Drive system for on-load tap changer and on-load tap changer assembly

Abstract

The utility model relates to a kind of drive system and on-load tap changer assembly for on-load tap changer.The drive system includes: transmission shaft assembly, it is configured to directly or indirectly with the on-load tap changer connection;Motor, it is configured to drive the transmission shaft assembly;Microswitch, it is configured to adjacent to the transmission shaft assembly arrangement and detect the rotation state of the transmission shaft assembly;Control device, it is configured to include timer or with timer electric connection, wherein, a predetermined time period can be set by the timer, wherein, the control device is configured to with the microswitch electric connection, to receive the switch signal from the microswitch in predetermined time period for fault identification.

Description

Technical Field

[0001] This application generally relates to the field of on-load tap changer technology, and in particular to a drive system and on-load tap changer assembly for an on-load tap changer. Background Technology

[0002] In power transmission and distribution systems, adjustable transformers, as core power equipment, bear the crucial task of adjusting the output voltage in real time according to changes in grid load and voltage fluctuations. Their operational stability directly determines the quality and safety of the power grid. Adjustable transformers primarily achieve voltage regulation by changing the turns ratio of their windings, and in this process, on-load tap changers (OLTCs) play an indispensable role. OLTCs can switch between taps while the transformer is operating under load, ensuring continuous and uninterrupted voltage regulation and preventing disruptions to industrial production and residential life due to power outages. They are widely used in transmission lines, substations, and large industrial enterprises.

[0003] The reliable operation of an on-load tap changer depends on its matching drive system and the transmission mechanism within the tap changer that forms a transmission connection with the drive system. The drive system typically consists of components such as a motor, transmission mechanism, and control device. Its core function is to precisely drive the tap changer contacts according to control commands to achieve tap switching.

[0004] However, in actual operation, the drive system of the on-load tap changer and its internal transmission mechanism are subject to multiple factors such as mechanical stress, electromagnetic interference, and changes in ambient temperature and humidity over a long period of time, making them prone to various faults, such as mechanical failures like wear and jamming of the transmission mechanism, and abnormal control signal transmission. If such faults are not detected and handled in a timely manner, they may cause the on-load tap changer to fail, preventing the adjustable transformer from regulating voltage normally, and may even lead to abnormal grid voltage. Therefore, real-time and effective fault monitoring of the on-load tap changer drive system is a key link in ensuring the stable operation of the adjustable transformer and even the entire power grid.

[0005] Therefore, with the increasing demands on the reliability of adjustable transformers in power systems, identifying or promptly detecting fault events in a cost-effective, simple, and efficient manner has become a pressing technical problem for those skilled in the art. Furthermore, after identifying a fault event, how to respond to it reasonably and cost-effectively and efficiently to reduce its impact is another pressing technical problem for those skilled in the art. Utility Model Content

[0006] Therefore, the purpose of this application is to provide a drive system and on-load tap changer assembly for an on-load tap changer that overcomes at least one deficiency in the prior art, thereby allowing for the identification or timely detection of fault events in a cost-effective, simple, and efficient manner. Furthermore, the drive system of some embodiments of this application also allows for a cost-effective, simple, and efficient response to the fault event, reducing the impact of the fault.

[0007] According to a first aspect of this application, a drive system for an on-load tap changer is provided, the drive system comprising: a drive shaft assembly configured to be directly or indirectly connected to the on-load tap changer; a motor configured to drive the drive shaft assembly; a micro switch configured to be arranged adjacent to the drive shaft assembly and to detect the rotational state of the drive shaft assembly; and a control device configured to include or be electrically connected to a timer, the timer being capable of setting a predetermined time period, wherein the control device is configured to be electrically connected to the micro switch to receive a switching signal from the micro switch within the predetermined time period for fault identification.

