Selector gear shifting positioning method and system of on-load tap-changer and selector

Abstract

The invention relates to the technical field of electrical equipment control, and discloses a selector gear shifting positioning method and system for an on-load tap-changer and a selector, and the method comprises the steps: setting the operation state of the selector according to the corresponding relation between the contact position of a static contact and a movable contact piece and the voltage change of the movable contact piece; a driving pulse signal is sent to the stepping motor to control the stepping motor to drive the movable contact, a feedback signal of a pulse encoder of the stepping motor is obtained, and according to the driving pulse signal and the feedback signal, the movement distance of the movable contact from the selector to each operation state is obtained; and the controller is used for correcting the movement distance according to the voltage signal acquired by the voltage detection loop to obtain a corrected movement distance, and resetting the accumulated pulse number of the driving pulse signal according to the corrected movement distance so as to carry out gear shifting positioning on the selector. According to the method disclosed by the invention, the accuracy and reliability of the gear shifting positioning result of the selector are improved, and abnormal early warning is realized.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment control technology, and in particular to a method, system, and selector for adjusting the tap position of an on-load tap changer. Background Technology

[0002] To cope with grid voltage fluctuations or load changes, on-load tap changers are typically used to adjust the output voltage of transformers. On-load tap changers can change the turns ratio of transformer windings without interrupting the load current, thus achieving precise output voltage regulation. They are crucial equipment for ensuring the stable operation of power systems. The selector of the on-load tap changer is the core actuator for voltage regulation. Its main function is to move the moving contact to connect with the stationary contacts of different taps inside the transformer, thereby completing the tap change. After the selector adjusts the tap, the stationary contact must be precisely positioned in the correct location of the moving contact. Any deviation can lead to poor contact and overheating, potentially causing equipment damage and, in severe cases, even affecting the normal operation of the entire power system.

[0003] In traditional control methods for on-load tap changer selector gear shifting, a combination of a motor, gearbox, and Geneva wheel is often used to achieve gear position control. Specifically, the motor drives the gearbox, which in turn moves the Geneva wheel, thereby actuating the moving contact of the selector to complete the gear shifting action. Simultaneously, the gearbox drives the gears to power the encoder mechanism, which outputs a gear position signal to locate the shifting position. However, traditional gear shifting methods rely solely on the encoder mechanism for gear position positioning. When the encoder mechanism malfunctions, such as encoder wear or abnormal signal transmission, it cannot be detected in time. This leads to inaccurate gear shifting positioning of the selector, resulting in poor contact between the moving and stationary contacts, overheating, and other problems, severely affecting the operational reliability of the on-load tap changer.

[0004] Therefore, improving the accuracy and reliability of the selector's tap position of on-load tap changers has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a method, system, and selector for adjusting the position of an on-load tap changer, in order to solve the technical problem of how to improve the accuracy and reliability of the position adjustment of an on-load tap changer, thereby achieving the effect of improving the accuracy and reliability of the position adjustment of an on-load tap changer.

[0006] In a first aspect, the present invention provides a method for adjusting and positioning the selector of an on-load tap changer, the selector comprising a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit, the voltage detection circuit being connected to the moving contact, the method comprising: The operating state of the selector is set according to the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact; A drive pulse signal is sent to the stepper motor to control the stepper motor to drive the moving contact, and the feedback signal of the pulse encoder of the stepper motor is obtained. Based on the drive pulse signal and the feedback signal, the movement distance of the moving contact when the selector reaches each of the operating states is obtained. The movement distance is corrected based on the voltage signal obtained by the voltage detection circuit to obtain the corrected movement distance. Based on the corrected movement distance, the cumulative number of pulses of the drive pulse signal is reset to adjust the gear positioning of the selector.

[0007] Preferably, setting the operating state of the selector based on the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact includes: When the left movable contact and the first odd stationary contact of the stationary contact are located in the first preset position, and the voltage of the movable contact is continuously stable, the selector is in a stable operating state. When the left moving contact of the moving contact is about to separate from the first odd stationary contact of the stationary contact, and the voltage of the moving contact changes from present to absent, and the operating state of the selector is the critical state of being energized; When the left moving contact is about to make contact with the second odd stationary contact of the stationary contact, and the voltage of the moving contact changes from zero to positive, and the operating state of the selector is the critical state of no power; When the left moving contact and the second odd stationary contact of the stationary contact are in the second preset position, and the voltage of the moving contact returns to stability, the selector's movement state is the next gear stable operation state.

