BG65708B1 - Power switch with vacuum arc-damping chambers for step voltage regulator - Google Patents

Abstract

The power switch is designed for switching under load of the deviations of the regulating winding of a power transformer, and in this way ensuring voltage adjustment of an operating transformer. The use of vacuum arc-damping chambers (ADC) does not result in any soiling of the insulation medium of the transformer, which may be transformer oil or elegas (CF6). Each phase of the power switch has two main ADCs switching off only the operational current, and one supplementary ADC switching off only the circulation current. In this way high electrical wear resistance is guaranteed. The application of ADC disconnectors connected in series can ensure improved pulse strength in degree. Parallel ADC contact systems can be used for increasing the rated current. The two main ADCs (1, 2) are connected by a known selector to two adjacent deviations (I, II) of a regulation winding (10). The supplementary ADC (3) is connected in series with a current limitation resistor (4) and in parallel of the closed main ADC by means of a switching contact unit (5, 6, 7). In case the main ADC (1, 2) cannot guarantee the desired pulse strength in degree, disconnectors (11, 12) are connected to them in series.

Description

Technical field

The invention relates to a power switch for a step voltage regulator, in which vacuum arc chambers are applied in order not to contaminate the insulation medium. It can be used both in oil transformers, and the transformer with an insulating medium gas (gas SF _6).

BACKGROUND OF THE INVENTION

A power switch with vacuum arc chambers (1) is known, comprising two main vacuum arc chambers and a switching contactor with a series resistor. The cam shaft is connected to the movable parts of the vacuum damping chambers and to the switching contact assembly. The hump channels are profiled such that the switching contact assembly first switches and connects the resistor in parallel to the open vacuum choke chamber after opening the closed vacuum choke chamber.

A disadvantage of the known power switch is that electric arcs appear when the switch is switched on. Therefore, the contamination of the transformer oil, which is the purpose of the use of vacuum damping chambers, is not avoided. Another disadvantage is that main booster chambers exclude sums from the rated and circulating current. This reduces electrical wear resistance. The disadvantage is that the degree isolation and the rated current are only provided by the vacuum damping chambers.

Also known is a power switch with vacuum choke chambers (2), comprising two main choke chambers and one auxiliary vacuum choke chamber, connected in series to the resistor and in parallel to only one main vacuum choke chamber, as a switching contact unit. Vacuum chambers are controlled by a drive shaft and a cam.

With this power switch, only the first drawback of / 1 / is avoided - the transformer oil is not contaminated and all other drawbacks remain.

Also known is a third power switch with vacuum choke chambers / 3 /, comprising two main vacuum choke chambers, a resistor with a sequentially connected auxiliary vacuum choke chamber and a switching contact assembly. The control of the switching contact assembly is carried out by the slow movement of the feeder of the switching springs mechanism and is intended only for transformers with unidirectional energy transfer. The power switch has a contact node parallel to the operating vacuum arc extinguisher, which is switched by slow motion.

The disadvantage of this power switch is that it is very complex and not versatile for use in any load-adjustable transformers. A disadvantage is that the insulation level is determined solely by the solution of the vacuum damping chambers, which is insufficient for transformers of higher voltage class. Another disadvantage is that the parallel contact unit opens before the jump start and if the motor drive is stopped due to power supply failure, it does not protect the vacuum choke chamber.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a power switch with vacuum arc chambers for a step voltage regulator that is of simplified construction and universal application. The main vacuum choke chambers shall only switch off the rated current and the auxiliary vacuum choke chamber only the circulating current. The power switch provides a higher insulation level of degree and a higher rated current than those guaranteed by vacuum arc chambers. Power switch allows different modifications to be used for all applications in load-adjustable applications

65708 B1 power transformers, including those with insulating medium elegas (SF ₆ gas).

The problem is solved by a power switch with vacuum arc chambers for a step voltage regulator comprising two vacuum arc chambers connected to an odd and odd fixed contact element; an auxiliary vacuum extinguisher chamber connected in series to a resistor and a switching contact unit, driving a control shaft with a command cam attached thereto and parallel to the closed main vacuum arc extinguisher chamber, a contact assembly, according to the invention prior to commencement of the switching chamber, resistors are connected by the switching contact assembly in parallel to the closed main arc chamber. An odd disconnector is connected between the fixed odd contact unit and the odd main boom chamber. In the same way, an even disconnector is connected between the fixed even contact element and the even main vacuum suction chamber. In the space between the vacuum damping chambers and the control drive shaft is a movable contact parallel to the closed vacuum damping chamber mounted on the control drive shaft or the associated cam.

