JP2000082366A - Automatic graduation tester of direct-current breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply verify that an operational circuit of a DC breaker goes tripping with the set current specified. SOLUTION: A first connector 20 is inserted between a hole current transformer 3 and a power supply circuit 5 and between the transformer 3 and a comparator 6. The arrangement includes an integrator 10, amperage converting calculator 13 and display 14, and a second connector 21 adaptible to the first 20 is connected with the end of the output lead of integrator 10 and the end of the power cable of the amperage calculator 13 and the integrator 10. The circuit is disconnected by the first connector 20 and one side of the first connector 20 is coupled with the second connector 21, and the output of the integrator 10 is fed to the comparator 6 to check that tripping is made with the specified value, and the integrator 10 and amperage calculator 13 are operated by the power supply circuit 5 for the hole transformer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC cut-off circuit capable of verifying that a trip command is given to a DC breaker when a DC main circuit current reaches a predetermined value without supplying a current to the DC main circuit. The present invention relates to an automatic scale tester for measuring instruments.

[0002]

2. Description of the Related Art FIG. 5 is a circuit diagram showing a conventional example of a trip circuit of a DC breaker. In this conventional circuit, a DC motor 4 as a load is operated by DC power from a DC power supply 1. Here, if the DC motor 4 flashes over or a short circuit fault occurs in this circuit, an excessive current flows, and there is a possibility that the DC power supply 1 may be damaged or the main circuit wire may be burnt out, leading to a serious accident. Thus, the excessive current is detected by the Hall current transformer 3 as a DC current detector, and when the detected value exceeds a predetermined value, a trip command is given to the DC circuit breaker 2 to open the circuit, so that the accident occurrence point is determined. Disconnect from the DC power supply 1 to prevent the accident from spreading. The generation of the trip command at this time will be described with reference to a conventional circuit shown in FIG.

In FIG. 5, reference numeral 3 denotes a Hall current transformer. When a magnetic flux is applied in a direction perpendicular to the current flowing through the Hall element, a voltage is generated in a direction perpendicular to both the current and the magnetic flux. This is the Hall effect, and the Hall voltage generated by the Hall element is proportional to the product of the current flowing through the element and the magnetic flux density perpendicular to the current. A device that detects the magnitude of the current flowing from this Hall voltage is a Hall current transformer, which has a simpler structure than a conventional DC current transformer composed of an iron core having square saturation characteristics. It is increasingly used for detecting large currents. Here, reference numeral 5 denotes a power supply circuit for supplying operating power to the Hall current transformer 3, which is connected to terminals P, M, and N of the Hall current transformer 3.

When the DC motor 4 as a load flashes over and an excessive current flows in the DC main circuit, a voltage signal proportional to the DC main circuit current is output from the terminal Sig of the Hall current transformer 3 as an operation circuit. Output to the comparator 6. Comparator 6 compares this voltage signal with the value set by scale value setting device 7 and, when detecting that the voltage signal has exceeded the set value of scale value setting device 7, comparator 6 outputs DC breaker 2. A trip signal is supplied to the trip coil 2C of the DC circuit breaker 2 to open the DC circuit breaker 2. The terminal GND of the hall current transformer 3 is a ground terminal.

[0005]

Since a circuit breaker is a very important device installed in order to prevent the spread of accidents, it is desired that the circuit breaker operates reliably when an excessive current flows in the DC main circuit. Therefore, when checking the operation of the circuit breaker, a signal equivalent to the trip signal is normally generated by a separate signal source, and this signal is supplied to the trip coil 2C instead of the trip signal output from the comparator 6. . However, in this case, only the breaking operation of the DC breaker 2 can be confirmed, and it is not possible to confirm whether or not a trip signal is generated at a predetermined current value. Therefore, a method of actually flowing an excessive current to the DC main circuit can be considered, but this is not an easy operation, and it is not easy for a user equipped with the DC breaker 2 to execute.

An object of the present invention is to make it possible to easily verify that a trip occurs at a predetermined current set by an operation circuit of a DC circuit breaker.

[0007]

In order to achieve the above object, an automatic graduation tester for a DC circuit breaker according to the present invention comprises a DC circuit breaker for a DC main circuit and a DC circuit for outputting a value proportional to the main circuit current. A current detector, and an operation circuit for outputting a trip command to the DC breaker when a detection value of the DC current detector exceeds a predetermined value. A simulated signal generator for outputting a value simulating the detected value of the simulated signal generator, and a simulated signal display for displaying an output value of the simulated signal generator. It is assumed that the output value of the vessel is input to the operation circuit.

