SU813519A1 - Switching-over device contactor - Google Patents

Description

(54) SWITCHING DEVICE CONTACTOR

This invention relates to load control devices for load voltage (RPN) in high power transformers and reactors. The contactors of the on-load tap-changers are made with main and arcing contacts. The main contacts pass most of the load current for a long time — between device switches. It is desirable that these contacts are not subjected to electrical power when switching the contactor. The arcing contacts pass only a small part of the load current in the continuous mode and the entire current through fractions of a second in the process of switching the contactor. Such devices include contactors with vacuum arc-suppressing chambers (VDK), since VDK contacts, used in on-load tap-changers, are capable of transmitting currents for only a few hundred amperes, except for -fysro, VDK are unstable to short-circuit currents. It is advisable to use massive multipoint main contacts in order to avoid sparking, increased mechanical wear and increase the size of the contactor to switch from a low speed from the drive, and arcing to a high speed from the energy storage device. A device for switching the load for stepwise transfo; In this case, in which the main, auxiliary H arcing (VDK) contacts are switched by means of three pumps, the pistons of which are kinematically connected to the ground-body, the valve and the hydraulic transmissions Cl. However, since all contacts are switched from the same drive unit, their speeds must be great. Failure to tight hydraulic transmissions violates the contact sequence, which leads to an accident. Closest to the proposed technical entity is the actuator of the contactor switching device for controlling the voltage of transformers under load, which performs three-step control of the contacts with different switching speeds: the actuator is a cam drum, moves at a low speed from the electromechanical drive the initial and final sections, while switching the main contacts. In the middle section, the drum moves from the springs at high speed, switching the VDC contacts. The joint motion of the drum and the drive shaft of the contactor in the initial and final portions is carried out with the help of spring-loaded balls, which enter both the holes in the shaft and roll in the drum. Before starting the accumulator of energy of the spring - the balls are extruded from the holes of the drum with the help of the profiled part 2.

The disadvantages of this contactor mechanism are the complexity of the ball follow-up and drum disengagement mechanism; large wear of the holes in the shaft and drum, in which there are balls; lack of reliability, due to the fact that the balls must quickly jump into the hole of the drum at the end of the last turn from; springs, otherwise there will be no joint movement of the shaft and the drum in the last section.

The purpose of the invention is to increase the reliability and increase the service life of the contactor.

The goal is achieved by the fact that the contactor of the switching device for regulating the voltage of transformers under load, containing the main and arcing contacts, the actuator, the energy accumulator, the locking and disconnecting mechanism of the actuator, is equipped with two single-rod hydraulic cylinders, on the rods of which there are movable main contacts of the contactor , two-rod hydraulic cylinder, with the rods of which the executive body is connected, and two end mechanically operated two-position spools interacting with the executive body of the contactee and having a hydraulic connection with the middle part of the two-rod hydraulic cylinder and with the front cavities of single-rod hydraulic cylinders hydraulically connected with the extreme parts of the two-rod hydraulic cylinder and with hydraulic actuator.

Such a constructive solution provides for a strictly sequential switching of massive main contacts at low speed from hydraulic input and lighter arcing contacts at high speed from springs -. This leads to an increase in the reliability of the contactor by reducing the mechanical wear of the main contacts and the absence of their electric erosion from arcing, as well as better maintaining the switching speed of the arcing contacts.

FIG. 1 shows a diagram of a single phase contactor; in fig. 2 illustrates an example of the use of a hydraulic actuator. To control the contactor of FIG. one.

The hydraulic actuator 1 includes an electric motor with hydraulic pump, hydraulic distributor, control hydraulic equipment, hydraulic transmissions of voters. A control valve, such as a spool type, is connected hydraulically with lines 2-5 to single-rod hydraulic cylinders 6 and 7, the rods of which are movable main contacts of the contactor. Current collector contacts 8 and 9 are electrically connected to the common point of the contactor, and contacts 10 and 11 are connected to groups of contacts of the voter. The hydraulic cylinders 6 and 7 are connected hydraulically by pipes 12 and 13 to the extreme parts of the two-rod hydraulic cylinder 14, and the pipes 15 and 16 are connected to two-way mechanically controlled spools 17 and 18, which are connected hydraulically to the middle part of the hydraulic cylinder 14 by pipes 19 and 20. The rods of this hydraulic cylinder are rigidly connected to the frame 21, which is elastically connected by means of the spring 22 to the actuating member 23, which, during its movements with the profile surfaces, acts on the levers 24 and 25, switching arcing contacts 26 (moving) vacuum arc suppression chambers 27.

