An on-load tap changer monitoring device, method, apparatus and storage medium

Abstract

The application discloses a kind of on-load tap-changer monitoring devices, methods, equipment and storage medium, the device includes position sensor, current sensor and information acquisition processor, position sensor is set to the transmission assembly of on-load tap-changer, for detecting the action information of on-load tap-changer switching knife switch, current sensor is set to the power electronic component of on-load tap-changer and the loop of switching switch, for detecting the current information of the power electronic component, information acquisition processor is used to receive action information and current information, and action information and current information are exported.The on-load tap-changer monitoring device of the embodiment of the application can monitor the action information of switching knife switch and the current information of power electronic component in real time by installing position sensor on transmission assembly, setting current sensor in the loop of power electronic component and switching switch, installation position is reasonable, and it is convenient to monitor on-load tap-changer internal information.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to an on-load tap changer monitoring device, method, equipment, and storage medium. Background Technology

[0002] On-load tap changers (OLTCs) are the core components of power transformers for voltage regulation. On-load tap changer technology is a crucial means of stabilizing voltage; it involves switching the transformer from one tap to another without interrupting power, thereby adjusting the effective number of turns in the transformer windings to achieve voltage regulation. Currently, there are two main technical approaches to on-load tap changers: mechanical and power electronic. Power electronic tap changers primarily include pure power electronic and hybrid mechanical-power electronic approaches. Using pure power electronic tap changers instead of mechanical ones results in arc-free switching and rapid operation, but it requires a large number of power electronic devices, leading to higher costs. The continuous current flow of these devices necessitates additional water-cooling equipment, resulting in significant losses and low reliability. Pure power electronic tap changers are currently in the theoretical research stage. Hybrid mechanical and power electronic tap changers, using semi-controlled power electronic components instead of mechanical switching switches, minimize arcing during switching and extend the lifespan of the on-load tap changer.

[0003] Currently, the internal operating status of on-load tap changers in transformers cannot be monitored. Conventional mechanical on-load tap changers are completely submerged in transformer oil, especially in high-voltage transformers where there is a voltage of several hundred kilovolts to ground, making it impossible to directly measure electrical signals in real time. The mechanical disconnectors rely on spring-loaded energy storage for actuation, which is driven by a motor; therefore, the precise timing of the disconnector's action cannot be determined from the motor's movement. Maintenance personnel cannot monitor the internal operating status of the tap changer in real time, and the operating condition of the on-load tap changer directly affects the operational safety of the on-load tap-changing transformer. Transformer fires caused by on-load tap changer failures can easily result in personal injury and significant equipment damage. Therefore, there is an urgent need to solve the problem of online monitoring of on-load tap changers during operation.

[0004] Existing technologies employ a Hall effect sensor installed at the tap changer drive motor coil, a vibration acceleration sensor installed on the tap changer contacts, and an angular displacement sensor fixedly mounted on the tap changer drive motor shaft. However, most existing on-load tap changers for transformers use a motor-driven shaft to power a trigger spring. Once the spring is fully charged, it drives the internal switching switch to complete the tap position change. The trigger spring's charging time is on the order of seconds (typically 2-6 seconds), and due to individual spring variations, the triggering time cannot be precisely controlled. Therefore, in practical applications, it is impossible to accurately provide the on-load tap changer displacement-time curve and total stroke. Consequently, existing technologies suffer from the problem of unreasonable sensor installation. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide an on-load tap changer monitoring device, method, equipment, and storage medium to solve the technical problem of unreasonable installation of existing monitoring devices.

[0006] The technical solution proposed in this invention is as follows:

[0007] A first aspect of this invention provides an on-load tap changer monitoring device, applied to a hybrid power electronic-mechanical on-load tap changer, comprising: a position sensor disposed on the transmission assembly of the on-load tap changer for detecting the operation information of the switching switch of the on-load tap changer; a current sensor disposed in the circuit of the power electronic assembly and the switching switch of the on-load tap changer for detecting the current information of the power electronic assembly; and an information acquisition processor connected to the position sensor and the current sensor respectively for receiving the operation information and the current information, and outputting the operation information and the current information.

[0008] Optionally, the transmission assembly includes a first transmission rod and a second transmission rod. The first transmission rod is disposed inside the on-load tap changer and connected to the switching knife switch. One end of the second transmission rod is connected to the first transmission rod, and the other end extends out of the housing of the on-load tap changer and is connected to the position sensor. The second transmission rod and the housing of the on-load tap changer are rotatably and sealingly connected.

[0009] Optionally, the position sensor includes a light source emitter, a light source receiver, and a blocking component. The blocking component is connected to and rotates coaxially with the second transmission rod. The light source emitter and the light source receiver are respectively disposed on the upper and lower sides of the blocking component. The blocking component has at least two light-transmitting holes. When the switching switch is closed, the light source emitter, the light-transmitting holes, and the light source receiver form a light source path. The light source emitter is used to emit light signals, and the light source receiver is used to detect whether a light signal is received.

