A vacuum on-load tap changer transition circuit with isolating contacts and a voltage regulating method

Abstract

The present invention discloses a transition circuit and a voltage regulating method of a vacuum on-load tap changer with an isolating contact. Two auxiliary vacuum contact branches and one main vacuum contact branch are designed. Each auxiliary vacuum contact branch includes an auxiliary vacuum contact, a transition resistor and an isolating contact. The task of cutting off the circulating current is taken turns by the two auxiliary vacuum contact branches. The switching procedure is symmetrical. The two auxiliary vacuum contact branches pass the same working current, so that the burning of the two auxiliary vacuum contacts is completely consistent, which reduces the switching task of the auxiliary vacuum contacts. The first isolating contact G1 and the second isolating contact G2 can form a fracture, which can be used as a protection switch for the auxiliary vacuum contact to prevent the branch from being always open after the auxiliary vacuum contact fails. Compared with the current transition circuit with a "single main vacuum contact and a single auxiliary vacuum contact" structure, the present invention can balance the switching capacity of the main vacuum contact and the auxiliary vacuum contact, and improve the electrical life of the entire vacuum on-load tap changer.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and more specifically to a transition circuit of a vacuum on-load tap changer with an isolation contact and a voltage regulation method. Background Art

[0002] The on-load tap changer is a switching device that provides a constant voltage for the transformer when the load changes. Its basic principle is to switch between the taps in the transformer winding without interrupting the load current, thereby changing the number of turns of the winding, that is, the voltage ratio of the transformer, and finally achieving the purpose of voltage regulation. At present, the on-load tap changers configured in the transformers of rectification, smelting, and railway traction are mostly fast resistor switching, and work on the principle that the arc contact system extinguishes the arc when the current passes through the zero point. This switching principle is particularly serious for the tap changer with frequent switching of the transformer, the failure rate of the switch is high, and the carbonization speed of the oil is fast, which increases the daily maintenance for the power supply department. The vacuum on-load tap changer mainly relies on the vacuum tube of the switching switch to achieve arc extinguishing, and the arc and hot gas are not exposed; the oil in the oil chamber of the tap changer will not be carbonized and polluted, and the oil does not need to be purified; the burning and corrosion of the contacts in the vacuum tube can be minimized. The on-load tap changer is mainly composed of a switching switch, a conversion selector, and an electric mechanism.

[0003] The on-load tap changer needs a transition circuit and a selection circuit for load switching. Different voltage regulation methods require different voltage regulation circuits. Therefore, the circuit of the on-load tap changer consists of three parts: a transition circuit, a selection circuit, and a voltage regulation circuit. The transition circuit is a series resistance circuit across the tap points. The corresponding mechanism is a switching switch or a selection switch. It is a tap changer for changing transformer windings under power. The tap changer uses the principle of the transition circuit to realize the tap change operation. According to the number of transition circuit resistors, there are single resistors, double resistors, four resistors or multiple resistors. According to the contact break, there are single break, double break, etc., which can be combined to form a variety of transition circuits. The transition circuit and the switching procedure have different effects on the contact task of the switching switch. Whether the arc can be reliably extinguished within the first half cycle depends largely on the required switching task.

[0004] The arc contact without transition resistor in the on-load tap changer is the main on-off contact, which is only responsible for breaking the load current; the arc contact with transition resistor is the auxiliary contact, which is only responsible for breaking the internal circulation current. According to the experience of UHV DC engineering, the load current of the single-column winding of the commutation transformer is generally 500 ～ 600A, the internal circulating current flowing through the transition resistor R is about 900 ～1000A, since the internal circulating current passing through the auxiliary vacuum contact is significantly greater than the load current, after multiple switching, the degree of ablation of the main vacuum contact and the auxiliary vacuum contact will be different, and the switching burden and electrical damage of the auxiliary vacuum contact will be more serious.

[0005] Therefore, it is necessary to provide a transition circuit which can reduce the switching task of the auxiliary vacuum contact and improve the electrical life of the on-load tap changer. Summary of the invention

[0006] The invention provides a transition circuit of a vacuum on-load tap changer with an isolating contact and a voltage regulating method, so as to solve the problem of how to improve the electrical life of the vacuum on-load tap changer.

[0007] In order to solve the above problems, according to one aspect of the present invention, a transition circuit of a vacuum on-load tap changer with an isolating contact is provided, the transition circuit comprising: a first main contact MC1, a second main contact MC2, a first auxiliary vacuum contact V1, a second auxiliary vacuum contact V2, a main vacuum contact V3, a first switch Z1, a first isolating contact G1, a second isolating contact G2, a first transition resistor R1 and a second transition resistor R2;

[0008] Among them, one end of the first main contact MC1 is connected to the odd-numbered tapping gear of the transformer voltage regulating winding; one end of the second main contact MC2 is connected to the even-numbered tapping gear of the transformer voltage regulating winding; one end of the first auxiliary vacuum contact V1 is respectively connected to the odd-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the first transition resistor R1; one end of the second auxiliary vacuum contact V2 is respectively connected to the even-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the second transition resistor R2; the first transition resistor R1 is connected to the neutral point of the transformer through the first isolation contact G1, and the second transition resistor R2 is connected to the neutral point of the transformer through the second isolation contact G2; one end of the main vacuum contact V3 is connected to the first switch Z1; the other ends of the main vacuum contact V3, the first main contact MC1 and the second main contact MC2 are all connected to the neutral point of the transformer for outputting load current;

[0009] When performing the task of cutting off the circulating current, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2, the first isolating contact G1 and the second isolating contact G2 are switched in turn to reduce the switching task of the auxiliary vacuum contacts and improve the electrical life of the on-load tap changer.

[0010] Preferably, when the first main contact MC1, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the conducting state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the first isolating contact G1 is in the closed state, the second isolating contact G2 is in the open state, the second main contact MC2 is in the open state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be connected through the first main contact MC1. Output; when the second main contact MC2, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1 is in the off state, the second isolating contact G2 is in the closed state, the first main contact MC1 is in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

[0011] Preferably, when the first main contact MC1, the first auxiliary vacuum contact V1, the main vacuum contact V3 and the first isolating contact G1 are all in the on state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the second isolating contact G2, the second auxiliary vacuum contact V2 and the second main contact MC2 are in the off state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1;

[0012] When the second main contact MC2, the second auxiliary vacuum contact V2, the main vacuum contact V3 and the second isolating contact G2 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1, the first auxiliary vacuum contact V1 and the first main contact MC1 are in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

[0013] Preferably, the first switch Z1 is a mechanical single-contact switch or a conversion switch.

