Remote gear shifting device for on-load tap-changer

Abstract

The invention relates to the field of transformer on-load tap-changers, and provides a transformer on-load tap-changer remote gear shifting device which is suitable for auxiliary gear shifting work of test items such as a power transformer direct-current resistance test, a transformation ratio test and an on-load tap-changer test. Comprising a conventional on-load tap-changer and further comprises a control chip electrically connected to a motor loop and a control loop in the on-load tap-changer. M bits in the control chip can be used as a plurality of hard buttons or HMI virtual buttons to be connected with input equipment; q bits in the control chip are a plurality of control interfaces and serve as output units, and a worker can change the running state of a corresponding relay on the Q bits by controlling input equipment of the M bits; a tester can remotely adjust the gear of the on-load tap-changer while operating the test instrument, test items such as a direct-current resistance test, a transformation ratio test and an on-load tap-changer test which need to change the gear of the tap-changer are independently completed, and manual gear adjustment is not needed.

Description

Technical Field

[0001] This invention relates to the field of on-load tap changers for transformers. As a remote tap changer adjustment device for on-load tap changers of transformers, it is suitable for auxiliary tap adjustment work in test items such as DC resistance test, turns ratio test, and on-load tap changer test of power transformers. Background Technology

[0002] In various transformer tests, tests such as DC resistance testing, turns ratio testing, on-load tap changer testing, and short-circuit impedance winding deformation testing require frequent tap position switching. To ensure test safety and efficiency, dedicated personnel are usually assigned to perform on-load tap changer switching. The switching process is typically stopped only after an employee discovers a problem using the emergency stop button. However, due to the limited capacity of on-site personnel, assigning dedicated personnel to adjust on-load tap changer positions can disrupt other tasks, reducing work efficiency and posing risks to personal safety and equipment.

[0003] Operating the on-load tap changer of a transformer is simple, requiring only the pressing of the up and down buttons on the electric mechanism, but still necessitates manual labor. Therefore, there is an urgent need to develop a remote tap changer switching device for transformers, allowing testing personnel to independently perform tap switching and test instrument operation, thus enabling more efficient allocation of on-site personnel and improving on-site work efficiency. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art and achieve the above-mentioned functions, the present invention provides a remote tap changer adjustment device for on-load tap changers.

[0005] This invention is achieved through the following technical solution: A remote adjustment device for an on-load tap changer includes a conventional on-load tap changer and a control chip electrically connected to the motor circuit and control circuit of the on-load tap changer. The M-position of the control chip can be used as several physical buttons or HMI virtual buttons to connect to input devices. The Q-position of the control chip is a number of control interfaces, serving as output units. Operators can change the operating state of the corresponding relays on the Q-position by controlling the input devices of the M-position. A relay a is provided between the common terminal 1L and the Q.0 interface in the control chip. A pair of normally open contacts S1 of the relay a are connected between two contacts of the on-load tap changer control circuit used for the upshift controller. A virtual button "upshift" is provided between the common terminal 1M and the M.0 interface on the M position as a control output. Q.0 is set as the output terminal of M.0. A relay b is provided between the common terminal 1L and the Q.1 interface in the control chip. A pair of normally open contacts S2 of the relay b are connected between two contacts of the downshift controller in the control circuit. A virtual button "downshift" is provided between the common terminal 1M of position M and the M.1 interface as a control output, and Q.1 is set as the output terminal of M.1. A virtual button, "Continuous Upshift Starter," is set between the common terminals 1M and M.2 of the M-position as a control output. Q.0 of the Q-position is set as the output of M.2. A virtual button, "Stop / Reset," is set between the common terminals 1M and M.5 as a control output. Q.3 of the Q-position is set as the output of M.5. Clicking the "Continuous Upshift" button enables the continuous upshifting function of the on-load tap changer, and clicking the "Stop / Reset" button stops the continuous upshifting. A virtual button, "Continuous Downshift Starter," is set between the common terminals 1M and M.3 of the M-position as a control output. Q.1 of the Q-position is set as the output of M.3. Clicking the "Continuous Downshift" button enables the continuous downshifting function of the on-load tap changer, and clicking the "Stop / Reset" button stops the continuous downshifting.

