current is passed, the number of paths through which the current flows in the forward cable 40 changes. For example, when a current is input to the first input terminal 20-1, the current flows through n forward cables 40, but when a current is input to the second input terminal 20-2, the current flows through (n-1) forward cables 40. Finally, the current value input to the input unit 2 and output from the output unit 5 can be calculated by dividing the measured value by the through-current sensor 10 by the number of forward cables 40 through which the current has flowed. For example, a computer may obtain the measured value by the through-current sensor 10 and the number of forward cables 40 through which the current has flowed, and calculate the current value output from the output unit 5.

[0018] The current cable 1 according to the first embodiment when n=3 will be described below with reference to the drawings. Figure 1 is a diagram showing the configuration of the current cable 1 according to the first embodiment when n=3. The input section 2 includes a first input terminal 20-1, a second input terminal 20-2, and a third input terminal 20-3. The relay section 4 includes a first relay terminal 41-1, a second relay terminal 41-2, and a third relay terminal 41-3. The output section 5 includes a first connection terminal 51-1, a second connection terminal, a third connection terminal 51-3, a first output terminal 30-1, a second output terminal 30-2, and a third output terminal 30-3. The first input terminal 20-1 and the first relay terminal 41-1 are connected by the first forward cable 40-1, the second input terminal 20-2 and the second relay terminal 41-2 are connected by the second forward cable 40-2, and the third input terminal 20-3 and the third relay terminal 41-3 are connected by the third forward cable 40-3.

[0019] Furthermore, the first output terminal 30-1 is connected to the second input terminal 20-2 and the second output terminal 30-2 by a first loopback cable 50-1, and the second output terminal 30-2 is connected to the third input terminal 20-3 and the third output terminal 30-3 by a second loopback cable 50-2.

[0020] Figure 2 shows an example of the use of the current cable 1 according to the first embodiment when n=3. The relay section 4 and the output section 5 are separated, and the first forward cable 40-1, the second forward cable 40-2, and the third forward cable 40-3 are passed through the through hole 11. The first loopback cable 50-1 and the second loopback cable 50-2 are passed outside the through-type current sensor 10 and not through the through hole 11.

[0021] Current is input to the current cable 1 from the first input terminal 20-1, the second input terminal 20-2, or the third input terminal 20-3. When current is input to the first input terminal 20-1, current flows through the first forward cable 40-1, the second forward cable 40-2, and the third forward cable 40-3 of the forward cable 40. In other words, the current cable 1 forms a circuit with 3 windings. When current is input to the second input terminal 20-2, current flows through the second forward cable 40-2 and the third forward cable 40-3. In other words, the current cable 1 forms a circuit with 2 windings. When current is input to the third input terminal 20-3, current flows through the third forward cable 40-3. In other words, the current cable 1 forms a circuit with 1 winding.

[0022] Figure 3 is a flowchart illustrating a measurement method using the current cable 1. The through-type current sensor 10 measures the current flowing through the forward cable 40 passing through the through-hole 11 (step S11). Subsequently, the computer calculates the current value output from the output unit 5 based on the measurement value from the through-type current sensor 10 and the number of forward cables 40 through which current flows (step S12). The number of forward cables 40 through which current flows can be obtained, for example, by inputting it into the computer by the user. Alternatively, the number of forward cables 40 through which current flows can also be obtained, for example, by a sensor attached to the input terminal 20 sensing the connection of the terminal.

[0023] As described above, the current cable 1 has a detachable relay section 4 and an output section 5, allowing the relay section 4 and output section 5 to be separated and the forward cable 40 to pass through the through-hole 11 of the through-type current sensor 10. Furthermore, by changing the input terminal 20 into which the current is input, the user can change the number of forward cables 40 through which current flows among the forward cables 40 passing through the through-hole 11, achieving an effect equivalent to increasing or decreasing the number of windings. This makes it possible to easily adjust the sensitivity of the current sensor.

[0024] (Second embodiment) The current cable 1 according to the second embodiment comprises m cable modules 6 (where m is an integer of 2 or more) and (m-1) inter-module cables 60. Each cable module 6 is the current cable 1 according to the first embodiment, where n=n x (1≦x≦m, n) x These are current cables where each of the numbers is an integer greater than or equal to 2.