The switch connected in series to the closed main vacuum arc extinguisher is switched on during the switch and is switched off within the last 15% of the switching time. The sequentially connected main vacuum booster chamber disconnector is switched off within the first 15% of the switching time and switched on for the remainder of the time. The switching contact assembly is connected in parallel to the opening main vacuum arc chamber for at least 85% of the switching time and then switched in parallel to the closing main vacuum arc chamber.

Disconnectors can have potential contacts, with the open disconnector its potential contact connected to one of the two terminals of the resistor.

In one embodiment, the switching contact assembly is comprised of a D-shaped current element mounted on a base, located on the auxiliary vacuum extinguishing chamber and insulated against it by an insulating support. One fixed contact element is mounted on the two main vacuum arc chambers. A roll pin is mounted on the insulating arm located on the drive shaft, which contacts the G-shaped conductor at the end of the changeover.

Alternatively, two cams are mounted on the drive shaft, one of which interacts with a roller connected to the auxiliary vacuum extinguisher and the other cam interacts with the rollers of the two main vacuum chambers. The two humps can be isolated from each other and to the drive shaft.

Each of the two disconnectors connected between the fixed contact elements and the main vacuum blowing chambers contains a two-arm curved lever centered on the contact tail connected to the corresponding main vacuum choke chamber. Contact plates with contact springs are mounted on one arm of the curved lever. On the other arm there is a groove which is functionally connected to a pin with a roller located on an insulating arm mounted to the drive shaft. With a three phase power switch with single phase contact queues positioned at a 30 ° angle, there are only three pins with rollers located at a 120 ° angle.

Another variant of disconnectors is when they are vertically open and are composed of two-handed levers with contact plates on one side and rollers on the other. The rollers are located in a profile groove located at the head of a cam mounted on the drive shaft. A variant is when the profile channel is located on the periphery of the hump.

Alternatively, the switching contact unit is coupled to a switching insulation shaft coupled to the slow loading motion of the spring energy accumulator, which can be made by means of a lever, slider and arm with a channel.

In the case of a three phase power switch with insulated phases, the drive shaft may be located in a cylindrical opening

65708 Bl along the axis of the command drive shaft.

The parallel contact unit may comprise as a guiding element a command drive shaft, the movable contact plates being arranged on one or two upper radial arms, respectively on one or two lower radial arms.

The advantage of the power switch with vacuum blowers according to the invention is that the two main vacuum choke chambers exclude only the rated current and the auxiliary vacuum choke chamber only the circulating current. By appropriately selecting the value of the resistor, the circulating current can be about two times smaller than the rated current. The main vacuum chambers shut down at 50% of operations, and the auxiliary ones at 100%. This could guarantee twice as much electrical durability as vacuum vacuum extinguishers.

Another advantage is that the use of disconnectors can provide high impulse insulation strength to the extent that it is limited by the solution of the contacts of the vacuum damping chambers. Thus, the power switch can also be applied to transformers with higher voltage class.

The advantage is that when using a parallel contact unit, the rated current of the power switch can be increased above that of the vacuum blower chambers and increase the reliability at the overload required by the standard.

The overall advantage is that a series of unified power switches can be implemented for various applications. Disconnectors or parallel contact units must only be installed for transformers with higher nominal parameters. The power switch will thus be able to be used for both oil-insulated transformers and elegas-insulated transformers (SF ₆ gas).

Explanation of the annexed figures

Exemplary embodiments of the power switch with vacuum arc chambers according to the invention are shown in the accompanying figures, of which:

Figure 1 is an electrokinematic circuit of the power switch;

Figure 2 is a diagram of the sequence of action of the main elements during a switch;

Figure 3 is a longitudinal section view of a three-phase power switch for regulation in a star center;

4 is a cross-sectional view of the power switch of FIG. 3;

Figure 5 is a longitudinal section view of a single-phase power switch;

6 is a cross-sectional view of the power switch of FIG. 5;

Figure 7 is a longitudinal section view of a three-phase isolated-phase power switch;

8 is a cross-sectional view of the power switch of FIG. 7.

