Patent Application
20250218654
The present invention claims priority benefits to Chinese Patent Application number 202210232941.2, entitled “a no-arc on-load tap changer, switching control method and electrical equipment”, filed on Mar. 9, 2022, with the China National Intellectual Property Administration (CNIPA), the entire contents of which are incorporated herein by reference.
The present invention belongs to the technical field of power transmission and transformation of power systems, and particularly relates to a no-arc on-load tap changer, a switching control method and electrical equipment.
The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.
Under the condition that the transformer has load current (on-load), it is necessary to use an on-load tap changer to switch the tap of one voltage of the transformer to the tap of another voltage, and to ensure that the power user does not lose power during the switching process. Wherein, the on-load tap changer refers to a voltage regulating device suitable for operating under transformer excitation or load and used to change the tap connection position of transformer windings, and the basic principle thereof is to realize the switching between the transformer winding taps without interrupting the load current, so as to change the number of turns of the winding, that is, the voltage ratio of the transformer, and finally realize the purpose of voltage regulation.
The resistance transition mode is generally adopted in the existing on-load tap changer to realize the switching process of two different voltage taps. However, the resistance transition mode has the defect of radian in the switching process.
Chinese application number CN2012105791965, CN2013105976862 and CN2014102602640 respectively introduced different no-arc on-load tap changers, but since the oil-immersed on-load tap changer is suitable to be driven by a rotary shaft, and the inventors have found that, the devices proposed in the above patents are mainly used in circuits composed of contactors or relay contacts, while the no-arc on-load tap changers composed of contactors or relays are not suitable for using in oil immersed transformers.
An on-load tap changer in the solution of the on-load tap changer provided in the Chinese application number CN2018102904704 has a structure driven by a rotary shaft, however, the inventor found that this patent is still complicated in operating structure because various switches are distributed on two or three rotary shafts which are not synchronized, so that when one rotary shaft needs to rotate, the other rotary shaft needs to be stationary; moreover, it lacks a coordination control mechanism between rotary shafts, a matching scheme between dynamic contacts and static contacts of rotary shafts, and a driving scheme for controlling switches.
In order to solve the technical problems existing in the background, the present invention provides a no-arc on-load tap changer, a switching control method, and electrical equipment, wherein the no-arc on-load tap changer is suitable for an oil-immersed transformer driven by a rotary shaft, and has the advantages of simple operation structure and less time for a complete switching process.
In order to achieve the above object, the present invention adopts the following technical solution.
A first aspect of the present invention provides a no-arc on-load tap changer.
In one or more embodiments, providing a first type of structure of the no-arc on-load tap changer, including at least two main switches, two change-over switches and two thyristor auxiliary modules; wherein, each of the two thyristor auxiliary modules includes two control switches; the two main switches include an originally-closed main switch and a to-be-closed main switch; the two main switches are connected in corresponding loops of a voltage regulating coil through taps of corresponding transformers; the two thyristor auxiliary modules are connected in parallel with the originally-closed main switch or the to-be-closed main switch according to a required time sequence during a switching process of main switch;
As an implementation mode, a first end of the each of the two thyristor auxiliary modules is suspended or connected in parallel with the originally-closed main switch before carrying out the switching process of main switch, and a voltage at both ends of the each of the two thyristor auxiliary modules is zero.
As an implementation mode, each of the control switches is also a rotary-shaft-type switch, and dynamic contacts of the control switches are also arranged on the rotary shaft.
As an implementation mode, all the static contacts of the two main switches and the two change-over switches are divided into at least two groups, each of the two groups of the static contacts is correspondingly mounted on a track, and the two tracks are centered on the rotary shaft and fixed.
As an implementation mode, a number of the static contacts in the each of the two groups of the static contacts are the same.
As an implementation mode, the static contacts in the each of the two groups of the static contacts are mounted on the two tracks with equal radians.