[0010] Optionally, the blocking member has a fixing hole in the middle, and the blocking member is engaged with the second transmission rod through the fixing hole.

[0011] Optionally, the on-load tap changer monitoring device further includes a control unit, one end of which is connected to the light source receiver and the other end of which is connected to the information acquisition processor. When the light source receiver does not receive a light signal, the control unit sends action information to the information acquisition processor.

[0012] Optionally, the on-load tap changer monitoring device further includes a voltage sensor, the two detection terminals of which are respectively connected to the two ends of the power electronic component, and the output terminal of the voltage sensor is connected to the information acquisition processor.

[0013] Optionally, the on-load tap changer monitoring device further includes a status monitoring display, which is connected to the information acquisition processor and is used to display action information and current information.

[0014] A second aspect of the present invention provides a method for monitoring on-load tap changers, applied to an on-load tap changer monitoring device as described in the first aspect of the present invention, comprising: acquiring the action information of the switching disconnector of the on-load tap changer and the current information of the power electronic components; determining whether the on-load tap changer is malfunctioning based on whether the interval between the start time of the action information and the start time of the current information, and / or whether the interval between the end time of the action information and the end time of the current information is less than a preset current over-limit protection threshold.

[0015] Optionally, determining whether an on-load tap changer is malfunctioning based on whether the interval between the start time of the action information and the start time of the current information, and / or whether the interval between the end time of the action information and the end time of the current information is less than a preset current over-limit protection threshold, includes: comparing whether the interval between the start time of the action information and the start time of the current information is less than a first over-limit protection threshold and a second over-limit protection threshold respectively; issuing a first-type abnormality warning when the interval between the start time of the action information and the start time of the current information is less than the first over-limit protection threshold; and issuing a first-type abnormality warning when the interval between the start time of the action information and the start time of the current information is less than the second over-limit protection threshold. When the protection threshold is exceeded, a second type of abnormal warning is issued, wherein the first over-limit protection threshold is greater than the second over-limit protection threshold; and / or, the interval between the end time of the action information and the end time of the current information is compared to whether it is less than the third over-limit protection threshold and the fourth over-limit protection threshold, wherein when the interval between the end time of the action information and the end time of the current information is less than the third over-limit protection threshold, a first type of abnormal warning is issued, and when the interval between the end time of the action information and the end time of the current information is less than the fourth over-limit protection threshold, a second type of abnormal warning is issued, wherein the third over-limit protection threshold is greater than the fourth over-limit protection threshold.

[0016] Optionally, the on-load tap changer monitoring method further includes: acquiring voltage information of power electronic components, and determining whether the on-load tap changer is malfunctioning based on whether the voltage information is greater than a preset overvoltage protection threshold.

[0017] A third aspect of the present invention provides an electronic device, including: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the on-load tap changer monitoring method as described in the second aspect of the present invention.

[0018] A fourth aspect of the present invention provides a computer-readable storage medium storing computer instructions for causing the computer to perform the on-load tap changer monitoring method as described in the second aspect of the present invention.

[0019] As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

[0020] This invention provides an on-load tap changer monitoring device, method, equipment, and storage medium. The device includes a position sensor, a current sensor, and an information acquisition processor. The position sensor is mounted on the transmission assembly of the on-load tap changer to detect the operation information of the switching switch. The current sensor is installed in the circuit of the power electronic components and the switching switch of the on-load tap changer to detect the current information of the power electronic components. The information acquisition processor is connected to both the position sensor and the current sensor to receive and output the operation and current information. This on-load tap changer monitoring device, by installing a position sensor on the transmission assembly and a current sensor in the circuit of the power electronic components and the switching switch, can monitor in real time the operation information of the switching switch and the current information of the power electronic components within a hybrid on-load tap changer (electric-mechanical hybrid). The installation positions are reasonable and facilitate monitoring of the internal information of the on-load tap changer. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the on-load tap changer monitoring device in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the power electronic-mechanical hybrid on-load tap changer in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the mechanical part of the hybrid on-load tap changer in an embodiment of the present invention;

[0025] Figure 4 for Figure 3 Enlarged view of section A in the middle;

[0026] Figure 5 This is a schematic diagram of the blocking component in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the switching switch in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the installation structure of the on-load tap changer monitoring device in another embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the topology of a hybrid on-load tap changer for power electronics and mechanical systems in another embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram showing the monitoring data under normal conditions in an embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram showing the monitoring data under scorching conditions in another embodiment of the present invention;

[0032] Figure 11 This is a flowchart of the on-load tap changer monitoring method in an embodiment of the present invention;