Examples of carrying out the invention

One phase of the power switch (Fig. 1) has a main even blower chamber 1, a main odd vacuum blower chamber 2 and an auxiliary vacuum blower chamber 3 located between them. the contact elements 6 and 7 of the switching contact unit 5 are respectively connected to the two main vacuum chambers 1 and 2. The odd fixed contact element 8 is connected in a known manner to the odd contact voter act I, and an even fixed contact element 9 is connected to even voter contact II. Contacts I and II are connected to a known control coil 10. An odd disconnector 11 is positioned between the odd vacuum blower chamber 1 and the odd fixed contact element 8. Similarly, an even disconnector 12 is positioned between the even vacuum blower chamber 2 and the even stationary contact element 9. Alternatively, the disconnectors 11 and 12 may have potential contacts 13 and 14 (indicated by a dashed line) to eliminate the remaining floating potential of the open part of the respective vacuum. and a fire extinguisher 1 or 2.

65708 Bl

The power switch has a bearing housing 15 on which is mounted a drive shaft 16 with arms 17. The functions of the arms 17 will be explained later. A profile control cam 18 is connected to the shaft 16, which by means of levers with rollers 19,20,21 determines the sequence of action of the vacuum damping chambers 1,2,3.

A parallel contact unit 22 is attached between the vacuum choke chambers 1, 2, 3 and the drive shaft 16, attached to the cam 18 or to the drive shaft 16. The parallel contact unit 22 has fixed contact elements 23 and 24 connected to the vacuum choke chambers 1 and 2 , contact plates 25 and fixed contacts 26 and 27 located on the carrier housing 15. The current terminal 28 of the power switch is connected to the fixed contacts 26 and 27. The command drive shaft 16 rotates abruptly when switching from a known spring energy accumulator 29.

The action sequence of elements 1,2,3, 5, 11,12 and 22 of FIG. 1 is shown in FIG. 2. In addition to the two extremes, both basic schemes are given.

- Opening the main vacuum chamber 1, which only extinguishes the operating current.

- Opening the auxiliary damping chamber 3, which extinguishes only the circulating current, at a value equal to the step voltage divided by the value of the resistor 4.

In reverse switching, the other main arc choke chamber 2 also extinguishes the operating current and the auxiliary vacuum choke chamber the circulating current. The latter performs twice as many commutations as the two main vacuum chambers. Separate switching off of the working and the circulating current allows to select such value of the resistor, whereby the circulating current is less than the working one. Thus, the electrical durability of the three vacuum damping chambers could be offset.

Three-phase power switch for regulation in the star center, made according to FIG. 1 and FIG. 2 is shown in FIG. 3 and FIG. 4. The three phases X, Y and Z are arranged in a circle, each phase occupying a sector of 120 °. The repeating elements of FIG. 1 are marked with the same numbers.

The supporting insulating structure of the vacuum damping chambers 1,2 and 3 for the three phases consists of an insulating cylinder 30 and an insulating plate attached to the supporting housing 15 and an additional insulating plate 32. In this case, the profile control cam 18 and 18.1 are two: the upper one for commanding the auxiliary vacuum extinguishing chamber 3 and the lower one for commanding the main vacuum damping chambers 1 and 2. This results in more favorable switching times. The humps 18 and 18.1 successively act on the rollers 19,20 and 21, each connected to the movable contact 33 of the respective vacuum choke 1, 2 and 3 by means of a D-shaped lever 34 and a pivot rod 35. The spring 36 provides the necessary contact pressure. The control cams 18 and 18.1 are secured to the drive shaft 16, which is mounted in the center of the circular support housing 15. The carrier of the parallel contact unit 22 is attached to the cams. The contact plates 25 are connected to the fixed contact element 23 of the odd vacuum choke 1. When switching, the contact plates 25 are detached from the contact element 23 and at the end of the switching are connected to the contact element 24 of the other main extinction chamber 2. The fixed contacts 26 and 27 are mounted on the supporting housing 15.