[0008] Preferably, obtaining the movement distance of the movable contact piece when the selector reaches each of the operating states based on the drive pulse signal and the feedback signal includes: Determine whether the first pulse count of the drive pulse signal and the second pulse count of the feedback signal are consistent. If not, perform pulse supplementation on the stepper motor to make the first pulse count and the second pulse count equal. After the pulse re-emission is completed, it is determined whether the first pulse count has reached the first preset pulse count. If so, the selector is in the energized critical state, and the first movement distance of the moving contact is obtained based on the first preset pulse count, the step angle of the stepper motor and the pulse frequency of the drive pulse signal when the selector reaches the energized critical state. Determine whether the first pulse count has reached the second preset pulse count. If so, the selector is in the power-off critical state. Based on the second preset pulse count, the step angle, and the pulse frequency, obtain the second movement distance of the moving contact when the selector reaches the power-off critical state. Determine whether the first pulse count has reached the third preset pulse count. If so, the selector is in the next gear stable operation state, and based on the third preset pulse count, the step angle, and the pulse frequency, obtain the third movement distance of the moving contact when the selector reaches the de-energized critical state.

[0009] Preferably, the step of correcting the movement distance based on the voltage signal obtained from the voltage detection circuit to obtain the corrected movement distance includes: When the selector is in the energized critical state, the voltage signal is used to determine whether there is a voltage difference between the left movable contact and the right movable contact. If so, pulse compensation is applied to the stepper motor until there is no voltage difference between the left movable contact and the right movable contact, so as to correct the first movement distance and obtain the corrected first movement distance. When the selector is in the critical state of no power, it is determined whether there is a voltage difference between the left moving contact and the right moving contact according to the voltage signal. If not, pulse compensation is performed on the stepper motor until there is a voltage difference between the left moving contact and the right moving contact, so as to correct the second movement distance and obtain the corrected second movement distance.

[0010] Preferably, resetting the cumulative pulse count of the drive pulse signal based on the corrected movement distance to adjust the selector's gear positioning includes: After the moving contact reaches the first movement distance after correction, the cumulative number of pulses of the drive pulse signal is reset; After the moving contact reaches the second running distance after correction, the cumulative number of pulses of the drive pulse signal is reset.

[0011] Preferably, the method further includes: When the selector is in the stable operation state of the next gear, the voltage signal is used to determine whether there is voltage between the left moving contact and the right moving contact. If not, an abnormal operation warning of the selector is issued. Determine whether the difference between the third movement distance and the preset distance meets the preset threshold judgment condition. If not, issue a warning for abnormal gear positioning.

[0012] Preferably, both the corrected first movement distance and the preset distance are 1 / 6 of the length of the moving contact piece.

[0013] Secondly, the present invention also provides a selector gear adjustment and positioning system for an on-load tap changer. The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit. The voltage detection circuit is connected to the moving contact to realize the selector gear adjustment and positioning method for the on-load tap changer described above. The system includes: an operating status determination module, a movement distance acquisition module, and a correction and reset module. The operating state determination module is used to determine the operating state of the selector and obtain a number of operating states of the selector. The operating state is set to reflect the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact. The motion distance acquisition module is used to send a drive pulse signal to the stepper motor to control the stepper motor to drive the moving contact, and to acquire the feedback signal of the pulse encoder of the stepper motor. Based on the drive pulse signal and the feedback signal, the motion distance of the moving contact when the selector reaches each of the operating states is obtained. The calibration and reset module is used to calibrate the movement distance based on the voltage signal obtained by the voltage detection circuit to obtain the calibrated movement distance, and to reset the cumulative number of pulses of the drive pulse signal based on the calibrated movement distance in order to adjust and position the selector.