[0008] The driving system of this application achieves advantageous technical effects by introducing the switching signal of at least one microswitch and the timing function of a timer: In terms of cost-effectiveness, both the microswitch and the timer are mature, low-cost components, eliminating the need for expensive, high-precision components, thus enabling the cost-effective construction of a fault identification system. Regarding identification efficiency and convenience, the solution does not require complex data models or external equipment. The control device can complete fault identification based on the switching signal from the microswitch within a predetermined time period, such as the number of switching signals. This reduces the system's computational power consumption and simplifies subsequent maintenance costs, achieving simple and efficient fault identification.

[0009] In some embodiments, the control device is configured to identify faults based on the number of times the switching signal appears or disappears within the predetermined time period.

[0010] In some embodiments, the control device is configured to identify a fault based on the fact that the switch signal has not undergone a state switch within the predetermined time period.

[0011] In some embodiments, the micro switch includes a trigger rod and a switch body, the trigger rod being configured to contact a contact section formed or attached to the drive shaft assembly as the drive shaft assembly rotates.

[0012] In some embodiments, the switch body may integrate a moving contact and a stationary contact. The mechanical force generated by the contact between the contact section and the trigger rod drives the trigger rod to move, which in turn drives the moving contact within the switch body to move, causing the moving contact to contact or separate from the stationary contact. Based on the switching of the contact / separation states of the moving and stationary contacts, the circuit loop can be "connected" or "disconnected," triggering the microswitch to output a corresponding switching signal. When the drive shaft assembly rotates normally, the predetermined contact between the trigger rod of the microswitch and the drive shaft assembly can generate a predetermined switching signal. Specifically, for each revolution of the drive shaft assembly, the microswitch switches states a predetermined number of times, thereby triggering a predetermined mode of switching signal. Therefore, during the normal rotation of the drive shaft assembly, according to the predetermined arrangement of its contact sections, the number of times the switching signal appears or disappears within a predetermined time period should meet a predetermined value. For example, within the corresponding time period of one revolution of the drive shaft assembly, the switching signal should appear or disappear once; if the number of times the switching signal appears or disappears deviates from this predetermined value, it indicates that the system may have a fault. Therefore, the control device can identify a fault based on the number of times the switch signal appears or disappears within the predetermined time period. In some embodiments, the control device can be configured to identify a fault based on the fact that the switch signal has not undergone a state switch within the predetermined time period.

[0013] In some embodiments, the drive system includes a first micro switch and a second micro switch, and the control device is configured to determine the rotation direction of the drive shaft assembly based on switching signals from the first micro switch and the second micro switch.

[0014] In some embodiments, the first microswitch and the second microswitch are arranged in a stacked manner.

[0015] In some embodiments, the trigger lever of the first micro switch is configured to contact a first contact section formed or mounted on the drive shaft assembly as the drive shaft assembly rotates.

[0016] In some embodiments, the trigger lever of the second micro switch is configured to contact a second contact section formed or mounted on the drive shaft assembly as the drive shaft assembly rotates.

[0017] In some embodiments, the first contact segment and the second contact segment are offset from each other circumferentially along the drive shaft assembly. Therefore, the control device can be configured to determine the rotation direction of the drive shaft assembly based on switching signals from the first and second microswitches. Specifically, this offset arrangement results in a sequential contact time between the trigger rods of the first and second microswitches and their corresponding contact segments when the drive shaft rotates, leading to a time difference in the switching signals output by the two switches. The control device collects and analyzes the switching signals output by the first and second microswitches, determining the rotation direction of the drive shaft assembly based on the generation order of the switching signals: if the switching signal of the first microswitch is generated before the second microswitch (i.e., the first signal trigger time is earlier than the second signal), then the drive shaft assembly is determined to rotate in a first direction; if the switching signal of the second microswitch is generated before the first microswitch (i.e., the second signal trigger time is earlier than the first signal), then the drive shaft assembly is determined to rotate in a second direction (opposite to the first direction).