[0033] Figure 12 This is a schematic diagram of the structure of the electronic device in an embodiment of the present invention;

[0034] Figure 13 This is a schematic diagram of the structure of a computer-readable storage medium in an embodiment of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] This invention provides an on-load tap changer monitoring device, applicable to a hybrid power electronic-mechanical on-load tap changer, such as... Figure 1 As shown, the on-load tap changer monitoring device includes:

[0037] A position sensor 403 is mounted on the drive assembly of the on-load tap changer and is used to detect the operation information of the switching disconnector of the on-load tap changer. Specifically, the on-load tap changer monitoring device of this embodiment is used to monitor a hybrid power electronic-mechanical on-load tap changer. Figure 2 As shown, a hybrid power electronic-mechanical on-load tap changer comprises electronic and mechanical parts. The electronic part mainly includes power electronic components, while the mechanical part mainly includes the housing and the tap changer and switching switch inside the housing. The structure of the mechanical part is as follows: Figure 3As shown, the device includes a rotating shaft 1, a transmission assembly, a switching switch, and a housing 14. The left side of the rotating shaft 1 is connected to an external drive motor. To control the operation of the internal switching switch, the external motor drives the rotating shaft 1 at the bottom, storing energy in the internal spring. Once the spring reaches its energy storage capacity, it releases, driving the switching switch to operate. In this embodiment, the switching switch is connected to the transmission assembly via a gear set. When the switching switch operates, it drives the transmission assembly to rotate. The upper end of the transmission assembly extends out of the housing 14 of the mechanical part. A position sensor 403 is located on the part of the transmission assembly that extends out of the housing 14 to monitor the rotational information of the transmission assembly, thereby monitoring the operation information of the switching switch.

[0038] A current sensor 401 is installed in the circuit of the power electronic components and the switching circuit of the on-load tap changer to detect the current information of the power electronic components. Specifically, the current sensor is a Hall sensor, located in the circuit of the power electronic components and the switching circuit. Specifically, by using a high-voltage cable led out from the circuit of the power electronic components and the switching circuit through the transformer bushing, it is possible to install a Hall sensor and a high-potential voltage sensor in the lead-out circuit. The Hall current sensor 401 is used to monitor the operating current during the tap changer switching process.

[0039] The information acquisition processor 402 is connected to the position sensor 403 and the current sensor 401 respectively, and is used to receive action information and current information, and output the action information and current information. Specifically, the information acquisition processor 402 includes an A / D conversion module, an I / O acquisition module, an information processing module, and a power supply module. The A / D conversion module uses an A / D converter to receive the analog signal collected by the Hall sensor, convert it into a digital signal, and transmit it to the information processing module. The I / O acquisition module is an I / O port used to receive the action signal collected by the position sensor 403 and transmit it to the information processing module. For example, the information processing module uses an FPGA processor chip, model EP4CE6E22I7, to perform AD signal filtering algorithm and per-unit processing suitable for the characteristics of on-load tap changer applications, and I / O signal communication encoding processing. The AD signal filtering algorithm and per-unit processing, and I / O signal communication encoding processing are existing technologies and will not be described in detail here. After processing, the data is output in a digital encoding manner, for example, to a corresponding display screen for easy monitoring by management personnel. The power supply module includes a voltage conversion circuit, which provides the power required for the operation of the A / D conversion module, I / O acquisition module, and information processing module. For example, the operating power supply of the A / D conversion module, I / O acquisition module, and information processing module is 5V, 3.3V, and 1.2V, respectively. The voltage conversion circuit converts the mains power or battery voltage into operating voltages of 5V, 3.3V, and 1.2V, respectively.

[0040] After outputting action and current information, relevant personnel or intelligent judgment terminals can determine whether the switching switch is malfunctioning and trigger an alarm based on the timing of the action and current information. Specifically, for example... Figure 6 As shown, in a hybrid on-load tap changer, the switching switch includes a moving contact and a stationary contact. The moving contact has a specially designed copper-tungsten arc-inducing point. During normal operation of the hybrid on-load tap changer, current only flows through the power electronic components after the stationary and moving contacts are completely separated. Therefore, there is a certain interval between the start time of the power electronic component's action information and the start time of the current information. The action signal of the position sensor 403 precedes the start time of the current signal given by the current sensor 401. When the tap changer switches frequently, and the copper-tungsten arc-inducing point of the moving contact is eroded, the separation time between the moving and stationary contacts shortens, and the start time of the current signal from the power electronic components gradually advances. Therefore, a current over-limit protection threshold can be set. When the advance is less than the current over-limit protection threshold, it indicates that the copper-tungsten arc-inducing point of the moving contact is severely eroded and requires maintenance. For example, if the advance is within 10ms of the start time of the position sensor 403, a current abnormality alarm is issued. Meanwhile, due to the erosion of the copper-tungsten arc-ignition point of the moving contact, the closing time is delayed because the gap is increased and the current carrying time of the power electronic components is prolonged. The time interval between the current end time of the power electronic components and the action information end time of the position sensor 403 is also gradually reduced. Therefore, the time interval between the end time can be compared with the current over-limit protection threshold to determine whether the copper-tungsten arc-ignition point erosion has occurred. For example, when the time interval between the current end time of the power electronic components and the action information end time of the position sensor 403 is less than 10ms, an alarm will be triggered.