As an implementation mode, when all the static contacts of the two main switches and the two change-over switches are divided into the two groups, relationships of radians of the static contacts on corresponding one of the two tracks are:
As an implementation mode, before the switching process of main switch, a normal operating state of the no-arc on-load tap changer is:
As an implementation mode, when three the dynamic contacts are provided on the rotary shaft, a first dynamic contact of the three dynamic contacts and a second dynamic contact of the three dynamic contacts respectively are arranged on each side of a third dynamic contact of the three dynamic contacts, then relationships of radians between the three dynamic contacts are:
Wherein W is the radian between the center positions of the static contacts on the first track, W1dynamic and W2dynamic respectively are the radian of the first dynamic contact and the second dynamic contact, ΔWdynamic is the radian of the gap between the first dynamic contact and the second dynamic contact.
As an implementation mode, the radians of the static contacts are greater than the radians of the dynamic contacts.
As an implementation mode, the radians of the static contacts are less than or equal to the radians of the dynamic contacts.
As an implementation mode, the breaking and closing of the control switch is controlled by a control mechanism.
As an implementation mode, the control mechanism is of a mechanical linkage mechanism.
As an implementation mode, the mechanical linkage mechanism includes a deflection shaft, wherein the deflection shaft is fixed on a rotary shaft and rotates along with the rotary shaft; a lever arm and a spring arm which can rotate around the deflection shaft are mounted on the deflection shaft; one end of the spring arm is provided with a contact; and the contact makes contact with or detached from corresponding ones of the control switches along with rotation of the rotary shaft, so that the corresponding ones of the control switches are broken and closed, respectively.
As an implementation mode, a control means for the control mechanism is realized by driving the change-over switches by the rotary shaft.
As an implementation mode, the structure of the two thyristor auxiliary modules is same.
As an implementation mode, the structure of the each of the two thyristor auxiliary modules comprises a pair of thyristors connected in reverse parallel; an RC series circuit is connected in parallel at two ends of the pair of the thyristors; a capacitor, a resistor and a diode are sequentially connected between a gate electrode and a cathode of each thyristor of the pair of the thyristors; an anode of the diode is connected with the cathode of corresponding one of the pair of the thyristors, and a cathode of the diode is connected with the gate electrode of the corresponding one of the pair of the thyristors; the gate electrodes of the pair of the thyristors are connected in series with one of the two control switches through a full-bridge rectifier circuit; two voltage-stabilizing tubes, a resistor, and another one of the two control switches are connected in series between the gate electrodes of the two the reverse-parallel-connected thyristors; wherein the two voltage-stabilizing tubes are connected in reverse series, the two voltage-stabilizing tubes are connected in series with the resistor and then connected with an output end of the full-bridge rectifier circuit, cathodes of the two voltage-stabilizing tubes corresponds to an anode output end of the full-bridge rectifier circuit, and anodes of the two voltage-stabilizing tubes corresponds to a cathode output end of the full-bridge rectifier circuit.
The present invention further provides a second type of structure of the no-arc on-load tap changer, including at least two main switches, two change-over switches and two thyristor auxiliary modules; wherein, each of the two thyristor auxiliary modules includes two control switches; the two main switches include an originally-closed main switch and a to-be-closed main switch; the two main switches are connected in corresponding loops of a voltage regulating coil through taps of corresponding transformers; the two thyristor auxiliary modules are connected with the originally-closed main switch or the to-be-closed main switch according to a required time sequence during the switching process of main switch.
The two main switches and the two change-over switches are all rotary-shaft-type switches, wherein the two main switches and corresponding ones of the two change-over switches are linked and synchronously rotated, respectively; corresponding main switches, change-over switches, and control switches are controlled to be broken and closed according to the preset time sequence, to realize that the load current is transferred from the originally-closed main switch to the to-be-closed main switch without interruption, and no arc in the breaking and closing process of each of the switches.
As an implementation mode, the control mechanism is of a mechanical linkage mechanism.
