EP3513419B1 - On-load tap changer, regulating transformer with on-load tap changer, and method for connecting an on-load tap changer - Google Patents

Description

The invention relates to an on-load tap-changer for a regulating transformer, a regulating transformer with such an on-load tap-changer and a method for switching such an on-load tap-changer.

As is well known, in the simplest case an on-load tap-changer comprises a fine selector with N tap contacts, each of which is to be connected to an associated tap of a control winding of a control transformer, and no preselector. This on-load tap-changer, which is also referred to as a linear on-load tap-changer, therefore has a position control range of N positions and a control transformer with this on-load tap-changer has a voltage control range of N voltages. To extend the voltage control range of the control transformer, it is known to equip the on-load tap-changer with a preselector in addition to its fine selector, which is also referred to as a tap selector. This can be designed as a reversing switch, coarse selector or multiple coarse selector. A reversing switch makes it possible to connect the control winding of the control transformer either in the same direction or in the opposite direction to the unregulated winding of the control transformer, which is also referred to as the main winding. With the help of a coarse selector or multiple coarse selector, it is possible to switch a part of the main winding, which is also referred to as the coarse stage, or several coarse stages, on or off, i.e. to optionally connect or not connect at least one coarse stage to the control winding.

For example, if the linear on-load tap-changer comprises a reversing switch in addition to its fine selector with N tap contacts, then the fine selector typically comprises a commutation contact to be connected to the main winding in addition to its tap contacts. Thus, this on-load tap-changer typically has a position control range of 2xN+1 positions, namely a lower position control range of N positions in which the reversing switch is set such that it connects the control winding in opposite directions to the main winding, an upper position control range of N positions in which the reversing switch is set such that it connects the control winding in the same direction to the main winding, and a middle position which corresponds to the commutation contact and in which the fine selector bridges the control winding. A A regulating transformer with this on-load tap changer typically has a voltage regulation range of 2xN+1 voltages.

For example, if the linear on-load tap-changer comprises a coarse selector in addition to its fine selector with N tap contacts, then the fine selector typically comprises, in addition to its tap contacts, a commutation contact to be connected to the main winding. Thus, this on-load tap-changer typically has a position control range of 2xN+1 positions, namely a lower position control range of N positions in which the coarse selector is set such that it does not connect the coarse step to the control winding, an upper position control range of N positions in which the coarse selector is set such that it connects the coarse step to the control winding, and a middle position which corresponds to the commutation contact and in which the fine selector bridges the control winding. A control transformer with this on-load tap-changer then typically has a voltage control range of 2xN+1 voltages.

DE 1 178 511 A describes a tap changer for regulating transformers with a load changeover switch, reversing switch and two alternately de-energizing tap selectors. Each tap selector comprises several fixed contacts that are connected to the regulated winding. The left tap selector additionally comprises a fixed contact that is not connected to anything, and in particular neither to the regulated nor to the unregulated winding, and is referred to as the idle tap. This known tap changer also comprises a changeover switch that establishes a temporary connection between the unregulated winding and the output of the load changeover switch. The tap selectors are coupled to the reversing switch and the changeover switch via intermittent gears in such a way that the connection is established within the time interval in which the tap selector runs to the idle tap and the reversing switch switches from one end position to the other, and vice versa.

DE 1 178 511 A also describes in her FIGS. 2 to 6 the course of a switching process of this known tap-changer in chronological order. In the case of switching down the voltage, the following process takes place: The reversing switch comprises a reversing switch arm which is connected to a contact 9 on the unregulated winding. The changeover switch comprises a changeover switch arm which is connected to contact 9. The initial position of the contacts shows FIG. 2 . In this position, the reversing switch arm connects the fixed contact 7 at the lower end of the regulated winding with contact 9 on the unregulated winding. With continued downshifting The tap selector arms run from the fixed contact 1 to the fixed contact 7 or from the fixed contact 2 to the fixed contact 6, whereby the load switching is carried out via the load changeover switch. The position of the FIG. 3 reached. In this position, the left tap selector arm contacts contact 6 and the right tap selector arm contacts contact 7, the reversing switch arm contacts contact 7, and the changeover switch arm contacts a left empty contact 0. The load changeover switch establishes the connection to the right tap selector arm and contact 7. When switching further, the changeover switch arm goes from the left empty contact 0 to a middle contact A, which is connected to the output of the load changeover switch. Then the reversing switch arm goes from contact 7 to an empty contact 0. During these switchings, the left tap selector arm runs from contact 6 to an empty step 8 of the tap selector. The position of the FIG. 4 The right tap selector arm then moves from contact 7 to contact 1 after the load changeover switch has previously switched to the left tap selector arm and the idle stage 8. The position of the FIG. 5 reached. When switching on, the reversing switch arm moves from empty contact 0 to contact 1 and the changeover switch arm from middle contact A to a right empty contact 0. During these switching operations, the left tap selector arm moves from contact 8 to contact 2 after the load changeover switch has previously switched back to the right selector arm and contact 1. The position of the FIG. 6 reached. In this position, the reversing switch arm connects contact 1 at the upper end of the regulated winding with contact 9 on the unregulated winding. The tap selectors then move from contact 1 to contact 7 or from contact 2 to contact 6 with continued switching. In this position, the lowest position of the oppositely connected regulated winding is reached, whereby the smallest voltage is removed. The voltage is increased in the reverse order.

DE 197 43 864 C1 describes a step switch based on the reactor switching principle for uninterrupted load switching using vacuum switching cells. In a housing, fixed selector contacts are provided for each phase, which can be switched by moving selector contacts. In this housing, fixed preselector contacts are provided for each phase, which can be switched by a moving preselector contact. In this housing, fixed bypass contacts are provided for each phase, which can be switched by a moving bypass contact. In this housing, a vacuum switching cell is provided for each phase, which can be operated by means of an energy storage device. In a separate side housing part, a drive mechanism is provided for operating all moving contacts and all vacuum switching cells in the corresponding Switching sequence is provided. In this known tap changer, all fixed contacts and all movable contacts as well as the vacuum switching cell of this phase are arranged separately for each phase together on a phase plate. Three insulating shafts extend through the housing and penetrate the three phase plates. The first insulating shaft actuates all movable selector contacts, the second insulating shaft actuates all movable preselector contacts, and the third insulating shaft actuates all movable bypass contacts and all vacuum switching cells. The drive mechanism has a single Geneva wheel which can be driven by a Geneva driver connected to a drive shaft and is connected to the first insulating shaft in such a way that with each switching the first insulating shaft can be rotated through an angle which corresponds to a switching step. The drive mechanism has first actuating means which act on the second insulating shaft and second actuating means which act on the third insulating shaft. The first actuating means consist of a roller on the Geneva wheel and a corresponding lever. When the Geneva wheel is in a certain position, the roller engages in a cutout in the lever, and the second insulating shaft can thus be pivoted through a certain angle of rotation. The second insulating shaft actuating the movable preselector contact is thus coupled to the drive shaft via the first actuating means, the Geneva wheel and the Geneva driver. Consequently, the first insulating shaft actuating the movable selector contacts and the second insulating shaft actuating the movable preselector contact are jointly coupled to the drive shaft via the Geneva wheel and the Geneva driver.

DE 197 43 864 C1 also describes in her FIG. 7 the typical sequence of this tap changer when switching from one tap to an adjacent tap for a phase. The left movable selector contact is connected in series with a left switching impedance and forms a left branch, and the right movable selector contact is connected in series with a right switching impedance and forms a right branch. The vacuum switching cell is connected between the two branches, and the corresponding connection to the load discharge is made by the by-pass contacts. In the stationary switching position according to FIG. 7a both movable selector contacts are connected to the same left tap, ie to the same left fixed selector contact. In the next stationary switching position according to FIG. 7f after the load changeover has been completed, the left movable selector contact is connected to the left fixed selector contact and the right movable selector contact is connected to the adjacent right fixed selector contact. This sequence is repeated with each subsequent load changeover.