[0014] Thirdly, the present invention also provides a selector for an on-load tap changer, wherein the selector is positioned by means of the above-described on-load tap changer selection method. The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit, wherein the voltage detection circuit is connected to the moving contact.

[0015] This application provides a method, system, and selector for adjusting the tap position of an on-load tap changer. Compared with the prior art, the beneficial effects of the embodiments of this application are as follows: The on-load tap changer selector gear adjustment and positioning method disclosed in this application sets the operating state of the selector based on the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact. The moving contact is driven by a stepper motor to achieve selector gear adjustment of the on-load tap changer. The movement distance of the moving contact in different operating states during one gear increase or one gear decrease is determined based on the feedback signal of the stepper motor. The voltage signal between the moving contacts is collected by a voltage detection circuit. The movement distance is corrected based on the voltage signal. Then, the cumulative number of drive pulse signals is reset based on the corrected movement distance to avoid cumulative errors caused by the accumulation of drive pulse signals, improve the accuracy and reliability of the selector gear adjustment and positioning results, and provide early warning when the selector is abnormal in operation or gear adjustment and positioning. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the steps of a selector setting method for an on-load tap changer provided in a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the selector structure and operating state transition of an on-load tap changer provided in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a selector gearing and positioning system for an on-load tap changer according to a preferred embodiment of the present invention; Figure label: 1-First odd stationary contact, 2-Second odd stationary contact, 3-Even stationary contact, 4-Left moving contact, 5-Right moving contact, 6-Voltage detection circuit, 7-Stepper motor, 11-Running status determination module, 12-Motion distance acquisition module, 13-Correction and reset module. Detailed Implementation

[0017] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and should not be construed as limiting the invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of this invention. In the description of this invention, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In the description of this invention, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Please see Figure 1 The schematic diagram shown illustrates the steps of a selector setting and positioning method for an on-load tap changer. In an embodiment of the present invention, a selector setting and positioning method for an on-load tap changer is provided, such as... Figure 2 The diagram shown illustrates the selector structure and operating state transition of an on-load tap changer. The selector includes a stepper motor 7, a stationary contact, a moving contact, and a voltage detection circuit 6. The voltage detection circuit 6 is connected to the moving contact. The method includes: S1. Based on the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact, the operating state of the selector is set; the function of the selector of the on-load tap changer is to move the moving contact to connect to the stationary contacts of different taps inside the transformer. The transformer's regulating winding will draw out multiple taps, each tap corresponding to a stationary contact, which is spherical. Figure 2 As shown, the stationary contact of the on-load tap changer selector of this application includes an odd-even stationary contact 3 and an even-even stationary contact 3. The odd-even stationary contact includes a first odd-even stationary contact 1 and a second odd-even stationary contact 2. The moving contact includes a left moving contact 4 and a right moving contact 5. The stationary contact is located between the left moving contact 4 and the right moving contact 5. During the up-and-down movement of the left moving contact 4, it only connects to the odd-even stationary contact, and during the up-and-down movement of the right moving contact 5, it only connects to the even-even stationary contact 3. The left moving contact 4 and the right moving contact 5 are connected to a common port through a switching switch. The voltage detection circuit 6 is connected to the left moving contact 4 and the right moving contact 5 and is used to detect the voltage between the left moving contact 4 and the right moving contact 5. When the left moving contact 4 is in contact with the odd-even stationary contact and the right moving contact 5 is in contact with the even-even stationary contact 3, because the odd-even stationary contact and the even-even stationary contact 3 are connected to nodes with different potentials in the circuit, a voltage difference is generated between the left moving contact 4 and the right moving contact 5, thus generating a voltage signal. When the left moving contact 4 is not in contact with the odd stationary contact, and the right moving contact 5 is in contact with the even stationary contact 3, since the left moving contact 4 and the right moving contact 5 are disconnected, there is no voltage difference between them, and no voltage signal is generated. Therefore, this application sets the operating state of the selector based on the correspondence between the contact positions of the stationary and moving contacts and the voltage change of the moving contacts.

