JPH0611305U - Current limiting device - Google Patents

Abstract

(57) [Summary] [Purpose] To simplify the structure of the resistor of the current limiting device that suppresses the fault current in the event of a short circuit or ground fault. A resistor 9a, in which a resistor 3a is wound around a spiral groove having a distance such that adjacent portions of the insulator 2a do not contact each other,
Similar to the resistor 9a, the insulator 2b and the resistor 9b formed by the resistor 3b are connected in parallel to the main contactor 1 and provided to face each other. Resistor 9 is provided at the end of resistors 9a and 9b.
An arc extinguishing chamber 4 for drawing in and extinguishing an arc 7 traveling along a and 9b is connected, and a limiting resistor 5 is provided in parallel with the main contact 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a current limiting device.

[0002]

[Prior art]

 It is well known that when a short circuit accident or a ground fault occurs in a power system, a fault current can be suppressed by inserting a resistor into the system.

FIG. 2 shows an example of a conventional current limiting device, in which a main contact 1 is connected in series to a main circuit 6 so as to open the electrode when an accident current is detected and generate an arc. The resistors 9a and 9b on which the arc 7 generated in the main contact 1 travels are connected in parallel to the main contact 1 and are arranged to face each other. When an accident is detected, the movable contactor 1b of the main contactor 1 opens, an arc 7 is generated, and the arc 7 is driven by the electromagnetic force generated by the current and magnetic field of the arc 7 itself, and the arc 7 moves on the resistors 9a and 9b. The vehicle runs in a direction away from the main contact 1. As a result, the path of the accident current is the fixed contact 1a, the resistor 9a, the arc 7, the resistor 9b, and the fixed contact 1c, and resistance is inserted into the system in proportion to the distance traveled by the arc 7. After traveling through the resistors 9a and 9b, the arc 7 is drawn into the arc extinguishing chamber 4 and extinguished at the first current 0 point. As a result, the fault current is commutated to the limiting resistor 5, the current limiting device performs a stable current limiting, and waits until it is disconnected by the circuit breaker.

Conventionally, the resistors 9a and 9b are formed on both sides of the metal body 10 in order to bend the metal body 10 in a bellows shape as shown in FIG. The arc travel path 12 is provided by pasting an insulator film 11 on and then cutting to insert resistance into the system.

[0005]

[Problems to be solved by the device]

 However, in the conventional resistors 9a and 9b of the current limiting device, for example, when a copper plate having a thickness t of 0.3 mm and a width A of 20 mm is used for the metal body 10 and the bending length B is 50 mm, In order to obtain the required resistance value, the total length is about 140 m and the number of bending times is about 2000 times, which makes the structure complicated and difficult to manufacture.

Therefore, the present invention changes the structure of the resistor to facilitate manufacturing.

[0007]

[Means for Solving the Problems]

 In the present invention, a pair of resistors, which are connected in parallel to the main contactor and are arranged to face each other, have a structure in which a resistor is wound around an insulator having spiral grooves.

[0008]

[Action]

 Since the resistor of the current limiting device configured as described above has a structure in which the resistor is wound around an insulator having a spiral groove, it is easy to manufacture.

[0009]

【Example】

 FIG. 1 shows an example of a current limiting device according to the present invention, which is connected to a main contact 1 in parallel with resistors 9a and 9b arranged opposite to each other, and to the ends of the resistors 9a and 9b. The arc-extinguishing chamber 4 and the limiting resistor 5 connected in parallel with the main contact 1. The resistor 9a has a resistor 3a wound around a spiral groove of the insulator 2a. Here, the spiral grooves are formed at intervals such that adjacent portions of the resistor 3a do not come into contact with each other and a potential difference generated when a fault current flows through the resistor 3a is maintained. One end of the antibody 3a is connected to the fixed contact 1a, and the other end is connected to the arc extinguishing chamber 4. Similarly, the resistor 9b is also formed by the insulator 2b and the resistor 3b. One end of the resistor 3b is connected to the fixed contact 1c, and the other end is connected to the arc extinguishing chamber 4.

When an accident is detected, the movable contactor 1b of the main contactor 1 opens, and an arc 7 is generated. The arc 7 is driven by the electromagnetic force generated by the current and magnetic field of the arc 7 itself, and the arcs 7 face each other in resistance. It runs on the resistors 3a, 3b between the devices 9a, 9b in the direction away from the main contact 1. As a result, the path of the fault current is the fixed contact 1a, the resistor 3a, the arc 7, the resistor 3b, and the fixed contact 1c, and the resistance is inserted into the system in proportion to the distance traveled by the arc 7. After traveling through the resistors 9a and 9b, the arc 7 is drawn into the arc extinguishing chamber 4 and extinguished at the first current zero point. As a result, the fault current is commutated to the limiting resistor 5, the current limiting device performs a stable current limiting, and waits until it is disconnected by the circuit breaker.

[0011]

[Effect of device]

 According to the present invention, a resistor for a current limiting device can be manufactured more easily than before.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a current limiting device of the present invention.

FIG. 2 is a diagram showing an example of a conventional current limiting device.

FIG. 3 is a perspective view showing the structure of the resistor.

[Explanation of symbols]

 1 Main Contact 1a, 1c Fixed Contact 1b Movable Contact 2a, 2b Insulator 3a, 3b Resistor 4 Arc-Extinguishing Chamber 5 Limiting Resistance 6 Main Circuit 7 Arc 9a, 9b Resistor 10 Metal Body 11 Insulator Film 12 Arc Road

Claims (1)

[Scope of utility model registration request] 1. A pair of resistors connected to the main contact in parallel and arranged to face each other, an arc-extinguishing chamber connected to the ends of the pair of resistors, and connected in parallel to the main contact. And a limiting resistor, wherein each of the pair of resistors has a structure in which a resistor is wound around an insulator having a spiral groove.