[0041] This invention provides an on-load tap changer monitoring device applied to a hybrid power electronic-mechanical on-load tap changer. It includes a position sensor 403, a current sensor 401, and an information acquisition processor 402. The position sensor 403 is mounted on the transmission assembly of the on-load tap changer to detect the operation information of the switching switch. The current sensor 401 is installed in the circuit of the power electronic components and the switching switch of the on-load tap changer to detect the current information of the power electronic components. The information acquisition processor 402 is connected to both the position sensor 403 and the current sensor 401 to receive and output the operation and current information. This on-load tap changer monitoring device, by installing the position sensor 403 on the transmission assembly and the current sensor 401 in the circuit of the power electronic components and the switching switch, can monitor the operation information of the switching switch and the current information of the power electronic components in the hybrid power electronic-mechanical on-load tap changer in real time. The installation positions are reasonable and facilitate monitoring of the internal information of the on-load tap changer.

[0042] In one embodiment, see Figure 3 , Figure 4 The transmission assembly includes a first transmission rod and a second transmission rod 4. The first transmission rod is disposed inside the on-load tap changer and connected to the switching knife switch. One end of the second transmission rod 4 is connected to the first transmission rod, and the other end extends out of the housing 14 of the on-load tap changer and is connected to the position sensor 403. The second transmission rod 4 and the housing 14 of the on-load tap changer are rotatably and sealingly connected. Specifically, the first transmission rod is rotatably mounted inside the on-load tap changer. Based on the internal structural requirements of the on-load tap changer, the first transmission rod includes a metal transmission rod 2 and an insulated transmission rod 3. One end of the metal transmission rod 2 is connected to the rotating shaft 1 and passes through the lower half of the on-load tap changer. The upper part of the on-load tap changer is its oil chamber. When passing through this part, the insulated transmission rod 3 is used. One end of the insulated transmission rod 3 is connected to the metal transmission rod 2, and the other end of the insulated transmission rod 3 is connected to the lower end of the second transmission rod 4. The upper end of the second transmission rod 4 extends outwards towards the outside of the on-load tap changer housing and is equipped with a position sensor 403. The second transmission rod 4 and the on-load tap changer housing 14 are connected by a bearing for rotational sealing. In this embodiment, by setting the second transmission rod 4 to install the position sensor 403, the position sensor 403 can detect the action information of the switching switch from outside the on-load tap changer. This is convenient to install and does not affect the operation of the on-load tap changer.

[0043] In one embodiment, see Figure 4 and Figure 5 The position sensor 403 includes a light source emitter 7, a light source receiver 8, and a blocking member 5. The blocking member 5 is connected to and coaxially rotates with the second transmission rod 4. The light source emitter 7 and the light source receiver 8 are respectively disposed on the upper and lower sides of the blocking member 5. The blocking member 5 has at least two light-transmitting holes 12. When the switching switch is closed, the light source emitter 7, the light-transmitting holes 12, and the light source receiver 8 form a light source path. The light source emitter 7 is used to emit light signals, and the light source receiver 8 is used to detect whether a light signal is received. Specifically, the blocking member 5 is disc-shaped with a fixing hole 13 at its center. The fixing hole 13 is used to engage with the second transmission rod 4. When the second transmission rod 4 rotates, the blocking member 5 rotates accordingly. The edge of the fixing hole 13 has four light-transmitting holes 12, which are evenly spaced at 90-degree intervals along the edge of the blocking member 5. By providing four light-transmitting holes 12, it avoids the possibility of misjudgment of action caused by obstruction due to some reason when there is only one light-transmitting hole.

[0044] The light source emitter 7 and the light source receiver 8 are fixed by the mounting bracket 6 on the top of the housing 14 and do not rotate with the second transmission rod 4. When the switch is closed, the light source emitter 7, the light-transmitting hole 12, and the light source receiver 8 are aligned along the light source path. The light emitted by the light source emitter 7 can pass through the light-transmitting hole 12, allowing the light source receiver 8 to receive the light signal. When the light source receiver 8 receives the light signal, it does not send an action signal to the information acquisition processor 402. When the switch rotates, it simultaneously drives the first and second transmission rods 4 to rotate, which in turn drives the blocking member 5 to rotate. At this time, the light-transmitting hole 12 of the blocking member 5 will deviate from the light source path. The blocking member 5 blocks the light emitted by the light source emitter 7, and the light source receiver 8 cannot receive the light signal, so it sends an action signal to the information acquisition processor 402. After the switch is completed, the next light-transmitting hole 12 is aligned with the light source path, the light source receiver 8 receives the light signal again, and stops sending action signals.

