JP2502103Y2 - SOG control device trip circuit - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trip circuit of a SOG (Storage Overcurrent Ground) control device installed at a high-voltage customer or a power receiving point.

[0002]

2. Description of the Related Art A conventional apparatus of this type is shown in FIG.
As shown in FIG. 5, the detailed circuit is composed of a control device 10 and a switch 20, a ground fault relay 11 is connected to the power supply 30 side of the control device 10, and a current limiting resistor R ₁ , a rectifier D and a capacitor C are connected. A capacitor charging circuit for accumulating trip is formed by the above, and the overcurrent detection device 12 is operated by the voltage appropriately divided by the resistors R ₂ and R ₃ . Reference numeral 13 is a contact of the trip output relay m.

Inside the switch 20, a trip coil 21 is provided.
Is a switch trip mechanism interlocking contact 22, an overcurrent detector CT
It is connected to the power supply line via the contact 23 of ₁ and the contact 24 of the overcurrent detector CT ₂ .

When a ground fault occurs, the ground fault current is detected by the zero-phase current transformer ZCT, and the ground fault relay 11 of the SOG controller 10 is detected.
Input to the switch, the output relay m is activated, the trip coil 21 of the switch 20 is excited, and the switch 20 is opened. Therefore, normally, the voltage between P _{1 and} P ₂ becomes no voltage after the switch is opened due to a ground fault.

At the time of overcurrent protection, after the power supply 30 becomes unvoltage due to the overcurrent accumulation trip, the capacitor C
The energy stored in the capacitor C → the relay contact 13 for tripping → the switch trip mechanism interlocking contact 22 →
The trip coil 21 is excited by the path of the trip coil 21, the switch is opened, and the switch trip mechanism interlocking contact 22 is opened.

FIG. 6 is a time chart during the above operation. (A) is the operation of the contact 13, (b) is the operation of the contact 22, (c) is the voltage change across the trip coil 21,
(D) shows the voltage across the capacitor C. As shown in this figure, during ground fault and overcurrent protection, the current flowing in the trip coil 21 is cut off by the switch trip mechanism interlocking contact 22 with a large breaking capacity, so the trip relay contact 13 is cut off. Does not require capacity.

[0007]

In this conventional circuit, in order to improve the reliability of the switch, it is desired to delete the switch trip mechanism interlocking contact 22, but if it is simply deleted, the following problem will occur.

The tripping coil 21 is excited and tripped by the trip of the power source 30, the capacitor C, the tripping relay contact 13 and the tripping coil 21 by the tripping operation at the time of ground fault protection. Circuit break is performed by the trip relay contact 13 because the switch trip mechanism interlocking contact 22 is deleted. However, since the conventional contact 13 lacks the breaking capacity, the output relay m has a large breaking capacity. There is a problem that has to be a relay.

However, at the time of overcurrent protection, the trip coil 21 is excited in the path of the capacitor C → tripping relay contact 13 → tripping coil 21, and the trip relay contact 1
When 3 is cut off, a small residual energy of the capacitor C is cut off, so the trip relay contact 13
Can be easily shut off even if it is small.

Therefore, the problem to be solved by the present invention is to provide a circuit which does not need to use a large relay even if the switch trip mechanism interlocking contact 22 is deleted.

[0011]

In order to solve this problem, the trip circuit of the SOG control device of the present invention is designed to connect a capacitor for tripping energy and a circuit on the power supply side, for exciting the trip coil and the trip coil. It is characterized in that an output contact of a control device for selectively switching connection with a circuit is provided.

[0012]

[Function] Normally, the capacitor is connected to the power supply side circuit and is charged to a predetermined voltage, but when the contact operates during ground fault protection, the capacitor is disconnected from the power supply side circuit and used for trip coil excitation. Switch to the circuit. The trip coil is excited by the electric charge stored in the capacitor and trips the switch, but then the potential across the capacitor is attenuated by the circuit time constant and finally becomes zero. After that, the contacts are restored. This eliminates the need to upsize the tripping main relay of the controller.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. In the figure, the elements having the same functions as those of the conventional circuit shown in FIG.

In the first embodiment shown in FIG. 1, a double throw contact 14 is used in place of the conventional trip relay contact 13, the common terminal is connected to the capacitor C, and the normally closed contact is connected to the power circuit side. , The normally open contact is connected to the trip circuit side.

In FIG. 1, when a ground fault or an overcurrent accident occurs in the high-voltage customer, the contact 14 is activated and the switch 2
Open 0 to prevent unnecessary power outages on distribution lines. Figure 2 shows the contact operation in case of a ground fault. When the ground fault is detected, the contact 14 of the output relay m (see FIG. 4) is switched to the trip circuit side. As a result, the electric charge stored in the capacitor C flows into the trip coil 21, the trip coil 21 is excited (FIG. 2B), and the switch 20 is opened. After the trip coil 21 is actuated, the electric charge stored in the capacitor C is rapidly attenuated as shown in FIG. 2C, and when the output relay m is restored, the breaking current is almost zero. Therefore, the output relay m may be a small relay having a small breaking capacity.

FIG. 3 is a circuit diagram showing a second embodiment of the present invention. In this example, the switching contacts 15 and 16 are used to perform the same operation.

[0018]

As described above, the present invention has the following effects.

Since the control contact inside the switch can be eliminated, the reliability is improved and the cost can be reduced.

Since the main trip relay for the control device does not have to be large, the shape does not become large and the cost does not increase.

[Brief description of drawings]

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

FIG. 2 is a time chart of each part showing the operation of the first embodiment.

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

FIG. 4 is a circuit diagram showing an overall configuration of a conventional SOG control device.

FIG. 5 is a circuit diagram showing details of a conventional example.

FIG. 6 is a time chart of each part showing the operation of the conventional example.

[Explanation of symbols]

10 control device, 11 ground fault relay, 12 overcurrent detection device, 13 tripping relay contact, 14, 15, 16
Contact, 20 switch, 21 trip coil, 22
Switch trip mechanism interlocking contact, 23, 24 Overcurrent detection device 12 contact, 30 power supply

Claims (1)

(57) [Scope of utility model registration request] 1. An output contact of a control device for selectively switching connection between a capacitor for energy storage trip and a circuit on a power source side and connection between the capacitor and a circuit for trip coil excitation. SOG control device trip circuit.