The switching contact assembly 5 is supported by a D-shaped conductive element 37 which is mounted on the axis of the auxiliary arc extinguishing chamber 3 on the base 38, connected electrically to the current element 37 via a flexible connection 39. The base 38 is isolated from the carrier 40 of the auxiliary arc extinguisher chamber 3 through an insulating pad 41. The two elements 38 and 40 are connected via wires 42 to the respective resistor 4. The resistors 4 are mounted on an insulating plate 43, which is affixed in a known manner to the insulating cylinder 30. tact unit 5 is switched to the fixed contact element 6 of the odd-numbered main vacuum arc-extinguishing chamber 1. The other main vacuum arc-extinguishing chamber 2 is mounted on the other stationary contact element 7. The switching contact unit 5 is switched intermittently at the end of the switch from the effects of

65708 Bl pin with roll 44 on D-member 37. The pin roll 44 is fixed to the insulating arm 17 mounted on the drive shaft 16.

The two disconnectors 11 and 12 are mounted on the respective contact queues 45 of the supports 46 to attach the main vacuum arc chambers 1 and 2. Two mirror-curved levers 47 with grooves 48 are supported on the contact queues 45. The pins 48 are actuated by rollers 49, fixed on insulating arms 17.1. For three-phase power switch, three pins with rollers 49, 120 ° apart, are sufficient. On the curved levers 47 are mounted contact pins with contact springs 50 which, when switched on, contact the contact elements 51 connected to the respective fixed contact element 8 or 9. The latter are secured to the contacts of a non-known known oil vessel by means of bolts 52. the movable contacts 33 to the carrier housing 15 are made through flexible connections 53. The current terminal 28 is connected to the carrier housing 15. With a three-phase power switch for a star center, the current terminal may be only one.

The known spring energy accumulator consists of a drive arm 54 connected to the drive shaft 16 and a loading arm 55 connected to a drive washer 56 by a reel 57. Two mirror-mounted carriages 58 move along the guide 59. Between the two carriages 58 are fastened to the guides. .

The power switch provided is with switches 11 and 12 that provide high impulse insulation strength. For transformers with lower insulation requirements, these disconnectors can be dropped, making construction simpler and less costly. Also, in parallel with the requirements for operating currents, drops in the rated current of the vacuum damping chambers may fall off the parallel contact unit 22.

The three-phase power switch of FIG. 3 and FIG. 4 can be used as a single phase. Increasing the rated current is achieved by switching on two or three phases. If only one phase is used, resistor 4 could be positioned in the space vacated by the other two phases, thereby reducing the height.

In order to reduce the diameter of a single-phase power switch according to the invention, the construction of FIG. 5 and FIG. 6. Repeating elements are identified by the same numbers. The two main 1s and 2s and the auxiliary 3 vacuum extinguisher are 120 ° apart from each other. Here, the switching contact assembly 5 remains switched on after switching in parallel to the open main arc chamber 2. During the next 2-to-1 switching, the rechargeable energy accumulator 29 starts charging. channel 64. The pin 61 and the slider 63 are guided into grooves at the bottom 65 of the spring-energy accumulator 29. The arm with the channel 64 is connected to a switch shaft 66, which at its upper part is made of insulating material. The upper end of the shaft 66 is located in bearing 67 and has a head 68 that carries the movable contacts of the switching contact assembly 5. The connection to resistor 4 is from contact queues 69, contact sector 70 and conductor 42. The other end of resistor 4 is connected to auxiliary vacuum damping chamber 3. In order to reduce the height, the resistor 4 may be formed by several series-connected packages.

Thus, before starting the speed switch, the switch contact unit 5 is moved from the contact element 6 to the contact element 7 and the electrical switching processes are such as those of the construction of FIG. 3 and FIG. 4.