[0045] In one embodiment, the on-load tap changer monitoring device further includes a control unit. One end of the control unit is connected to the light source receiver 8, and the other end is connected to the information acquisition processor 402. When the light source receiver 8 does not receive a light signal, the control unit sends action information to the information acquisition processor 402. The control unit uses a microcontroller to process the information from the light source receiver 8. In other embodiments, a light source receiver 8 with an integrated control unit can be used, eliminating the need for an additional control unit.

[0046] In one embodiment, such as Figure 6 As shown, the on-load tap changer monitoring device also includes a voltage sensor. The two detection terminals of the voltage sensor are connected to both ends of the power electronic component, and the output terminal of the voltage sensor is connected to the information acquisition processor 402. Specifically, a high-potential voltage sensor is used. It can directly measure the electrical signal quantities during the tap changer switching operation. A high-voltage cable is led out from the transformer insulating bushings at both ends of the power electronic component of the on-load tap changer's electronic part and connected to the voltage sensor. The information acquisition processor 402 acquires the voltage signal of the power electronic component through the voltage sensor, sets the overvoltage protection value of the power electronic component according to system requirements, determines whether the switching process is normal based on the voltage signal of the power electronic component, and issues an overvoltage protection alarm or a transformer tripping request.

[0047] In one embodiment, the on-load tap changer monitoring device further includes a status monitoring display, which is connected to the information acquisition processor 402 and is used to display operation information and current information. In addition, the monitoring display is also used to display the voltage signal detected by the voltage sensor. Specifically, the monitoring display plots and displays operation curves, current curves, and voltage curves based on the voltage signal, operation information, and current information. It sets overvoltage protection thresholds and current over-limit protection thresholds according to system requirements. When an overvoltage condition occurs in the power electronic components, it issues an overvoltage alarm or a transformer trip request. When a power over-limit occurs in the power electronic components (i.e., the current lead time or the cutoff action time interval is less than the current over-limit protection threshold), it issues a tap changer contact erosion alarm or a transformer trip request.

[0048] Specifically, the topology diagram of the monitored mechanical-electric-electronic hybrid on-load tap changer in this embodiment is as follows: Figure 8 As shown, the switching switch can be equivalent to a first switch 100, a second switch 200, a third switch 300, and a fourth switch 400. The power electronic components include a first power electronic switch 701, a second power electronic switch 702, and a third power electronic switch 703. Specific operating curves, current curves, and voltage curves are shown below. Figure 9 and Figure 10 As shown. In Figure 9 and Figure 10 The waveforms shown are, from top to bottom, the voltage curve of the third power electronic switch 703, the current curve of the third power electronic switch 703, the voltage curve of the second power electronic switch 702, the current curve of the second power electronic switch 702, the voltage curve of the first power electronic switch 701, the current curve of the first power electronic switch 701, the operating curve of the first switch 100 disconnector, and the operating curve of the second switch 200 disconnector. Figure 9 The waveforms are those during normal operation, with the lead time of the current curves for the second switch 200 disconnector and the third power electronic switch 703 being 17ms.

[0049] When frequent switching of the disconnector leads to erosion of the copper-tungsten arc-ignition point of the contacts, the start time of the current curve of the power electronic switch gradually advances, and the advance amount gradually decreases. When the advance amount is less than 10ms, an alarm is triggered; when the advance amount is less than 2ms, a request is made for transformer tripping and maintenance. For example... Figure 10 The falling edge of the operating curve of the first switch 100 disconnector ( Figure 10 The time interval between the left-hand side (falling edge) and the right-hand side (rising edge) of the current curve of the first power electronic switch 701 and the starting moment is the corresponding lead time. Figure 10The 9ms lead time indicates severe erosion of the copper-tungsten arc-ignition point of the moving contact, triggering an alarm. Simultaneously, due to the erosion of the copper-tungsten arc-ignition point, the closing time is delayed because the gap widens, increasing the current-carrying time of the power electronic components. This leads to a decrease in the interval between the end time of the action information and the end time of the current information; in other words, the cutoff action interval also decreases with the erosion of the copper-tungsten arc-ignition point. When the interval between the end time of the current-carrying of the power electronic components and the end time of the action curve of the position sensor 403 is less than 10ms, for example... Figure 10 The interval between the rising edge of the action curve of the second switch 200 disconnector and the end of the current curve of the first power electronic switch 701 is the cut-off action time interval. When the cut-off action time interval is less than 10ms, an alarm is triggered. When the time interval between the current cut-off of the power electronic component and the cut-off action time of the position sensor 403 is less than 5ms, a request is made for transformer tripping and maintenance.