DE 960 303 C concerns a tap selector for transformer control systems. This has two selectors, a load switch and a reversing switch. The transformer has an excitation winding and a tapped winding. The fixed contacts of the selectors are arranged on insulating rods and in a circle around a shaft.

A blind contact is fitted under the fixed contacts of each selector. The selectors each have movable contacts that are moved radially around an axis to switch the fixed contacts. The load switch is arranged above the selector levels and the preselector is arranged below the selector levels.

EN 10 2013 110 653 A1 relates to a tap changer for a power transformer having at least one main winding and one control winding, with a preselector and a fine selector, which has at least one fine selector contact. In addition to the fine selector contact, the fine selector has at least one auxiliary switch that can be operated independently of it and has at least one auxiliary switching element that contacts taps of the control winding at least largely without arcing. This makes it possible to carry out the switching operations of the tap changer largely without gas.

DE 29 36 534 A1 describes a contact arrangement in a tap selector for transformers, in which, according to a Figure 1 In the embodiment shown, a main winding, a fine winding provided with taps for selector arms for voltage adjustment and a coarse winding arranged on the same leg of the transformer are provided for each phase. The selector arms are connected via a load changeover switch to the phase conductor of the transformer whose voltage is to be regulated. A changeover switch is connected with its outer contacts to the beginning and end of the coarse winding. The center contact of the changeover switch is connected to the center contact of a reversing switch, which in turn has outer contacts that are connected to the beginning and end of the fine winding. In addition, an auxiliary tap is arranged in the path covered by the selector arms, which is electrically connected to the center contact of an auxiliary changeover switch, the outer contacts of which are connected to the beginning and end of the coarse winding. Against this background, the invention proposes the subject matter of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

In the following, a formulation of the type "A is connected to B" corresponds to a formulation of the type "A is connected to B", a formulation of the type "A is connected to B" includes the meanings "A is directly electrically connected to B" and "A is indirectly, i.e. via C, electrically connected to B", and a formulation of the type "A is connected to B" has the meaning "A is directly electrically connected to B".

• einen Feinwähler, der umfasst
  • mehrere Wählerfestkontakte, die einen Kommutierungskontakt, der mit einer zugeordneten Anzapfung einer Stammwicklung des Regeltransformators verbunden werden kann oder soll, und mehrere Stufenkontakte, die jeweils mit einer zugeordneten Anzapfung einer Regelwicklung des Regeltransformators verbunden werden können, umfassen;
  • einen ersten Wählerarm, der wahlweise jeden der Wählerfestkontakte kontaktieren kann;
  • einen zweiten Wählerarm, der wahlweise jeden der Wählerfestkontakte kontaktieren kann;
• einen Vorwähler, der von einer ersten Stellung in eine zweite Stellung und umgekehrt umgeschaltet werden kann und mit der Regelwicklung und der Stammwicklung verbunden werden kann oder soll und der umfasst
  • einen ersten Vorwählerfestkontakt,
  • einen zweiten Vorwählerfestkontakt,
  • einen dritten Vorwählerfestkontakt, der in der ersten Stellung mit dem ersten Vorwählerfestkontakt und in der zweiten Stellung mit dem zweiten Vorwählerfestkontakt verbunden ist;
• einen Lastumschalter, der von einer ersten Stellung in eine zweite Stellung und umgekehrt umgeschaltet werden kann und der umfasst
  • einen ersten Anschluss, der mit dem ersten Wählerarm verbunden ist,
  • einen zweiten Anschluss, der mit dem zweiten Wählerarm verbunden ist;
  • eine Ableitung, die in der ersten Stellung mit dem ersten Anschluss und in der zweiten Stellung mit dem zweiten Anschluss verbunden ist;
    wobei
• wenn der Vorwähler umgeschaltet werden soll oder muss, dann
  • die Wählerarme derart eingestellt sind oder werden, dass einer der Wählerarme den Kommutierungskontakt kontaktiert und der andere Wählerarm keinen der Stufenkontakte kontaktiert,
  • eine Umschaltung des Lastumschalters beginnt, bevor die Umschaltung des Vorwählers beendet ist.

The invention proposes, according to a first aspect, a method for switching an on-load tap changer according to claims 6-12, wherein the on-load tap changer comprises

• a fine selector that includes
  • a plurality of selector fixed contacts comprising a commutation contact which can or should be connected to an associated tap of a main winding of the regulating transformer and a plurality of tap contacts which can each be connected to an associated tap of a regulating winding of the regulating transformer;
  • a first voter arm that can optionally contact any of the voter contacts;
  • a second voter arm that can optionally contact any of the voter contacts;
• a preselector which can be switched from a first position to a second position and vice versa and which can or should be connected to the control winding and the main winding and which comprises
  • a first pre-selector fixed contact,
  • a second preselector fixed contact,
  • a third preselector fixed contact which is connected to the first preselector fixed contact in the first position and to the second preselector fixed contact in the second position;
• a load changeover switch which can be switched from a first position to a second position and vice versa and which comprises
  • a first terminal connected to the first selector arm,
  • a second terminal connected to the second selector arm;
  • a lead connected to the first terminal in the first position and to the second terminal in the second position;
    where
• if the preselector should or must be switched, then
  • the selector arms are or will be set in such a way that one of the selector arms contacts the commutation contact and the other selector arm does not contact any of the step contacts,
  • a changeover of the load diverter switch begins before the changeover of the pre-selector is completed.

This switching of the load changeover switch is the one that takes place when the selector should or must be switched. In contrast to this, the »normal« Switching of the load changeover switch under load, also known as load switching. During this load switching, the selector arms contact different selector fixed contacts and are therefore at different potentials, and the current path leading from the control winding to the discharge line changes without interruption from one selector arm to the other. Since this change should take place without interruption, both selector arms are typically connected to the discharge line for at least a short time, so that a circulating current flows through them, the load changeover switch and the control winding due to the different potentials applied to them.

According to the proposed method, the selector arms are therefore set during these switching operations of the load changeover switch and the preselector such that one of the selector arms contacts the commutation contact and the other selector arm does not contact any of the tap contacts. During these switching operations, for example, one of the selector arms can contact the commutation contact and the other selector arm can be in an intermediate position between the commutation contact and one of the tap contacts, but both selector arms can also contact the commutation contact. In addition, the selector arms can, for example, change their respective positions during these switching operations as long as the above condition is met, according to which one contacts the commutation contact and the other does not contact any of the tap contacts.

As is known, the preselector should or must be switched, for example, when the on-load tap-changer receives a switching command from a control device coupled to it to carry out a tap change from the currently set start position to a target position, and when a) the start position belongs to one of the position control ranges, for example to the lower or upper position control range, and the target position belongs to another of the position control ranges, for example to the upper or lower position control range, or when b) the start position is the middle position and the target position belongs to one of the position control ranges, or when c) the target position is the middle position and the start position belongs to one of the position control ranges.

This method allows the selector and load changeover switch to be operated simultaneously, at least for a certain period of time. This saves the additional time and control effort required to operate the selector, which significantly simplifies and speeds up the entire switching process of the on-load tap changer required for a tap change. This method also allows the The changeover of the load diverter switch ends before the changeover of the pre-selector begins, and thus the load diverter switch and pre-selector are operated one after the other.

• während der Umschaltung des Vorwählers die Umschaltung des Lastumschalters erfolgt; und/oder
• die Umschaltung des Lastumschalters genau einmal erfolgt. Vorzugsweise ist spezifiziert, dass
• während der Umschaltung des Lastumschalters kein Kreisstrom fließt.

Preferably it is specified that

• the load changeover switch is switched during the changeover of the preselector; and/or
• the load changeover switch is switched exactly once. Preferably, it is specified that
• no circulating current flows during the switching of the load changeover switch.

This can be achieved, for example, by having one of the selector arms contact the commutation contact and the other selector arm not contacting any of the step contacts.