[0018] In some embodiments, the control device is configured to control the motor to move toward a safe tap position when a fault is detected, wherein the drive system includes a limiting structure for locking the drive shaft assembly at the safe tap position.

[0019] In some embodiments, the drive system includes a transmission mechanism that is tractively connected to the drive shaft assembly, and the limiting structure is provided on the transmission mechanism for engaging with and locking the drive shaft assembly at the safe disengagement position.

[0020] In some embodiments, the transmission mechanism includes a Maltese wheel driven by the transmission shaft assembly, a gear mechanism driven by the Maltese wheel, and a lever mechanism driven by the gear mechanism. The limiting structure formed on the lever mechanism can extend into a limiting groove on the transmission shaft assembly to lock the transmission shaft assembly.

[0021] In some embodiments, a gear portion is provided below the Maltese wheel, the gear portion being configured to drive the gear mechanism, a drive pin is provided below the gear mechanism, the drive pin being configured to drive a first lever mechanism, the first lever mechanism being configured to drive a second lever mechanism, and the limiting structure being formed on the second lever mechanism.

[0022] In some embodiments, the drive system includes a current sensor, and the control device is configured to connect to the current sensor to determine whether the safe tap position has been reached based on measurements taken by the current sensor.

[0023] This application's drive system, through the collaborative design of a "safe tap position limit structure" and "motor current monitoring and positioning," constructs a low-cost and high-efficiency fault response solution. After fault event identification, this solution can achieve a safe switching of the system's state using a simple and reliable mechanical structure combined with current monitoring, effectively reducing the damage caused by the fault to the system.

[0024] According to a second aspect of this application, an on-load tap changer assembly is provided, the on-load tap changer assembly including an on-load tap changer and a drive system for the on-load tap changer, characterized in that the drive system is configured as a drive system for an on-load tap changer according to some embodiments of this application. Attached Figure Description

[0025] The present application will now be described in more detail with reference to the accompanying drawings and specific embodiments. The schematic drawings are briefly described below:

[0026] Figure 1 A simplified schematic diagram of an on-load tap changer assembly according to some embodiments of this application is shown;

[0027] Figure 2 An exemplary perspective view shows the arrangement of the drive shaft assembly and micro switches within the drive system according to this application;

[0028] Figure 3 A view is shown of an exemplary limiting scheme for the drive system according to this application in the safe tap position. Detailed Implementation

[0029] The present application will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present application. However, it should be understood that the present application can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present application more complete and to fully illustrate the scope of protection of the present application to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0030] In the various embodiments described, the same reference numerals or element names are used for the same elements, and the disclosure contained throughout the specification can be applied semantically to elements with the same reference numerals or element names. Furthermore, in the various embodiments, the number, implementation, and / or arrangement of elements are not limited to the examples shown, but other numbers, implementations, and / or arrangements can be selected according to actual needs.

[0031] In this document, spatial relation terms such as "up," "down," "left," "right," "front," "back," "high," and "low" are used to describe the relationship between one feature and another in the accompanying drawings. It should be understood that spatial relation terms include not only the orientation shown in the drawings but also different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a feature previously described as "below" other features can now be described as "above" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be interpreted accordingly.

[0032] In this document, the term “A or B” includes both “A and B” and “A or B”, rather than exclusively including only “A” or only “B”, unless otherwise specified.

[0033] In this document, the terms "illustrative" or "exemplary" mean "serving as an example, instance, or illustration." Any implementation described herein by example is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, this application is not limited to any stated or implied theory given in the foregoing technical field, background art, utility model content, or specific embodiments.

[0034] In this document, the term “substantially” means any minor variation caused by design or manufacturing defects, device or component tolerances, environmental influences and / or other factors.

[0035] Additionally, terms such as “first,” “second,” etc., may be used in this document for reference purposes only and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the words “first,” “second,” and other such numerical terms relating to structures or elements do not imply order or sequence.