[0050] In addition, a high-potential voltage sensor is used to monitor the voltage across the power electronic components during on-load tap changer switching. During normal on-load tap changer switching, the withstand voltage waveform across the power electronic components is normal. Taking a ±800kV converter transformer as an example, the corresponding withstand voltage peak is determined based on its inter-stage voltage, operating current, and transition resistance. The withstand voltage peak during switching should not exceed 10kV. When an abnormality occurs during the switching process, such as a short circuit in the switching switch, the power electronic components withstand a voltage exceeding 10kV. Figure 10 When the voltage of the first power electronic switch 701, the second power electronic switch 702, or the third power electronic switch 703 exceeds 10kV, apply for transformer tripping and maintenance.

[0051] The working principle of the on-load tap changer monitoring device in this embodiment of the invention is as follows:

[0052] 1. Upon power-on, the information acquisition processor 402 resets and begins acquiring information from the Hall sensor and high-potential voltage sensor. The status monitoring display starts working and is in a standby state, awaiting the formal switching and recording of status information by the mechanical power electronic on-load tap changer.

[0053] 2. When the mechanical-electric-electronic hybrid on-load tap changer starts switching, the switching switch actuates, driving the first and second transmission rods 4 to rotate, which in turn rotates the blocking member 5. The blocking member 5 blocks the light signal, and the light source receiver 8 cannot receive the light signal. The control unit sends a switching start signal to the information acquisition processor 402. The information acquisition processor 402 sends the switching start signal to the status monitoring display. The status monitoring display starts the automatic trigger function and begins recording the voltage, action, and current information uploaded by the information acquisition processor 402 after the trigger time. When the switching switch actuates, the blocking member 5 rotates to its position, and the light source receiver 8 receives light again. The control unit sends a switching completion signal to the information acquisition processor 402. The information acquisition processor 402 sends the switching completion signal to the status monitoring display, and the display ends the switching record for this time.

[0054] 3. The status monitoring display plots voltage curves, action curves, and current curves based on the start and end times of the switching action recorded during the switching process, and based on the voltage information, action information, and current information uploaded by the information acquisition processor 402.

[0055] 4. Set overvoltage protection values ​​and current over-limit protection thresholds for power electronic components according to system requirements, and determine whether the switching process is normal. Use the voltage curve of the power electronic components to determine if the switching process is normal; if the voltage is too high, issue an overvoltage protection alarm or a transformer trip request. Set the current over-limit protection threshold according to system requirements, and use the current curve of the power electronic components and the mechanical disconnector's operating position information to determine if the switching process is normal; if an abnormality occurs, issue a contact erosion alarm or a transformer trip request.

[0056] 5. Wait for the next tap changer switch to switch, and repeat the previous judgment process.

[0057] This invention also provides an on-load tap changer monitoring method, applied to the on-load tap changer monitoring device as described in the above embodiments of this invention, such as... Figure 11 As shown, the method includes: step S100: obtaining the action information of the switching switch of the on-load tap changer and the current information of the power electronic components; step S200: determining whether the on-load tap changer is abnormal based on whether the interval between the start time of the action information and the start time of the current information, and / or whether the interval between the end time of the action information and the end time of the current information is greater than the preset current over-limit protection threshold.

[0058] Specifically, the action information of the switching switch and the current information of the power electronic components are obtained through the position sensor 403 and the current sensor 401. In the hybrid on-load tap changer, the switching switch includes a moving contact and a stationary contact. The moving contact has a specially designed copper-tungsten arc-ignition point. During normal operation of the hybrid on-load tap changer, because current only flows through the power electronic components after the stationary and moving contacts are completely separated, there is a certain interval between the start time of the action information of the power electronic components and the start time of the current information. The action signal of the position sensor 403 precedes the start time of the current signal given by the current sensor 401. When the tap changer switches frequently, and the copper-tungsten arc-ignition point of the moving contact is eroded, the separation time between the moving and stationary contacts will shorten as the arc-ignition point is eroded, and the start time of the current signal of the power electronic components will gradually advance. Therefore, a current over-limit protection threshold can be set. When the advance is less than the current over-limit protection threshold, it indicates that the copper-tungsten arc-ignition point of the moving contact is severely eroded and needs to be repaired. For example, if the current abnormality alarm is triggered within 10ms of the start time of the position sensor 403, an alarm will be issued. Simultaneously, due to the erosion of the copper-tungsten arc-ignition point of the moving contact, the closing time is delayed because the gap widens, increasing the current flow time of the power electronic components. The time interval between the current termination time of the power electronic components and the end time of the action information from the position sensor 403 also gradually decreases. Therefore, the time interval can be compared with the current over-limit protection threshold to determine whether an abnormality of copper-tungsten arc-ignition point erosion has occurred. For example, if the time interval between the current termination time of the power electronic components and the end time of the action information from the position sensor 403 is less than 10ms, an alarm will be triggered.