As an implementation mode, the mechanical linkage mechanism includes a deflection shaft, wherein the deflection shaft is fixed on a rotary shaft and rotates along with the rotary shaft; a lever arm and a spring arm which can rotate around the deflection shaft are mounted on the deflection shaft; one end of the spring arm is provided with a contact; and the contact makes contact with or detach from a corresponding control switch along with rotation of the rotary shaft, so that the corresponding control switch is broken and closed.
As an implementation mode, the control means of the control mechanism is realized by driving change-over switches by the rotary shaft.
As an implementation mode, the structure of the two thyristor auxiliary modules is same.
As an implementation mode, each of the two thyristor auxiliary module includes a pair of thyristors connected in reverse parallel; an RC series circuit is connected in parallel at two ends of the reverse-parallel-connected thyristors; a capacitor, a resistor and a diode are sequentially connected between a gate electrode and a cathode of each of the reverse-parallel-connected thyristors; an anode of the diode is connected with the cathode of the corresponding one of the reverse-parallel-connected thyristors, and a cathode of the diode is connected with the gate electrode of the corresponding one of the reverse-parallel-connected thyristors; the gate electrodes of the two the reverse-parallel-connected thyristors are connected in series with one of the two control switches through a full-bridge rectifier circuit; two voltage-stabilizing tubes, a resistor, and another one of the two control switches are connected in series between gate electrodes of the two the reverse-parallel-connected thyristors; wherein the two voltage-stabilizing tubes are connected in reverse series; the two voltage-stabilizing tubes are connected in series with the resistor and then connected with an output end of the full-bridge rectifier circuit; cathodes of the two voltage-stabilizing tubes corresponds to an anode output end of the full-bridge rectifier circuit; and anodes of the two voltage-stabilizing tubes corresponds to a cathode output end of the full-bridge rectifier circuit.
A second aspect of the present invention provides as witching control method for a no-arc on-load tap changer.
In one or more embodiments, the present invention provides a first type of the switching control method for the no-arc on-load tap changer, including:
As an implementation mode, a rotation mode of the rotary shaft includes a clockwise rotation and a counterclockwise rotation.
As an implementation mode, the process of one-time switching of main switch, including:
As an implementation mode, before the switching of main switch, voltages between two ends of each of the two thyristor auxiliary modules are made to zero.
The present invention further provides a second type of the switching control method for the no-arc on-load tap changer, including:
A third aspect of the present invention provides an electric accessory.
In one or more embodiments, the electric accessory includes:
Compared with the prior art, the present invention has the advantages that:
Advantages of additional aspects of the present invention will be set forth in part in the following description, and in part will become apparent from the following description, or may be learned by practice of the present invention.
The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary examples of the present invention and descriptions thereof are used to explain the present invention, and do not constitute an improper limitation of the present invention.
In figures: 1, tap I; 2, tap II; 3, tap III; 4, rotary shaft; 5, fixed plate; 6, deflection shaft; 7, lever arm; 8, spring arm; 9, first circular hoop; 10, second circular hoop; 11, switch KB1; 12, switch KB2.
The present invention will now be further described below with reference to the accompanying drawings and embodiments.
It should be pointed out that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those usually understood by a person of ordinary skill in the art to which the present invention belongs.
It should be noted that the terms used herein are merely used for describing specific implementations, and are not intended to limit exemplary implementations of the present invention. As used herein, the singular form is also intended to include the plural form unless the context clearly dictates otherwise. In addition, it should further be understood that, terms “include” and/or “including” used in this specification indicate that there are features, steps, operations, devices, components, and/or combinations thereof.
In order to solve the problems that the existing no-arc on-load tap changer in the background art is not suitable for an oil-immersed transformer, and even if the no-arc on-load tap changer is suitable for the oil-immersed transformer, various switches are respectively distributed on two or three rotary shafts which are not synchronous, when one rotary shaft needs to rotate, the other rotary shaft needs to be stationary, the operation structure is complex, and a rotary shaft coordination control mechanism, a dynamic contact and a static contact matching scheme of the rotary shaft and a driving scheme for controlling the switch are lacking. To solve the above problems, a no-arc on-load tap changer and a corresponding switching control method are provided by the present invention.