[0014] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the method realizes the conversion of a tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, comprising:

[0015] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0016] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0017] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0018] The first auxiliary vacuum contact V1 is disconnected to generate an arc. After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to disconnect to form a break. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0019] The first auxiliary vacuum contact V1 is closed, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0020] The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

[0021] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, comprising:

[0022] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0023] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0024] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N It flows from the odd-numbered tap position end through the first switch Z1 and the main vacuum contact V3 for output;

[0025] The second auxiliary vacuum contact V2 is disconnected to generate an arc. After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to disconnect to form a break. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0026] Close the second auxiliary vacuum contact V2, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0027] When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contact MC1 and then closes the first isolating contact G1. The tap change operation is completed and the first level voltage regulation is completed.

[0028] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the method realizes the conversion of a tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, comprising:

[0029] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0030] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0031] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn, and simultaneously disconnects the first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2. At this time, the first auxiliary vacuum contact V1 generates an arc. In this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0032] After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to be disconnected to form a fracture, and the second isolating contact G2 is adjusted to be closed. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0033] The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0034] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, comprising:

[0035] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0036] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0037] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the odd-numbered tapping position end, the current flows through the first switch Z1 and the main vacuum contact V3, and simultaneously disconnects the second auxiliary vacuum contact V2 and the first auxiliary vacuum contact V1. At this time, the second auxiliary vacuum contact V2 generates an arc. In this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0038] After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to be disconnected to form a break, and the first isolating contact G1 is adjusted to be closed. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0039] The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the first main contact MC1 is closed. The load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0040] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the method realizes the conversion of a tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, comprising:

[0041] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0042] When the second isolating contact G2 is closed, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0043] The main vacuum contact V3 is disconnected to generate an arc; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0044] The second auxiliary vacuum contact V2 is closed, the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1. N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0045] The first auxiliary vacuum contact V1 is disconnected to generate an arc, and the first switch Z1 is adjusted to disconnect the main vacuum contact V3 from the odd-numbered tap position end. At this time, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0046] Adjust the first switch Z1 so that the main vacuum contact V3 is connected to the even-numbered tap position end. At this time, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0047] Close the main vacuum contact V3, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0048] The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

[0049] According to another aspect of the present invention, a method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as described above is provided, characterized in that the tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, comprising:

[0050] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0051] The main vacuum contact V3 is disconnected to generate an arc, and the first isolating contact G1 is closed at the same time; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0052] The first auxiliary vacuum contact V1 is closed, and the first switch Z1 is adjusted at the same time, so that the main vacuum contact V3 is connected to the odd-numbered tapping position end, and the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0053] The second auxiliary vacuum contact V2 is disconnected to generate an arc; after the arc in the second auxiliary vacuum contact V2 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0054] Close the main vacuum contact V3, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0055] The second isolation contact G2 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0056] When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0057] The present invention provides a transition circuit and a voltage regulating method for a vacuum on-load tap changer with an isolating contact. Two auxiliary vacuum contact branches and one main vacuum contact branch are designed. Each auxiliary vacuum contact branch includes an auxiliary vacuum contact, a transition resistor and an isolating contact. The task of cutting off the circulating current is taken turns by the two auxiliary vacuum contact branches. The switching procedure is symmetrical. The two auxiliary vacuum contact branches pass the same working current, so that the burning of the two auxiliary vacuum contacts is completely consistent, which reduces the switching task of the auxiliary vacuum contacts. The first isolating contact G1 and the second isolating contact G2 can form a fracture, which can be used as a protection switch for the auxiliary vacuum contact to prevent the branch from being always open after the auxiliary vacuum contact fails. Compared with the current transition circuit with a "single main vacuum contact and a single auxiliary vacuum contact" structure, the present invention can balance the switching capacity of the main vacuum contact and the auxiliary vacuum contact, and improve the electrical life of the entire vacuum on-load tap changer. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0059] Figure 1 A circuit diagram of a vacuum on-load tap changer transition circuit 100 with isolation contacts according to an embodiment of the present invention;

[0060] Figure 2(a) to Figure 2(j) A schematic diagram of a switching process from an odd-numbered tapping position to an even-numbered tapping position of a double-resistance transition circuit of a vacuum on-load tap changer according to the first embodiment of the present invention;

[0061] 3(a) and 3(b) are schematic diagrams of a working timing diagram of a gear switching of a double-resistance transition circuit of a vacuum on-load tap changer according to Embodiment 1 of the present invention;

[0062] Figure 4(a) to Figure 4(i) A schematic diagram of a switching process from an odd-numbered tapping position to an even-numbered tapping position of a double-resistance transition circuit of a vacuum on-load tap changer according to a second embodiment of the present invention;

[0063] 5( a ) and 5( b ) are schematic diagrams of a working timing diagram of a gear switching of a double-resistance transition circuit of a vacuum on-load tap changer according to a second embodiment of the present invention;

[0064] Figure 6(a) to Figure 6(i) A schematic diagram of a switching process of a double-resistance transition circuit of a vacuum on-load tap changer from an odd-numbered tap position to an even-numbered tap position according to a third embodiment of the present invention;

[0065] 7( a ) and 7( b ) are schematic diagrams of a working timing diagram of a gear switching of a vacuum on-load tap changer double-resistance transition circuit according to Embodiment 3 of the present invention;

[0066] Figure 8 The circuit diagram is another circuit diagram of a vacuum on-load tap changer transition circuit with isolation contacts according to an embodiment of the present invention. DETAILED DESCRIPTION