• der Vorwähler umfasst
  • einen Vorwählerbewegtkontakt, der eine erste Stellung, in der er den ersten Vorwählerfestkontakt kontaktiert, eine zweite Stellung, in der er den zweiten Vorwählerfestkontakt kontaktiert, und eine Zwischenstellung, in der er keinen der Vorwählerfestkontakte kontaktiert, einnehmen kann;
• zum Umschalten des Vorwählers von der zweiten in die erste Stellung
  • in einem Schritt a) der Vorwählerbewegtkontakt von der zweiten Stellung in die Zwischenstellung bewegt wird;
  • in einem Schritt b) der Lastumschalter umgeschaltet wird;
  • in einem Schritt c) der Vorwählerbewegtkontakt von der Zwischenstellung in die erste Stellung bewegt wird;
    und umgekehrt.

Preferably it is specified that

• the pre-selector includes
  • a preselector moving contact which can assume a first position in which it contacts the first preselector fixed contact, a second position in which it contacts the second preselector fixed contact, and an intermediate position in which it does not contact any of the preselector fixed contacts;
• to switch the preselector from the second to the first position
  • in a step a) the preselector moving contact is moved from the second position to the intermediate position;
  • in step b) the load changeover switch is switched;
  • in a step c) the preselector moving contact is moved from the intermediate position to the first position;
    and vice versa.

• zum umgekehrten Umschalten des Vorwählers, also von der ersten in die zweite Stellung,
  • in einem Schritt a') der Vorwählerbewegtkontakt von der ersten Stellung in die Zwischenstellung bewegt;
  • in einem Schritt b') der Lastumschalter umgeschaltet;
  • in einem Schritt c') der Vorwählerbewegtkontakt von der Zwischenstellung in die zweite Stellung bewegt.

Thus,

• for reverse switching of the preselector, i.e. from the first to the second position,
  • in a step a') the preselector moving contact moves from the first position to the intermediate position;
  • in a step b') the load changeover switch is switched;
  • in a step c') the preselector moving contact is moved from the intermediate position to the second position.

The selector moving contact can be designed in any way as required, for example as a contact finger in a housing.

For example, step a) can be started before, simultaneously with or after the start of step b). For example, step c) can be ended simultaneously with or after the start of step b) and/or before, simultaneously with or after the end of step b).

Step a') can, for example, be started before, simultaneously with or after step b'). Step c') can, for example, be ended simultaneously with or after step b') and/or before, simultaneously with or after the end of step b').

• der Lastumschalter umfasst
  • einen beweglichen Umschaltkontakt, der eine erste Stellung, in der er den ersten Anschluss kontaktiert, eine zweite Stellung, in der er den zweiten Anschluss kontaktiert, und eine Brückungsstellung, in der er beide Anschlüsse kontaktiert, einnehmen kann;
• in Schritt b) der Umschaltkontakt von der ersten Stellung in die Brückungsstellung und danach von der Brückungsstellung in die zweite Stellung geschaltet wird;
• in Schritt b') der Umschaltkontakt von der zweiten Stellung in die Brückungsstellung und danach von der Brückungsstellung in die erste Stellung geschaltet wird.

Preferably it is specified that

• the load switch includes
  • a movable changeover contact which can assume a first position in which it contacts the first terminal, a second position in which it contacts the second terminal, and a bridging position in which it contacts both terminals;
• in step b) the changeover contact is switched from the first position to the bridging position and then from the bridging position to the second position;
• in step b') the changeover contact is switched from the second position to the bridging position and then from the bridging position to the first position.

The changeover contact can be designed in any manner as required, for example like the movable center contact of a rotary switch, in which the movable center contact is rotated, or like the movable center contact of a pull switch, in which the movable center contact is pulled or pressed.

• der Lastumschalter umfasst
  • einen Schalter, der zwischen die Anschlüsse geschaltet ist;
  • einen Widerstand, der zwischen den zweiten Anschluss und den zweiten Wählerarm geschaltet ist,

• der Schalter während Schritt b) und Schritt b') geschlossen ist.

Preferably it is specified that

• the load switch includes
  • a switch connected between the terminals;
  • a resistor connected between the second terminal and the second selector arm is switched on,

• the switch is closed during step b) and step b').

• einen Feinwähler, der umfasst
  • mehrere Wählerfestkontakte, die einen Kommutierungskontakt, der mit einer Stammwicklung des Regeltransformators verbunden werden kann oder soll, und mehrere Stufenkontakte, die jeweils mit einer zugeordneten Anzapfung einer Regelwicklung des Regeltransformators verbunden werden können oder sollen, umfassen;
  • einen ersten Wählerarm, der wahlweise jeden der Wählerfestkontakte kontaktieren kann;
  • einen zweiten Wählerarm, der wahlweise jeden der Wählerfestkontakte kontaktieren kann;
• einen Vorwähler, der von einer ersten Stellung in eine zweite Stellung und umgekehrt umgeschaltet werden kann und mit der Regelwicklung und der Stammwicklung verbunden werden kann oder soll und der umfasst
  • einen ersten Vorwählerfestkontakt,
  • einen zweiten Vorwählerfestkontakt,
  • einen dritten Vorwählerfestkontakt, der in der ersten Stellung mit dem ersten Festkontakt und in der zweiten Stellung mit dem zweiten Vorwählerfestkontakt verbunden ist;
• einen Lastumschalter, der von einer ersten Stellung in eine zweite Stellung und umgekehrt umgeschaltet werden kann und der umfasst
  • einen ersten Anschluss, der mit dem ersten Wählerarm verbunden ist,
  • einen zweiten Anschluss, der mit dem zweiten Wählerarm verbunden ist;
  • eine Ableitung, die in der ersten Stellung mit dem ersten Anschluss und in der zweiten Stellung mit dem zweiten Anschluss verbunden ist;
• eine gemeinsame Antriebswelle für den Vorwähler, den Feinwähler und den Lastumschalter,
  wobei
• der Vorwähler, der Feinwähler und der Lastumschalter jeweils separat an die Antriebswelle gekoppelt sind.

According to a second aspect, the invention proposes an on-load tap changer of a control transformer, wherein the control transformer has a main winding (12) and a control winding (13) with several taps, the on-load tap changer (11) comprising

• a fine selector that includes
  • a plurality of selector fixed contacts comprising a commutation contact which can or should be connected to a main winding of the regulating transformer and a plurality of tap contacts which can or should each be connected to an associated tap of a regulating winding of the regulating transformer;
  • a first voter arm that can optionally contact any of the voter contacts;
  • a second voter arm that can optionally contact any of the voter contacts;
• a preselector which can be switched from a first position to a second position and vice versa and which can or should be connected to the control winding and the main winding and which comprises
  • a first pre-selector fixed contact,
  • a second preselector fixed contact,
  • a third preselector fixed contact connected to the first fixed contact in the first position and to the second preselector fixed contact in the second position;
• a load changeover switch which can be switched from a first position to a second position and vice versa and which comprises
  • a first terminal connected to the first selector arm,
  • a second terminal connected to the second selector arm;
  • a derivation which in the first position is connected to the first terminal and in the second position is connected to the second terminal;
• a common drive shaft for the preselector, the fine selector and the load changeover switch,
  where
• the preselector, the fine selector and the load changeover switch are each separately coupled to the drive shaft.

The separate coupling enables a simple and robust design as well as a flexible and easy adaptation of the on-load tap-changer and a significantly simplified and accelerated switching process of the on-load tap-changer and thus error-free function.

• der Vorwähler umfasst
  • einen Vorwählerbewegtkontakt, der eine erste Stellung, in der er den ersten Vorwählerfestkontakt kontaktiert, eine zweite Stellung, in der er den zweiten Vorwählerfestkontakt kontaktiert, und eine Zwischenstellung, in der er keinen der Vorwählerfestkontakte kontaktiert, einnehmen kann.

Preferably it is specified that

• the pre-selector includes
  • a preselector moving contact which can assume a first position in which it contacts the first preselector fixed contact, a second position in which it contacts the second preselector fixed contact, and an intermediate position in which it does not contact any of the preselector fixed contacts.

• einen beweglichen Umschaltkontakt, der eine erste Stellung, in der er den ersten Anschluss kontaktiert, eine zweite Stellung, in der er den zweiten Anschluss kontaktiert, und eine Brückungsstellung, in der er beide Anschlüsse kontaktiert, einnehmen kann.

