RU85260U1 - AUTOMATIC OPERATING SWITCH ELECTROMAGNETIC DRIVE - Google Patents

Abstract

An electromagnetic drive of an automatic high-speed circuit breaker, comprising a magnetic circuit, an armature and a control coil, characterized in that an additional coil is arranged on the magnetic circuit, in which a capacitor and a forcing contact are mounted, the electric circuit of the additional coil being divided by a switch having one normally open and one normally closed contacts, with an electric circuit of a series-connected capacitor and boost contact.

Description

The utility model relates to electrical engineering, in particular, to electromagnetic drives of switching devices.

Electromagnetic drives as part of high-speed automatic circuit breakers are known from the following sources:

1. Patent for the invention №2334299 RU, 2007;

2. Power equipment of traction substations of railways (collection of reference materials). JSC Russian Railways, a branch of the Design Bureau for Electrification of Railways. - M.: “TRANSIZDAT”, 2004, p.238-242.

3. Reference for the adjustment of electrical equipment of industrial enterprises. Ed. M.G. Zimenkova, G.V. Rosenberg, E.M. Feskova. - 3rd ed., Revised. and add. - M .: Energoatomizdat, 1983, p. 236-238.

The closest to the patentable should be considered an electromagnetic drive by the first source. It contains a magnetic circuit with a control coil located on its central core, the main anchor and the free trip anchor.

When the electromagnetic drive is turned on, a switching current flows through the control coil, while the main armature and free trip armature are attracted to the magnetic circuit (upstream position). To ensure free tripping of the circuit breaker, an upstream position is provided, provided by the free tripping anchor. Then, the switching current of the coil is transferred to the holding, much smaller value. In this case, the free trip anchor drops from the magnetic circuit, and the main anchor remains in the pulled position.

When the switch is turned off, the current in the coil stops. The magnetic flux in the magnetic circuit gradually decreases and reaches the value at which the main armature cannot be held in an attracted position. Drive moves to off position.

The disadvantage of this electromagnetic drive is a rather long time when the main armature falls off the magnetic circuit at the moment the circuit breaker disconnects the short circuit due to the long-term decay of the magnetic flux in the magnetic circuit, which is extremely undesirable when extinguishing large emergency currents.

The objective of the utility model is the creation of an electromagnetic drive circuit breaker automatic high-speed reliable in operation.

The technical result achieved in the claimed utility model is to increase performance by reducing the time for the decay of the residual magnetic flux of the magnetic circuit.

The specified technical result is achieved in that the electromagnetic drive, consisting of a magnetic circuit, an armature and a control coil, has an additional coil connected in series with a capacitor and an forcing key, and the electric circuit of the additional coil is divided by a switch having one normally open and one normally closed contacts, with an electric circuit of a series-connected capacitor and boost contact.

With this embodiment of the electromagnetic drive, it becomes possible to control the residual magnetic flux of the magnetic circuit during the shutdown process, namely, to reduce the time for demagnetization of the magnetic circuit. Thus, the speed of the electromagnetic drive is achieved.

The utility model is illustrated by an example implementation. Figure 1 schematically shows the electromagnetic drive of a circuit breaker automatic high-speed when turned on, figure 2 is the same at the time of shutdown.

The electromagnetic drive of the automatic high-speed circuit breaker contains a magnetic circuit 1, an anchor 2, a control coil 3. An additional coil 4 is attached to the magnetic circuit 1. A capacitor 5 and a boost contact 6 are connected in series to the terminals of the additional coil 4. The electrical circuit of the capacitor 5 and the boost contact 6 are connected in series the electric circuit of the auxiliary coil 4 with a switch having one normally closed contact 7 and one normally open contact 8.

The electromagnetic drive circuit breaker automatic high-speed operates as follows.

When the electromagnetic drive is turned on, a switching current is supplied to the control coil 3. At this point, the boost contact 6 is open (figure 1). Under the action of the current of the control coil 3, a magnetic flux is created in the magnetic circuit 1, which develops sufficient electromagnetic force to drive the armature 2. The armature 2 is attracted to the magnetic circuit 1. After a certain period of time (usually 0.5 seconds), the current in the control coil 3 switches from inclusive to holding, much smaller in size. Simultaneously with the switching of the current, the force contact 6 is switched to the on position. In the magnetic circuit: an additional coil — normally closed contact 8 of the switch — forcing key — capacitor (4-8-6-5) - self-induction EMF occurs and capacitor 5 is charged. In this case, the armature 2 remains attracted to the magnetic circuit 1. In the event of an emergency mode (short circuit current), the current in the control coil 3 decreases to zero. Since the magnetic flux in the magnetic system does not stop instantly, therefore, the armature 2 does not immediately fall away from the magnetic circuit 1, but only after a certain period of time, which is necessary for the demagnetization of the system. For a quick shutdown, it is necessary to discharge the capacitor 5 to an additional coil 4. For this, the contacts 7 and 8 of the switch are switched respectively to the on (for contact 8) and off (for contact 7) positions. In this case, the capacitor is discharged to an additional coil 4, which creates a magnetic flux in the magnetic circuit 1 directed in the opposite direction to the residual magnetic flux. The magnetic circuit 1 will immediately demagnetize, and therefore the anchor 2 will fall away from the magnetic circuit 1 with a sufficiently high speed.

Thus, due to the use of an additional coil, capacitor, boosting key and switch in the electromagnetic drive device, the speed of operation of the electromagnetic drive during shutdown is achieved, and therefore, high reliability of both the drive and the switch in which it is built is ensured.

Claims (1)

An electromagnetic drive of an automatic high-speed circuit breaker, comprising a magnetic circuit, an armature and a control coil, characterized in that an additional coil is arranged on the magnetic circuit, in which a capacitor and a forcing contact are mounted, the electric circuit of the additional coil being divided by a switch having one normally open and one normally closed contacts, with an electric circuit of a series-connected capacitor and boost contact.