[0067] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0068] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0069] Figure 1 FIG. 1 is a circuit diagram of a vacuum on-load tap changer transition circuit 100 with isolation contacts according to an embodiment of the present invention. Figure 1As shown, the transition circuit of the vacuum on-load tap changer with isolating contacts provided in the embodiment of the present invention is designed with two auxiliary vacuum contact branches and one main vacuum contact branch, each auxiliary vacuum contact branch includes an auxiliary vacuum contact, a transition resistor and an isolating contact, the circulating current cutting task is performed by the two auxiliary vacuum contact branches in turn, the switching procedure is symmetrical, the two auxiliary vacuum contact branches pass the same working current, so that the burning of the two auxiliary vacuum contacts is completely consistent, thereby reducing the switching task of the auxiliary vacuum contacts; the first isolating contact G1 and the second isolating contact G2 can form a fracture, which can serve as a protection switch for the auxiliary vacuum contact to prevent the branch from being always open after the auxiliary vacuum contact fails; compared with the current transition circuit with a "single main vacuum contact and a single auxiliary vacuum contact" structure, the present invention can balance the switching capacity of the main vacuum contact and the auxiliary vacuum contact, thereby improving the electrical life of the entire vacuum on-load tap changer. A vacuum on-load tap changer transition circuit 100 with isolating contacts provided in an embodiment of the present invention comprises: a first main contact MC1, a second main contact MC2, a first auxiliary vacuum contact V1, a second auxiliary vacuum contact V2, a main vacuum contact V3, a first switch Z1, a first isolating contact G1, a second isolating contact G2, a first transition resistor R1 and a second transition resistor R2; wherein, one end of the first main contact MC1 is connected to the odd-numbered tapping gear of the transformer voltage regulating winding; one end of the second main contact MC2 is connected to the even-numbered tapping gear of the transformer voltage regulating winding; one end of the first auxiliary vacuum contact V1 is respectively connected to the odd-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the first transition resistor R1; one end of the second auxiliary vacuum contact V2 is respectively connected to the even-numbered tapping gear of the transformer voltage regulating winding; The even-numbered tapping gear of the transformer voltage regulating winding is connected to the first switch Z1, and the other end is connected to one end of the second transition resistor R2; the first transition resistor R1 is connected to the neutral point of the transformer through the first isolating contact G1, and the second transition resistor R2 is connected to the neutral point of the transformer through the second isolating contact G2; one end of the main vacuum contact V3 is connected to the first switch Z1; the other ends of the main vacuum contact V3, the first main contact MC1 and the second main contact MC2 are all connected to the neutral point of the transformer for outputting load current; when performing the circulating current cutting task, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2, the first isolating contact G1 and the second isolating contact G2 are switched in turn to reduce the switching task of the auxiliary vacuum contact and improve the electrical life of the on-load tap changer.

[0070] Preferably, when the first main contact MC1, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the conducting state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the first isolating contact G1 is in the closed state, the second isolating contact G2 is in the open state, the second main contact MC2 is in the open state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1;

[0071] When the second main contact MC2, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1 is in the off state, the second isolating contact G2 is in the closed state, the first main contact MC1 is in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

[0072] Preferably, the first switch Z1 is a mechanical single-contact switch or a conversion switch.

[0073] In the embodiment of the present invention, the first switch Z1 is a mechanical single-contact switch, including a first static contact 12, a second static contact 13 and a moving contact 11; the first static contact 12 is connected to the odd-numbered tap position; the second static contact 13 is connected to the even-numbered tap position; one end of the moving contact 11 is connected to the main vacuum contact V3, and the other end is slidably connected to the first static contact 12 and the second static contact 13.

[0074] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention can realize the conversion of the tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, and includes:

[0075] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0076] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0077] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I NFrom the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0078] The first auxiliary vacuum contact V1 is disconnected to generate an arc. After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to disconnect to form a break. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0079] The first auxiliary vacuum contact V1 is closed, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0080] The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

[0081] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention can realize the conversion of the tap selector of the on-load tap changer from an even-numbered tap position to an odd-numbered tap position, and includes:

[0082] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0083] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0084] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N It flows from the odd-numbered tap position end through the first switch Z1 and the main vacuum contact V3 for output;

[0085] The second auxiliary vacuum contact V2 is disconnected to generate an arc. After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to disconnect to form a break. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0086] Close the second auxiliary vacuum contact V2, the load current I NFrom the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0087] When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contact MC1 and then closes the first isolating contact G1. The tap change operation is completed and the first level voltage regulation is completed.

[0088] In the first embodiment of the present invention, the connection status of each component is: when the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the first main contact MC1 is turned on, the second main contact MC2 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, and the main vacuum contact V3 is turned on, the moving contact 11 of the first switch Z1 is connected to its first static contact 12, the first isolating contact G1 is closed, the second isolating contact G2 is turned off, and the load current is output through the first main contact MC1. When the tap selector of the on-load tap changer is connected to the even-numbered tapping position of the transformer voltage regulating winding, the second main contact MC2 is turned on, the first main contact MC1 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, and the main vacuum contact V3 is turned on. The moving contact 11 of the first switch Z1 is connected to its second static contact 13, the first isolating contact G1 is turned off, and the second isolating contact G2 is closed, and the load current is output through the second main contact MC2.

[0089] In the first embodiment of the present invention, it is assumed that the initial position of the conversion selector of the tap selector of the on-load tap changer remains unchanged, and the gear number of the on-load tap changer is consistent with the number of the tap selector contact group, and the gear of the on-load tap changer is to rise from an odd gear N to an even gear N+1. When the tap selector is connected to the odd tap gear of the transformer voltage regulating winding, as shown in Figure 2(a), the first main contact MC1 is turned on, the second main contact MC2 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, and the main vacuum contact V3 is turned on, the moving contact 11 of the first switch Z1 is connected to its first static contact 12, the first isolating contact G1 is closed, the second isolating contact G2 is turned off, and the load current is output through the first main contact MC1. The tap selector is converted from an odd tap gear to an even tap gear, and the specific operation method includes:

[0090] (1) As shown in Figure 2(a), the first main contact MC1 is closed and the load current I N Output through the first main contact MC1;

[0091] (2) As shown in FIG2(b), the first main contact MC1 is disconnected, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0092] (3) As shown in FIG. 2( c ), the main vacuum contact V3 is disconnected to generate an arc. After the arc is extinguished, the load current I N The voltage U1 flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence. At this time, the recovery voltage U1 at both ends of the main vacuum contact V3 V3 =I N ×R1;