[0036] Some embodiments of this application will now be described in more detail with reference to the accompanying drawings.

[0037] Figure 1 A simplified schematic diagram of an on-load tap changer assembly 100 according to some embodiments of this application is shown. Figure 1 As shown, the on-load tap changer assembly 100 may include an on-load tap changer 10 and a drive system 20 for the on-load tap changer 10.

[0038] The drive system 20 may include a motor 22, a drive shaft assembly 21, and a control device 24. The motor 22 can drive the drive shaft assembly 21 via a motor shaft and optionally via a transmission mechanism. The drive shaft assembly 21 may include, for example, a drive shaft and other mechanisms optionally formed or attached to the drive shaft. The drive system 20 may be directly or indirectly connected to the on-load tap changer 10, more specifically, to a transmission mechanism within the on-load tap changer 10, for example, via the drive shaft assembly 21. The control device 24 of the drive system 20 may include a control unit and a power unit (e.g., a converter), the control unit of which may, for example, operate the power unit via a bus to control the operation of the motor 22.

[0039] The on-load tap changer 10 may include one or more of a selector, an on-load switcher, and a preselector. In order to drive the switching process of the on-load tap changer 10, the drive shaft assembly 21 of the drive system 20 may act directly or indirectly on the on-load tap changer 10, i.e., on the selector and / or the on-load switcher and / or the preselector, so as to switch from the current tap position to the target tap position.

[0040] Figure 2 An exemplary perspective view shows the arrangement of the drive shaft assembly 21 and the micro switch 23 within the drive system 20 according to this application.

[0041] like Figure 1 and 2 As shown, the drive system 20 may include at least one microswitch 23 (two microswitches 23-1 and 23-2 are shown exemplarily in the figure), the microswitch 23 may be configured to be arranged adjacent to the drive shaft assembly 21 and to detect the rotational state of the drive shaft assembly 21. Figure 1 As shown, the drive system 20 may include a transmission housing, in which a transmission shaft assembly 21 and a corresponding micro switch may be installed. The micro switch 23 may be electrically connected to the control device 24 to transmit a switching signal characterizing the rotational state of the transmission shaft assembly 21 to the control device 24.

[0042] In some embodiments, each microswitch 23 may include a trigger rod 31 and a switch body 32, the switch body 32 integrating a moving contact and a stationary contact. The trigger rod 31 may be configured to contact a contact section 211 formed or attached to the drive shaft assembly 21 as the drive shaft assembly 21 rotates. The mechanical force generated by the contact drives the trigger rod 31 to move, thereby causing the moving contact within the switch body 32 to move, making the moving contact contact or separate from the stationary contact. Based on the above-mentioned switching of the contact / separation state of the moving contact and the stationary contact, the circuit loop can be "connected" or "disconnected", triggering the microswitch 23 to output a corresponding switching signal.

[0043] Therefore, during normal tap-to-switch operation, i.e., when the drive shaft assembly 21 rotates normally, the predetermined contact between the trigger rod 31 of the micro switch 23 and the contact section 211 of the drive shaft assembly 21 generates a predetermined switching signal. Specifically, for each revolution of the drive shaft assembly 21, the micro switch 23 triggers a switching signal of a predetermined pattern. In some embodiments, the micro switch 23 outputs a switching signal when the trigger rod 31 is in contact with the contact section 211 of the drive shaft assembly 21, and does not output a switching signal when the trigger rod 31 is not in contact with the contact section 211 of the drive shaft assembly 21. In other embodiments, the micro switch 23 does not output a switching signal when the trigger rod 31 is in contact with the contact section 211 of the drive shaft assembly 21; and outputs a switching signal when the trigger rod 31 is not in contact with the contact section 211 of the drive shaft assembly 21. Based on this, during normal rotation of the drive shaft assembly 21, according to the predetermined arrangement of its contact section 211, the number of times the switching signal appears or disappears within a predetermined time period should meet a predetermined value. For example, within the corresponding time period of one revolution of the drive shaft assembly 21, the switch signal should appear or disappear once; if the number of times the switch signal appears or disappears deviates from this predetermined value, it indicates that there may be a fault in the system.