The present embodiment provides a no-arc on-load tap changer, which includes at least two main switches, two change-over switches and two thyristor auxiliary modules; wherein, each of the two thyristor auxiliary modules includes two control switches; that the two main switches comprise an originally-closed main switch and a to-be-closed main switch; the two main switches are connected in corresponding loops of a voltage regulating coil through corresponding transformer taps; the two thyristor auxiliary modules are connected in parallel with the originally-closed main switch or the to-be-closed main switch according to a required time sequence during the switching of main switch;
The no-arc on-load tap changer of the present embodiment uses the rotary shaft as power, is suitable for oil-immersed transformers, and the no-arc on-load tap changer is composed of rotating sliding contacts, and a structure thereof is shown in
In the present embodiment, the control switches are also a rotary-shaft-type switch, and the dynamic contacts of the control switches are also arranged on the rotary shaft.
The static contacts of all the main switches and the change-over switches are divided into at least two groups, each of the two groups of the static contacts is correspondingly mounted on one track, and the tracks corresponding to the two groups take a rotary shaft as the center and are fixed; wherein, the tracks are a circular insulating frame, and does not move along with the rotary shaft. The dynamic contacts are mounted on the rotary shaft and rotate along with the rotary shaft.
Wherein, before the switching of the no-arc on-load tap changer, one end of each of the thyristor auxiliary modules is suspended or connected in parallel with the originally-closed main switch. And, before the switching of the no-arc on-load tap changer, the voltages between both ends of the thyristor auxiliary modules are zero.
In a switching process of the no-arc on-load tap changer, the thyristor auxiliary modules are respectively connected in parallel with the originally-closed main switch or the to-be-closed main switch according to a required time sequence.
The present embodiment takes a number of the groups of the static contacts as two, that is, there are two tracks; each of the groups of the static contacts has three static contacts, and the number of the dynamic contacts is three, as an example.
It can be understood that, in other embodiments, a person skilled in the art can specifically set the number of dynamic contacts and the number of the groups of the static contacts according to actual situations.
In the present embodiment, there are three static contacts on the first track, and the three static contacts are arranged in sequence; the radian of the gap between the center positions of the first and second static contacts on the first track is equal to W, and the radian of the gap between the center positions of the second and third static contacts on the first track is also equal to W; there are also static contacts on the second track, and the number of static contacts on the second track is equal to the number of static contacts on the first track; the center line of each static contact on the first track correspondingly overlaps with the center line of each static contact on the second track respectively, and the one of the static contacts on the first track and the one of the static contacts on the second track that with overlapped centerlines are connected and further sequentially connected with the tap I, the tap II and the tap III of the transformer coil L1 respectively.
The radians of the three static contacts on the first track are the same, equal to W1; the radians of the three static contacts on the second track are the same, equal to W2; and the radians of the gaps between the static contacts on the second track are the same, equal to ΔW=(W−W2). For convenience of explanation, the structure diagram of the rotary shaft the no-arc on-load tap changer of
In the present embodiment, there are three dynamic contacts on the rotary shaft, such as the dynamic contact J3, the dynamic contact Q1 and the dynamic contact Q2; the dynamic contacts are mounted on the rotary shaft to rotate along with the rotary shaft; and the dynamic contact Q1 and the dynamic contact Q2 are respectively arranged on two sides of the dynamic contact J3.
The dynamic contact J3 respectively connected or disconnected with the three static contacts on the first track in turn when rotating along with the rotary shaft, to realize the connection and disconnection of the main switch; when the dynamic contact Q1 and the dynamic contact Q2 respectively connected or disconnected with the three static contacts on the second track in turn when rotating along with the rotary shaft, to realize the conversion of the change-over switch; the center position of the dynamic contact Q1 is on the second track on the left side of the center of the dynamic contact J3, and an included angle there between is 0.5 W; the center position of the dynamic contact Q2 is on the second track on the right side of the center of the dynamic contact J3, and an included angle there between is 0.5 W.