[0021] In a preferred embodiment of this application, based on the voltage change between the left movable contact 4 and the right movable contact 5, the selector's one-stage upshift or one-stage downshift process is divided into three stages: the energized to de-energized transition stage, the de-energized stage, and the de-energized to energized transition stage. These three stages correspond to four operating states of the selector: stable operating state, energized critical state, de-energized critical state, and next-stage stable operating state. In the stable operating state, the voltage between the left movable contact 4 and the right movable contact 5 is stable. At this time, the left movable contact 4 is in contact with the first odd stationary contact 1, and the contact point is located at 1 / 6 of the total length of the left movable contact 4, starting from the upper end. The right movable contact 5 is in contact with the even stationary contact 3, and the contact point is located at 1 / 6 of the total length of the right movable contact 5, starting from the lower end. The force between the movable contact and the stationary contact is uniform, the contact point has good contact, and the contact resistance is minimal when conducting. Figure 2 As shown in (a), the voltage signal collected by the voltage detection circuit 6 is stable at this time. When a gear shift is required, the moving contact moves downward. At this time, due to the movement of the moving contact, the contact point fluctuates dynamically, and the voltage between the left moving contact 4 and the right moving contact 5 begins to fluctuate. The voltage signal collected by the voltage detection circuit 6 also begins to fluctuate. When the left moving contact 4 moves to the critical point where it is in contact with the first stationary contact 1, that is, the left moving contact 4 and the first stationary contact 1 are about to separate, as shown in (a). Figure 2 As shown in (b), the selector is in a critical energized state at this time. There is no voltage between the left moving contact 4 and the right moving contact 5, which is reflected in the voltage signal as a change from present to absent. The selector transitions from a stable operating state to a critical energized state during the transition from energized to de-energized phase. The moving contact moves further downwards. When the left moving contact 4 separates from the first odd stationary contact 1, the first odd stationary contact 1 and the second odd stationary contact 2 are in a suspended state. Only the right moving contact 5 is in contact with the even stationary contact 3. The voltage between the left moving contact 4 and the right moving contact 5 is 0, and the voltage detection circuit 6 cannot collect a voltage signal. This continues until the left moving contact 4 and the second odd stationary contact 2 are at the critical contact point, that is, the left moving contact 4 is about to contact the second odd stationary contact 2 of the stationary contact. The selector enters a critical de-energized state. The selector transitions from a critical energized state to a critical de-energized state during the de-energized phase. Figure 2As shown in (c), the selector is in a critical state of no power at this time. The voltage between the left moving contact 4 and the right moving contact 5 reappears, reflected in the voltage signal as a change from zero to positive. The moving contact moves further downward, and the selector enters the transition from no power to power. At this time, the voltage detection circuit 6 collects the voltage signal, but the voltage signal is unstable and fluctuates. When the contact point of the left moving contact 4 and the second odd stationary contact 2 is located at 1 / 6 of the total length of the left moving contact 4 (starting from the lower end of the left moving contact 4), and the contact point of the right moving contact 5 and the even stationary contact 3 is located at 1 / 6 of the total length of the right moving contact 5 (starting from the upper end of the right moving contact 5), the selector is in the stable operation state of the next gear, completing one gear shifting process. The transition from the critical state of no power to the stable operation state of the next gear is the transition from no power to power. Figure 2 As shown in (d), the voltage between the left moving contact 4 and the right moving contact 5 returns to stability, which is reflected in the voltage signal as the voltage signal recovering from fluctuation to stability. For a downshifting process, it is only necessary to move the moving contact upward. The three stages appear in the following order: the stage of switching from energized to de-energized, the stage of de-energized, and the stage of switching from de-energized to energized. The operating state of the selector changes in the following order: stable operating state, energized critical state, de-energized critical state, and stable operating state of the next gear.

[0022] S2. A drive pulse signal is sent to the stepper motor to control the stepper motor to drive the moving contact piece, and the feedback signal of the pulse encoder of the stepper motor is obtained. Based on the drive pulse signal and the feedback signal, the movement distance of the moving contact piece in each of the selected states is obtained. In a preferred embodiment of this application, the movement of the moving contact piece is driven by the stepper motor 7. A drive pulse signal is sent to the stepper motor 7. Each time the stepper motor 7 receives a drive pulse signal, it rotates a fixed angle, thereby driving the left moving contact piece 4 and the right moving contact piece 5 to move a fixed distance. A pulse encoder is installed on the stepper motor 7. The pulse encoder generates a feedback signal based on the operation of the stepper motor 7. Based on the drive pulse signal and the feedback signal, the movement of the moving contact piece is judged to obtain the movement distance of the moving contact piece in each operating state.