Preferably, the load changeover switch comprises

• a movable changeover contact which can assume a first position in which it contacts the first terminal, a second position in which it contacts the second terminal, and a bridging position in which it contacts both terminals.

• einen Schalter, der zwischen die Anschlüsse geschaltet ist;
• einen Widerstand, der zwischen den zweiten Anschluss und den zweiten Wählerarm geschaltet ist.

Preferably, the load changeover switch comprises

• a switch connected between the terminals;
• a resistor connected between the second terminal and the second selector arm.

• der Vorwähler umfasst
  • einen Vorwähler-Treiber auf der ersten Seite, der drehfest auf der Antriebswelle sitzt und einen ersten Vorwähler-Mitnehmer trägt;
  • ein Vorwähler-Malteserrad auf der ersten Seite, das drehbar an der Vorwählergrundplatte gelagert ist und einen zweiten Vorwähler-Mitnehmer trägt;
  • eine Wippe auf der ersten Seite, die schwenkbar an der Vorwählergrundplatte gelagert ist und ein Maul für den zweiten Vorwähler-Mitnehmer aufweist;
• die Vorwählerfestkontakte und der Vorwählerbewegtkontakt auf der zweiten Seite der Vorwählergrundplatte angeordnet sind;
• die Wippe drehfest mit dem Vorwählerbewegtkontakt verbunden ist;
• der erste Vorwähler-Mitnehmer derart mit dem Vorwähler-Malteserrad zusammenwirkt, dass sich bei einer vollständigen Drehung des Vorwähler-Treibers das Vorwähler-Malteserrad nur um einen Bruchteil einer vollständigen Drehung dreht, wobei dieser Bruchteil einem Schaltvorgang des Feinwählers von einem Wählerfestkontakt auf einen benachbarten Wählerfestkontakt entspricht;
• der zweite Vorwähler-Mitnehmer derart mit der Wippe zusammenwirkt, dass, wenn einer der Wählerarme einen der Stufenkontakte kontaktiert, der zweite Vorwähler-Mitnehmer bei einer Drehung des Vorwähler-Malteserrads um den Bruchteil nicht in das Maul eingreift und, wenn einer der Wählerarme den Kommutierungskontakt kontaktiert und der andere Wählerarm keinen der Stufenkontakte kontaktiert, der zweite Vorwähler-Mitnehmer in das Maul derart eingreift, dass der Vorwählerbewegtkontakt umgeschaltet wird.

Preferably it is specified that

• the pre-selector includes
  • a pre-selector driver on the first side, which is non-rotatably mounted on the drive shaft and carries a first pre-selector driver;
  • a pre-selector Geneva wheel on the first side, which is rotatably mounted on the pre-selector base plate and carries a second pre-selector driver;
  • a rocker on the first side, which is pivotally mounted on the pre-selector base plate and has a mouth for the second pre-selector driver;
• the preselector fixed contacts and the preselector moving contact are arranged on the second side of the preselector base plate;
• the rocker is connected in a rotationally fixed manner to the preselector moving contact;
• the first preselector driver interacts with the preselector Geneva wheel in such a way that, during a complete rotation of the preselector driver, the preselector Geneva wheel only rotates by a fraction of a complete rotation, this fraction corresponding to a switching operation of the fine selector from one selector fixed contact to an adjacent selector fixed contact;
• the second preselector driver interacts with the rocker in such a way that, when one of the selector arms contacts one of the step contacts, the second preselector driver does not engage in the mouth when the preselector Geneva wheel rotates by the fraction, and, when one of the selector arms contacts the commutation contact and the other selector arm does not contact any of the step contacts, the second preselector driver engages in the mouth in such a way that the preselector moving contact is switched.

• die Vorwählerfestkontakte von der ersten Seite durch die Vorwählergrundplatte hindurch bis auf die zweite Seite geführt sind.

Preferably it is specified that

• the selector fixed contacts are led from the first side through the selector base plate to the second side.

As is known, the preselector serves to connect the control winding to the main winding in different ways and can be designed in any way as required, for example as a reversing switch or coarse selector or multiple coarse selector.

• der Vorwähler als Wender ausgebildet ist;
• der erste Vorwählerfestkontakt mit einem Ende der Regelwicklung verbunden werden kann oder soll;
• der zweite Vorwählerfestkontakt mit einem zweiten Ende der Regelwicklung verbunden werden kann oder soll;
• der dritte Vorwählerfestkontakt mit der Stammwicklung verbunden werden kann oder soll.

Preferably it is specified that

• the pre-selector is designed as a turner;
• the first selector fixed contact can or should be connected to one end of the control winding;
• the second selector fixed contact can or should be connected to a second end of the control winding;
• the third selector fixed contact can or should be connected to the main winding.

• der dritte Vorwählerfestkontakt mit dem Kommutierungskontakt ständig verbunden ist. Vorzugsweise ist spezifiziert, dass
• der Vorwähler als Grobwähler ausgebildet ist;
• der erste Vorwählerfestkontakt mit einem ersten Ende der Stammwicklung verbunden werden kann oder soll;
• der zweite Vorwählerfestkontakt mit einer Anzapfung der Stammwicklung verbunden werden kann oder soll;
• der dritte Vorwählerfestkontakt mit einem Ende der Regelwicklung verbunden werden kann oder soll.

Preferably, and especially in this case, it is specified that

• the third selector fixed contact is permanently connected to the commutation contact. Preferably it is specified that
• the pre-voter is trained as a rough voter;
• the first selector fixed contact can or should be connected to a first end of the main winding;
• the second selector fixed contact can or should be connected to a tap of the main winding;
• the third selector fixed contact can or should be connected to one end of the control winding.

• der erste Vorwählerfestkontakt mit dem Kommutierungskontakt ständig verbunden ist. Vorzugsweise umfasst der Laststufenschalter
• eine erste Kopplungseinrichtung, die den Vorwähler an die Antriebswelle koppelt;
• eine zweite Kopplungseinrichtung, die den Feinwähler an die Antriebswelle koppelt; wobei
• die Kopplungseinrichtungen separat voneinander aufgebaut sind und/oder keine gemeinsamen Bauteile aufweisen.

Preferably, and especially in this case, it is specified that

• the first selector fixed contact is permanently connected to the commutation contact. Preferably, the on-load tap changer comprises
• a first coupling device coupling the preselector to the drive shaft;
• a second coupling device which couples the fine selector to the drive shaft; wherein
• the coupling devices are constructed separately from one another and/or do not have any common components.

• eine dritte Kopplungseinrichtung, die den Lastumschalter an die Antriebswelle koppelt; wobei
• die dritte Kopplungseinrichtung und die erste und/oder zweite Kopplungseinrichtung separat voneinander aufgebaut sind und/oder keine gemeinsamen Bauteile aufweisen.

Preferably, the on-load tap-changer comprises

• a third coupling device which couples the load changeover switch to the drive shaft;
• the third coupling device and the first and/or second coupling device are constructed separately from one another and/or do not have any common components.

The first coupling device can be designed in any manner as required and can comprise, for example, the preselector driver, the preselector Geneva wheel and the rocker.

With each of the proposed on-load tap-changers and with each of the proposed regulating transformers, one of the proposed methods can be carried out as an example.

Each of the proposed tap changers and each of the proposed control transformers can, for example, be designed and/or serve and/or be suitable for carrying out and/or being able to carry out one of the proposed methods.

The explanations relating to one of the aspects of the invention, in particular to individual features of this aspect, also apply analogously to the other aspects of the invention.

In the following, embodiments of the invention are explained in more detail by way of example with reference to the accompanying drawings. The individual features resulting therefrom are not, however, restricted to the individual embodiments, but can be connected and/or combined with individual features described above and/or with individual features of other embodiments. The details in the drawings are to be interpreted as merely illustrative and not restrictive. The reference symbols contained in the claims are not intended to restrict the scope of protection of the invention in any way, but merely refer to the embodiments shown in the drawings.