A normal operating state of the no-arc on-load tap changer of the present embodiment before switching is that: the dynamic contact J3 on the rotary shaft is located on the center line of the static contact W1, and the dynamic contact Q1 and the dynamic contact Q2 are respectively located on the center line of the gaps.
In the present embodiment, the thyristor auxiliary module M1 and the thyristor auxiliary module M2 have same a main circuit, and the main circuit of each of the two thyristor auxiliary modules includes a pair of thyristors connected in reverse parallel; an RC series circuit is connected in parallel at two ends of the reverse-parallel-connected thyristors; a capacitor, a resistor and a diode are sequentially connected between a gate electrode and a cathode of each of the reverse-parallel-connected thyristors; an anode of the diode is connected with the cathode of the corresponding one of the reverse-parallel-connected thyristors, and a cathode of the diode is connected with the gate electrode of the corresponding one of the reverse-parallel-connected thyristors; the gate electrodes of the two the reverse-parallel-connected thyristors are connected in series with one of the two control switches through a full-bridge rectifier circuit; two voltage-stabilizing tubes, a resistor, and another one of the two control switches are connected in series between gate electrodes of the two the reverse-parallel-connected thyristors; wherein the two voltage-stabilizing tubes are connected in reverse series; the two voltage-stabilizing tubes are connected in series with the resistor and then connected with an output end of the full-bridge rectifier circuit; cathodes of the two voltage-stabilizing tubes corresponds to an anode output end of the full-bridge rectifier circuit; and anodes of the two voltage-stabilizing tubes corresponds to a cathode output end of the full-bridge rectifier circuit.
Specifically, as shown in
It should be noted that the specific working process of the thyristor auxiliary module has been disclosed in the Chinese application number 201810290470.4, and will not be repeated here.
In the present embodiment, the thyristor auxiliary module M1 is connected to the control switches KA1 and KB1, and the thyristor auxiliary module M2 is connected to the control switches KA2 and KB2.
The dynamic contact J3 is connected with the public endpoint; two ends of the main circuit of the thyristor auxiliary module M1 are connected with the dynamic contact Q1 and the public endpoint, respectively; and two ends of the main circuit of the thyristor auxiliary module M2 are connected with the dynamic contact Q2 and the public endpoint, respectively.
In the specific implementation process, the control switches KA1 and KA2 are mounted on the rotary shaft, and when the control switches KA1 and KA2 rotate with the rotary shaft, two concentric circles can be drawn respectively, which are respectively called: the third track and the fourth track. A static contact W3 is provided on the third track in a region between the center line of the first static contact on the first track and the center line of the second static contact on the first track, and a static contact W4 is provided on the fourth track in this region. Similarly, the static contacts W3 and W4 repeatedly appear respectively on the third track and the fourth track in a region between the center line of the second static contact on the first track and the center line of the third static contact on the first track, as shown in
When the control switch KA1 rotates with the rotary shaft and meets the static contact W3, the control switch KA1 closes; when it leaves the static contact W3, the control switch KA1 is broken. When the control switch KA2 rotates with the rotary shaft and meets the static contact W4, the control switch KA2 closes; when it leaves the static contact W4, the control switch KA2 is broken. It can be seen that the static contact W3 and the static contact W4 may not necessarily be made of metal materials, they only need to be able to touch the control switch KA1 to close or the control switch KA2 to close.
When the rotary shaft rotates clockwise, before the dynamic contact J3 leaves the static contact W1, the control switch KA1 must contact the static contact W3; after the dynamic contact J3 leaves the static contact W1, the control switch KA1 is allowed to leave the static contact W3; before the dynamic contact J3 contacts another static contact W1, the control switch KA2 must contact the static contact W4; after the dynamic contact J3 contacts another static contact W1, the control switch KA2 is allowed to leave the static contact W4; and, the control switch KA2 is allowed to contact the static contact W4 at least after the time interval t1 after the control switch KA1 leaves the static contact W3.
