CN2152285Y

CN2152285Y - Loaded tapping switch

Info

Publication number: CN2152285Y
Application number: CN 93211580
Authority: CN
Inventors: 赵亚和; 周星君
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-05-10
Filing date: 1993-05-10
Publication date: 1994-01-05
Anticipated expiration: 2003-05-10

Abstract

The utility model relates to a loaded tapping switch, which is used in a transformer of a power transforming and transmitting network. The utility model is a device which can automatically transform the turns ration of the transformer to regulate voltage under a loaded condition. The utility model adopts a step motor (3) as an actuator of a controller to directly drive a main shaft (7) of a switch. A shaft of the step motor (3) is directly and fixedly connected with an upper cover (15) which is extended by the main shaft (7). When the step motor (3) moves once to drive the main shaft (7) to have one-time step movement synchronously, a switching contact group (8) arranged on the main shaft is driven to rotate by a tap. The switching contact group is rotate to a preselection fixing contact group from a current fixing contact group (9), and the once switching is completed.

Description

Loaded tapping switch

The utility model relates to a kind of on load tap changer, is used for the transformer of power transmission and transformation network, be a kind of can be under the bringing onto load situation turn ratio of conversion transformer automatically, adjust the device of voltage.

Since nineteen twenty-six German Jie Sen (Jansen-Patent 474613) had invented the load voltage-regulating method of " moment switching, resistor transition ", this method was followed in on-load voltage regulation always.At present, according to the on load tap changer of this principle design, no matter be combined type or composite type in the prior art, all form by mechanical driving part and switching part two large divisions.They exist common problem: technological requirement height, manufacture difficulty are big, often produce the tripping and the malfunction of switch in actual use because of mechanical breakdown, have a strong impact on the reliability of switch, particularly mechanical driving part ［ 1 ］ and switching part ［ 2 ］ and place the indoor combined type on load tap changer of same insulated enclosure.The structure of combined type on load tap changer as shown in Figure 1.During switching, handle motor ［ 3 ］ with electric control, make energy-storaging spring ［ 5 ］ accumulation of energy by gearing ［ 4 ］, once spring ［ 5 ］ is when being positioned at extreme position, just rapid release, drive indexing trough wheel mechanism ［ 6 ］ and do a stepping, the sheave of switch spindle ［ 7 ］ and indexing trough wheel mechanism ［ 6 ］ rotates synchronously, make the electric switch groups ［ 8 ］ that is fixed on the main shaft ［ 7 ］ be transformed into position in advance with being connected of fixed contact group ［ 9 ］ from current location, change the turn ratio of transformer, reach the purpose of adjusting voltage.Because mechanical driving part ［ 1 ］ is in the same grease chamber with switching part ［ 2 ］, its oil of metal fillings severe contamination of mechanical wear very easily causes short circuit.In addition, spring release can the time impact that produces, quickened the wearing and tearing of part and loosening, reduced the reliability that electrically contacts part, easily cause the seepage of insulating cylinder ［ 10 ］ again and influence the normal operation of transformer.

The purpose of this utility model is to avoid outside the above-mentioned deficiency of the prior art, and a kind of do not have intermediate mechanical running part and the high on load tap changer of operational reliability are provided.

The purpose of this utility model is achieved in that the switching part that keeps former combined type on load tap changer, adopts the actuator of stepping motor as electric controller, directly the driving switch main shaft.Switch spindle is stretched out loam cake, and the axle of stepping motor directly is connected mutually with it.The every motion of stepping motor once, promptly the driving switch main shaft is synchronously made step motion one time, the switching contact group that drives on it turns over a tap, is transformed into preliminary election fixed contact group position from current fixed contact group position, finishes once to switch.Stepping motor have step angle accurately, characteristics such as noninertia, running be reliable, so directly drive the switch spindle of switching part, can thoroughly solve all drawbacks that on load tap changer is caused because of a little transmission of machine with stepping motor.Simultaneously, owing to the step frequency of stepping motor can steplessly be adjusted, so the on load tap changer of this form is applicable to the different various models of number of taps.When the number of taps of on load tap changer was n, the angle of circumference R between each tap was:

R＝ (360°－S)/(n)

Wherein: S is the nonclient area angle of circumference, and is selected by design.Step angle as selected stepping motor is r, and it is B=R/r that then each switching needs the step number of stepping.Represent the step frequency of motor with F, whenever finish and once switch needed time T and can be represented by the formula:

T＝B／F＝ (360°－S)/(F·r·n)

On load tap changer requires to finish switching in 40～60 milliseconds.With the difference of number of taps n, each switching needs the step number B of stepping just different.By regulating the frequency F of stepping motor, can satisfy T requirement switching time of the different various on load tap changeres of number of taps.

Introduce an embodiment of the present utility model below in conjunction with accompanying drawing:

Fig. 1 is the combined type on load tap changer,

Fig. 2 is the utility model on load tap changer,

Fig. 3 is the schematic diagram of the utility model on load tap changer.