[0059] The on-load tap changer monitoring method of this invention utilizes the characteristic that the interval between the start time of the action information and the start time of the current information, as well as the interval between the end time of the action information and the end time of the current information, decreases as the degree of copper-tungsten arc ignition point erosion increases. By real-time monitoring of the action information of the switching knife switch and the current information of the power electronic components in the hybrid power electronic-mechanical on-load tap changer, and judging whether the on-load tap changer is abnormal based on whether the interval between the start time of the action information and the start time of the current information, and / or the interval between the end time of the action information and the end time of the current information is greater than a preset current over-limit protection threshold, it can determine whether the on-load tap changer is abnormal. It can monitor the operation of the on-load tap changer in real time without opening the on-load tap changer, providing a new approach to monitoring on-load tap changers. Moreover, the monitoring of action information and current information is convenient and does not affect the operation of the on-load tap changer.

[0060] In one embodiment, determining whether an on-load tap changer is malfunctioning based on whether the interval between the start time of the action information and the start time of the current information, and / or the interval between the end time of the action information and the end time of the current information is less than a preset current over-limit protection threshold, includes: comparing whether the interval between the start time of the action information and the start time of the current information is less than a first over-limit protection threshold and a second over-limit protection threshold, respectively; issuing a first type of abnormality warning when the interval between the start time of the action information and the start time of the current information is less than the first over-limit protection threshold, and issuing a second type of abnormality warning when the interval between the start time of the action information and the start time of the current information is less than the second over-limit protection threshold, wherein the first over-limit protection threshold is greater than the second over-limit protection threshold. For example, the first and second over-limit protection thresholds are set to 10ms and 2ms, respectively. When the interval between the start time of the action information and the start time of the current information is less than 10ms, a first type of abnormality warning is issued, which is a contact erosion alarm; when the interval between the start time of the action information and the start time of the current information is less than 2ms, a second type of abnormality warning is issued, which is a request for transformer tripping for maintenance.

[0061] And / or, compare the interval between the end time of the action information and the end time of the current information to see if it is less than the third over-limit protection threshold and the fourth over-limit protection threshold, respectively. When the interval between the end time of the action information and the end time of the current information is less than the third over-limit protection threshold, a first-class abnormal warning is issued; when the interval between the end time of the action information and the end time of the current information is less than the fourth over-limit protection threshold, a second-class abnormal warning is issued. The third over-limit protection threshold is greater than the fourth over-limit protection threshold. For example, the third and fourth over-limit protection thresholds are set to 10ms and 5ms, respectively. When the interval between the end time of the action information and the end time of the current information is less than 10ms, a first-class abnormal warning is issued, which is a contact erosion alarm; when the interval between the end time of the action information and the end time of the current information is less than 5ms, a second-class abnormal warning is issued, which is a request for transformer tripping for maintenance.

[0062] In one embodiment, the on-load tap changer monitoring method further includes: acquiring voltage information of power electronic components, and determining whether the on-load tap changer is malfunctioning based on whether the voltage information is greater than a preset overvoltage protection threshold. The method also determines whether a voltage exceeding the preset overvoltage protection threshold exists during the switching process based on the voltage information, and if such a voltage exceeds the preset overvoltage protection threshold, an overvoltage protection alarm or transformer tripping request is issued.

[0063] This invention also provides an electronic device, such as... Figure 12As shown, the system includes a memory 501 and a processor 502, which are interconnected. The memory 501 stores computer instructions, and the processor 502 executes these computer instructions to perform the steps in the on-load tap changer monitoring method of the above embodiments of the present invention. The processor 502 and the memory 501 can be connected via a bus or other means. The processor 502 can be a central processing unit (CPU). The processor 502 can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips. The memory 501, as a non-transitory computer storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs, and modules, such as the corresponding program instructions / modules in the embodiments of the present invention. The processor 502 executes various functional applications and data processing by running non-transitory software programs, instructions, and modules stored in the memory 501, thereby implementing the steps in the on-load tap changer monitoring method in the above method embodiments. The memory 501 may include a program storage area and a data storage area. The program storage area may store the application program required for operating the device and at least one function; the data storage area may store data created by the processor 502, etc. Furthermore, the memory 501 may include a high-speed random access memory 501, and may also include non-transitory memory 501, such as at least one disk storage device 501, a flash memory device, or other non-transitory solid-state memory 501. In some embodiments, the memory 501 may optionally include memory 501 remotely located relative to the processor 502, and these remote memories 501 can be connected to the processor 502 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. One or more modules are stored in the memory 501, and when executed by the processor 502, perform the steps in the on-load tap changer monitoring method as described in the above method embodiments. The specific details of the aforementioned electronic device can be understood by referring to the relevant descriptions and effects in the above method embodiments, and will not be repeated here.