When the rotary shaft rotates counter clockwise, before the dynamic contact J3 leaves the static contact W1, the control switch KA2 must contact the static contact W4; after the dynamic contact J3 leaves the static contact W1, the control switch KA2 is allowed to leave the static contact W4; before the dynamic contact J3 contacts another static contact W1, the control switch KA1 must contact the static contact W3; after the dynamic contact J3 contacts another static contact W1, the control switch KA1 is allowed to leave the static contact W3; and, the control switch KA1 is allowed to contact the static contact W3 at least after the time interval t1 after the control switch KA2 leaves the static contact W4.
In order to ensure that the time interval t1 is greater than the set time (e.g. 0.015 seconds), the rotary shaft should not rotate too fast. If the rotary shaft takes T seconds to make one revolution, then:
In the present embodiment, there is also a control mechanism on the rotary shaft. When the rotary shaft rotates clockwise and before the KA1 leaves the static contact W3, the control mechanism must open the control switch KB1 and close the control switch KB2. When the rotary shaft rotates counterclockwise and before the KA2 leaves the static contact W3, the control mechanism must close the control switch KB1 and open the control switch KB2.
The principle of the switching control of the no-arc on-load tap changer of the present embodiment is as follows:
Wherein, a rotation mode of the rotation of the rotary shaft includes a clockwise rotation and a counterclockwise rotation.
A one-time switching process of main switch of the present embodiment includes:
Referring to
Referring to
The switching control process when the no-arc on-load tap changer of the present embodiment rotates clockwise is as follows:
The switching control process when the no-arc on-load tap changer of the present embodiment rotates counterclockwise is as follows:
Both the no-arc on-load tap changer of the present embodiment and the existing oil-immersed on-load tap changer use a rotary shaft as driving power, and various switches and contacts can be operated in the oil tank of the oil-immersed transformer. Therefore, the no-arc on-load tap changer of the present invention can be reformed on the basis of the basic structure of the existing oil-immersed on-load tap changer.
The driving force of the existing oil-immersed on-load tap changer comes from an AC motor. In order to prevent the switch switching process from being interrupted due to power loss, the existing on-load tap changer has a spring release mechanism, and if the switch switching process loses power, the spring release mechanism can ensure that the on-load tap changer has a complete switching process. However, the spring energy storage time is longer, and the spring energy storage is carried out only after receiving the switching instruction, and the complete switching process of the existing on-load tap changer is longer. The structure of spring energy storage mechanism and spring energy release mechanism of on-load tap changer is complex, the operation vibration is large, and the failure rate is high.
The no-arc on-load tap changer of the present embodiment can be driven by a DC motor and electrically stored, and the no-arc on-load tap changer can eliminate the spring energy storage mechanism and the spring energy release mechanism.
It should be noted here that the driving motor of the oil-immersed on-load tap changer of the present embodiment may be a DC motor. AC power supply originally supplying power to AC motor supplies power to DC motor through bridge rectifier circuit and voltage stabilizing circuit, output of bridge rectifier circuit is connected in parallel with capacitor energy storage circuit, and stored electric energy of capacitor energy storage circuit can at least provide on-load tap changer to complete one complete operation. The electrical energy storage can be performed before the switching command is received, so that the time of a complete switching process of the no-arc on-load tap changer of the present embodiment is relatively short. Thus, the spring energy storage mechanism and the spring energy release mechanism of the no-arc on-load tap changer of the present embodiment can be eliminated.
The no-arc on-load tap changer of the present embodiment cancels the transition resistance, and there is no heating device in the switching process. In this way, the switching process does not have to have a fast mechanism (ensuring that the transition resistance is energized for no more than 40 milliseconds) as in the existing on-load tap changer. The switching process of the no-arc on-load tap changer of the present embodiment can be completed in tens of seconds. Therefore, the no-arc on-load tap changer of the present invention can be reformed on the basis of the basic structure of the existing oil-immersed non-excitation tap changer.