The parallel contact unit 22 in this case is combined with the control shaft 16, which conducts current in parallel with the operating main arc chamber 2. The control shaft 16 has upper two arms 22 and lower two arms 22.1, on which upper contact plates 25 and lower contact plates are arranged. plates 25.1. The arms 22 and 22.1 are two, because when switching, the shaft 16 rotates at an angle of 90 ° (in this case clockwise). If a spring energy accumulator 29 with a higher rotation angle is used, the arms 22 and 22.1 may be single. The design allows the two main arc chambers 1 and 2 to be located at a smaller angle than

65708 Bl auxiliary damping chamber 3. The lower contact plates 25.1 are connected to a D-shaped contact element 71 which is secured to the supporting housing 15, near the insulating cylinder 30, in order not to interfere with the movement of the control cam 18. Between the fixed contact elements 8 and 9 and the corresponding main vacuum choke chambers 1 and 2 can be respectively mounted on the disconnectors 11 and 12, similar to those of FIG. 3 and FIG. 4. In this case, the lower requirements for the insulation level of the degree of connection is directly through the flexible conductors 72.

The constructions of the disconnectors 11 and 12 and of the parallel contact unit 22 are analogous to a three-phase power switch with three isolated phases arranged at one level 120 ° each (Fig. 7 and Fig. 8). In these figures, the elements of the same designation are identified by the same numbers. Here, the supporting housing 15, the insulating cylinder 30 and the insulating plate 31 are divided into three sectors spaced apart by an insulation distance “S”.

The three phases X, Y and Z are secured by supporting insulation cylinders 73 to a common housing 74. The drive shaft 16 with cam 18 is also isolated, being connected to the spring energy accumulator 29 via insulation tubes 75, peripheral gear 76 and central gear wheel ΊΊ.

In FIG. 7 illustrates various modifications of the power disconnector according to the invention. In the left longitudinal section of one phase, there are both sequential disconnectors 11 and 12 and a parallel contact unit 22, which acts in a similar manner to that of FIG. 3 and FIG. 4. In the right longitudinal section, a simplified version is shown in which the requirements for the insulating step level are lower and the rated current is less than that of the vacuum damping chambers. With great unification, complexity and overall dimensions are reduced.

In contrast to FIG. 3 and FIG. 4, the consecutive disconnectors 11 and 12 open not horizontally but vertically, providing an isolation distance of "h". Their control is carried out from the cam 16 attached to the command shaft 78 with a front profile channel 79. The curved levers of the disconnectors 11 and 12 have spherically shaped rolls 80 that run along the channel 79.

A disconnect variant is shown in FIG. 9. Profile channel 49.1 is located on the periphery of cylindrical cam 78.1.

The switching contact assembly 5 operates similarly to that of FIG. 5 and FIG. 6. In the case, however, for greater compactness; it is located axially in command shaft 16,

In the one-way energy transfer of the adjustable power transformer, a switching contact unit 5 can be used to ensure that 50% of the shutdown of the main choke chambers occurs at the difference from the rated circulating current and the remaining 50% at the rated current. This could increase the electrical resistance of the power switch.

In FIG. 7 the main and main fire extinguishers were switched on and off. Here, when the corresponding roll 19,20,21 of the cam 18 is pressed, the corresponding vacuum extinguishing chamber 1,2,3 is switched on. The contact pressure is exerted by unspecified springs mounted on the lever system 34. The disconnection is accomplished by the tension spring 81.

Notwithstanding the various embodiments, the operation of the power switch according to the invention is the same. In the starting position (Fig. 1), the switching contact unit is connected to the working vacuum damping chamber (in this case 1), parallel to it is connected the parallel contact unit 22, the disconnector 11 is closed and the disconnector 12 is open. Upon release of the spring energy accumulator 29, the drive shaft 16 is rotated in a clockwise direction at a certain angle, usually about 90 °. First, close the disconnector 12 (Fig. 2) and open the parallel contact unit 22. Then close the auxiliary vacuum extinguisher chamber 3 and open the main vacuum extinguisher chamber 1. The first electric arc due to the operating current of transformer. Further, the suction cup 2 is closed and the auxiliary suction cup 3 is opened. Its arc is caused by the circulating current. A horse is closed at the end of the process

65708 Bl stroke assembly 22 in parallel with the vacuum choke chamber 2, open the disconnector 11 and jump the contact assembly 5. It is reversed in the same way. With the switches of FIG. 5, 6, 7, 8 switching is the same. The difference is that pin 5 switches in parallel from slow motion.