[0093] (4) As shown in FIG. 2( d ), after the arc in the main vacuum contact V3 is completely extinguished, the moving contact of the transfer switch Z1 rotates from connecting to the first stationary contact 12 to connecting to the second stationary contact 13, and the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0094] (5) As shown in FIG. 2( e ), the main vacuum contact V3 is closed, the transition circuit is bridged, and a circulating current I is generated. C1 =U S / R1; load current I N flows through the conversion switch Z1 and the main vacuum contact V3 output; if the voltage regulation direction is the upshift direction, the current I flowing through the main vacuum contact V3 V3 =I N +I C1 If the voltage regulation direction is downshift direction, the current I flowing through the main vacuum contact V3 V3 =I N -I C1 ; wherein the U S is the on-load tapchanger level voltage;

[0095] (6) As shown in FIG. 2( f ), the first auxiliary vacuum contact V1 is disconnected to generate an arc; the load current I N The recovery voltage at both ends of the first auxiliary vacuum contact V1 is U V1 =U S ;

[0096] (7) As shown in Figure 2(g), after the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 opens to form a break, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0097] (8) As shown in Figure 2(h), the first auxiliary vacuum contact V1 is closed, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0098] (9) As shown in Figure 2(i), the second main contact MC2 is closed, and the load current I NFlows through the second main contact MC2 for output;

[0099] (10) As shown in Figure 2(j), the second isolating contact G2 is closed, and the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0100] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit switching procedure is shown in FIG3( a ).

[0101] In the first embodiment of the present invention, when the tap selector of the on-load tap changer is connected to the even-numbered tap of the transformer voltage regulating winding, the second main contact MC2 is turned on, the first main contact MC1 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, and the main vacuum contact V3 is turned on. The moving contact 11 of the first switch Z1 is connected to its second static contact 13, the first isolating contact G1 is turned off, and the second isolating contact G2 is closed, and the load current is output through the second main contact MC2. When the tap selector is switched from the even-numbered tapping gear to the odd-numbered tapping gear, the specific operation method includes:

[0102] (1) The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0103] (2) The main vacuum contact V3 is disconnected to generate an arc. After the arc is extinguished, the load current I N The voltage flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. At this time, the recovery voltage across the main vacuum contact V3 is U V3 =I N ×R2;

[0104] (3) After the arc in the main vacuum contact V3 is completely extinguished, the moving contact 11 of the first switch Z1 is adjusted to rotate from the second stationary contact 13 to the first stationary contact 12, and the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0105] (4) The main vacuum contact V3 is closed, the transition circuit is bridged, and a circulating current is generated. Load current I N From the odd-numbered tapping position end, the current I flows through the first switch Z1 and the main vacuum contact V3 in turn; at this time, if the voltage regulation direction is the upshift direction, the current I flowing through the main vacuum contact V3 V3 =I N +I C2If the voltage regulation direction is downshift direction, the current I flowing through the main vacuum contact V3 V3 =I N -I C2 ; wherein the U S is the on-load tapchanger level voltage;

[0106] (5) The second auxiliary vacuum contact V2 is disconnected to generate an arc; the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; at this time, the recovery voltage across the second auxiliary vacuum contact V2 is U V2 =U S ;

[0107] (6) After the arc in the second auxiliary vacuum contact V2 is completely extinguished, adjust the second isolating contact G2 to be in the disconnected state to form a break. The load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0108] (7) The second auxiliary vacuum contact V2 is closed, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0109] (8) Close the first main contact MC1, so that the load current I N Flows through the first main contact MC1 and outputs;

[0110] (8) Close the first isolating contact G1, the load current I N The voltage flows through the first main contact MC1 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0111] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit switching procedure is shown in FIG3( b ).

[0112] In the first embodiment of the present invention, the switching tasks of the vacuum on-load tap changer transition circuit are shown in the following table:

[0113]

[0114] Among them, I N is the load current; Us is the on-load tap changer level voltage; R1 and R2 are transition resistors.

[0115] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention can realize the conversion of the tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, and includes:

[0116] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0117] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0118] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn, and simultaneously disconnects the first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2. At this time, the first auxiliary vacuum contact V1 generates an arc. In this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0119] After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to be disconnected to form a fracture, and the second isolating contact G2 is adjusted to be closed. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0120] The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0121] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention can realize the conversion of the tap selector of the on-load tap changer from an even-numbered tap position to an odd-numbered tap position, and includes:

[0122] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0123] The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0124] By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the odd-numbered tapping position end, the current flows through the first switch Z1 and the main vacuum contact V3, and simultaneously disconnects the second auxiliary vacuum contact V2 and the first auxiliary vacuum contact V1. At this time, the second auxiliary vacuum contact V2 generates an arc. In this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0125] After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to be disconnected to form a break, and the first isolating contact G1 is adjusted to be closed. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0126] The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the first main contact MC1 is closed. The load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0127] In the second embodiment of the present invention, the initial state of each element is the same as that of the first embodiment, and will not be described in detail here.

[0128] In the second embodiment of the present invention, when the tap selector is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, as shown in FIG4(a), the first main contact MC1 is turned on, the second main contact MC2 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, the main vacuum contact V3 is turned on, the moving contact 11 of the first switch Z1 is connected to its first static contact 12, the first isolating contact G1 is closed, the second isolating contact G2 is turned off, and the load current is output through the first main contact MC1. When the tap selector is switched from the odd-numbered tapping gear to the even-numbered tapping gear, the specific operation method includes:

[0129] (1) As shown in Figure 4(a), the first main contact MC1 is closed and the load current I N Output through the first main contact MC1;

[0130] (2) As shown in FIG4(b), the first main contact MC1 is disconnected, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0131] (3) As shown in FIG. 4( c ), the main vacuum contact V3 is disconnected to generate an arc. After the arc is extinguished, the load current I NThe recovery voltage U at both ends of the main vacuum contact V3 flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence. V3 =I N ×R1;

[0132] (4) As shown in FIG. 6( d ), after the arc in the main vacuum contact V3 is completely extinguished, the moving contact of the transfer switch Z1 leaves the first stationary contact 12, and the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0133] (5) As shown in FIG. 4( e ), the moving contact of the transfer switch Z1 is connected to the second stationary contact 13, and the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0134] (6) As shown in FIG. 4( f ), the main vacuum contact V3 is closed, the transition circuit is bridged, and a circulating current I is generated. C1 =U S / R1; load current I N Flows through the conversion switch Z1 and the main vacuum contact V3 output; at this time, if the voltage regulation direction is the upshift direction, the current I flowing through the main vacuum contact V3 V3 =I N +I C1 If the voltage regulation direction is downshift direction, the current I flowing through the main vacuum contact V3 V3 =I N -I C1 ; wherein the U S is the on-load tapchanger level voltage;

[0135] (7) As shown in FIG. 4( g ), the first auxiliary vacuum contacts V1 and V2 are disconnected at the same time, and V1 generates an arc; the load current I N The recovery voltage at both ends of the first auxiliary vacuum contact V1 is U V1 =U S ;

[0136] (8) As shown in Figure 4(h), after the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 opens to form a break, and the second isolating contact G2 closes at the same time, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0137] (9) As shown in Figure 4(i), the first auxiliary vacuum contacts V1 and V2 are closed at the same time, and the second main contact MC2 is closed. The load current I NThe voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0138] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit switching procedure is shown in FIG5(a).