The no-arc on-load tap changer of the present embodiment has simple structure, small operation vibration and low failure rate. The no-arc on-load tap changer with the structure shown in
The present embodiment provides a no-arc on-load tap changer, and a structure thereof is the same as that of Embodiment 1. The difference is that in the present embodiment, a mechanical linkage mechanism is used to control the control switches KB1 and KB2.
As shown in
Wherein, the working process of the mechanical linkage mechanism of the present embodiment is as follows:
When the rotary shaft 4 rotates clockwise, the lever arm 7 encounters the second circular hoop 10, the second circular hoop 10 pushes the lever arm 7 to rotate counterclockwise around the deflection shaft 6, the lever arm 7 drives the spring arm 8 to rotate counterclockwise, the contact on the spring arm 8 contacts the contact of the switch KB2, and the switch KB2 closes. Until the lever arm 7 leaves the second hoop 10 and encounters another gap, the lever arm 7 returns to the center line of the gap; the spring arm 8 also returns to the center line of the gap, the contact on the spring arm 8 leaves the contact of the switch KB2, and the switch KB2 is broken.
When the rotary shaft 4 rotates counterclockwise, the lever arm 7 encounters the first circular hoop 9, the first circular hoop 9 pushes the lever arm 7 to rotate clockwise around the deflection shaft 6, the lever arm 7 drives the spring arm 8 to rotate clockwise, the contact on the spring arm 8 contacts the contact of the switch KB1, and the switch KB1 closes. Until the lever arm 7 leaves the first circular hoop 9 and encounters another gap, the lever arm 7 returns to the center line of the gap, the spring arm 8 also returns to the center line of the gap, the contact on the spring arm 8 leaves the contact of the switch KB1, and the switch KB1 is broken.
It can be understood here that a person skilled in the art can specifically design the structure of the mechanical linkage mechanism according to the actual situation, which is not described in detail here.
It should be noted that the switching control process of the no-arc on-load tap changer of the present embodiment is the same as the switching control process of the no-arc on-load tap changer of Embodiment 1, and is not repeated here.
The present embodiment provides a no-arc on-load tap changer, and a structure thereof is the same as that of Embodiment 1. The difference is that the control means for controlling the control switches KB1 and KB2 in the present embodiment is realized by driving change-over switches by the rotary shaft.
In “Electrical Mechanism of On-Load Tap Changer”, edited by Zhu Yinghao et al., published by China Electric Power Press, 2012, p 63-66, it has introduced that a change-over switch MTF driven by rotary shaft can constitute the control switches KB1 and KB2. Four static contacts of the change-over switch MTF in this book are MTF1, MTF2, MTF3 and MTF4 respectively; and, the change-over switch can be switched between two states: (1) the first contact and the third contact are conductive, and the second contact and the fourth contact are disconnected; (2) the first contact and the third contact are disconnected, and the second contact and the fourth contact are conductive. Contacts MTF1 and MTF3 can be used as both ends of control switch KB1, respectively; and contacts MTF2, MTF4 can be used as both ends of control switch KB2, respectively.
It should be pointed out that the change-over switch MTF introduced in “ElectricalMechanism of On-load Tap Changer” is a switch for high current, and the control switches KB1 and KB2 are the switches for small current. Therefore, it is necessary to reduce the size according to the working principle of change-over switch MTF to realize the function of control switches KB1 and KB2. Detailed analysis, no longer repeated here.
It should be noted that the switching control process of the no-arc on-load tap changer of the present embodiment is the same as the switching control process of the no-arc on-load tap changer of Embodiment 1, and is not repeated here.