[0025] The x-th module intermodal cable 60 (1 ≤ x ≤ m-1) is the nth output section of the x-th cable module. x The output terminal is connected to the first forward cable of the (x+1) cable module. The x-module inter-module cable 60 and the first forward cable of the (x+1) cable module are permanently connected by soldering or other means.

[0026] The current cable 1 according to the second embodiment, when m=2, n1=3, and n2=3, will be described below with reference to the drawings. Figure 4 is a diagram showing the current cable 1 according to the second embodiment when m=2, n1=3, and n2=3. The current cable 1 comprises a first cable module 6-1, a second cable module 6-2, and an inter-module cable 60-1.

[0027] The first input section 2a and the first relay section 4a are connected. More specifically, the first input terminal 20-1a and the first output terminal 30-1a are connected by the first forward cable 40-1a, the second input terminal 20-2a and the second output terminal 30-2a are connected by the second forward cable 40-2a, and the third input terminal 20-3a and the third output terminal 30-3a are connected by the third forward cable 40-3a. Furthermore, the first output terminal 30-1a is connected between the second input terminal 20-2a and the second output terminal 30-2a by the loopback cable 50-1a, and the second output terminal 30-2a is connected between the third input terminal 20-3a and the third output terminal 30-3a by the loopback cable 50-2a.

[0028] The second input section 2b and the second relay section 4b are connected. More specifically, the first input terminal 20-1b and the first output terminal 30-1b are connected by the first forward cable 40-1b, the second input terminal 20-2b and the second output terminal 30-2b are connected by the second forward cable 40-2b, and the third input terminal 20-3b and the third output terminal 30-3b are connected by the third forward cable 40-3b. Furthermore, the first output terminal 30-1b is connected between the second input terminal 20-2b and the second output terminal 30-2b by the loopback cable 50-1b, and the second output terminal 30-2b is connected between the third input terminal 20-3b and the third output terminal 30-3b by the loopback cable 50-2b.

[0029] Furthermore, the third output terminal 30-3a of the first output unit 5a is connected to the first forward cable 40-1b of the second cable module by the first inter-module cable 60-1.

[0030] Users of the current cable 1, as in the first embodiment, disconnect the relay unit 4 and the output unit 5 in each cable module 6, and then pass the forward cable 40 through the through-hole 11 of the through-type current sensor 10. The loopback cable 50 is routed outside the through-type current sensor 10 and not through the through-hole 11. After that, the relay unit 4 and the output unit 5 are connected.

[0031] Current is input to the current cable 1 from one of the six input terminals 20, and current is output from the third output terminals 30-3b of the second output unit 5b. Depending on the input terminal 20 to which current is input, the number of forward cables 40 through which current flows changes from one to six. As described above, the current cable 1 according to the second embodiment can pass more forward cables 40 than the number of terminals in the input unit 2 and output unit 5 through the through-hole 11 of the through-type current sensor 10, and the sensitivity of the through-type current sensor 10 can be adjusted over a wider range.

[0032] In the above explanation, it was assumed that the values ​​of n1 and n2 are equal, that is, that the input unit 2 has the same number of input terminals 20, but they do not have to be the same number. For example, if n1=3 and n2=4, the first input unit 2a and the first output unit 5a may each have 3 input terminals 20 and 30 output terminals, and the second input unit 2b and the second output unit 5b may each have 4 input terminals 20 and 30 output terminals.

[0033] <Other Embodiments> Although one embodiment of this invention has been described in detail above with reference to the drawings, the specific configuration is not limited to that described above, and various design changes can be made without departing from the spirit of this invention. [Explanation of symbols]

[0034] 1 Current cable, 2 Input section, 4 Relay section, 5 Output section, 10 Through-type current sensor, 11 Through-hole, 20 Input terminal, 30 Output terminal, 40 Forward cable, 41 Relay terminal, 50 Loopback cable, 51 Connection terminal, 60 Inter-module cable

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