[0006] Furthermore, a virtual button "Set Gear" is set between the common terminal 1M and M.6 interfaces as a control output, setting Q.0 and Q.1 on the Q position as the output terminals of M.6 on the M position; by clicking the "Set Gear" button, the tap changer can be adjusted to the corresponding gear.

[0007] Furthermore, a virtual button "cycle shifting" is set between the common terminal 1M and the M.7 interface as a control output, and Q.0 and Q.1 on the Q position are set as the output terminals of M.7.

[0008] Furthermore, a relay c is provided between the common terminal 1L and the Q.2 interface in the control chip, and a pair of normally open contacts S5 of the relay c are connected between two contacts of the emergency stop controller in the control circuit. A virtual button "emergency stop controller" is provided between the common terminal 1M and the M.4 interface as a control output, and Q.2 is set as the output terminal of M.4.

[0009] The beneficial effects of this invention are: The transformer on-load tap changer remote control device is suitable for on-site testing personnel to independently adjust the on-load tap changer positions and perform tests on testing instruments. It mainly includes the following beneficial effects: 1. Test personnel can remotely adjust the on-load tap changer position while operating the test instrument, and independently complete test items that require changing the tap changer position, such as DC resistance test, transformation ratio test, and on-load tap changer test, without occupying manpower for position adjustment.

[0010] 2. When grinding the oxide film of the on-load tap changer and testing the short-circuit impedance of the winding deformation, continuous gear adjustment is required. The cyclic gear adjustment function can free up manpower and avoid mechanical repetitive work.

[0011] 3. The simulated on-load tap changer time relay function can temporarily replace the function of the on-load tap changer time relay when it fails, preventing the on-load tap changer from slipping. The time can be set according to the actual site conditions.

[0012] 4. The on-load tap changer position switching detection device is used to determine the operation of the on-load tap changer. Normally, employees judge the switching status by observing the on-load tap changer's operation and then manually press the emergency stop button to stop the switch. The on-load tap changer position switching detection device judges the status by detecting the motor current. If an abnormality is detected, it will stop the switching operation simultaneously with an audible and visual alarm, shortening the response time and improving the safety of the device.

[0013] 5. This invention uses a wireless communication remote control device, which has low requirements on the location of the test personnel. Attached Figure Description

[0014] Figure 1 Wiring diagram for CPU core chip; Figure 2 A schematic diagram of a human-computer interaction interface; Figure 3 This is the motor circuit diagram in an on-load tap changer; Figure 4 This is the control circuit diagram for an on-load tap changer; In the picture: 1. Control chip, 2. Relay a, 3. Relay b, 4. Relay c. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0016] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0017] Figure 3 and Figure 4In China, symbols such as "K for contactor, M for motor" are electrical standard symbols, and Figure 3 and Figure 4 This is familiar to those working in the fields of on-load tap changer electrical circuits, transformers, and electromechanical equipment. For details, please refer to the electrical schematic diagram of the CMA7 type on-load tap changer, so there is no need to elaborate further.

