JP2560382Y2 - Switch DC signal detection device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a single-pulse DC control signal applied to a power switch such as a circuit breaker, a disconnector, a ground switch, and the like. Related to the device.

[0002]

2. Description of the Related Art In recent years, predictive maintenance has been performed for power equipment used in substations and the like for maintenance and the like. This predictive maintenance is to constantly monitor the status of the equipment to detect and confirm the presence or absence of an abnormality, and to notify the operator if an abnormality is detected. The power equipment is a circuit breaker, disconnector, ground switch. For example, when a switch is instructed to open and close, the switch monitors whether the command is correctly given, and based on the monitoring, monitors whether the switch operates normally in accordance with the operation command. Is to be reported.

For example, FIG. 3A shows a single pulse waveform of a DC control signal (for example, ON) input to a switch operation / control circuit through a signal line, and FIG. 3B shows a single pulse waveform from the switch. The waveforms of the operation completion signal are shown. By monitoring the signal waveform and the time t from the reception of the signal to the completion of the operation, it is possible to predict and maintain the state of the switch from the result.

As described above, in predicting maintenance of a power switch, in a conventional device, as shown in FIG. 4, an iron core 2 forming a magnetic circuit is provided around a signal line 1 and an iron core is provided. Hall element 3 in an annular magnetic circuit formed by
Are arranged, and the presence / absence of a DC control signal is detected in a state where the Hall element 3 is insulated from the control circuit.

A device for detecting an alternating current using this Hall element (current conversion device) is disclosed in Japanese Utility Model Laid-Open No. 57-130.
No. 277 is also described in the specification and drawings of the microfilm. In this microfilm, an iron core is formed by joining two pieces of iron core bodies in a ring shape, and a void portion is formed by a gap between the joining portions. A magnetic element such as a Hall element is provided in the (gap), and the semiconductor element is supported by an insulating spacer having a small thermal expansion, and the spacer and the reinforcing lead are connected to the semiconductor element to improve reliability. Is described.

On the other hand, when the detection accuracy of the DC control signal waveform is not required to be high, that is, when the DC control signal waveform is differentiated and detected without any difficulty in the determination, as shown in FIG. An annular closed core 4 that forms a closed magnetic path through which the wire 1 penetrates is provided, and a coil 5 is wound around the core 4,
A signal is detected by connecting both ends of the coil 5 to, for example, an oscilloscope via an amplifier 6.

[0007] JP-A-2-90065 discloses that
As an apparatus for detecting an alternating current, an apparatus in which a plurality of divided cores are annularly connected to form an iron core is described.

[0008]

The conventional device shown in FIG. 4 and the AC current detecting device described in the microfilm each use a Hall element, which is expensive and expensive. A power supply and an amplifier to be connected are required, and the number of parts is large and the cost is high.

Further, in the case of the so-called closed magnetic circuit type shown in FIG. 5, since the closed circuit core 4 formed in a ring shape is used in advance, the closed circuit core 4 cannot be attached unless the signal line 1 is first penetrated or cut. .

In any of the conventional devices shown in FIGS. 4 and 5, for example, a direct current control signal, that is, a direct current signal which is not inverted to + or-is detected. Residual magnetic flux gradually remains and accumulates on the iron core, and it is necessary to adjust the waveform by applying an appropriate bias on the receiving side of the detection signal. Further, if the iron core is saturated with residual magnetism, signal detection cannot be performed at all.

That is, in the case of the conventional device, the influence of the residual magnetic flux is not considered at all, and a differential waveform of the magnetic flux proportional to the signal current is obtained. However, since the direction of the magnetic flux is always one direction, it is shown in FIG. as such, the remaining residual magnetic flux phi ₀ in the iron core 4, by the residual magnetic flux phi _0, deteriorates the responsiveness of the rising portion of the signal waveform, there is a problem that the detection accuracy decreases.

In order to solve this problem, as shown in FIG. 7, a coil 8 connected to a battery 6 via a resistor 7 is wound around a closed circuit core 4 and is excited so that the residual magnetic flux φ ₀ becomes zero. However, in this case, there is a problem that the battery 6, the resistor 7, and the coil 8 are required, the number of components is increased, and the device becomes complicated and expensive.

The present invention has been made in consideration of such problems of the prior art, and its object is to make it possible to detect a DC control signal by making it inexpensive and easy to install. In addition, a DC control signal detection device for a switch that can prevent the generation of residual magnetic flux and improve the response of the rising portion, and furthermore, has a low output impedance and can amplify the detection output as it is. Is to provide.

[0014]

In order to achieve the above object, a DC control signal detecting device for a switch according to the present invention comprises a plurality of core elements annularly connected so as to surround a signal line of a DC control signal. And a liner is formed between the ring-shaped divided cores through which the signal lines penetrate, and the coupling surfaces of the respective core element bodies, and residual magnetic flux remains in the divided cores by passing the DC control signal. And a coil wound around the split core and detecting the DC control signal, and a shunt provided between both ends of the coil to reduce an output impedance between both ends of the coil. And a resistor.