The difference between the present embodiment and Embodiment 1 is that the radians of the static contacts are reduced and the radians of the dynamic contacts are increased, as shown in
The structure of the rotary shaft of the no-arc on-load tap changer of the present embodiment is shown in
The rotary shaft of the embodiment is provided with at least three dynamic contacts: the dynamic contact J3, the dynamic contact Q1 and the dynamic contact Q2; the dynamic contacts are mounted on the rotary shaft and rotates along with the rotary shaft; when the dynamic contact J3 rotates along with the rotary shaft, the dynamic contact J3 is respectively connected with the three static contacts on the first track in sequence; when the dynamic contact Q1 and the dynamic contact Q2 rotate along with the rotary shaft, the dynamic contact Q1 and the dynamic contact Q2 are respectively connected with the three static contacts on the second track in sequence; the center position of the dynamic contact Q1 is on the second track on the left side of the center position of the dynamic contact J3, and the included angle between two the center positions is0.5 W; and the center position of the dynamic contact Q2 is on the second track on the right side of the center position of the dynamic contact J3, and the included angle between two the center positions is 0.5 W.
The radian of the contact of the dynamic contact J3 is W1dynamic, the radians of the contacts of the dynamic contact Q1 and the dynamic contact Q2 are W2dynamic, and the radian of the gap between the dynamic contact Q1 and the dynamic contact Q2 is ΔWdynamic=(W−W2dynamic). Let: 0<ΔW<W1dynamic<0.5 W<W2dynamic, as shown in
It should also be noted that the breaking and closing of the control switches in the present embodiment is controlled by the control mechanism. The control mechanism may be implemented by using the second embodiment or the third embodiment or other existing control mechanisms, and a person skilled in the art may specifically select the control mechanism according to the actual situation, which is not repeated here.
The switching control method of the no-arc on-load tap changer of the present embodiment is the same as that of the no-arc on-load tap changer of Embodiment 1, and is not repeated here. The no-arc on-load tap changer of the present embodiment has the same contents as the no-arc on-load tap changer of Embodiment 1, and is not repeated here.
By comparing
The present embodiment provides a no-arc on-load tap changer, which include sat least two main switches, two change-over switches and two thyristor auxiliary modules; wherein, each of the two thyristor auxiliary modules includes two control switches; the two main switches comprise an originally-closed main switch and a to-be-closed main switch; the two main switches are connected in corresponding loops of a voltage regulating coil through corresponding transformer taps; the two thyristor auxiliary modules are connected with the originally-closed main switch or the to-be-closed main switch according to a required time sequence during the switching of main switch; and
It should be noted here that the control mechanism is a mechanical linkage mechanism and the structure thereof may adopt the specific structure of the mechanical linkage mechanism described in Embodiment 2, or may adopt the control mechanism described in Embodiment 3. Those skilled in the art can make specific settings according to actual conditions, and will not be described here.
In the present embodiment, the structures of the two thyristor auxiliary modules are the same, and the specific structure thereof is shown in
The switching control method of the no-arc on-load tap changer of the present embodiment includes:
In one or more embodiments, providing an electric accessory, including:
The transformer in the present embodiment is an oil-immersed transformer or a transformer with an oil-immersed vacuum on-load tap changer.
The electric accessory can be constructed in any manner according to requirements, for example as a compensation choke for influencing reactive power in an alternating power grid or as a local power grid transformer or power transformer or adjustable transformer or phase-shifting transformer or rectifier transformer or reactive power compensation device; and/or configured such that the device includes at least one or no additional regulating winding and/or at least one or no additional no-arc on-load tap changer and/or at least one mains winding.
One of the proposed methods can be implemented, for example, with each of the proposed on-load tap changers and each of the proposed devices.
Preferably, each on-load tap changer of the proposed no-arc on-load tap changer can be configured and/or used and/or adapted such that each no-arc on-load tap changer of the proposed no-arc on-load tap changer implements and/or can implement one of the proposed methods. Preferably, each of the proposed devices may be configured and/or used and/or adapted such that each of the proposed devices implements and/or may implement one of the proposed methods.
The foregoing descriptions are merely preferred embodiments of the present invention but are not intended to limit the present invention. A person skilled in art may make various alterations and variations to the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210232941.2 | Mar 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2023/076537 | 2/16/2023 | WO |