[0023] In a preferred embodiment of this application, it is determined whether the first pulse count of the drive pulse and the second pulse count of the feedback signal are consistent. If they are, it indicates that the stepper motor 7 moves according to the preset first pulse count and the stepper motor 7 is running normally. If not, it indicates that the stepper motor 7 is running abnormally, that is, it has lost a step and needs to perform pulse re-sending to make the first pulse count of the drive pulse signal and the second pulse count of the feedback signal equal, so as to ensure the accuracy of the stepper motor 7 driving the moving contact piece to move a certain distance.

[0024] Furthermore, when the stepper motor 7 is running normally, it is determined whether the first pulse count has reached the first preset pulse count. If so, the selector is in the energized critical state, and the first movement distance of the moving contact is obtained according to the first preset pulse count, the step angle of the stepper motor 7, and the pulse frequency of the drive pulse signal. When the stepper motor 7 is running normally, it is determined whether the first pulse count has reached the second preset pulse count. If so, the selector is in the de-energized critical state, and the second movement distance of the moving contact is obtained according to the second preset pulse count, the step angle, and the pulse frequency. When the stepper motor 7 is running normally, it is determined whether the first pulse count has reached the third preset pulse count. If so, the selector is at the next stable operating point, and the third movement distance of the moving contact is obtained according to the third preset pulse count, the step angle, and the pulse frequency. The determination of the first preset pulse count is based on the first distance, step angle, and pulse frequency between the selector's position from the contact position between the left moving contact 4 and the first stationary contact 1 in the stable operating state to the contact position between the left moving contact 4 and the first stationary contact 1 in the energized critical state. This represents the number of pulses required for the stepper motor 7 to move the moving contact a first distance. The first distance is... Figure 2 L1, as shown, is 1 / 6 of the total length of the moving contact piece, ensuring uniform force and good contact between the left moving contact piece 4 and the stationary contact. The determination of the second preset pulse number is based on the second distance from the contact position between the left moving contact piece 4 and the first stationary contact 1 at the energized critical state to the centerline of the left moving contact piece 4, the step angle, and the pulse frequency. This represents the number of pulses required for the stepper motor 7 to move the moving contact piece a second distance. The second distance is... Figure 2 L2, as shown, is 1 / 3 of the total length of the moving contact piece. The determination of the third preset pulse number is based on the third distance, step angle, and pulse frequency between the contact position of the left moving contact piece 4 and the second stationary contact 2 when the selector moves from the contact position of the left moving contact piece 4 and the second stationary contact 2 in the de-energized critical state to the contact position of the left moving contact piece 4 and the second stationary contact 2 in the stable operation state of the next gear. This represents the number of pulses required for the stepper motor 7 to move the moving contact piece a third distance. The third distance is... Figure 2 L3 is shown.

[0025] S3. Based on the voltage signal obtained by the voltage detection circuit, the movement distance is corrected to obtain the corrected movement distance. Based on the corrected movement distance, the cumulative number of pulses of the drive pulse signal is reset to adjust the position of the selector. In the preferred embodiment of this application, the voltage detection circuit 6 is used to determine the contact state of the moving contact and the stationary contact, as well as the operating state of the selector. When there is a difference between the operating state of the selector determined by the voltage signal and the operating state of the selector determined by the stepper motor 7, the stepper motor 7 is pulsed to correct the movement distance of the moving contact. Specifically, when the selector is in the energized critical state, the voltage signal should change from having voltage to having no voltage. Based on the voltage signal, it is determined whether there is voltage between the left moving contact 4 and the right moving contact 5. If so, it indicates that the left moving contact 4 and the first stationary contact 1 have not yet separated. Then, pulse supplementation is performed on the stepper motor 7 until there is no voltage between the left moving contact 4 and the right moving contact 5, indicating that the left moving contact 4 has separated from the first stationary contact 1, thus correcting the first movement distance and obtaining the corrected first movement distance. When the selector is in the de-energized critical state, the voltage signal should change from having no voltage to having voltage. Based on the voltage signal, it is determined whether there is voltage between the left moving contact 4 and the right moving contact 5. If not, it indicates that the left moving contact 4 and the second stationary contact 2 have not yet made contact. Then, pulse supplementation is performed on the stepper motor 7 until there is a voltage difference between the left moving contact 4 and the right moving contact 5, indicating that the left moving contact 4 and the second stationary contact 2 have made contact, thus correcting the second movement distance and obtaining the corrected second movement distance.