[0139] In the second embodiment of the present invention, when the tap selector is connected to the even-numbered tapping position of the transformer voltage regulating winding, as shown in FIG2(j), the second main contact MC2 is turned on, the first main contact MC1 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned on, the main vacuum contact V3 is turned on, the moving contact of the transfer switch Z1 is connected to its first static contact 13, the second isolating contact G2 is closed, the first isolating contact G1 is turned off, and the load current is output through the second main contact MC2. When the tap selector is switched from the even-numbered tapping position to the odd-numbered tapping position, the specific operation method includes:

[0140] (1) The second main contact MC2 is disconnected, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0141] (2) The main vacuum contact V3 is disconnected to generate an arc. After the arc is extinguished, the load current I N The recovery voltage U across the main vacuum contact V3 flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. V3 =I N ×R2;

[0142] (3) After the arc in the main vacuum contact V3 is completely extinguished, the moving contact of the transfer switch Z1 leaves the second static contact 13, and the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0143] (4) The moving contact of the switch Z1 is connected to the first stationary contact 12, and the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0144] (5) The main vacuum contact V3 is closed, the transition circuit is bridged, and a circulating current is generated. Load current I N Flows through the conversion switch Z1 and the main vacuum contact V3 output; at this time, if the voltage regulation direction is the upshift direction, the current I flowing through the main vacuum contact V3 V3 =I N +I C2 If the voltage regulation direction is downshift direction, the current I flowing through the main vacuum contact V3V3 =I N -I C2 ; wherein the U S is the on-load tapchanger level voltage;

[0145] (6) The second auxiliary vacuum contacts V2 and V1 are disconnected at the same time, V2 generates an arc; the load current I N The recovery voltage at both ends of the second auxiliary vacuum contact V2 is U V2 =U S ;

[0146] (7) After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 opens to form a break, and at the same time the first isolating contact G1 closes, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0147] (8) The first auxiliary vacuum contacts V1 and V2 are closed simultaneously, and the first main contact MC1 is closed. The load current I N The voltage flows through the first main contact MC1 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0148] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit conversion procedure is shown in FIG5( b ).

[0149] In the second embodiment of the present invention, the switching tasks of the vacuum on-load tap changer transition circuit are shown in the following table:

[0150]

[0151]

[0152] Among them, I N is the load current; Us is the on-load tap changer level voltage; R1 and R2 are transition resistors.

[0153] Preferably, when the first main contact MC1, the first auxiliary vacuum contact V1, the main vacuum contact V3 and the first isolating contact G1 are all in the on state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the second isolating contact G2, the second auxiliary vacuum contact V2 and the second main contact MC2 are in the off state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1;

[0154] When the second main contact MC2, the second auxiliary vacuum contact V2, the main vacuum contact V3 and the second isolating contact G2 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1, the first auxiliary vacuum contact V1 and the first main contact MC1 are in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

[0155] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention is characterized in that the tap selector of the on-load tap changer is switched from an odd-numbered tap position to an even-numbered tap position, comprising:

[0156] The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0157] When the second isolating contact G2 is closed, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0158] The main vacuum contact V3 is disconnected to generate an arc; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output;

[0159] The second auxiliary vacuum contact V2 is closed, the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1. N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence; if the switching direction is upshift / downshift direction, the current flowing through the first auxiliary vacuum contact V1 or The current flowing through the second auxiliary vacuum contact V2 or Among them, the U S is the on-load tapchanger level voltage;

[0160] The first auxiliary vacuum contact V1 is disconnected to generate an arc, and the first switch Z1 is adjusted to disconnect the main vacuum contact V3 from the odd-numbered tap position end. At this time, the load current I NIt flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence; if the switching direction is upshift / downshift direction, the recovery voltage across the first auxiliary vacuum contact V1 is U V1 =U S -I N ×R2 / U V1 =U S +I N ×R2;

[0161] Adjust the first switch Z1 so that the main vacuum contact V3 is connected to the even-numbered tap position end. At this time, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0162] Close the main vacuum contact V3, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0163] The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

[0164] The method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolation contacts as described above in the embodiment of the present invention is characterized in that the tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, comprising:

[0165] The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn;

[0166] The main vacuum contact V3 is disconnected to generate an arc, and the first isolating contact G1 is closed at the same time; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0167] The first auxiliary vacuum contact V1 is closed, and the first switch Z1 is adjusted at the same time, so that the main vacuum contact V3 is connected to the odd-numbered tapping position end, and the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. NThe current flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence; if the switching direction is upshift / downshift direction, the current flowing through the second auxiliary vacuum contact V2 is or The current flowing through the first auxiliary vacuum contact V1 Among them, the U S is the on-load tapchanger level voltage;

[0168] The second auxiliary vacuum contact V2 is disconnected to generate an arc; after the arc in the second auxiliary vacuum contact V2 is completely extinguished, the load current I N The voltage flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence; if the switching direction is upshift / downshift, the recovery voltage across the second auxiliary vacuum contact V2 is U V1 =U S -I N ×R1 or U V1 =U S +I N ×R1;

[0169] Close the main vacuum contact V3, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0170] The second isolation contact G2 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output;