[0015]

In the DC control signal detecting device for a switch according to the present invention having the above-described structure, a split core in which a plurality of core elements are connected in a ring shape is used. It does not need to be cut or cut and can be easily attached.

Further, since a gap having a length such that no residual magnetic flux remains due to the passage of the DC control signal is formed in the divided iron core, the residual magnetic flux is not accumulated, and the rising portion of the DC control signal is accurately detected. Can be.

Furthermore, a shunt resistor is provided between both ends of the coil wound around the split iron core, so that its output impedance is reduced, and the detected output can be amplified as it is.

That is, while using a split core,
By providing a gap of a predetermined length in this iron core,
It is inexpensive and easy to install, and no residual magnetic flux peculiar to DC signal detection is accumulated. In addition, a shunt resistor can be provided to lower the output impedance, and the power switch A DC control signal detection device for a switch suitable for detecting a DC control signal can be provided.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. (Example 1) In Example 1 shown in FIG. 1, reference numeral 9 denotes an annular divided core in which a signal line 1 of a DC control signal for a switch is penetrated, and two semi-annular iron core bodies 9 a. , 9b are connected with a flat liner 10 therebetween, and the combined members are tightened from the outer periphery with a tightening band 11, so that a gap by the liner 10 is formed in a gap between the iron core bodies 9a, 9b. I have.

The gap is set to a length (gap length) in which no residual magnetic flux due to the passage of the DC control signal remains.

If no gap is provided, residual magnetic flux is accumulated and eventually saturates. However, if a gap is provided so that the cores do not directly contact each other, the presence of the gap increases the magnetic resistance. Therefore, there is no magnetism that is consumed here.

Reference numeral 12 denotes a coil wound around the iron core 9,
A shunt resistor 13 is connected between both ends, and the coil 1
Terminals a and b at both ends of the device 2 are connected to an oscilloscope via an amplifier.

This is because when the signals at both ends of the coil are directly input to the amplifier as shown in FIG. 5, the output impedance of the coil 12 alone is high and noise is likely to enter. Shunt resistor 1
3 to solve this problem by lowering the output impedance.

If the resistance value of the shunt resistor 13 is extremely small, the output voltage between the terminals a and b becomes small and measurement becomes difficult. As a result, the S / N ratio deteriorates.
It must be set to an appropriate size.

As a result of conducting various experiments, for example, when a signal as shown in FIG. 3A is given for 60 msec as a break command signal of the circuit breaker, the gap length is 10 to 40 μm and the number of turns of the coil 12 is 600. Turn, shunt resistance 1
It has been confirmed that when 3 is set to 20Ω, the rising portion of the DC control signal can be faithfully detected.

(Embodiment 2) Next, in Embodiment 2 shown in FIG. 2, a ring-shaped split iron core 14 having a signal line 1 penetrated is formed by a U-shaped first iron core element 14a and a rod-shaped second iron core element. Body 14b.
a, 14b are connected via a liner 15 to form a gap formed by the liner 15, and the first iron core body 14a
In this case, the same effect as that of the first embodiment can be obtained.

[0027]

[Effects of the Invention] Since the present invention is configured as described above, the following effects can be obtained. Since the DC control signal applied to the power switch is detected by penetrating the signal line through the split iron core, there is no need to penetrate or cut the signal line in advance, making it easy to install. In addition, when a predictive maintenance function is added to an existing switch for electric power, it can be easily attached and realized, and moreover, the cost is lower than when a Hall element is used.

Moreover, since a predetermined length of gap is formed in the split core so that no residual magnetic flux remains, the rising portion of the control signal can be detected accurately.

Further, since a shunt resistor is provided between both ends of the coil, the output impedance can be reduced and the noise-free detection output can be amplified as it is.

That is, while using a split core,
By providing a gap of a predetermined length in this iron core, a synergistic effect can be achieved in which the problems of cost reduction, simplification of mounting, etc., and the problem of residual magnetic flux peculiar to DC signal detection can be solved at once. Accordingly, a low impedance detection output without noise can be obtained, and a DC control signal device suitable for detecting a DC control signal of a power switch can be provided.

[Brief description of the 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.

FIG. 6B is a view for explaining residual magnetic flux of the closed core in FIG. 5;
It is a -H characteristic view.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Signal line 9,14 Split-type iron core 9a, 9b, 14a, 14b Iron core body 10,15 Liner 12,16 Coil 13 Shunt resistor

Claims (1)

(57) [Scope of request for utility model registration] 1. A DC control signal detecting device for a switch for detecting a single-pulse DC control signal applied to a power switch such as a circuit breaker, a disconnector, a ground switch, etc., wherein the signal line of the DC control signal is provided. a plurality of core element coupled to the ring to surround and a segmented core annular said signal line through transmural, formed across the liner between coupling surfaces of each core element,
Wherein a gap through the residual magnetic flux in the split-type iron core Ri by the over is set to a length that does not remain in the DC control signal, is wound on the segmented core, Ru <br/> detect said DC control signal A DC control signal detection device for a switch, comprising: a coil; and a shunt resistor provided between both ends of the coil to reduce an output impedance between both ends of the coil.