[0044] Therefore, the control device 24 can receive switching signals from the micro switch 23 within a predetermined time period for fault identification. To this end, the control device 24 of this application may include a timer 25 or be electrically connected to a timer, which can be set to a predetermined time period to provide a time reference for fault identification. For example, the control device 24 may start the timing operation of the timer 25 based on the activation of a switching process (e.g., the issuance of a control command for controlling the motor 22). When the timer 25 reaches the set predetermined time period, a trigger signal is transmitted to the control device 24. Thus, the control device 24 can identify a fault based on the number of times the switching signal appears or disappears within the predetermined time period. In some embodiments, the control device 24 may be configured to identify a fault based on the fact that the switching signal has not undergone a state switch within the predetermined time period, for example, no switching signal is received.

[0045] In some embodiments, the drive system 20 may include a first microswitch 23-1 and a second microswitch 23-2, thereby enabling redundant fault identification based on switching signals from the first microswitch 23-1 and the second microswitch 23-2. Figure 2As shown, the first microswitch 23-1 and the second microswitch 23-2 can be stacked on the side of the drive shaft assembly 21, ensuring effective engagement between their trigger rods 31 and the contact section 211 of the drive shaft assembly 21. The trigger rod 31 of the first microswitch 23-1 can be configured to contact, for example, periodically, the first contact section formed or mounted on the drive shaft assembly 21 as the drive shaft assembly 21 rotates; the trigger rod 31 of the second microswitch 23-2 can be configured to contact, for example, periodically, the second contact section formed or mounted on the drive shaft assembly 21 as the drive shaft assembly 21 rotates. In some embodiments, the first and second contact sections are staggered in the circumferential direction of the drive shaft assembly 21. Thus, the control device 24 can be configured to determine the rotation direction of the drive shaft assembly 21 based on the switching signals from the first microswitch 23-1 and the second microswitch 23-2. Specifically, this misaligned arrangement causes a sequential contact time between the trigger rods 31 of the first and second microswitches 23-1 and 23-2 and their corresponding contact sections 211 when the drive shaft rotates, resulting in a time difference in the switch signals output by the two switches. The control device 24 collects and analyzes the switch signals output by the first and second microswitches 23-1 and 23-2, and determines the rotation direction of the drive shaft assembly 21 based on the generation order of the switch signals: if the switch signal of the first microswitch 23-1 is generated before the second microswitch 23-2 (i.e., the first signal trigger time is earlier than the second signal), then it is determined that the drive shaft assembly 21 rotates in the first direction; if the switch signal of the second microswitch 23-2 is generated before the first microswitch 23-1 (i.e., the second signal trigger time is earlier than the first signal), then it is determined that the drive shaft assembly 21 rotates in the second direction (opposite to the first direction).

[0046] The driving system 20 of this application achieves advantageous technical effects by introducing the switching signal of at least one microswitch 23 and the timing function of a timer 25: In terms of cost-effectiveness, both the microswitch 23 and the timer 25 are mature, low-cost components, eliminating the need for expensive, high-precision components, thus enabling the cost-effective construction of a fault identification system. Regarding identification efficiency and convenience, the solution does not require complex data models or external devices. The control device 24 can complete fault identification based on the switching signal from the microswitch 23 within a predetermined time period, such as the number of switching signals. This reduces the system's computational power consumption and simplifies subsequent maintenance costs, achieving simple and efficient fault identification.

