JPH0545867U - SOG control device trip circuit - Google Patents

Abstract

(57) [Summary] [Structure] The connection between the storage capacitor (C) and the circuit on the power supply side, and the connection between the capacitor (C) and the trip coil (21) excitation circuit are selectively switched. A trip circuit of an SOG controller provided with an output contact (14) of the controller (10). [Effect] Since the control contact inside the switch (20) can be eliminated, the reliability is improved and the cost can be reduced. Since the main trip relay of the control device (10) does not have to be large, the shape does not become large and the cost does not increase.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a trip circuit of a SOG (Storage Overcurrent Group) control device installed at a high-voltage customer or a power receiving point.

[0002]

[Prior Art]

This type of conventional device comprises a control device 10 and a switch 20, as shown in the overall configuration of FIG. 4 and the detailed circuit of FIG. 5, and a ground fault relay 11 is connected to the power source 30 side of the control device 10. , A current limiting resistor R ₁ , a rectifier D and a capacitor C form a capacitor charging circuit for energy storage trip, and the overcurrent detection device 12 is activated by a voltage appropriately divided by the resistors R ₂ and R ₃ . Has become. Reference numeral 13 is a contact of the trip output relay m.

[0003] Inside switch 20, connected to the power supply line via a mechanism interlocking contact 22 tripping the tripping coil 21 switch, over-current detector CT ₁ contact 23, the overcurrent detector contacts 24 of CT ₂ Has been done.

When a ground fault occurs, the ground fault current is detected by the zero-phase current transformer ZCT and is input to the ground fault relay 11 of the SOG control device 10 to activate the output relay m, thereby switching the switch 20. The trip coil 21 is excited to open the switch 20. Therefore, normally, the voltage between P _{1 and} P ₂ becomes zero after the switch is opened due to the ground fault.

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

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, and (d) is The voltage across the capacitor C is shown. 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]

[Problems to be solved by the device]

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

The tripping operation at the time of ground fault protection causes the tripping coil 21 to be excited and tripped by the path of the power supply 30 → capacitor C → tripping relay contact 13 → tripping coil 21. Circuit breaker will be performed at the trip relay contact 13 because the switch trip mechanism interlocking contact 22 has been deleted. However, the conventional contact 13 lacks the breaking capacity, so the output relay m has a high breaking capacity. There is a problem in making a large relay.

However, at the time of overcurrent protection, the trip coil 21 is excited along the path of the capacitor C → the trip relay contact 13 → the trip coil 21, and when the trip relay contact 13 is cut off, the capacitor C is disconnected. Since a small amount of residual energy is cut off, even if the trip relay contact 13 is small, it can be easily cut off.

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

[0011]

[Means for Solving the Problems]

 In order to solve this problem, the trip circuit of the SOG control device of the present invention selectively connects the capacitor for the energy storage trip and the circuit on the power supply side, and the connection between the capacitor and the circuit for trip coil excitation. It is characterized in that an output contact of the control device for switching is provided.

[0012]

[Action]

 Normally, the capacitor is connected to the circuit on the power supply side and charged to a specified voltage, but when the contact operates during protection against ground fault, the capacitor is disconnected from the circuit on the power supply side and switched to the trip coil excitation 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. Then reset the contacts. This eliminates the need to upsize the main trip relay of the controller.

[0013]

【Example】

 Hereinafter, the present invention will be described in detail based on embodiments.

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. In the figure, elements having the same functions as those of the conventional circuit shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment shown in FIG. 1, a double throw type 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 supply 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 to open the switch 20 and prevent unnecessary power failure of the distribution line. Figure 2 shows the contact operation during 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 to 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. 2 (c), and the cutoff current is almost zero when the output relay m 1 is restored. 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]

[Effect of the device]

 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 tripping main relay of the control device does not have to be made 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)

[Scope of utility model registration request] 1. An output contact of a control device is provided for selectively switching connection between a storage trip capacitor and a circuit on the power supply side and connection between the capacitor and a trip coil excitation circuit. The trip circuit of the SOG controller.