JPH0514930U - Signal detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a signal detection device capable of inexpensively, easily, and accurately detecting a DC control signal applied to a device such as a switch. [Structure] An annular split iron core 9 having a gap while passing a signal line 1 of a DC control signal as a primary winding.
And a coil 1 which is wound around the iron core 9 to form a secondary winding.
2 and the DC control signal is detected from both ends of the coil 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a signal detection device suitable for predictive maintenance of power equipment such as switches.

[0002]

[Prior Art]

 In recent years, power equipment used in substations and the like has come to perform predictive maintenance for maintenance. This predictive maintenance is a system that constantly monitors the status of the equipment, confirms that the equipment is not abnormal, and reports it if there is an abnormality.

Among the power devices, a switch such as a circuit breaker, a disconnector, or a grounding switch determines whether or not a predetermined operation command is correctly given when a switching operation is commanded during predictive maintenance. The operation is monitored and it is monitored whether or not it operates normally by this operation command.

For example, FIG. 3A shows a waveform of a DC control signal (for example, ON) input to the operation and control circuit of the switch through a signal line, and FIG. 3B shows the operation completion from the switch. The signal waveforms are shown respectively, and predictive maintenance is possible by monitoring the signal waveform and the time t from signal reception to operation completion.

As described above, the detection of the DC control signal is an important factor for predictive maintenance in the switch, and conventionally, in order to obtain the signal waveform of this control signal, as shown in FIG. An iron core 2 forming a magnetic circuit is provided around the wire 1, and a Hall element 3 is arranged in this magnetic circuit so that a signal waveform is detected in a state insulated from a control circuit.

When the accuracy of the signal waveform is not required, that is, when the signal waveform is detected in a differentiated form and the determination is not hindered, as shown in FIG. An annular closed core 4 is provided, which penetrates as a wire, and a coil 5 is wound around this core 4 as a secondary winding. I'm trying to do it.

[0007]

[Problems to be solved by the device]

 However, in the above-described conventional signal detection device, in the case of using the Hall element 3 shown in FIG. 4, the Hall element 3 itself is expensive and requires a power supply and an amplifier connected to it. I have a problem.

Further, in the case of the so-called current transformer shown in FIG. 5, since the closed-circuit iron core 4 is used, there is a drawback that it cannot be attached to the signal wire 1 in a live state, and moreover, the iron core 4 of this kind is used. Since residual magnetic flux remains in, it is necessary to apply a bias on the receiving side to adjust the waveform.

That is, when a direct current is detected using the closed core 4, a waveform obtained by differentiating the magnetic flux proportional to the signal current is obtained, but since the direction of the magnetic flux is always constant, as shown in FIG. In some cases, the residual magnetic flux φ ₀ remains in the closed-circuit core 4, the response of the rising portion of the signal waveform is poor, and accuracy becomes a problem. Therefore, as shown in FIG. 7, the coil 8 connected to the battery 6 via the resistor 7 is wound around the closed core 4 provided with the primary and secondary windings, and the residual magnetic flux φ ₀ becomes zero. It is necessary to take measures such as exciting.

The present invention has been made in view of the above problems of the conventional technology, and its purpose is to perform signal detection inexpensively and easily and to obtain a good signal waveform. It is to provide a signal detection device capable of obtaining

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, in the signal detecting device of the present invention, a ring-shaped split core having a gap through which a signal wire of a DC control signal applied to a device such as a switch is passed as a primary winding. A coil which is wound around this iron core to form a secondary winding is provided.

[0012]

[Action]

 In the above-mentioned configuration, since the split core is used, even for a live signal line, the iron core can be split and easily attached without power failure. As a result, the residual magnetic flux does not remain and the signal waveform of the DC control signal can be detected more faithfully.

[0013]

【Example】

 An example will be described with reference to FIGS. 1 and 2. In the first embodiment shown in FIG. 1, reference numeral 9 denotes an annular split iron core having a signal wire 1 of a DC control signal for a switch as a primary winding, and two semi-annular iron core elements 9 a and 9b are connected by sandwiching the plate-like liner 10 and the combined body is tightened from the outer periphery by a tightening band 11, so that a gap is formed by the liner 10 between the core element bodies 9a and 9b. ing.

Reference numeral 12 is a coil wound around an iron core 9 to form a secondary winding. A shunt resistor 13 is connected in parallel, and both terminals a and b of the coil 12 are connected to an oscilloscope via an amplifier. Has been done.

Here, in the circuit in which both ends of the coil are directly input to the amplifier as shown in FIG. 5, there is a defect that the impedance is high and noise easily enters, but the shunt resistor 13 is connected to both ends of the coil 12. This can solve this problem. However, when this resistance value is small, the output voltage between the terminals a and b is small, making measurement difficult, resulting in poor S / N.

Therefore, as a result of conducting various experiments in the examples, a DC control signal was faithful to the signal current 5A of the signal line 1 with a gap length of 10 to 40 microns, a coil 5 winding number of 600 turns, and a shunt resistance of 20Ω. It has been confirmed that the waveform can be detected.

Next, in a second embodiment shown in FIG. 2, an annular split iron core 14 having the signal line 1 penetrating is configured by a U-shaped first iron core element body 14a and a rod-shaped second iron core element body 14b. Then, the two element bodies 14a and 14b are coupled to each other through the liner 15 to form a gap by the liner 15, and the coil 16 is attached to the first iron core element body 14a.

[0018]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. Since the DC control signal applied to devices such as switches is detected by penetrating the signal line through the split core, this core can be split and attached to the signal line of the circuit breaker during operation. In addition, it can be easily applied even when the power supply cannot be stopped, such as in substations, and the handling is simple, and it is cheaper than when using a Hall element. Moreover, since a gap is formed in the split core to prevent residual magnetic flux from remaining, a good initial signal waveform can be retained and more accurate signal detection can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a signal detection device according to the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is a waveform diagram of a DC control signal and an operation completion signal.

FIG. 4 is a perspective view of a conventional example.

FIG. 5 is a perspective view of another conventional example.

6 is a diagram for explaining the residual magnetic flux of the closed core in FIG.
It is a -H characteristic figure.

FIG. 7 is a perspective view showing an improved example of FIG.

[Explanation of symbols]

 1 Signal line 9,14 Split type iron core 12,16 Coil

Claims (1)

[Scope of utility model registration request] 1. A signal detection device for detecting a DC control signal applied to a device such as a switch, which is a ring-shaped split core having a signal wire of the DC control signal as a primary winding and having a gap. And a coil that is wound around the iron core to form a secondary winding.