Claims (10)

Claims 1. Power switch with vacuum arc chambers for a stepped voltage regulator comprising two main vacuum arc chambers connected to an odd and odd fixed contact element, one auxiliary vacuum arc chambers connected in series with a resistor and a switching contact switch, to it a command hump and a contact node parallel to the closed vacuum damping chamber, characterized in that, before switching, a cuvette extinguisher (3) and a series resistor (4) connected therewith by the switching contact assembly (5), in parallel with the closed main vacuum extinguishing chamber (1), between the fixed odd contact element (8) and the odd main vacuum extinguisher chamber (1) is connected an odd disconnector (11), respectively, between the fixed even contact element (9) and the even vacuum suction chamber (2) is connected an even disconnector (12), and in the space between the vacuum fire extinguishers (1, 2, 3) ) and the Command Drive a chewing shaft (16) is arranged parallel to the closed vacuum exhaust chamber (1), a contact assembly (22) mounted on the drive shaft (16) or on the associated cam (18). 2. Vacuum extinguishing chamber power switch according to claim 1, characterized in that the switch (11) connected in series to the closed main vacuum extinguisher (1) is switched on during the switch and is switched off within the last 15% of the duration. switch, and the sequentially connected main vacuum booster chamber (2) connected to the switch (12) is switched off within the first 15% of the switching time and switched on for the rest of the time while switching this contact unit (5) is connected in parallel to the opening main vacuum boom (1) for at least 85% of the switching time and then switched in parallel to the closing main vacuum boom (2). A power switch with vacuum damping chambers according to claims 1 and 2, characterized in that the disconnectors (11,12) can have potential contacts (13 and 14) and, with the open disconnector (12), its potential contact (14) is connected to one of the two terminals of the resistor (4). Power switch with vacuum arc chambers according to claims 1 and 2, characterized in that the switch contact unit (5) consists of a D-shaped conductive element (37) mounted on a base (38) located on the auxiliary vacuum arc. chamber (3) and insulated therewith insulating pad (41), one fixed contact element (6,7) is mounted on the two main vacuum damping chambers (1, 2) and on the insulating arm (17) of the command drive shaft (16) there is a roller pin (44), functionally connected with the L-shaped conductive element (37). 5. Power switch with vacuum damping chambers according to claims 1 and 2, characterized in that two cam (18, 18.1) are mounted on the drive shaft (16), one of which (18) interacts with a roll (21). ) connected to the auxiliary vacuum extinguisher (3) and the other cam (18.1) interacts with the rollers (19, 20) of the two main vacuum extinguishers (1,2), the cam (18,18.1) being insulated against each other and against the drive shaft (16). 6. Vacuum damping chamber power switch according to Claims 1 and 2, characterized in that each of the two disconnectors (11, 12) comprises a two-lever curved arm (47) centered on the contact tail (45) connected to the respective a main vacuum boom (1, 2), on one arm of the curved lever (47) contact plates (11, 12) with contact springs (50) are mounted, and the other arm has a channel (48), which 65708 Bl is functionally connected to a roll pin (49) mounted on an insulating arm (17.1), with only three roll roll pins for a single phase phase switch with contact queues (45) located at a 30 ° angle (49), located at an angle of 120 ° to one another. 7. Power switch with vacuum damping chambers according to claims 1 and 2, characterized in that it has vertically open disconnectors (11,12), consisting of two-handed levers with contact plates on one side and rollers (80) on the other side. , the rollers (80) being located in a profile groove (79) located on the cam face (78) or in a profile groove (79.1) located on the periphery of the cam (78.1) mounted on the drive shaft (16). 8. Vacuum damping chamber power switch according to claim 1, characterized in that the switching contact shaft (5) is connected to a switching insulating shaft (66) which is connected to the slow charging motion of the spring-energy accumulator (29) by rod (62), slider (63) and shoulder with groove (64). A power switch with vacuum damping chambers according to claims 1 and 8, characterized in that the drive shaft (16) has a cylindrical opening in which the switching insulation shaft (66) is located. A power switch with vacuum damping chambers according to claim 1, characterized in that the parallel contact unit (22) contains as a guiding element the drive shaft (16) and the movable contact plates (25) are arranged on one or two upper radials arms (22), respectively, on one or two lower radial arms (22.1).