[0047] In a further improved embodiment of this application, the control device 24 is configured to have a fault response triggering function, that is, when a system fault is detected, it can automatically initiate a preset safety measure response process. Specifically, the control device 24 can be configured to control the motor 22 to run towards the safe tap position 1 when a fault is detected, that is, to control the motor 22 to stop its current operation and run towards the predetermined safe tap position. In some embodiments, the safe tap position may, for example, correspond to the first tap position 1. In the safe tap position 1, the portion of the adjusting winding connected to the main winding is minimized or even completely disconnected from the main winding, thereby minimizing the risk of faults and ensuring that the system is in a low-risk state after a fault reset, facilitating subsequent maintenance or restart.

[0048] To further improve the positioning reliability of the safety tap position (tap1), the drive system 20 adds a dedicated limiting structure 44 at the safety tap position. This limiting structure 44 is configured to mechanically lock the drive shaft assembly 21, that is, by forcibly limiting the further rotation of the drive shaft assembly 21 at the safety tap position, it ensures that after the motor 22 drives the drive shaft assembly 21 to reach the safety tap position, it can stably maintain that position.

[0049] Figure 3 A view is shown illustrating an exemplary limiting scheme for the drive system according to this application in the safe tap position (tap1). As... Figure 3 As shown, the drive system 20 may include a transmission mechanism 40 that forms a transmission connection with the drive shaft assembly 21, and the limiting structure 44 may be integrated into the transmission mechanism. When the drive shaft assembly 21 is driven by the motor 22 to the safe tap position tap1, the limiting structure 44 on the transmission mechanism engages with the drive shaft assembly 21 and locks the drive shaft assembly 21 by mechanical engagement or abutment. As an example, the transmission mechanism 40 may include a Maltese wheel 41 and a gear mechanism 42. For example, the Maltese wheel 41 may form a direct transmission connection with the drive shaft assembly 21, and a gear portion (not shown) is provided below the Maltese wheel 41, which meshes with the subsequent gear mechanism 42 to achieve power transmission. A drive pin (not shown) is provided below the gear mechanism 42. The drive pin is configured to drive the first lever mechanism 43-1 to move, for example, rotate or swing. The first lever mechanism 43-1 can continue to drive the second lever mechanism 43-2 to move, for example, rotate or swing. The limiting structure 44 can be formed on the second lever mechanism 43-2. ​​When the second lever mechanism 43-2 moves to a preset position, the limiting structure 44 can extend into a preset limiting groove on the transmission shaft assembly 21. Through the tight cooperation between the groove and the limiting structure, a forced restriction on the rotational freedom of the transmission shaft assembly 21 is formed, locking the transmission shaft assembly 21.

[0050] To reliably identify when the motor 22 has reached the safe tap position, the drive system 20 may also include a current sensor 26 (see [link]). Figure 1 The current sensor 26 can be configured to detect and output a measured value characterizing the operating current of the motor 22 in real time, providing status monitoring data to the control device 24. Accordingly, the control device 24 is electrically connected to the current sensor 26 and is configured to determine whether the motor 22 has driven the drive shaft assembly 21 to the safe tap position based on the real-time measured value output by the current sensor 26. When the drive shaft assembly 21 is locked by the limiting structure (i.e., mechanical jamming occurs), the operating load of the motor 22 increases instantaneously, and the operating current of the motor 22 rises significantly. Based on this characteristic, the control device 24 can be configured to determine that the drive shaft assembly 21 has reached the safe tap position when a significant increase in current value is detected (e.g., the current value exceeds a preset normal operating threshold). Subsequently, the control device 24 can output a stop command to stop further operation of the motor 22, completing the entire fault response process.

[0051] The drive system 20 of this application constructs a low-cost and high-efficiency fault response solution by introducing a collaborative design of a "safe tap position limit structure" and a "motor 22 current monitoring and positioning". After fault event identification, this solution can realize the safe switching of the system state by combining a simple and reliable mechanical structure with current monitoring, effectively reducing the damage caused by the fault to the system.