[0171] When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

[0172] In the third embodiment of the present invention, the connection state of each element is: when the first main contact MC1, the first auxiliary vacuum contact V1, the main vacuum contact V3 and the first isolating contact G1 are all in the conducting state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the second isolating contact G2, the second auxiliary vacuum contact V2 and the second main contact MC2 are in the disconnected state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1. When the second main contact MC2, the second auxiliary vacuum contact V2, the main vacuum contact V3 and the second isolating contact G2 are all in the conducting state, the first switch Z1 is connected to the even-numbered tapping gear end of the transformer winding, the first isolating contact G1, the first auxiliary vacuum contact V1 and the first main contact MC1 are in the disconnected state, and the tap selector of the on-load tap changer is connected to the even-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

[0173] In the third embodiment of the present invention, it is assumed that the initial position of the conversion selector of the tap selector of the on-load tap changer remains unchanged, and the gear number of the on-load tap changer is consistent with the number of the tap selector contact group, and the gear of the on-load tap changer is to rise from an odd gear N to an even gear N+1. When the tap selector is connected to the odd tap gear of the transformer voltage regulating winding, as shown in Figure 6(a), the first main contact MC1 is turned on, the second main contact MC2 is turned off, the first auxiliary vacuum contact V1 is turned on, the second auxiliary vacuum contact V2 is turned off, and the main vacuum contact V3 is turned on, the moving contact of the conversion switch Z1 is connected to its first static contact 12, the first isolating contact G1 is closed, and the second isolating contact G2 is turned off. The tap selector is converted from an odd tap gear to an even tap gear, and the specific operation method includes:

[0174] (1) As shown in Figure 6(a), the first main contact MC1 is closed and the load current I N Output through the first main contact MC1;

[0175] (2) As shown in FIG6(b), the first main contact MC1 is disconnected, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0176] (3) As shown in FIG6(c), the second isolating contact G2 is closed, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0177] (4) As shown in FIG. 6( d ), the main vacuum contact V3 is disconnected to generate an arc. After the arc is extinguished, the load current I NThe recovery voltage U at both ends of the main vacuum contact V3 flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence. V3 =I N ×R1;

[0178] (5) As shown in FIG. 6( e ), the second auxiliary vacuum contact V2 is closed, the transition circuit is bridged, and a circulating current I is generated. C =U S / (R1+R2); half of the load current The other half of the load current flows through the first auxiliary vacuum contact V1, the first transition resistor R1, and the first isolation contact G1. The current flowing through the second auxiliary vacuum contact V2, the second transition resistor R2, and the second isolation contact G2 is output; at this time, if the voltage regulation direction is the upshift direction, the current flowing through the first auxiliary vacuum contact V1 is The current flowing through the second auxiliary vacuum contact V2 If the voltage regulation direction is the downshift direction, the current flowing through the first auxiliary vacuum contact V1 is The current flowing through the second auxiliary vacuum contact V2 Among them, the U S is the on-load tapchanger level voltage;

[0179] (6) As shown in FIG. 6( f ), the first auxiliary vacuum contact V1 is disconnected, an arc is generated, and at the same time, the moving contact of the switch Z1 leaves the first stationary contact 12; the load current I N It flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence; if the voltage regulation direction is the upshift direction, the recovery voltage across the first auxiliary vacuum contact V1 is U V1 =U S -I N ×R2; if the voltage regulation direction is the downshift direction, the recovery voltage across the first auxiliary vacuum contact V1 is U V1 =U S +I N ×R2;

[0180] (7) As shown in FIG. 6( g ), the moving contact of the transfer switch Z1 rotates to connect to the second stationary contact 13, and the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0181] (8) As shown in Figure 6(h), the main vacuum contact V3 is closed and the first isolating contact G1 is opened. The load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0182] (9) As shown in Figure 6(i), the second main contact MC2 is closed, and the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0183] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit switching procedure is shown in FIG. 7( a ).

[0184] In the third embodiment of the present invention, when the tap selector of the on-load tap changer is connected to the even-numbered tap of the transformer voltage regulating winding, as shown in FIG6(i), the second main contact MC2 is turned on, the first main contact MC1 is turned off, the first auxiliary vacuum contact V1 is turned off, the second auxiliary vacuum contact V2 is turned on, the main vacuum contact V3 is turned on, the moving contact of the transfer switch Z1 is connected to its second static contact 13, the second isolating contact G2 is closed, the first isolating contact G1 is turned off, and the load current is output through the second main contact MC2. When the tap selector is switched from the even-numbered tapping gear to the odd-numbered tapping gear, the specific operation method includes:

[0185] (1) The second main contact MC2 is disconnected, and the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0186] (2) The main vacuum contact V3 is disconnected to generate an arc, and the first isolating contact G1 is closed at the same time; after the arc of V3 is extinguished, the load current I N The recovery voltage U across the main vacuum contact V3 flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. V3 =I N ×R2;

[0187] (3) The moving contact of the transfer switch Z1 is disconnected from the second static contact 13, and the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output;

[0188] (4) The first auxiliary vacuum contact V1 is closed, and at the same time, the moving contact of the switch Z1 is connected to the first static contact 12, and the transition circuit is bridged, generating a circulating current I C1 =U S / (R1+R2); half load current The other half of the load current flows through the second auxiliary vacuum contact V2, the second transition resistor R2, and the second isolation contact G2. The current flows through the first auxiliary vacuum contact V1, the first transition resistor R1, and the first isolation contact G1 for output; at this time, if the voltage regulation direction is the upshift direction, the current flowing through the second auxiliary vacuum contact V2 is The current flowing through the first auxiliary vacuum contact V1 If the voltage regulation direction is downshift direction, the current flowing through the second auxiliary vacuum contact V2 is The current flowing through the first auxiliary vacuum contact V1 Among them, the U S is the on-load tapchanger level voltage;

[0189] (5) The second auxiliary vacuum contact V2 is disconnected to generate an arc. After the arc is extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in turn; if the voltage regulation direction is the upshift direction, the recovery voltage across the second auxiliary vacuum contact V2 is U V1 =U S -I N ×R1; if the voltage regulation direction is the downshift direction, the recovery voltage across the second auxiliary vacuum contact V2 is U V1 =U S +I N ×R1;

[0190] (6) Close the main vacuum contact V3, the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0191] (7) Disconnect the second isolating contact G2, the load current I N It flows through the conversion switch Z1 and the main vacuum contact V3 output in turn;

[0192] (8) Close the first main contact MC1, the load current I N The voltage flows through the first main contact MC1 and is output, the tap change operation is completed, and the switch completes the first-level voltage regulation.