[0018] In the prior art, the on-load tap changer consists of a motor circuit ( Figure 3 ) and control loop ( Figure 4 Composed of two parts, the on-load tap changer can be controlled by adjusting the upshift and downshift switches. Taking upshifting as an example, the operation is as follows: Pressing button S1 energizes the K1 coil. Simultaneously, the normally open contact of contactor K1 closes, energizing the brake contactor K3 coil. This closes the main contacts of relays K1 and K3, starting motor M1. At the same time, the coil of the sliding protection time relay K21 is energized and begins its delayed operation. Furthermore, it can be seen that the normally closed contact of button S1 and the normally closed contact of contactor K1 cuts off the excitation circuit of contactor K2 coil, thus achieving electrical interlocking. After the motor starts running, the progressive position display panel rotates out of the green zone, and the cam limit switch S14 closes first. At this time, the contactor K1 coil can also be powered by S14, forming a mechanically self-holding energized circuit with the K1 coil energized. When the progressive position display panel of the electric mechanism rotates one more division, cam switch S13 actuates, closing to energize the coil of intermediate relay K20. This causes the normally closed contact of K20 to open, cutting off the electrical self-holding circuit of relay K1. Thus, contactor K1 coil can only be powered through S14. Simultaneously, the normally open contact of relay K20 closes, forming an electrical self-holding circuit for K20 coil as well. When the motor reaches the 30.5th division, S13 opens, cutting off the mechanical self-holding circuit of K20 coil. K20 coil can only be energized and engaged through the electrical self-holding circuit of normally open contacts K3 and K20. When the first-stage tap changer operation is completed, cam switch S14 opens, contactor K1 coil de-energizes and releases, the normally open contact of contactor K1 opens, contactor K3 coil de-energizes and releases, disconnecting the motor main circuit, and motor M1 stops running.

[0019] As described above, in the existing technology, the on-load tap changer switching is a purely mechanical process, mainly relying on the energization of the K3 coil to activate the motor M for shifting. S1 and S2, as shifting switches, do not affect the operation process. Therefore, as long as it can be remotely controlled... Figure 4 When S1 and S2 are energized, remote tap position control of the on-load tap changer can be achieved.

[0020] The connection method and control logic in this embodiment are as follows: 1. The on-load tap changer can be upgraded by clicking the "Upgrade" button in the HMI.

[0021] Regarding device connections, connect relay a2 to... Figure 1 Between the common terminal 1L and Q.0 interface, and connect the pair of normally open contacts of relay a2 to the two contacts of the on-load tap changer control circuit used for the upshift controller (i.e. Figure 4 In the middle, S1 between 3 and 4). A virtual button "upgrade" is set between the common terminal 1M and the M.0 interface as the control output. Q.0 is set as the output terminal of M.0. That is, when the "upgrade" button is clicked, the relay a2 between the common terminal 1L and the Q.0 interface is energized and closed, the normally open contact is closed, and the above-mentioned S1 is energized to start the on-load tap changer upgrade procedure.

[0022] 2. The on-load tap changer can be downgraded by clicking the "Downgrade" button in the HMI.

[0023] Regarding device connections, connect relay b3 to... Figure 1 Between the common terminal 1L and Q.1 interface, and connect a pair of normally open contacts of the relay between the two contacts of the downshift controller in the control circuit (i.e. Figure 4 In the middle, S2 between 3 and 4). A virtual button "Upgrade" is set between the common terminal 1M and the M.1 interface as a control output. Q.1 is set as the output terminal of M.1. That is, when the "Downgrade" button is clicked, the relay b3 between the common terminal 1L and the Q.1 interface is energized and closed, the normally open contact is closed, the above-mentioned S2 is energized, and the on-load tap changer downgrade procedure is started.

[0024] 3. Clicking the "Continuous Upgrade" button enables the continuous upgrade function of the on-load tap changer. The upgrade number can be entered in the "Continuous Up / Down Grade Number Input" box. Clicking the "Stop / Reset" button will stop the continuous upgrade.

[0025] Regarding device connectivity, a connection method with upshift functionality is adopted. Furthermore, a virtual button, "Continuous Upshift Starter," is set as a control output between the common 1M and M.2 interfaces. Q.0 is set as the output of M.2, and the variable "Continuous Upshift / Downshift Input Value" is set and associated with the HMI's "Continuous Upshift / Downshift Digit Input" box. A virtual button, "Stop / Reset," is set as a control output between the common 1M and M.5 interfaces, and Q.3 is set as the output of M.5.