FIG. 1

eine schematische Seitenansicht einer bevorzugten Ausführungsform eines Laststufenschalters mit einem Feinwähler, einem Vorwähler und einem Lastumschalter;

FIG. 2

eine erste Seite einer bevorzugten Ausführungsform eines Feinwählers für den Laststufenschalter der FIG. 1;

FIG. 3

die erste Seite des Feinwählers der FIG. 2 bei entferntem Malteserrad;

FIG. 4

eine zweite Seite des Feinwählers;

FIG. 5

eine erste Seite einer bevorzugten Ausführungsform eines Vorwählers für den Laststufenschalter der FIG. 1 bei teilweise ausgeschnittenem Malteserrad;

FIG. 6

eine zweite Seite des Vorwählers;

FIG. 7

eine erste Seite einer bevorzugten Ausführungsform eines Lastumschalters für den Laststufenschalter der FIG. 1;

FIG. 8

eine zweite Seite des Lastumschalters;

FIG. 9

einen Schaltplan für eine erste Ausführungsform eines Regeltransformators, der den Laststufenschalter der FIG. 1 umfasst, wobei sich der Laststufenschalter in einer Ausgangsposition befindet;

FIG. 9a-h

die einzelnen Schaltphasen einer ersten Ausführungsform eines Schaltablaufs einer Stufenschaltung des Laststufenschalters in dem Regeltransformator der FIG. 9;

FIG. 10

ein Zeitablaufdiagramm des Schaltablaufs der FIG. 9 bis FIG. 9h;

FIG. 11

ein Zeitablaufdiagramm einer zweiten Ausführungsform des Schaltablaufs;

FIG. 12

ein Zeitablaufdiagramm einer dritten Ausführungsform des Schaltablaufs;

FIG. 13

einen Schaltplan für eine zweite Ausführungsform eines Regeltransformators.

The drawings show in

FIG. 1

a schematic side view of a preferred embodiment of an on-load tap changer with a fine selector, a preselector and a load diverter switch;

FIG. 2

a first side of a preferred embodiment of a fine selector for the on-load tap changer of the FIG. 1 ;

FIG. 3

the first page of the fine selector of the FIG. 2 with the Maltese wheel removed;

FIG. 4

a second side of the fine selector;

FIG. 5

a first side of a preferred embodiment of a preselector for the on-load tap changer of the FIG. 1 with the Maltese wheel partially cut out;

FIG. 6

a second page of the pre-selector;

FIG. 7

a first side of a preferred embodiment of a load diverter switch for the on-load tap changer of the FIG. 1 ;

FIG. 8th

a second side of the diverter switch;

FIG. 9

a circuit diagram for a first embodiment of a regulating transformer which controls the on-load tap changer of the FIG. 1 wherein the on-load tap-changer is in a starting position;

FIG. 9a-h

the individual switching phases of a first embodiment of a switching sequence of a tap change of the on-load tap changer in the control transformer of the FIG. 9 ;

FIG. 10

a timing diagram of the switching sequence of the FIG. 9 to FIG. 9h ;

FIG. 11

a timing diagram of a second embodiment of the switching sequence;

FIG. 12

a timing diagram of a third embodiment of the switching sequence;

FIG. 13

a circuit diagram for a second embodiment of a regulating transformer.

In FIG. 1 a preferred embodiment of an on-load tap changer 11 is shown schematically. In this embodiment, the on-load tap changer 11 is constructed according to the resistance principle and has three fine selectors 20, three preselectors 40 and three load changeover switches 60. Each fine selector 20, each preselector 40 and each load changeover switch 60 is assigned to a specific phase of a regulating transformer ( FIG. 9 ). A single-phase variant of the on-load tap changer 11 would therefore only comprise a fine selector 20, a pre-selector 40 and a load changeover switch 60. Each fine selector 20 is mounted on a fine selector base plate 21, each pre-selector 40 on a pre-selector base plate 41, and each load changeover switch 60 on a load changeover switch base plate 61. The individual base plates 21, 41, 61 preferably consist of an insulating material such as plastic or fiber-reinforced plastic (e.g. a mixture of polyamide or polyphthalamide with glass fibers). They are individually pushed onto at least one rod 16 and are held in place by this. The plates 21, 41, 61 can also be attached in other ways, e.g. using spacers, molded-on webs or additional plates. A common drive shaft 17 drives all fine selectors 20, pre-selector 40 and load changeover switch 60. In this embodiment, the drive shaft 17 extends through the plates 21, 41, 61. The drive shaft 17 is preferably driven by a motor 19 via a bevel gear 18, but can also be driven directly, i.e. without an intermediate Gearbox which drives engine 19.

In FIG. 2 , FIG. 3 and FIG. 4 1 shows one of the fine selectors 20, which is designed according to a preferred embodiment. The fine selector base plate 21 has a first side 211 and a second, opposite side 212. FIG. 2 and 3 show the first page 211, on which nine voter contacts 200...208 ( FIG. 3 ) are arranged behind a first selector Geneva wheel 24. Five of these nine selector fixed contacts 200...208 are connected to five lines 22, via which they can be connected to associated taps of a control winding 13 of the control transformer. The selector fixed contacts 200...208 extend from the first side 211 through the fine selector base plate 21 to the second side 212. The selector fixed contacts 200...208 are preferably made of copper and are additionally silver-plated. The first selector Geneva wheel 24 has a first selector arm 26 mounted so as to be radially movable on its rear side facing the fine selector base plate 21 and is mounted on a first bearing axis 25 so as to be rotatable about an axis 23. The bearing axis 25 is designed as a separate part which is mechanically connected to the fine selector base plate 21. However, the bearing axle 25 can be injection-molded during the manufacture of the fine selector base plate 21 and formed as a unit with it. A first selector driver 27 is arranged next to the first selector Geneva wheel 24 and is driven via the drive shaft 17. The first selector driver 27 has a first selector driver 28 which engages in the first selector Geneva wheel 24 and rotates it.

When the fine selector 20 is operated, the first selector driver 27 is rotated by 360°. When interacting with the first selector Geneva wheel 24, during this complete rotation of the first selector driver 27, the first selector Geneva wheel 24 is only rotated incrementally, i.e. by a fraction of a complete rotation. The combination of the first selector driver 27 and the first selector Geneva wheel 24 converts the continuous rotary motion of the first selector driver 27 into a step-by-step or step-by-step rotation of the first selector Geneva wheel 24. The combination of Geneva wheel and driver enables both parts to lock against each other even in the idle state, i.e. before or after the fine selector 20 is operated. FIG. 4 shows the second side 212 of the fine selector base plate 21. On the second side 212, analogous to the first side 211, a second selector Geneva wheel 34 with a second selector arm 36 (not shown) is mounted. The second selector Geneva wheel 34 is also mounted on a second bearing axis 35 so as to be rotatable about the axis 23. A second selector driver 37 is arranged next to the second selector Geneva wheel 34 and is operated by the same drive shaft 17 as the first selector driver 27. The second selector driver 37 has a second selector driver 38 which engages in the second selector Geneva wheel 34 and thereby rotates it. The second selector Geneva wheel 34 and thus the second selector arm 36 are driven step by step by the drive shaft 17 via the second selector driver 37 in a similar way to the first selector Geneva wheel 24 and the first selector arm 26.

The nine selector fixed contacts 200...208 (not shown) are arranged analogously to the first side 211 behind the second selector Geneva wheel 34. The remaining four selector fixed contacts 200...208, which are not connected to the five lines on the first side 211, are connected to four further lines 22, via which they can be connected to associated taps of the control winding 11.