[0026] In a preferred embodiment of this application, the operating state of the selector is further determined based on the voltage signal. If the operating state of the selector determined by the stepper motor 7 is inconsistent with the operating state of the selector determined by the voltage signal, the movement distance of the moving contact is corrected by pulse compensation to improve the accuracy and reliability of the selector gearing positioning of the on-load tap changer.

[0027] In a preferred embodiment of this application, after the moving contact reaches the first movement distance after correction, the cumulative number of pulses of the drive pulse signal is reset. After the moving contact reaches the second movement distance after correction, the cumulative number of pulses of the drive pulse signal is reset. During the selector adjustment process of the on-load tap changer, by resetting the cumulative number of pulses of the drive pulse signal at a specific position, the cumulative error caused by the accumulation of the drive pulse signal can be avoided, further improving the accuracy and reliability of the selector adjustment positioning of the on-load tap changer.

[0028] In a preferred embodiment of this application, when the selector is in the next stable operating state, the voltage between the left movable contact 4 and the right movable contact 5 should return to stability. The voltage signal is used to determine whether there is voltage between the left movable contact 4 and the right movable contact 5. If not, it indicates that the selector is malfunctioning and an abnormal operation warning is issued.

[0029] In another preferred embodiment of this application, it is determined whether the difference between the third movement distance and the preset distance meets the preset threshold judgment condition. If not, an abnormal adjustment positioning warning is issued. The preset distance is 1 / 6 of the total length of the moving contact piece to ensure that the force between the right moving contact piece 5 and the even stationary contact 3 is uniform and the contact point is in good contact. When the difference between the third movement distance and the preset distance is less than the preset error threshold, it indicates that the moving contact piece and the stationary contact are in the optimal position for the selector to operate stably. If not, it indicates that there is a large error in the selector's adjustment positioning, and an abnormal adjustment positioning warning is issued.

[0030] In a preferred embodiment of this application, the operating state of the selector is set according to the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact. The moving contact is driven by a stepper motor to achieve selector gear adjustment of the on-load tap changer. The movement distance of the moving contact in different operating states during a single upshift or downshift of the selector is determined according to the feedback signal of the stepper motor. The voltage signal between the moving contacts is collected by a voltage detection circuit. The movement distance is corrected according to the voltage signal. Then, the cumulative number of drive pulse signals is reset based on the corrected movement distance to avoid cumulative errors caused by the accumulation of drive pulse signals, improve the accuracy and reliability of the selector gear adjustment positioning result, and provide early warning when the selector is abnormal in operation or gear adjustment positioning.

[0031] Accordingly, such as Figure 3 The schematic diagram shown is of the structure of the selector adjustment and positioning system for an on-load tap changer. Based on a method for adjusting and positioning the selector of an on-load tap changer, this embodiment of the invention also provides a selector adjustment and positioning system for an on-load tap changer, which implements the method for adjusting and positioning the selector of an on-load tap changer disclosed in this embodiment of the invention. The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit. The voltage detection circuit is connected to the moving contact. The system includes: an operating state determination module 11, a movement distance acquisition module 12, and a correction and reset module 13. The operating state determination module 11 is used to determine the operating state of the selector and obtain a plurality of operating states of the selector. The operating state is set to reflect the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact. The motion distance acquisition module 12 is used to send a drive pulse signal to the stepper motor to control the stepper motor to drive the moving contact piece, and to acquire the feedback signal of the pulse encoder of the stepper motor. Based on the drive pulse signal and the feedback signal, the motion distance of the moving contact piece when the selector reaches each of the operating states is obtained. The calibration and reset module 13 is used to calibrate the movement distance based on the voltage signal obtained by the voltage detection circuit to obtain the calibrated movement distance, and to reset the cumulative number of pulses of the drive pulse signal based on the calibrated movement distance in order to adjust and position the selector.