By Fig. 1,2 as can be known, the utility model on load tap changer has kept the switching part 2 of former combined type on load tap changer, and loam cake 12 also is equipped with position indicating device 13.Adopt the actuator of stepping motor 3, replace the whole mechanical driving part 1 of former combined type on load tap changer as electric controller.The axle of stepping motor 3 directly is connected mutually with the switch spindle 7 that switching part 2 stretches out loam cake 12.Position indicating device 13 is installed between bracing frame 11 and the loam cake 12, is by unthreaded hole dish 15, the optoelectronic position indicating device that light-emitting diode 14 and photodiode 16 are formed.Unthreaded hole dish 15 is fixed on the switch spindle 7, it one group with the concentric circumference of main shaft 7 on be that every group of fixed contact group 9 is provided with one group and counts to the binary system unthreaded hole with respect to each tap position of switch.Light-emitting diode 14 and photodiode 16 are installed in respectively on loam cake 12 and the bracing frame 11 corresponding to the unthreaded hole position on the unthreaded hole dish 15, and unthreaded hole dish 15 rotates synchronously with switch spindle 7.The tap position difference, light-emitting diode 14 is promptly different with photodiode 16 pairing unthreaded holes, and the photosignal that photodiode 16 is received is just different.The tap position that can show switch behind the input electric controller.

After switch assembles, at the indoor transformer oil that is full of of the insulated enclosure of forming by insulating cylinder 10 and loam cake 12.The fixed contact group 9 of on load tap changer is connected with the transformer coil tap respectively.Have to carry and divide the electric controller of being furnished with the band microprocessor by switch, electric controller links to each other with position indicating device 13 with the stepping motor 3 of on load tap changer respectively by shielded multiconductor cable.Before entering running, at first, regulate the operating frequency of stepping motor 3 to guarantee in 40～60 seconds, finishing cut-grafting by controller according to the number of taps of the on load tap changer that uses.Simultaneously, controller detects and notes initial tap position by position indicating device 13.

On load tap changer enters postrun situation as shown in Figure 3.When the signal voltage of taking from electrical network when controller surpasses specified pressure regulation precision (± 2.5% or ± 5%), controller sends the power drive signal, stepping motor 3 follow procedures are rotated once, driving switch main shaft 7 is synchronously made step motion one time, drive the tap of switching contact group 8 steppings on it, forward pre-selected locations to being connected by current location of fixed contact group 9, the switching of a tap is finished in motor 3 automatic stalls.Switch spindle 7 turns over a tap, and unthreaded hole dish 15 also synchronously moves once.Optoelectronic position indicating device 13 is just with new tap position signal input controller.When the tap position of being imported when position indicating device 13 is the limit tap position of on load tap changer, controller will be taken measures, and restriction stepping motor 3 can only be towards the folk prescription that does not go beyond the limit of to running.Therefore this position indicating device 13 has also played the position limitation protection effect.

Compared with prior art the advantage that has of the utility model is: (1) is owing to adopt the direct driving switch main shaft of stepper motor, do not have and impact, and avoided the metal fillings of machine driving generation in traditional load ratio bridging switch to the pollution of transformer oil, driving error is little, has greatly improved operational reliability and the service life of load ratio bridging switch; (2) stepper motor running reliable, accurately, step frequency can stepless adjustment characteristic, can guarantee 40～60 milliseconds requirement switching time, therefore this load ratio bridging switch can be made into the different various models of number of taps; (3) simple in structure, process easy for installationly, can save raw material 40%, reduce cost 20%.

Claims

1, a kind of on load tap changer, have by switch spindle, the switching contact group, with the corresponding fixed contact group of number of taps, insulating cylinder, the switching part that bracing frame etc. are formed, loam cake and position indicating device, it is characterized in that: adopt stepping motor [3] as the direct driving switch main shaft of the actuator of controller [7], main shaft [7] stretches out loam cake [12], the axle of stepping motor [3] directly is connected mutually with it, the every motion of stepping motor [3] once, be that driving main shaft [7] is synchronously made step motion one time, the switching contact group [8] that drives on it turns over a tap, forward preliminary election fixed contact group to from current fixed contact group [9], finish once and switch.

2, on load tap changer according to claim 1 is characterized in that: described position indicating device ［ 13 ］ is by unthreaded hole dish ［ 15 ］, the optoelectronic position indicating device that light-emitting diode group ［ 14 ］ and the quick diode group in pass ［ 16 ］ are formed, unthreaded hole dish ［ 15 ］ is fixed on the main shaft ［ 7 ］, on it one group with the concentric circumference of main shaft ［ 7 ］ on, each tap position with respect to switch is that every group of fixed contact group ［ 9 ］ is provided with one group of ordered series of numbers binary system unthreaded hole, light-emitting diode group ［ 14 ］ and photodiode group ［ 16 ］ are arranged at the both sides of unthreaded hole dish ［ 15 ］ respectively corresponding to the unthreaded hole position on the unthreaded hole dish ［ 15 ］, unthreaded hole dish ［ 15 ］ rotates synchronously with main shaft ［ 7 ］, the tap position difference, light-emitting diode group ［ 14 ］ is promptly different with the unthreaded hole on the pairing unthreaded hole dish of photodiode group ［ 16 ］［ 15 ］, and the photosignal of photodiode group ［ 16 ］ input controller is just different.