In FIG. 5 and FIG. 6 1 shows one of the preselectors 40, which is designed according to a preferred embodiment. The preselector base plate 41 has a first side 411 and a second, opposite side 412. FIG. 5 show the first side 411. A preselector Geneva wheel 44 is attached to this, which is mounted on a first bearing axis 45 so as to be rotatable about a first axis 43. The first bearing axis 45 is designed as a separate part that is mechanically connected to the preselector base plate 41. The first bearing axis 45 can, however, be injection-molded onto the preselector base plate 41 during manufacture and can be formed as a unit with it. A preselector driver 42 is arranged next to the preselector Geneva wheel 44 and is seated on the drive shaft 17 in a rotationally fixed manner. The first preselector driver 42 has a first preselector driver 421 which can engage in the preselector Geneva wheel 44 and thereby rotates it step by step. Furthermore, a rocker 46 is attached to the first side 411, which is mounted on a second bearing axis 48 so as to be pivotable about a second axis 47. The second bearing axis 48 is also designed as a separate part that is mechanically connected to the preselector base plate 41. However, the second bearing axis 48 can be molded onto the preselector base plate 41 during manufacture and can be designed as a unit with it. The rocker 46 has a mouth 461 that interacts with a second preselector driver 441 that protrudes from the back of the preselector Geneva wheel 44 that faces the preselector base plate 41.

FIG. 6 shows the second side 412 of the preselector base plate 41. A first, a second and a third preselector fixed contact 401, 402, 403 of the preselector 40 are arranged on this. The first and second preselector fixed contact 401, 402 are led from the first side 411 through the preselector base plate 41. up to the second page 412 and with Lines 49, via which they can be connected to the ends of the control winding 13. The third preselector fixed contact 403 can be connected to a main winding via a line 49, which is led from the first side 411 through the preselector base plate 41 to the second side 412. 12 of the regulating transformer. The preselector fixed contacts 401...403 are preferably made of copper and are additionally silver-plated. Furthermore, the second side 412 comprises a preselector moving contact 404, which is spring-mounted in a contact housing 50. The contact housing 50 is fixedly connected to the bearing axis 48 so that the pivoting movement of the rocker 46 is transmitted to the preselector moving contact 404. In the first position, this contacts the first preselector fixed contact 401, in the second position the second preselector fixed contact 402 and in the intermediate position neither of these two contacts.

To operate the preselector 40, the preselector driver 42 is rotated by 360° by the drive shaft 17. The first preselector driver 421 engages the preselector Geneva wheel 44 with each complete rotation of the preselector driver 42 and moves it by a fraction of a complete rotation. This fraction corresponds to a switching operation of the fine selector 20 from a selector fixed contact 200...208 to an adjacent selector fixed contact 200...208. During these switching operations, the rocker 46 remains untouched because the second preselector driver 441 has not yet reached the position in which it engages in the mouth 461. Only when one of the two selector arms 26, 36 contacts the commutation contact 200 and the other of the two selector arms 26, 36 does not contact any of the step contacts 201...208 does the second preselector driver 441 engage in the mouth 461 and pivots the rocker 46. The pivoting movement of the rocker 46 also pivots the second bearing axis 48 and thus the contact housing 50 with the preselector moving contact 404. The preselector moving contact 404 is thereby switched from the first to the second position or from the second to the first position, depending on the switching direction.

This preselector 40 can be used either as a reversing switch or as a coarse selector, depending on how it is connected to the control winding 13 and the main winding 12.

In FIG. 7 and FIG. 8th 1 shows one of the load diverter switches 60, which is designed according to a preferred embodiment. The load diverter switch base plate 61 is preferably made of an insulating material such as plastic or fiber-reinforced plastic (eg a mixture of polyamide or polyphthalamide with glass fibers) and has a first side 611 and a second, opposite side 612. FIG. 7 shows the first side 611. On this is a switch 62, which in this embodiment is a vacuum interrupter is designed, fastened to the load changeover switch base plate 61 by means of holders 63. The vacuum interrupter 62 comprises a fixed contact 621 and a moving contact 622, via which the vacuum interrupter 62 is opened or closed. Furthermore, on the first side 611, a cam disk 64 is attached to the drive shaft 17 in a rotationally fixed manner. Between the cam disk 64 and the moving contact 622, a rocker arm 65 is rotatably mounted in such a way that when the cam disk 64 is rotated, an end 651 of the rocker arm 65 moves along a contour 641 of the cam disk 64 and thereby actuates the vacuum interrupter 62, ie closes or opens via its moving contact 622. The moving contact 622 is guided in a holder when actuated.

FIG. 8th shows the second side 612 of the load switch base plate 61. A resistor 66 is arranged on the second side 612. Furthermore, a first gear 67, which corresponds to the cam disk 64 on the first side 611, is rotatably mounted on the second side 612. The drive shaft 17 In the example shown here, the cam disc 64, the load switch base plate 61 and the first gear 67 pass through and drive the cam disc 64 and the first gear 67. Furthermore, a switching element 68 is provided, which is connected to a combination of a second gear 69, which is connected to the first gear 67 meshes and is driven by a connecting rod 70, is mounted on the second side 612. By actuating the drive shaft 17, the switching element 68 is actuated via the gears 67, 69 and the connecting rod 70. Here, the rotary motion of the drive shaft 17 is converted into a linear motion of the switching element 68. The switching element 68 is designed as a bridging switch, for example, but can also be designed as a rotary switch, for example.

The arrangement of the individual parts, in particular the vacuum interrupter 62, the resistor 66 and the switching element 68, can be distributed over the first and/or the second side 611, 612 of the load diverter switch base plate 61 as required. The vacuum interrupter 62 and the switching element 68 can also be actuated in any manner as required, for example via gears and/or Geneva wheels and/or connecting rods.

In this embodiment, the on-load tap changer 11 comprises a first coupling device which couples the preselector 40 to the drive shaft 17, a second coupling device which couples the fine selector 20 to the drive shaft 17, and a third coupling device which couples the load diverter switch 60 to the drive shaft 17. The first coupling device comprises the preselector driver 42, the preselector Geneva wheel 44 and the rocker 46. The second coupling device comprises the selector drivers 27, 37 and the selector Geneva wheels 24, 34. The third coupling device comprises the cam disc 64, the rocker arm 65, the gears 67, 69 and the connecting rod 70. These three coupling devices are therefore constructed separately from one another and have no common components.

In FIG. 9 is a circuit diagram for one phase of a first embodiment of a three-phase regulating transformer which controls the on-load tap changer 11 of the FIG. 1 and a main winding 12 and a control winding 13 with several taps. The commutation contact 200 is connected to one end of the main winding 12, and the step contacts 201...208 are each connected to an associated tap of the control winding 13.

In this embodiment, the preselector 40 is used as a reversing switch and serves to connect the control winding 13 optionally in the same direction or in opposite directions to the main winding 12. The first preselector fixed contact 401 is connected to a first end of the control winding 13, the second preselector fixed contact 402 is connected to a second end of the control winding 13, and the third preselector fixed contact 403 is connected to one end of the main winding 12 and permanently to the commutation contact 200.

In this embodiment, the load diverter switch 60 comprises, in addition to the switch 62 and the resistor 66, a first connection 601, a second connection 602, and a movable changeover contact 604 which is connected to a discharge line 603 of the on-load tap changer 11 and the regulating transformer. The changeover contact 604 is designed as a bridging switch and contacts the first connection 601 in a first position, the second connection 602 in a second position, and both connections 601, 602 in a bridging position. In the first position, it connects the discharge line 603 to the first connection 601, in the second position, the discharge line 603 to the second connection 602, and in the bridging position, both connections 601, 602 to the discharge line 603. The first connection 601 is connected to the first selector arm 26 via a main branch 14. The second terminal 602 is connected to the second selector arm 36 via an auxiliary branch 15, with the resistor 66 connected in series between them. The switch 62 is connected between the terminals 601 and 602.

In FIG. 9 and FIG. 9a to h shows a first embodiment of a switching sequence of a step switching of the on-load tap changer 11. Through this step switching, the on-load tap changer 11 switches, for example, from the commutation contact 200 to the eighth step contact 208, which can also be referred to as a switching from a position 9 to a position 8. of the on-load tap changer 11. In position 9, the selector arms 26, 36 contact the commutation contact 200 and the preselector 40 is in the first position. In position 8, the selector arms 26, 36 contact the eighth tap contact 208 and the preselector 40 is in the second position. Consequently, the preselector 40 must be operated in this tap switching.