[0064] This invention also provides a computer-readable storage medium, such as... Figure 13As shown, a computer program 601 is stored on the storage medium. When executed by a processor, this program implements the steps in the on-load tap changer monitoring method described in the above embodiments. The storage medium also stores audio and video stream data, feature frame data, interactive request signaling, encrypted data, and a preset data size. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory. Those skilled in the art will understand that all or part of the processes in the methods described in the above embodiments can be implemented by a computer program instructing related hardware. The computer program 13 can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memory.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A kind of on-load tap changer monitoring device, it is applied to electric power electronic mechanical hybrid on-load tap changer, it is characterized in that, include: A position sensor is installed on the drive assembly of the on-load tap changer to detect the action information of the switching knife switch of the on-load tap changer. A current sensor is installed in the circuit of the power electronic component of the on-load tap changer and the switching switch to detect the current information of the power electronic component. Current only flows through the power electronic component after the stationary contact and the moving contact are completely separated. An information acquisition processor, connected to both the position sensor and the current sensor, receives and outputs motion and current information. It compares the interval between the start time of the motion information and the start time of the current information to see if it is less than a first over-limit protection threshold and a second over-limit protection threshold, respectively. If the interval is less than the first over-limit protection threshold, a first-type abnormality warning is issued; if the interval is less than the second over-limit protection threshold, a second-type abnormality warning is issued. The first over-limit protection threshold is greater than... The second over-limit protection threshold; and / or, comparing whether the interval between the end time of the action information and the end time of the current information is less than the third over-limit protection threshold and the fourth over-limit protection threshold respectively. When the interval between the end time of the action information and the end time of the current information is less than the third over-limit protection threshold, a first type of abnormal warning is issued. When the interval between the end time of the action information and the end time of the current information is less than the fourth over-limit protection threshold, a second type of abnormal warning is issued. The third over-limit protection threshold is greater than the fourth over-limit protection threshold. The first type of abnormal warning is a contact erosion alarm, and the second type of abnormal warning is a request for transformer tripping maintenance. The transmission assembly includes a first transmission rod and a second transmission rod. The first transmission rod is disposed inside the on-load tap changer and connected to the switching knife switch. One end of the second transmission rod is connected to the first transmission rod, and the other end extends out of the housing of the on-load tap changer and is connected to the position sensor. The second transmission rod and the housing of the on-load tap changer are rotatably and sealingly connected.

2. The on-load tap changer monitoring device of claim 1, wherein, The position sensor includes a light source emitter, a light source receiver, and a blocking component. The blocking component is connected to and rotates coaxially with the second transmission rod. The light source emitter and the light source receiver are respectively disposed on the upper and lower sides of the blocking component. The blocking component has at least two light-transmitting holes. When the switching switch is closed, the light source emitter, the light-transmitting holes, and the light source receiver form a light source path. The light source emitter is used to emit light signals, and the light source receiver is used to detect whether a light signal is received.

3. The on-load tap changer monitoring device of claim 2, wherein, The blocking member has a fixing hole in the middle, and the blocking member is engaged with the second transmission rod through the fixing hole.

4. The on-load tap changer monitoring device according to claim 2, characterized in that, It also includes a control unit, one end of which is connected to the light source receiver and the other end of which is connected to the information acquisition processor. When the light source receiver does not receive a light signal, the control unit sends action information to the information acquisition processor.

5. The on-load tap changer monitoring device according to claim 1, characterized in that, It also includes a voltage sensor, the two detection terminals of which are respectively connected to the two ends of the power electronic component, and the output terminal of the voltage sensor is connected to the information acquisition processor.

6. The on-load tap changer monitoring device according to claim 1, characterized in that, It also includes a status monitoring display, which is connected to the information acquisition processor and is used to display action information and current information.

7. A method for monitoring on-load tap changers, applied to the on-load tap changer monitoring device as described in any one of claims 1 to 6, characterized in that, include: Obtain the operation information of the switching disconnector of the on-load tap changer and the current information of the power electronic components; The on-load tap changer is judged to determine whether an abnormality has occurred based on the interval between the start time of the action information and the start time of the current information, and / or whether the interval between the end time of the action information and the end time of the current information is less than a preset current over-limit protection threshold.

8. The on-load tap changer monitoring method according to claim 7, characterized in that, Also includes: Obtain the voltage information of the power electronic components, and determine whether the on-load tap changer is malfunctioning based on whether the voltage information is greater than a preset overvoltage protection threshold.

9. An electronic device, characterized in that, include: The system includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the on-load tap changer monitoring method as described in any one of claims 7 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a computer to perform the on-load tap changer monitoring method as described in any one of claims 7 to 8.

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