[0008] Alternatively, a first wire can be connected and disconnected at a time between the DC current detector and its operating power supply and between the DC current detector and the operation circuit.
Insert the connector. A simulation signal generator that outputs a value simulating a detection value of the DC current detector, and a simulation signal display that displays an output value of the simulation signal generator;
The terminal of the electric wire for transmitting the output value of the simulation signal generator, the terminal of the electric wire for supplying operating power to the simulation signal generator, and the terminal of the electric wire for supplying operating power to the simulation signal display have a second terminal. A connector is provided, and the second connector has a structure compatible with the first connector. Connecting one of the first connector and the second connector when the electric wire is disconnected by the first connector, supplying power from the operating power supply to the simulation signal generator and the simulation signal display, and The output value of the signal generator is supplied to the operation circuit.

Alternatively, the simulation signal generator is an integrator configured to hold an output value of the simulation signal generator when the operation circuit outputs a trip command. Alternatively, the simulation signal generator is an integrator configured to hold an output value of the simulation signal generator when the auxiliary contact of the DC circuit breaker indicates that the DC circuit breaker is open.

[0010]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. FIG. 1 shows a DC power supply 1, a DC breaker 2, a trip coil 2C, and a Hall current transformer 3 shown in FIG. , The DC motor 4, the power supply circuit 5, the comparator 6, and the scale value setting device 7 have the same names, applications, and functions as those of the conventional circuit described above with reference to FIG.

The circuit of the first embodiment shown in FIG. 1 is different from the circuit of the prior art shown in FIG. 5 in that an integrator 10 as a simulation signal generator, a start signal contact 11, a reset signal contact 12, a current value converter 13, a display. In the operation test, the Hall current transformer 3 and the comparator 6 are separated from each other, and the output of the integrator 10 is input to the comparator 6. Will be described below.

An integrator 10 as a simulation signal generator starts its operation by a start signal contact 11 and increases its output voltage at a speed corresponding to the integration time. The output of this integrator 10 is as described above. As described above, when the output value of the integrator 10 exceeds the value set by the scale value setting device 7, a trip signal is given from the comparator 6 to the trip coil 2C, and the DC breaker 2 Open circuit. The output value of the integrator 10 at this time is an analog quantity, which is converted into a digital quantity by the current value converter 13 and then displayed on the display 14 so that the DC breaker 2 trips at a predetermined value. Can be read. If the integration time is long, the integrator 10
Since the output rise speed is slow, the current value converter 1
It is possible to read the trip current value only by installing an analog meter in place of 3 and the display 14.

After the trip of the DC breaker 2 is confirmed, the output of the integrator 10 is reset to zero by the reset signal contact 12. The power supply circuit 15 includes the integrator 10 and the current value converter 1
The operation power supply 3 supplies power to the display 14 if necessary. FIG. 2 is a circuit diagram showing a second embodiment of the present invention. The circuit of the second embodiment is the same as the first embodiment shown in FIG.
The difference is that the power supply circuit 15 is removed from the circuit of the embodiment, and the first connector 20 and the second connector 21 are added. Since all the other components are the same, the description of the same parts will be omitted.

In the circuit of the second embodiment, the Hall current transformer 3
And a wire connecting the power supply circuit 15, that is, P, M, N, and a wire Sig connecting the Hall current transformer 3 and the comparator 6,
The first connector 20 is inserted in the middle of the ground wire GND, and the circuit can be cut by pulling out the first connector 20. On the other hand, the terminal of the output circuit of the integrator 10 is provided with the second connector 21 with the symbol Sig, and the terminals of the power supply circuit of the integrator 10 and the current value converter 13 are with the symbols P, M, N. The second connector 21 is connected, and the second connector 21 has a structure that can be connected to the first connector 20.

When performing a trip test of the DC circuit breaker 2, first, the first connector 20 is pulled out and the Hall current transformer 3 is pulled out.
Is disconnected from the operation circuit. Next, by connecting the operation circuit side of the first connector 20 and the second connector 21, the signal output from the integrator 10 is input to the comparator 6, so that the current value when the DC breaker 2 is opened is displayed. It is possible to know whether or not the trip current value is appropriate by reading with the device 14. If the integrator 10 and the current value converter 13 are configured to operate with the power from the power supply circuit 5 for the Hall current transformer 3, the power supply circuit 15 for them can be omitted.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention. The circuit of the third embodiment differs from that of the second embodiment shown in FIG. 10 is different from that of FIG. That is, the circuit of the third embodiment holds the output of the integrator 10 when the comparator 6 outputs the trip signal, and displays the value on the display 14.

FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention. In the circuit of the fourth embodiment, a breaker auxiliary contact 30 is provided on a DC breaker 2 and a trip signal from a comparator 6 is provided. When the DC breaker 2 is opened, the breaker auxiliary contact 30 is input to the integrator 10 as a hold signal, which is different from the second embodiment already described in FIG. That is, the circuit of the fourth embodiment holds the output of the integrator 10 when the DC breaker 2 is opened by the trip signal, and displays the value on the display 14.

Although the present invention has been described by taking a contact type DC breaker as an example, the present invention can be applied to a non-contact type DC breaker using a semiconductor switch element such as a GTO thyristor. Of course.

[0019]

According to the conventional DC circuit breaker, it was not possible to confirm that a trip would occur at a predetermined current unless a large current was actually supplied to the main circuit. According to the present invention, the simulated signal generator outputs a gradually increasing trip signal and has a circuit configuration capable of displaying the value, so that it is not necessary to flow a large current directly to the main circuit, and the simulated signal generator can be simplified. The effect that the trip operation of the DC breaker and its operation value can be confirmed is obtained. Further, if the DC current detector and the operation circuit are connected via a connector, and the connector is pulled out and the connector provided at the terminal of the simulation signal generator is inserted into the connector, the test can be performed. It can be implemented quickly and smoothly. Also, since the power supply circuit of the DC current detector is not used at this time, if this power supply circuit has a circuit configuration that can be used for the power supply of the simulated signal generator and the display, the effect that the trip test can be performed at a lower price is obtained. Can also be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional example of a DC circuit breaker trip circuit.

[Explanation of symbols]

 Reference Signs List 1 DC power supply 2 DC circuit breaker 2C trip coil 3 Hall current transformer as DC current detector 4 DC motor as load 5, 15 Power supply circuit 6 Comparator as operation circuit 7 Scale value setting device 10 Simulated signal generator Integrator 11 Start signal contact 12 Reset signal contact 13 Current value converter as simulation signal display 14 Display 20 First connector 21 Second connector 30 Circuit breaker auxiliary contact

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Koji Konno, Inventor 1-1-1, Tanabe-Shinda, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term within Fuji Electric Co., Ltd. 5G028 FB01 FB02 FC03 5G034 AC04

Claims (4)

[Claims] 1. A DC circuit breaker inserted in a DC main circuit, a DC current detector for outputting a value proportional to a current flowing in the DC main circuit, and a detection value of the DC current detector being inputted. An operation circuit that outputs a trip command to the DC breaker when the value exceeds a predetermined value.A DC simulation circuit that outputs a value simulating a detection value of the DC current detector. A generator and a simulation signal display for displaying an output value of the simulation signal generator, wherein an output value of the simulation signal generator is input to the operation circuit instead of a detection value of the DC current detector. An automatic scale tester for DC breakers. 2. A DC breaker inserted in a DC main circuit, a DC current detector for outputting a value proportional to a current flowing in the DC main circuit, and a detection value of the DC current detector. And an operation circuit for outputting a trip command to the DC breaker when the value exceeds a predetermined value.The operation of the connection wire between the DC current detector and its operating power supply. A first connector for simultaneously disconnecting and disconnecting a connection wire between the DC current detector and the operation circuit; and a simulation signal generator for outputting a value simulating a detection value of the DC current detector. A simulation signal display for displaying an output value of the simulation signal generator, an end of a wire for supplying power for operation to the simulation signal generator and the simulation signal display, and an output value of the simulation signal generator. The second wire provided at the end of the wire to be transmitted A second connector compatible with the first connector, wherein one of the first connectors when the electric wire is disconnected by the first connector and the second connector are connected, and the simulated signal generator and the simulated signal are simulated from the operation power supply. An automatic scale tester for a DC circuit breaker, which supplies power to a signal display and supplies an output value of the simulation signal generator to the operation circuit. 3. The automatic graduation tester for a DC circuit breaker according to claim 1, wherein said simulated signal generator is configured to output a trip command when said operating circuit outputs a trip command. An automatic scale tester for a DC circuit breaker, comprising an integrator configured to hold the output value of the DC breaker. 4. The automatic graduation tester for a DC breaker according to claim 1, wherein the simulated signal generator has an auxiliary contact of the DC breaker indicating an open circuit of the DC breaker. An automatic scale tester for a DC circuit breaker, comprising an integrator configured to hold the output value of the simulation signal generator at the time of the execution.