[0032] For specific limitations regarding the selector setting and positioning system for an on-load tap changer, please refer to the above-described limitations regarding the selector setting and positioning method for an on-load tap changer, which will not be repeated here. Those skilled in the art will recognize that the various modules and steps described in conjunction with the embodiments disclosed in this invention can be implemented in hardware, software, or a combination of both. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0033] Accordingly, based on a selector adjustment and positioning method for an on-load tap changer, this embodiment of the invention also provides an on-load tap changer selector, which is adjusted and positioned using the on-load tap changer selection and positioning method disclosed in this embodiment of the invention. The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit, and the voltage detection circuit is connected to the moving contact.

[0034] For specific limitations regarding the selector of an on-load tap changer, please refer to the above-mentioned limitations on the selector's range adjustment and positioning method for an on-load tap changer, which will not be repeated here.

[0035] In summary, the on-load tap changer selector adjustment and positioning method, system, and selector provided in this application address the technical problem of improving the accuracy and reliability of on-load tap changer selector adjustment and positioning. The method includes: setting the operating state of the selector based on the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact; sending a drive pulse signal to a stepper motor to control the stepper motor to drive the moving contact, and obtaining the feedback signal from the stepper motor's pulse encoder; obtaining the movement distance of the moving contact when the selector reaches each operating state based on the drive pulse signal and the feedback signal; correcting the movement distance based on the voltage signal obtained from the voltage detection circuit to obtain the corrected movement distance; and resetting the cumulative pulse count of the drive pulse signal based on the corrected movement distance to perform selector adjustment and positioning. The on-load tap changer selector adjustment and positioning method disclosed in this application provides high accuracy and reliability of the selector adjustment and positioning results, and provides early warnings when the selector operates abnormally or the adjustment and positioning is abnormal.

[0036] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0037] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for adjusting and positioning the selector of an on-load tap changer, characterized in that, The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit, wherein the voltage detection circuit is connected to the moving contact, and the method includes: The operating state of the selector is set according to the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact; A drive pulse signal is sent to the stepper motor to control the stepper motor to drive the moving contact, and the feedback signal of the pulse encoder of the stepper motor is obtained. Based on the drive pulse signal and the feedback signal, the movement distance of the moving contact when the selector reaches each of the operating states is obtained. The movement distance is corrected based on the voltage signal obtained by the voltage detection circuit to obtain the corrected movement distance. Based on the corrected movement distance, the cumulative number of pulses of the drive pulse signal is reset to adjust the gear positioning of the selector.

2. The selector setting and positioning method for an on-load tap changer as described in claim 1, characterized in that, The step of setting the operating state of the selector based on the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact includes: When the left movable contact and the first odd stationary contact of the stationary contact are located in the first preset position, and the voltage of the movable contact is continuously stable, the selector is in a stable operating state. When the left moving contact of the moving contact is about to separate from the first odd stationary contact of the stationary contact, and the voltage of the moving contact changes from present to absent, the operating state of the selector is the energized critical state. When the left moving contact is about to make contact with the second odd stationary contact of the stationary contact, and the voltage of the moving contact changes from zero to positive, the operating state of the selector is the critical state of no power. When the left moving contact and the second odd stationary contact of the stationary contact are in the second preset position, and the voltage of the moving contact returns to stability, the selector's movement state is the next gear stable operation state.