The starting position for this switching sequence is in FIG. 9 In this initial position, the on-load tap changer 11 is in position 9, the load diverter switch 60 is in the first position and the switch 62 is closed.

In a step a, the preselector moving contact 404 is separated from the second preselector fixed contact 402 and thus brought into the intermediate position. The on-load tap changer 11 is now in the position of FIG. 9a .

In a step b, the load changeover switch 60 is switched. The changeover contact 604 is first set to the bridging position according to FIG. 9b1 and then continue to the second position according to FIG. 9b2 The switch 62 is then opened. This completes the first switching of the load changeover switch 60, during which no circulating current has flowed. The preselector moving contact 404 is still in the intermediate position on the way to the first preselector fixed contact 401. The on-load tap changer 11 is now in the position of FIG. 9b3 .

In a step c, the preselector moving contact 404 is contacted with the first preselector fixed contact 401 and thus brought into the second position. This completes the switching of the preselector 40. The on-load tap changer 11 is now in the position of FIG.9c .

Now follow the switching steps required to complete the step change to position 8.

In a step d, the first selector arm 26 is separated from the commutation contact 200 and contacted with the eighth tap contact 208. The on-load tap changer 11 is now in the position of FIG. 9d .

In a step e, the switch 62 is closed so that the auxiliary branch 15 is connected to the main branch 14 via the switch 62 and a circulating current Ic flows through the on-load tap-changer 11 and the control winding 13. The on-load tap-changer 11 is now in the position of FIG.9e .

In a step f, the changeover contact 604 is first again set to the bridging position according to FIG. 9f1 and then continue to the first position according to FIG. 9f2 The switch 62 is then opened again, whereby the auxiliary branch 15 and the main branch 14 are separated and the circuit current Ic ceases. This completes a second, »normal« switching of the load diverter switch 60, which represents a load switching. The on-load tap changer 11 is now in the position of FIG. 9f3 .

In a step g, the second selector arm 36 is separated from the commutation contact 200 and contacted with the eighth tap contact 208. The on-load tap changer 11 is now in the position of FIG. 9g .

In a step h, the switch 62 is closed. This completes the load switching to the tap contact 201 and also the tap switching from position 9 to position 8. The on-load tap changer 11 is now in the end position of the FIG. 9am .

If, for example, the step switching is to be carried out in the opposite direction, i.e. from position 8 to position 9, the procedure shown in FIG. FIG. 9 to FIG. 9h described switching sequence in exactly the reverse order.

FIG. 10 shows a timing diagram of the switching sequence of the FIG. 9 to FIG. 9h The rows arranged from top to bottom show the positions of the switch 62, the changeover contact 604, the first selector arm 26, the second selector arm 36 and the preselector moving contact 404 over time for a complete step change from position 8 to position 9 or vice versa. The vertical dashed line marks the time at which the switching of the preselector 40 must be completed at the latest or may be started at the earliest, namely when one of the selector arms 26, 36 contacts the commutation contact 200 and the other selector arm no longer or still not contacted.

For those in FIG. 9 to h, the timing diagram is to be read from right to left. The timing diagram shows that first, according to step a, the preselector moving contact 404 is moved from the second position to the intermediate position, then according to sub-steps b1 and b2, the changeover contact 604 is moved from the first position to the bridge position and from there to the second position, then according to sub-step b3, the switch 62 is opened, and then according to step c, the preselector moving contact 404 is moved from the intermediate position to the first position. When looking at the timing diagram from left to right, this process takes place in exactly the reverse order.

In FIG. 11 A timing diagram of a second embodiment of the switching sequence is shown. This embodiment is similar to the first embodiment in FIG. 11 , so that the differences are explained in more detail below. In this embodiment, as in the first embodiment, first the preselector moving contact 404 is moved to the intermediate position according to step a and then the changeover contact 604 is moved from the first position to the bridge position according to sub-step b1. Then, however, unlike in the first embodiment, the preselector moving contact 404 is moved from the intermediate position to the first position according to step c, at the same time the changeover contact 604 is moved from the bridge position to the second position according to sub-step b2 and the switch 62 is then opened according to sub-step b3. Thus, in this embodiment, the switching of the preselector 40 is completed before the switching of the load changeover switch 60. In the opposite direction, as a difference to the first embodiment of the switching sequence, the switch 62 is actuated before the preselector moving contact 404.

In FIG. 12 A timing diagram of a third embodiment of the switching sequence is shown. This embodiment is similar to the first embodiment in FIG. 11 , so that the differences are explained in more detail below. In this embodiment, when considering the switching sequence in both directions, the switching of the load changeover switch 60 and the preselector 40 are started and ended simultaneously.

In FIG. 13 A circuit diagram for one phase of a second embodiment of the regulating transformer is shown. This embodiment is similar to the first embodiment of the FIG. 9 , so that the differences are explained in more detail below. In this embodiment, the main winding 12 comprises a tap 121, which forms the upper end of a coarse stage of the main winding 12. The lower end of the main winding 12 forms the lower end of the coarse stage.

In this embodiment, the preselector 40 is used as a coarse selector and serves to optionally connect the coarse stage to the control winding 13 or not. The first preselector fixed contact 401 is connected to the lower end of the main winding 12 and permanently to the commutation contact 200. The second preselector fixed contact 402 is connected to the tap 121 of the main winding 12. The third preselector fixed contact 403 is connected to one end of the control winding 13.

REFERENCE SIGNS

11

On-load tap changer

12

Main winding of the regulating transformer

121

Tapping of 12

13

Control winding of the control transformer

14

Main branch of 11

15

Auxiliary branch of 11

16

Rod

17

Drive shaft of 11

18

Bevel gear

19

engine

20

Fine selector of 11

200

Commutation contact of 20

201...208

Step contacts of 20

200... 208

Voter contacts of 20

21

Fine selector base plate

211/212

first/second page of 21

22

cables

23

axis

24

first voter Maltese bike

25

first bearing axis

26

first voting arm

27

first voter driver

28

first voter taker

29

Connection

34

second voter Maltese wheel

35

second bearing axis

36

second voting arm

37

second voter driver

38

second voter-carrier

39

Connection

40

Pre-selection of 11

401/402/403

first/second/third preselector fixed contact of 40

404

Preselector moving contact of 40

41

Pre-selector base plate

411/412

first/second page of 41

42

Pre-selector driver

421

first pre-selector driver

43

first axis

44

Pre-selector Maltese wheel

441

second preselector driver

45

first bearing axis

46

Seesaw

461

Mouth of 46

47

second axis

48

second bearing axis

49

cables

50

Contact housing

60

Load changeover switch of 11

601/602

first/second connection of 60

603

Derivative of 60

604

movable changeover contact of 60

61

Load diverter switch base plate

611/612

first/second page of 61

62

Switch

621/622

Fixed contact/moving contact of 60

63

holder

64

Cam disc

641

Contour of 64

65

rocker arm

651

an end to 65

66

Resistance

67

first gear

68

Switching element

69

second gear

70

Connecting rod

Claims (12)

1. Method for switching an on-load tap changer (11) according to Claims 6 to 12, wherein the on-load tap changer (11) comprises

   - a tap selector (20) which comprises

   • a plurality of selector fixed contacts (200...208) comprising a commutation contact (200), which can be connected to the main winding (12) of the regulating transformer, and a plurality of tap contacts (201...208) which can in each case be connected to an assigned tap of the tap winding (13) of the regulating transformer;

   • a first selector arm (26) which can selectably contact each of the selector fixed contacts (200 ... 208); and

   • a second selector arm (36) which can selectably contact each of the selector fixed contacts (200 ... 208) ;

   - a change-over selector (40) which can be switched over from a first setting to a second setting and vice versa, and which can be connected to the tap winding (13) and the main winding (12), and comprises

   • a first change-over selector fixed contact (401),

   • a second change-over selector fixed contact (402), and

   • a third change-over selector fixed contact (403) which is connected in the first setting to the first change-over selector fixed contact (401) and in the second setting to the second change-over selector fixed contact (402); and

