SU1198601A1 - High-speed automatic circuit breaker - Google Patents

Description

The invention relates to electrical engineering, in particular to protective circuit breakers, designed to automatically turn off electrical circuits during current overloads, short circuits and can be used primarily to protect semiconductor converter plants and thyristor drives of low and medium power.

The aim of the invention is to increase ι speed by ensuring the opening of one of the contact pairs with a time delay.

FIG. 1 shows a high-speed circuit breaker in the first shutdown stage; in fig. 2 - the same, 1 in the open position; in fig. 3 - the same, in the closed position.

High-speed circuit breaker includes a housing 1, arcing chambers 2, a double-break contact system with a fixed contact 3 and moving contacts 4 located on either side of the contact 3, a switching mechanism consisting of a sleeve 5 installed in the guides 6 of the housing 1.

In the hole of the sleeve 5 is inserted into the rod 7, which is held in the sleeve 5 using the stop 8, made on the upper end of the rod 7. The rod 7 serves for kinematic communication between the actuator (not shown) and the sleeve 5. The sleeve 5 is pivotally connected to the movable contacts 4 when levers 9 and 10. At the junction of the lever 10 with the sleeve 5 or with the contact 4 in one of the hinged parts, for example in the sleeve 5, a groove 11 is made to allow the lever 10 to idle. So that the moving and fixed contacts are connected time after tel. The length of the groove 11 is determined by calculation and depends on the time required for the offensive.

current limiting since the start of the shutdown. The movable contacts 4 are connected to current-carrying tires 12 and equipped with a spring "13 contact pressing.

High-speed circuit breaker operates as follows.

When moving the rod 7 down under the action of the actuator, the sleeve 5 also moves together with the rod 7 down due to interaction with the stop 8. In turn, the sleeve 5 moves the levers 9 and 10, while the lever 9 simultaneously opens the corresponding contact pair and the lever 10 at the initial moment of time it moves in the groove 11 of the sleeve 5 to idle until the onset of current limitation, provided by the opening of the first contact pair. In this case, the opposing force is halved, which allows to increase the speed of the switch and, consequently, to accelerate the process of current limiting. Further movement of the sleeve 5 down allows you to move through the levers 9 and 10 contacts 4 to obtain a complete solution, overcoming the resistance of the compressive springs 13. In the lowest position of the sleeve 5, the levers 9 and 10 are set at an angle to its longitudinal axis close to 99 °. As a result, the resultant force acting along the levers 9 and 10 changes the sign to the opposite and equalizes the action of the cocked springs 13, i.e. the contacts 4 are on the stop, providing a reliable open circuit.

The switch is turned on when the rod 7 of the sleeve 5 moves upwards, which moves the levers 9 and 10 through the horizontal position, thereby releasing the springs 13. The latter carry out further displacement of the levers 9 and 10, thereby bringing together the contacts 4 with the contact 3 and ensuring the specified contact pressure.

1198601

FIG. 2

1198601

FIG. 3

Claims (2)

1. A QUICKLESS AUTOMATIC SWITCH, comprising a housing, arcing chambers, a contact system with two contact pairs, an actuation mechanism with a rod and a sleeve, and an articulated lever mechanism for coupling the contact system with an actuation mechanism, the levers of which are located symmetrically relative to the actuator stem, differing that, in order to increase speed by ensuring the opening of one of the contact pairs with a time delay, the contact system is designed as a fixed and two moving contacts, and in the place of one of the articulated joints of the hinge-lever mechanism with other elements of the switch in the lever or in the specified switch element connected with it, the groove is made so that the connection of the moving and fixed contacts is carried out sequentially in time. 2. Switch on π. 1, characterized in that the groove is made in the sleeve. with one 3 1198601 > FIG. one 2 119860!