3. The selector setting and positioning method for an on-load tap changer as described in claim 2, characterized in that, The step of obtaining the movement distance of the movable contact piece when the selector reaches each of the operating states based on the drive pulse signal and the feedback signal includes: Determine whether the first pulse count of the drive pulse signal and the second pulse count of the feedback signal are consistent. If not, perform pulse supplementation on the stepper motor to make the first pulse count and the second pulse count equal. After the pulse re-emission is completed, it is determined whether the first pulse count has reached the first preset pulse count. If so, the selector is in the energized critical state, and the first movement distance of the moving contact is obtained based on the first preset pulse count, the step angle of the stepper motor and the pulse frequency of the drive pulse signal when the selector reaches the energized critical state. Determine whether the first pulse count has reached the second preset pulse count. If so, the selector is in the power-off critical state. Based on the second preset pulse count, the step angle, and the pulse frequency, obtain the second movement distance of the moving contact when the selector reaches the power-off critical state. Determine whether the first pulse count has reached the third preset pulse count. If so, the selector is in the next gear stable operation state, and based on the third preset pulse count, the step angle, and the pulse frequency, obtain the third movement distance of the moving contact when the selector reaches the de-energized critical state.

4. The selector setting and positioning method for an on-load tap changer as described in claim 3, characterized in that, The step of correcting the movement distance based on the voltage signal obtained from the voltage detection circuit to obtain the corrected movement distance includes: When the selector is in the critical state of being energized, it is determined whether there is voltage between the left movable contact and the right movable contact based on the voltage signal. If so, pulse compensation is performed on the stepper motor until there is no voltage between the left movable contact and the right movable contact, so as to correct the first movement distance and obtain the corrected first movement distance. When the selector is in the critical state of no power, the voltage signal is used to determine whether there is voltage between the left moving contact and the right moving contact. If not, pulse compensation is sent to the stepper motor until there is voltage between the left moving contact and the right moving contact, so as to correct the second movement distance and obtain the corrected second movement distance.

5. The selector setting and positioning method for an on-load tap changer as described in claim 4, characterized in that, The step of resetting the cumulative pulse count of the drive pulse signal based on the corrected movement distance to adjust the selector's gear positioning includes: After the moving contact reaches the first movement distance after correction, the cumulative number of pulses of the drive pulse signal is reset; After the moving contact reaches the second running distance after correction, the cumulative number of pulses of the drive pulse signal is reset.

6. The selector setting and positioning method for an on-load tap changer as described in claim 4, characterized in that, The method further includes: When the selector is in the stable operation state of the next gear, the voltage signal is used to determine whether there is voltage between the left moving contact and the right moving contact. If not, an abnormal operation warning of the selector is issued. Determine whether the difference between the third movement distance and the preset distance meets the preset threshold judgment condition. If not, issue a warning for abnormal gear positioning.

7. The selector setting and positioning method for an on-load tap changer as described in claim 6, characterized in that, The corrected first movement distance and the preset distance are both 1 / 6 of the length of the moving contact piece.

8. A selector setting and positioning system for an on-load tap changer, used to implement the selector setting and positioning method for an on-load tap changer as described in any one of claims 1-7, characterized in that, The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit. The voltage detection circuit is connected to the moving contact. The system includes: a running status determination module, a motion distance acquisition module, and a correction and reset module. The operating state determination module is used to determine the operating state of the selector and obtain a number of operating states of the selector. The operating state is set to reflect the correspondence between the contact position of the stationary contact and the moving contact and the voltage change of the moving contact. The motion distance acquisition module is used to send a drive pulse signal to the stepper motor to control the stepper motor to drive the moving contact, and to acquire the feedback signal of the pulse encoder of the stepper motor. Based on the drive pulse signal and the feedback signal, the motion distance of the moving contact when the selector reaches each of the operating states is obtained. The calibration and reset module is used to calibrate the movement distance based on the voltage signal obtained by the voltage detection circuit to obtain the calibrated movement distance, and to reset the cumulative number of pulses of the drive pulse signal based on the calibrated movement distance in order to adjust and position the selector.

9. A selector for an on-load tap changer, wherein the selector setting and positioning method for an on-load tap changer as described in any one of claims 1-7 is used for setting and positioning, characterized in that, The selector includes a stepper motor, a stationary contact, a moving contact, and a voltage detection circuit, wherein the voltage detection circuit is connected to the moving contact.

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