 When the piston of the hydraulic cylinder 14 moves and cocking the spring 22, the actuator 23 stops with the help of the latch 28. The actuator 23 is released from the stopper at the end of the charging of the spring 22 with the help of lugs 29 fixed on the frame 21. The lugs 29 with the latch levers 28 are the mechanism uncoupling. In the case of use for controlling the hydraulic contactor, the pipelines 2-5 (Fig. 2) are hydraulically connected to the distribution spool 30. The overall design of the spool and the other hydraulic connections remain unchanged. The spool of the OZO is hydraulically connected by pipelines 31 and 32 to the hydraulic cylinders of the selector 33, pipelines 34, 35 and 36 to the control direction spools and the pumping line of the hydraulic pump. The spool rotor is mechanically coupled to the hydropushers. All of the latter elements are indicated by block 37. Pipe 38 connects the hydraulic transmissions of the selector 33 to the control direction slide spool block 37, 39, 40 and 41 - annular grooves with the slots of the spool rotor 30. The circles on the body of the spool 30 are marked.

The operation of the contactor when switching to one stage of adjustment is carried out as follows.

After starting the electric motor with the hydraulic pump, switching the spool valves at node 37,

turning the spool 30 by one step, turning on the contact of the voter (oil enters the hydrocylinder voter through the pipeline 34, the spool 30 and one of the pipelines 31) oil passes through the pipe 32 into the groove 40 of the spool 30 (FIG. 2) and further along the pipeline 2 (FIG. 1) enters the rod end of the hydraulic cylinder 6 and turns off the right main contact. Breaking the electrical connection between pins 8 and 10 When moving the piston of the hydraulic cylinder 6, the oil is drained from the front cavity through conduit 15 through the spool 17, through conduits 19, 13 and 4, the annular groove 39 of the spool 30, which is always connected to the drain - the transformer tank. Pipeline 3 is locked by the spool rotor 30. If the piston of the hydraulic cylinder 14 (oil enters the pipeline 12) moves due to the increased pressure drop on the discharge line, the valve 17 will switch from its spring and the drain will directly pass through it. After the full displacement of the piston of the hydraulic cylinder 6, the oil through the pipeline 12 enters the right cavity of the hydraulic cylinder 14 and begins to move its piston to the left together with the frame 21. At the same time, the right part of the spring 22 is compressed and its left part is stretched as the executive body 23 of the contactor remains stationary, locked by a latch 28 From the left cavity of the hydraulic cylinder 14, the oil is drained through a pipe line 13 and 4, an annular groove 39 of the valve 30. At the end of the displacement of the piston of the hydraulic cylinder 14, the protrusion 29 retracts the latch lever 28 and the executive RGANI 23 under the action of the spring 22 rapidly moves to the left. In this case, the actuator 23 with its own: with its spherical surfaces turns the levers 24 and 25, which with their other arms switch the moving contacts 26 of the vacuum arcing chambers 27 at high speed. In the movement of the actuator, the actuator 23 switches the spool with its emphasis 18. Oil from the cylinder cavity 14 flows through the pipeline 20. through the valve 18, the pipeline 16 into the front cavity of the hydraulic cylinder 7 of the left main contact. After the piston of the hydraulic cylinder 7 is moved, its rod electrically connects contacts 9 and 11. Drain the oil from the rod end of the hydraulic cylinder 7 through pipe 4 and the annular groove 39. After full movement of the hydraulic cylinder-7 piston

to the left the oil through the pipeline 5, the annular groove 41 of the spool 30, the third pipe through the distributor 37, one of the pipelines 35, through the spool 30 and one of the pipelines 31 goes to disconnect the contact-selector 33.

Thus, the proposed device of the contactor allows to switch the contacts of the contactor strictly sequentially and at different speeds:

0, the main contacts are switched from the hydraulic drive with a low speed determined by the hydraulic pump capacity and the sizes of single rod hydraulic cylinders 6 and 7. The arcing contacts 5 — VDC contacts — are switched from the spring 22 at a high speed determined by the characteristic of the spring, moving masses, gear, and cam

0 profiles of the actuator 23 and the levers 24 and 25. The use of a hydraulic actuator allows plug-in main contacts of the contactor, which reduces the size of the contactor, especially for large currents — over 2000 A.

5 All this increases the reliability and service life of the contactor.

Claims (2)

1. The patent of Switzerland No. 497815, cl. H 02 R 13/06, 1971. 2. USSR author's certificate number 517060, cl. H 01 F 29/04, 1975. ff