   - a diverter switch (60) which can be switched over from a first setting to a second setting and vice versa, and which comprises

   • a first terminal (601) connected to the first selector arm (26),

   • a second terminal (602) connected to the second selector arm (36), and

   • a diverter line (603) connected in the first setting to the first terminal (601) and in the second setting to the second terminal (602);
   wherein,

   - when the change-over selector (40) is to be switched over,

   • the selector arms set in such a manner that one of the selector arms (26, 36) contacts the commutation contact (200) and the other selector arm does not contact any of the tap contacts (201...208),

   • wherein

   • switching-over of the diverter switch (60) begins before switching-over of the change-over selector (40) has ended.
2. Method according to Claim 1, wherein

   • switching-over of the diverter switch (60) takes place during switching-over of the change-over selector (40).
3. Method according to one of the preceding claims, wherein

   - switching-over of the diverter switch (60) takes place exactly once;

   - during the switching-over of the diverter switch (60) there is no flow of circulating current.
4. Method according to any one of the preceding claims,
   wherein

   - the change-over selector (40) comprises

   • a change-over selector moving contact (404) able to assume a first setting in which it contacts the first change-over selector fixed contact (401), a second setting in which it contacts the second change-over selector fixed contact (402), and an intermediate setting in which it does not contact either of the change-over selector fixed contacts (401, 402);

   - for switching-over of the change-over selector (40) from the second to the first setting

   • in a step a) the change-over selector moving contact (404) is moved from the second setting to the intermediate setting;

   • in a step b) the diverter switch (60) is switched over;

   • in a step c) the change-over selector moving contact (404) is moved from the intermediate setting to the first setting;

   and vice versa;

   - the diverter switch (60) comprises

   • a movable transfer contact (604) able to assume a first setting in which it contacts the first terminal (601), a second setting in which it contacts the second terminal (602), and a bridging setting in which it contacts both terminals (601, 602) ;

   - in step b)

   • in the case of switching-over of the change-over selector (40) from the second to the first setting, the transfer contact (604) is switched from the first setting to the bridging setting and thereafter from the bridging setting to the second setting; and

   • in the case of reverse switching-over of the change-over selector (40), the transfer contact (604) is switched from the second setting to the bridging setting and thereafter from the bridging setting to the first setting.
5. Method according to the preceding claim, wherein

   - the diverter switch (60) comprises

   • a switch (62) connected between the terminals (601, 602); and

   • a resistance (66) connected between the second terminal (602) and the second selector arm (36); and

   - the switch (62) is closed during step b).
6. On-load tap changer (11) for a regulating transformer, wherein the regulating transformer has a main winding (12), a tap winding (13) with a plurality of taps, the on-load tap-changer (11) comprising

   - a tap selector (20) which comprises

   • a plurality of selector fixed contacts (200...208) comprising a commutation contact (200), which is connected to a main winding (12) of the regulating transformer, and a plurality of tap contacts (201...208), which are in each case connected to an assigned tap of a tap winding (13) of the regulating transformer;

   • a first selector arm (26) which can selectably contact each of the selector fixed contacts (200 ... 208); and

   • a second selector arm (36) which can selectably contact each of the selector fixed contacts (200 ... 208) ;

   - a change-over selector (40) which can be switched over from a first setting to a second setting and vice versa, and which can be connected to the tap winding (13) and the main winding (12) and comprises

   • a first change-over selector fixed contact (401),

   • a second change-over selector fixed contact (402), and

   • a third change-over selector fixed contact (403) which is connected in the first setting to the first change-over selector fixed contact (401) and in the second setting with to second change-over selector fixed contact (402);

   - a diverter switch (60) which can be switched over from a first setting to a second setting and vice versa, and which comprises

   • a first terminal (601) connected to the first selector arm (26),

   • a second terminal (602) connected to the second selector arm (36),

   • a diverter line (603) connected in the first setting to the first terminal (601) and in the second setting to the second terminal (602), and

   - a common drive shaft (17) for the change-over selector (40), the tap selector (20) and the diverter switch (60),
   wherein

   - the change-over selector (40), the tap selector (20) and the diverter switch (60) are each separately coupled to the drive shaft (17),

   characterized in that

   • the change-over selector (40) comprises a change-over selector base plate (41) with a first side (411) and a second, opposite side (412);

   • the drive shaft (17) extends through the change-over selector base plate (41) and is rotatably mounted thereon.
7. On-load tap changer (11) according to the preceding claim, wherein

   - the change-over selector (40) comprises

   • a change-over selector moving contact (404) able to assume a first setting in which it contacts the first change-over selector fixed contact (401), a second setting in which it contacts the second change-over selector fixed contact (402), and an intermediate setting in which it contacts neither of the change-over selector fixed contacts.
8. On-load tap changer (11) according to one of Claims 6 or 7, comprising

   - a movable transfer contact (604) able to assume a first setting in which it contacts the first terminal (601), a second setting in which it contacts the second terminal (602) and a bridging setting in which it contacts both terminals (601, 602) ;

   - a switch (62) connected between the terminals (601, 602); and

   - a resistance (66) connected between the second terminal (602) and the second selector arm (36).
9. On-load tap changer (11) according to one of claims 6 to 8, wherein

   • a change-over selector driver (42) on the first side (411), which driver is seated on the drive shaft (17) to be secure against relative rotation and carries a first change-over selector entrainer (421) ;

   • a change-over selector Geneva wheel (44) on the first side (411), which wheel is rotatably mounted on the change-over selector base plate (41) and carries a second change-over selector entrainer (441);

   • a rocker (46) on the first side (411), which rocker is pivotably mounted on the change-over selector base plate (41) and has a mouth (461) for the second entrainer (441);

   - the change-over selector fixed contacts (401, 402, 403) and the change-over selector moving contact (404) are arranged on the second side (412) of the change-over selector base plate (41);

   - the rocker (46) is connected to the change-over selector moving contact (404) to be secure against relative rotation;

   - the first entrainer (421) co-operates with the change-over selector Geneva wheel (44) in such a manner that in the case of a complete revolution of the change-over selector driver (42) the change-over selector Geneva wheel (44) rotates through only a fraction of a complete revolution, wherein this fraction corresponds to a switching process of the tap selector (20) from one selector fixed contact (200...208) to an adjacent selector fixed contact (200 ... 208);

   - the second entrainer (441) co-operates with the rocker (46) in such a manner that when one of the selector arms contacts one of the tap contacts (201...208) the second entrainer (441) in the case of rotation of the change-over selector Geneva wheel (44) through the fraction does not engage in the mouth (461), and when one of the selector arms contacts the commutation contact (200) and the other selector arm does not contact any of the tap contacts (201...208) the second entrainer (441) engages in the mouth (461) in such a manner that the change-over selector moving contact (404) is switched over.
10. On-load tap changer (11) according to one of Claims 6 to 9, wherein

    - the change-over selector (40) is constructed as a reversing change-over selector;

    - the first change-over selector fixed contact (401) can be connected to a first end of the tap winding (13) ;

    - the second change-over selector fixed contact (402) can be connected to a second end of the tap winding (13) ;

    - the third change-over selector fixed contact (403) can be connected to the main winding (12);

    - the third change-over selector fixed contact (403) is constantly connected to the commutation contact (200) .
11. On-load tap changer (11) according to one of Claims 6 to 10, wherein

    - the change-over selector (40) is constructed as a coarse change-over selector;

    - the first change-over selector fixed contact (401) can be connected to an end of the main winding (12);

    - the second change-over selector fixed contact (402) can be connected to a tap of the main winding (12);

    - the third change-over selector fixed contact (403) can be connected to an end of the tap winding (13); and

    - the first change-over selector fixed contact (401) is constantly connected to the commutation contact (200) .
12. On-load tap changer (11) according to one of Claims 6 to 11, comprising

    - a first coupling device coupling the change-over selector (40) to the drive shaft (17); and

    - a second coupling device coupling the tap selector (20) to the drive shaft (17);
    wherein

    - the coupling devices are constructed separately from one another and/or have no common components.

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