[0026] The program control logic is programmed as follows: Enter the number of consecutive upshifts in the "Continuous Upshift / Downshift Digit Input" box on the HMI. After clicking the "Continuous Upshift Initiator" virtual button, a numerical comparison is performed. When the "Continuous Upshift Counter" value is less than the input value, the "Continuous Upshift Initiator" is activated, and an upshift occurs after a 7-second delay. At this time, the "Continuous Upshift Counter" value is incremented by 1. After each upshift, a second comparison is performed, until the "Continuous Upshift Counter" count is greater than or equal to the input value, at which point the operation stops. During continuous upshifting, the input value can be set to 0 by clicking the "Stop / Reset" virtual button, stopping continuous upshifting in the next comparison round.

[0027] The reason for setting a delayed start is that the on-load tap changer's shifting action time is approximately 5.5 seconds, and it is not advisable to connect S1 (i.e., ...) during the start-up period. Figure 4 In the middle, S1 and S2 (i.e., between 3 and 4) Figure 4 In the middle, S2 between 3 and 4), so it is set to start every 7 seconds. The specific value can be modified according to the actual situation on site.

[0028] 4. Clicking the "Continuous Downshift" button enables the continuous downshift function of the on-load tap changer. The downshift number is the value entered in the "Continuous Up / Downshift Number Input" box. Clicking the "Stop / Reset" button will stop the continuous downshift.

[0029] Regarding device connectivity, a downshifting function is used. A virtual button, "Continuous Upshift Starter," is configured as a control output between the common 1M and M.3 interfaces. Q.1 is set as the output of M.3, and the variable "Continuous Upshift / Downshift Input Value" is set and associated with the HMI's "Continuous Upshift / Downshift Digit Input" box. A virtual button, "Stop / Reset," is configured as a control output between the common 1M and M.5 interfaces, with Q.3 set as the output of M.5.

[0030] The program control logic is programmed as follows: Enter the number of consecutive downshifts in the "Continuous Up / Downshift Digit Input" box on the HMI. After clicking the "Continuous Downshift Initiator" virtual button, a numerical comparison is performed. When the "Continuous Downshift Counter" variable is less than the input value, the "Continuous Downshift Initiator" is activated, and a downshift is performed after a 7-second delay. At this time, the "Continuous Downshift Counter" value is incremented by 1. After each downshift, a second comparison is performed, until the "Continuous Downshift Counter" count is greater than or equal to the input value, at which point the action stops. During continuous downshifting, the input value can be set to 0 by clicking the "Stop / Reset" virtual button, stopping continuous upshifting in the next comparison round.

[0031] 5. By clicking the "Set Gear" button, you can adjust the tap changer to the corresponding gear. Enter the desired gear in the "Set Gear" box.

[0032] Regarding device connectivity, a connection method with upshift and downshift functions is adopted. Furthermore, a virtual button "Set Gear / Adjust Gear" is set as a control output between the common 1M and M.6 interfaces, with Q.0 and Q.1 set as outputs of M.6, and a variable "Set Gear / Adjust Gear Position" is set and associated with the HMI's "Set Gear / Adjust Gear Position" box. A virtual button "Stop / Reset" is set as a control output between the common 1M and M.5 interfaces, with Q.3 set as an output of M.5.

[0033] The program control logic is programmed as follows: A value is assigned to the variable "Gear Position" via the HMI "Gear Setting" box. After clicking the virtual "Gear Setting" button, the value is compared with the current gear. If the value is positive, its absolute value is assigned to the "Continuous Up / Down Gear Number Input" and the continuous upshifting function is activated. If the value is negative, its absolute value is assigned to the "Continuous Up / Down Gear Number Input" and the continuous downshifting function is activated. If the value is 0, nothing happens. These two functions complete the gear switching process, as described above.