[0193] Among them, when the tap selector is switched from an even-numbered tap position to an odd-numbered tap position, the transition circuit conversion procedure is shown in FIG7( b ).

[0194] In the third embodiment of the present invention, the switching tasks of the vacuum on-load tap changer transition circuit are shown in the following table:

[0195]

[0196]

[0197] Among them, I Nis the load current; Us is the on-load tap changer level voltage; R1 and R2 are transition resistors.

[0198] Figure 8 FIG. 2 is a circuit diagram of another vacuum on-load tap changer transition circuit with isolating contacts according to an embodiment of the present invention. Figure 8 As shown, only Figure 1 The first switch Z1 in the circuit is set as a switching switch, and the other components are Figure 1 The components are the same as in Figure 1 The functions and effects of the transition circuit shown are also the same and will not be described in detail here.

[0199] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0200] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0201] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0202] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0203] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0204] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A vacuum on-load tap changer transition circuit with isolating contacts, characterized in that: The transition circuit includes: a first main contact MC1, a second main contact MC2, a first auxiliary vacuum contact V1, a second auxiliary vacuum contact V2, a main vacuum contact V3, a first switch Z1, a first isolation contact G1, a second isolation contact G2, a first transition resistor R1 and a second transition resistor R2; Among them, one end of the first main contact MC1 is connected to the odd-numbered tapping gear of the transformer voltage regulating winding; one end of the second main contact MC2 is connected to the even-numbered tapping gear of the transformer voltage regulating winding; one end of the first auxiliary vacuum contact V1 is respectively connected to the odd-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the first transition resistor R1; one end of the second auxiliary vacuum contact V2 is respectively connected to the even-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the second transition resistor R2; the first transition resistor R1 is connected to the neutral point of the transformer through the first isolation contact G1, and the second transition resistor R2 is connected to the neutral point of the transformer through the second isolation contact G2; one end of the main vacuum contact V3 is connected to the first switch Z1; the other ends of the main vacuum contact V3, the first main contact MC1 and the second main contact MC2 are all connected to the neutral point of the transformer for outputting load current; When performing the task of cutting off the circulating current, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2, the first isolating contact G1 and the second isolating contact G2 are switched in turn to reduce the switching task of the auxiliary vacuum contact and improve the electrical life of the on-load tap changer; The following method is used to realize the switching of the tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 is disconnected to generate an arc. After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to disconnect to form a break. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 is closed, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

2. A vacuum on-load tap changer transition circuit with isolating contacts, characterized in that: The transition circuit includes: a first main contact MC1, a second main contact MC2, a first auxiliary vacuum contact V1, a second auxiliary vacuum contact V2, a main vacuum contact V3, a first switch Z1, a first isolation contact G1, a second isolation contact G2, a first transition resistor R1 and a second transition resistor R2; Among them, one end of the first main contact MC1 is connected to the odd-numbered tapping gear of the transformer voltage regulating winding; one end of the second main contact MC2 is connected to the even-numbered tapping gear of the transformer voltage regulating winding; one end of the first auxiliary vacuum contact V1 is respectively connected to the odd-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the first transition resistor R1; one end of the second auxiliary vacuum contact V2 is respectively connected to the even-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the second transition resistor R2; the first transition resistor R1 is connected to the neutral point of the transformer through the first isolation contact G1, and the second transition resistor R2 is connected to the neutral point of the transformer through the second isolation contact G2; one end of the main vacuum contact V3 is connected to the first switch Z1; the other ends of the main vacuum contact V3, the first main contact MC1 and the second main contact MC2 are all connected to the neutral point of the transformer for outputting load current; When performing the task of cutting off the circulating current, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2, the first isolating contact G1 and the second isolating contact G2 are switched in turn to reduce the switching task of the auxiliary vacuum contact and improve the electrical life of the on-load tap changer; The following method is used to realize the switching of the tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn, and simultaneously disconnects the first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2. At this time, the first auxiliary vacuum contact V1 generates an arc. In this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to be disconnected to form a fracture, and the second isolating contact G2 is adjusted to be closed. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

3. A vacuum on-load tap changer transition circuit with isolating contacts, characterized in that: The transition circuit includes: a first main contact MC1, a second main contact MC2, a first auxiliary vacuum contact V1, a second auxiliary vacuum contact V2, a main vacuum contact V3, a first switch Z1, a first isolation contact G1, a second isolation contact G2, a first transition resistor R1 and a second transition resistor R2; Among them, one end of the first main contact MC1 is connected to the odd-numbered tapping gear of the transformer voltage regulating winding; one end of the second main contact MC2 is connected to the even-numbered tapping gear of the transformer voltage regulating winding; one end of the first auxiliary vacuum contact V1 is respectively connected to the odd-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the first transition resistor R1; one end of the second auxiliary vacuum contact V2 is respectively connected to the even-numbered tapping gear of the transformer voltage regulating winding and the first switch Z1, and the other end is connected to one end of the second transition resistor R2; the first transition resistor R1 is connected to the neutral point of the transformer through the first isolation contact G1, and the second transition resistor R2 is connected to the neutral point of the transformer through the second isolation contact G2; one end of the main vacuum contact V3 is connected to the first switch Z1; the other ends of the main vacuum contact V3, the first main contact MC1 and the second main contact MC2 are all connected to the neutral point of the transformer for outputting load current; When performing the task of cutting off the circulating current, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2, the first isolating contact G1 and the second isolating contact G2 are switched in turn to reduce the switching task of the auxiliary vacuum contact and improve the electrical life of the on-load tap changer; The following method is used to realize the switching of the tap selector of the on-load tap changer from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; When the second isolating contact G2 is closed, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; The second auxiliary vacuum contact V2 is closed, the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1. N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; The first auxiliary vacuum contact V1 is disconnected to generate an arc, and the first switch Z1 is adjusted at the same time to disconnect the main vacuum contact V3 from the odd-numbered tapping position end. At this time, the load current IN flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; Adjust the first switch Z1 so that the main vacuum contact V3 is connected to the even-numbered tap position end. At this time, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; Close the main vacuum contact V3, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