[0052] The following exemplifies the normal switching process, fault identification process, and safety measure response process of the on-load tap changer 10, specifically using the scenario of the on-load tap changer 10 switching from tap position tap3 to tap position tap4 as an example.

[0053] During normal switching, when a switching operation from tap position 3 to tap position 4 needs to be performed, the specific steps are as follows: After receiving the switching command, the control device 24 sends a control signal to the power unit, which drives the motor 22 to start running; the power output of the motor 22 is transmitted to the transmission shaft assembly 21 via the motor shaft (optionally via a transmission mechanism), and the transmission shaft assembly 21 directly or indirectly drives the on-load tap changer 10 to initiate the switching action from tap position 3 to tap position 4; at the same time as the switching process is activated, the control device 24 starts the timer 25 to begin timing for a predetermined time period; simultaneously, through communication with the transmission shaft assembly 21... The microswitches 23 arranged adjacent to the drive shaft assembly 21 monitor the rotation state of the drive shaft assembly 21 in real time and obtain the switching signal characterizing the rotation. Within the predetermined time period set by the timer 25, if the microswitches 23 output a switching signal that conforms to the predetermined pattern (for example, the switching signal appears or disappears a preset number of times for each rotation of the drive shaft assembly 21), the control device 24 determines that the drive shaft assembly 21 is rotating normally and the switching process is normal. After the on-load tap changer 10 completes the switching from tap position tap3 to tap position tap4, the control device 24 sends a stop command to the motor 22, the motor 22 stops running, and the entire normal switching process is terminated.

[0054] During the fault identification process, if the following abnormal situation occurs during the switching process from tap position 3 to tap position 4, the control device 24 will trigger fault identification: After the timer 25 is started, within the set predetermined time period, the micro switch 23 does not generate a switching signal that conforms to the predetermined pattern (for example, no switching signal output, or the number of times the switching signal appears or disappears deviates from the preset value). This abnormal situation indicates that the drive shaft assembly 21 has not rotated effectively, and the on-load tap changer 10 has not performed the switching operation as instructed. Based on this, the control device 24 determines that the system has malfunctioned.

[0055] During the safety response process, once the control device 24 detects the aforementioned fault, it will immediately initiate the preset safety response procedure. The specific steps are as follows: The control device 24 first sends an emergency stop command to the motor 22 to stop the current switching drive operation of the motor 22 and prevent the fault from escalating; after the emergency stop, the control device 24 sends a new drive command to the motor 22 to control the motor 22 to adjust its direction, driving the drive shaft assembly 21 to move the on-load tap changer 10 toward the preset safe tap position (in this example, the safe tap position is set to tap position 1, where the adjustment winding is connected to the main winding at the minimum or no connection at all, resulting in the lowest fault risk); when the drive shaft assembly 21 moves to the position corresponding to tap position 1 under the drive of the motor 22, the limiting structure set at the safe tap position in the drive system 20 and the preset limiting recess on the drive shaft assembly 21 are engaged. The slotted engagement, through mechanical locking or abutment, forcibly restricts the further rotation of the drive shaft assembly 21, achieving stable locking of the drive shaft assembly 21 in the safe tap position. During the process of the motor 22 driving towards the safe tap position, the current sensor 26 associated with the motor 22 detects the operating current of the motor 22 in real time and transmits the current measurement value to the control device 24. When the drive shaft assembly 21 is locked by the limiting structure (i.e., mechanical jamming occurs), the operating load of the motor 22 increases sharply, the current value rises significantly and exceeds the preset normal operating threshold. After detecting the abnormal rise in current, the control device 24 determines that the on-load tap switch 10 has reached the safe tap position, and then sends a final stop command to the motor 22. The motor 22 stops running, the entire fault safety response process is completed, and the system is stably in a low-risk safe tap position, facilitating subsequent maintenance or restart operations.

