CN1036811C - Load Selector used for switch of adjustable transformer - Google Patents

Abstract

The invention relates to a load selector for tap switches on tapped transformers. Such a load selector has two selector contacts which can be moved independently of one another, a vacuum switch which switches the load current being assigned to one of the selector contacts and a vacuum switch which switches the compensating current between two adjacent taps being assigned to the other selector contact. A third vacuum switch is arranged in series with the vacuum switch which switches the load current and carries it continuously, and the two vacuum switches arranged in series can be actuated at approximately the same time.

Description

The load selector that is used for the adjustable transformer shunting switch

The present invention relates to a kind of two movable load selectors that divide contact point that have that are used for the adjustable transformer shunting switch.

A kind of like this load selector is disclosed among the DE4223439.

This known load selector has the branch contact point of two separate activities, wherein load current and long-term through-flow vacuum switch are cut-off in one of the additional connection of the branch contact point of first activity, the branch contact point of second activity is additional to be connected one and has been connected in series cut-offfing the balanced balanced current between adjustable transformer two adjacent taps and the switch of this current path being provided of an effective resistance, before first fen contact point leaves present fixed contact, the second movable contact point that divides all can arrive new fixed contact in each switch over travel, and this and switch orientation independent.

But this load selector can not guarantee to prevent restriking of electric arc when the vacuum switch tripping operation of cut-offfing load current, can not prevent that vacuum loss and other problem from appearring in this switch.

Therefore the objective of the invention is to improve a kind of like this load selector, it can provide maximum protection to preventing the vacuum switch generation functional fault that cut-offs load current.

Above-mentioned purpose of the present invention is to realize like this, to with cut-off load current and allow first of vacuum switch series connection that this electric current continues to flow through movablely to divide that contact point is additional to be connected a preferably identical vacuum switch of structure, and the vacuum switch of two serial connections is almost operated simultaneously.

People know in order to improve the error protection ability, can will have the fracture scheme replacement of the vacuum circuit-breaker of single break with two tandem taps.Adopt a vacuum switch to realize among U.S. Pat-PS3283101, the fixing contact acting in conjunction of this bridging contact and two disposed adjacent with movable bridging contact of installing; And the open text DE-OS2125296 of Germany has introduced another kind of form of implementation, and it has two and is contained in the axial breakpoint of configuration successively in the common chamber.

In this case, all require vacuum switch to have the special structure of making especially, this involves great expense switch.On the contrary, device of the present invention is made of two independent vacuum switches, and is meant two switch elements that structure is identical.

The invention has the beneficial effects as follows that the series connection by described two vacuum switches has improved whole load selector reliability greatly.If seal and bad it decreased owing to cause in new electric arc or the vacuum switch one when for example disconnecting, can not cause fault.

Though the vacuum switch that breaks down can not normally disconnect, finish this function by another vacuum switch of series connection with it.

In other words, in normal operating state, the vacuum switch of described two series connection side by side disconnects basically, if one of them breaks down, another then finishes this switching function reliably.

According to mathematical law, the probability that two vacuum switches break down simultaneously is very little, therefore can ignore in practice.

The present invention is further described below with reference to the accompanying drawings for example.

Fig. 1 is the schematic diagram of first embodiment of load selector of the present invention.

Fig. 2 is relevant time sequential routine figure, represents the state of contact when one repeatedly stepping is changed.

Fig. 3 is the schematic diagram of second embodiment of load selector of the present invention.

Fig. 1 represents the schematic diagram of load selector of the present invention.The tap of tap coil and fixed contact n, (n+1) ..., (n+m) being connected, these fixed contacts can be arranged ringwise or orthoscopic is arranged.It comprises that via one two same vacuum switch SKV and the series circuit of ZKV are connected to common conductor, and as described in the main application, also comprise a movable auxiliary contact HKW who does not independently have mechanical couplings, it is connected on the common wire via the series circuit of an auxiliary switch HKV and switching resistance R, and this auxiliary switch can be made of vacuum switch.Fig. 2 has represented relevant sequential chart, this be from n to (n+1), (n+2), and return the sequential chart in repeatedly stepping when conversion of (n+1).

Fig. 3 represents the load selector schematic diagram that another has changed, wherein switch element is contained on the moveable arm, here this moveable arm is supporting main contacts SKM, and movable independently auxiliary contact HKW is loading with insulating, and is electrically connected with the arm that supports main contacts SKM.

Claims (3)

1. the load selector that is used for the adjustable transformer shunting switch, have two movable contact points that divide, wherein one of the additional connection of the branch contact point of first activity is cut-off load current and is continued through-flow vacuum switch, the branch contact point of second activity is additional to connect cut-offfing the balanced balanced current between adjustable transformer two adjacent taps and the switch of this current path being provided of a serial connection switching resistance, the first movable contact point that divides also supports like that as the second movable contact point that divides, they move independently of each other, between do not exist the coupling and influence each other, before first fen contact point leaves present fixed contact, the second movable contact point that divides all can reach new fixed contact position in each switch motion, and with the switch orientation independent, it is characterized in that

First movable divides that contact point (SKM) is additional to be connected one and comprise and cut-offs load current and continue the through-flow vacuum switch (SKV) and the series circuit of another vacuum switch (ZKV), and the vacuum switch of these two serial connections (SKV, ZKV) almost action simultaneously.

2. according to the load selector of claim 1, it is characterized in that (SKV ZKV) is the identical switch of structure to these two vacuum switches that are connected in series.

3. according to any load selector in the aforementioned claim, it is characterized in that, the second movable additional connection of contact point (HKW) switch (HKV) that divides, and be connected in series one the switching resistance (R), (SKV ZKV) constitutes a construction unit jointly for this series circuit and QA first minute subsequently contact point (SKM) and the vacuum switch that is connected in series with it.

Images