4. The transition circuit according to claim 1 or 2, characterized in that: When the first main contact MC1, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the conducting state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the first isolating contact G1 is in the closed state, the second isolating contact G2 is in the open state, the second main contact MC2 is in the open state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1; When the second main contact MC2, the first auxiliary vacuum contact V1, the second auxiliary vacuum contact V2 and the main vacuum contact V3 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1 is in the off state, the second isolating contact G2 is in the closed state, the first main contact MC1 is in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

5. The transition circuit according to claim 3, characterized in that: When the first main contact MC1, the first auxiliary vacuum contact V1, the main vacuum contact V3 and the first isolating contact G1 are all in the on state, the first switch Z1 is connected to the odd-numbered tapping gear end of the transformer winding, the second isolating contact G2, the second auxiliary vacuum contact V2 and the second main contact MC2 are in the off state, and the tap selector of the on-load tap changer is connected to the odd-numbered tapping gear of the transformer voltage regulating winding, the load current can be output through the first main contact MC1; When the second main contact MC2, the second auxiliary vacuum contact V2, the main vacuum contact V3 and the second isolating contact G2 are all in the on state, the first switch Z1 is connected to the even-numbered tap position end of the transformer winding, the first isolating contact G1, the first auxiliary vacuum contact V1 and the first main contact MC1 are in the off state, and the tap selector of the on-load tap changer is connected to the even-numbered tap position of the transformer voltage regulating winding, the load current can be output through the second main contact MC2.

6. The transition circuit according to claim 1, 2 or 3, characterized in that: The first switch Z1 is a mechanical single-contact switch or a conversion switch.

7. A method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as claimed in claim 1 or 2, characterized in that: The tap selector of the on-load tap changer is switched from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 is disconnected to generate an arc. After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to disconnect to form a break. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 is closed, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

8. A method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as claimed in claim 1 or 2, characterized in that: The tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, including: The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N It flows from the odd-numbered tap position end through the first switch Z1 and the main vacuum contact V3 for output; The second auxiliary vacuum contact V2 is disconnected to generate an arc. After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to disconnect to form a break. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; Close the second auxiliary vacuum contact V2, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contact MC1 and then closes the first isolating contact G1. The tap change operation is completed and the first level voltage regulation is completed.

9. A method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as claimed in claim 1 or 2, characterized in that: The tap selector of the on-load tap changer is switched from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to make the main vacuum contact V3 conductive with the even-numbered tapping position end. During this process, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn, and simultaneously disconnects the first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2. At this time, the first auxiliary vacuum contact V1 generates an arc. In this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; After the arc in the first auxiliary vacuum contact V1 is completely extinguished, the first isolating contact G1 is adjusted to be disconnected to form a fracture, and the second isolating contact G2 is adjusted to be closed. During this process, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

10. A method for voltage regulation using a transition circuit of a vacuum on-load tap changer with isolating contacts as claimed in claim 1 or 2, characterized in that: The tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, including: The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The main vacuum contact V3 is disconnected to generate an arc. After the arc in the main vacuum contact V3 is completely extinguished, the first switch Z1 is adjusted to connect the main vacuum contact V3 to the odd-numbered tapping position end. During this process, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; By closing the main vacuum contact V3, the transition circuit is bridged, generating a circulating current, and the load current I N From the odd-numbered tapping position end, the current flows through the first switch Z1 and the main vacuum contact V3, and simultaneously disconnects the second auxiliary vacuum contact V2 and the first auxiliary vacuum contact V1. At this time, the second auxiliary vacuum contact V2 generates an arc. In this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; After the arc in the second auxiliary vacuum contact V2 is completely extinguished, the second isolating contact G2 is adjusted to be disconnected to form a break, and the first isolating contact G1 is adjusted to be closed. During this process, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The first auxiliary vacuum contact V1 and the second auxiliary vacuum contact V2 are closed at the same time, and then the first main contact MC1 is closed. The load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

11. A method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolating contacts as claimed in claim 3, characterized in that: The tap selector of the on-load tap changer is switched from an odd-numbered tap position to an even-numbered tap position, including: The first main contact MC1 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; When the second isolating contact G2 is closed, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The main vacuum contact V3 is disconnected to generate an arc; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; The second auxiliary vacuum contact V2 is closed, the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1. N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; The first auxiliary vacuum contact V1 is disconnected to generate an arc, and the first switch Z1 is adjusted at the same time to disconnect the main vacuum contact V3 from the odd-numbered tapping position end. At this time, the load current IN flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; Adjust the first switch Z1 so that the main vacuum contact V3 is connected to the even-numbered tap position end. At this time, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; Close the main vacuum contact V3, the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The second main contact MC2 is closed, so that the load current I N The voltage flows through the second main contact MC2 and then closes the second isolating contact G2. The tap change operation is completed and the first-level voltage regulation is completed.

12. A method for voltage regulation using the transition circuit of the vacuum on-load tap changer with isolating contacts as claimed in claim 3, characterized in that: The tap selector of the on-load tap changer is switched from an even-numbered tap position to an odd-numbered tap position, including: The second main contact MC2 is disconnected, and the load current I N From the even-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn; The main vacuum contact V3 is disconnected to generate an arc, and the first isolating contact G1 is closed at the same time; after the arc in the main vacuum contact V3 is completely extinguished, the load current I N The current flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence for output; The first auxiliary vacuum contact V1 is closed, and the first switch Z1 is adjusted at the same time, so that the main vacuum contact V3 is connected to the odd-numbered tapping position end, and the transition circuit is bridged, and half of the load current I N The other half of the load current I flows through the second auxiliary vacuum contact V2, the second transition resistor R2 and the second isolation contact G2 in sequence. N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; The second auxiliary vacuum contact V2 is disconnected to generate an arc; after the arc in the second auxiliary vacuum contact V2 is completely extinguished, the load current I N It flows through the first auxiliary vacuum contact V1, the first transition resistor R1 and the first isolation contact G1 in sequence for output; Close the main vacuum contact V3, the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; The second isolation contact G2 is disconnected, and the load current I N From the odd-numbered tap position end, it flows through the first switch Z1 and the main vacuum contact V3 in turn for output; When the first main contact MC1 is closed, the load current I N The voltage flows through the first main contactor MC1 and is output, the tap change operation is completed, and the first-level voltage regulation is completed.

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