[0056] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of this application. The various embodiments disclosed herein can be combined in any way without departing from the spirit and scope of this application. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A drive system for an on-load tap changer, characterized in that, The drive system (20) includes: The drive shaft assembly (21) is configured to be directly or indirectly connected to the on-load tap changer (10); The motor (22) is configured to drive the drive shaft assembly; A micro switch (23) is configured to be arranged adjacent to the drive shaft assembly and to detect the rotational state of the drive shaft assembly (21); The control device (24) is configured to include or be electrically connected to a timer (25) that can be set for a predetermined time period, wherein the control device is configured to be electrically connected to the micro switch (23) to receive a switching signal from the micro switch for fault identification within the predetermined time period.

2. The drive system for an on-load tap changer according to claim 1, characterized in that, The control device is configured to control the motor (22) to move toward a safe tap position when a fault is detected, wherein the drive system (20) includes a limiting structure (44) for locking the drive shaft assembly (21) at the safe tap position.

3. The drive system for an on-load tap changer according to claim 2, characterized in that, The drive system (20) includes a current sensor (26), and the control device (24) is configured to connect to the current sensor (26) to determine whether the safe tap position has been reached based on the measurement value of the current sensor (26).

4. The drive system for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The control device (24) is configured to identify faults based on the number of times the switch signal appears or disappears within the predetermined time period.

5. The drive system for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The control device (24) is configured to identify a fault based on the fact that the switch signal has not undergone a state switch during the predetermined time period.

6. The drive system for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The micro switch (23) includes a trigger rod (31) and a switch body (32). The trigger rod (31) is configured to contact a contact section (211) formed or attached to the drive shaft assembly (21) as the drive shaft assembly (21) rotates.

7. The drive system for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The drive system (20) includes a first micro switch (23-1) and a second micro switch (23-2), and the control device (24) is configured to determine the rotation direction of the drive shaft assembly (21) based on the switching signals from the first micro switch and the second micro switch.

8. The drive system for an on-load tap changer according to claim 7, characterized in that, The first micro switch (23-1) and the second micro switch (23-2) are stacked together.

9. The drive system for an on-load tap changer according to claim 8, characterized in that, The trigger rod of the first micro switch (23-1) is configured to contact a first contact section formed or mounted on the drive shaft assembly as the drive shaft assembly rotates; The trigger lever of the second micro switch (23-2) is configured to contact a second contact section formed or mounted on the drive shaft assembly as the drive shaft assembly rotates. The first contact section and the second contact section are offset from each other along the circumference of the drive shaft assembly.

10. The drive system for an on-load tap changer according to claim 2 or 3, characterized in that, The drive system includes a transmission mechanism (40) that is driveably connected to the drive shaft assembly, and the transmission mechanism is provided with the limiting structure (44) for engaging with and locking the drive shaft assembly (21) at the safe disengagement position.

11. The drive system for an on-load tap changer according to claim 10, characterized in that, The transmission mechanism (40) includes a Maltese wheel (41) that is driven to the transmission shaft assembly, a gear mechanism (42) that is driven to the Maltese wheel, and a lever mechanism that is driven to the gear mechanism (42). The limiting structure (44) formed on the lever mechanism can extend into the limiting groove on the transmission shaft assembly (21) to lock the transmission shaft assembly.

12. The drive system for an on-load tap changer according to claim 11, characterized in that, A gear section is provided below the Maltese wheel (41), the gear section being configured to drive the gear mechanism (42), a drive pin is provided below the gear mechanism (42), the drive pin being configured to drive the first lever mechanism (43-1), the first lever mechanism (43-1) being configured to drive the second lever mechanism (43-2), and the limiting structure (44) is formed on the second lever mechanism (43-2).

13. An on-load tap changer assembly, the on-load tap changer assembly (100) comprising an on-load tap changer (10) and a drive system (20) for the on-load tap changer, characterized in that, The drive system is configured as a drive system for an on-load tap changer according to any one of claims 1 to 12.

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