[0034] 6. By clicking the "Cyclic Up / Down Tap" button, the on-load tap changer can be cyclically switched from the lowest to the highest tap. The number of taps of the current transformer can be entered in "On-load tap changer tap position".

[0035] Regarding device connectivity, a connection method with upshift and downshift functions is adopted. Furthermore, a virtual button for "gear setting / adjustment" is installed between the common 1M and M.7 interfaces as a control output, and Q.0 and Q.1 are set as output terminals of M.7.

[0036] The program control logic is programmed as follows: Enter the current transformer tap number in the "On-Load Tap Changer Tap Position Number" box. After clicking the "Cyclic Up / Down Tap Position" virtual button, compare the transformer tap number with the current position. If the current position is not equal to the transformer tap number, activate the up-tapping function. Cycle until the current position matches the transformer tap number, then activate the down-tapping function. If the current position equals the transformer tap number, activate the down-tapping function. Cyclicly until the current position is 1, then activate the up-tapping function again, thus achieving cyclic switching between the maximum and minimum tap positions.

[0037] 7. Simulates the time relay function of on-load tap changer. The emergency stop time of the time relay can be set in the HMI "Time Relay Time Setting". It is mainly used for anti-slip function when the on-load tap changer body time relay fails.

[0038] Regarding device connections, connect relay C4 to... Figure 1 Between the common terminal 1L and Q.2 interface, and connect the pair of normally open contacts of relay C4 to the two contacts of the emergency stop controller in the control circuit (i.e. Figure 4(At position Q (C1-C2)). Furthermore, set the variable "Time Relay Value" and associate it with the HMI "Time Relay Time Setting" input box. After setting the time relay time, press the "Upshift Controller" / "Downshift Controller" virtual button to start the timer. Once the set time is reached, relay C4 is energized for an emergency stop.

[0039] 8. Clicking the "Emergency Stop" button can interrupt the current action and achieve an emergency stop of the on-load tap changer.

[0040] Regarding device connections, connect relay C4 to... Figure 1 Between the common terminal 1L and Q.2 interface, and connect a pair of normally open contacts of the relay between the two contacts of the emergency stop controller in the control circuit (i.e. Figure 4 (At position Q (C1-C2)). Furthermore, a virtual button "Emergency Stop Controller" is set between the common terminal 1M and the M.4 interface as the control output. Q.2 is set as the output terminal of M.4. That is, when the virtual button is pressed, the relay C4 is energized, the normally open contact closes, the two ends of the relay C4 are energized, and the current on-load tap changer operation is interrupted.

[0041] The human-computer interaction interface can achieve the following functions through virtual buttons: 1. The on-load tap changer can be upgraded by clicking the "Upgrade" button in the HMI.

[0042] 2. The on-load tap changer can be downgraded by clicking the "Downgrade" button in the HMI.

[0043] 3. Clicking the "Continuous Upgrade" button enables the continuous upgrade function of the on-load tap changer. The upgrade number is the value entered in the "Continuous Up / Down Grade Number Input" box. Clicking the "Stop / Reset" button will stop the continuous upgrade.

[0044] 4. Clicking the "Continuous Downshift" button enables the continuous downshift function of the on-load tap changer. The downshift number is the value entered in the "Continuous Up / Downshift Number Input" box. Clicking the "Stop / Reset" button will stop the continuous downshift.

[0045] 5. By clicking the "Set Gear" button, you can adjust the tap changer to the corresponding gear. Enter the desired gear in the "Set Gear" box.

[0046] 6. By clicking the "Cyclic Up / Down Tap" button, the on-load tap changer can be cyclically switched from the lowest to the highest tap. The number of taps of the current transformer can be entered in "On-load tap changer tap position".

[0047] 7. Simulates the time relay function of on-load tap changer. The emergency stop time of the time relay can be set in the HMI "Time Relay Time Setting". It is mainly used for anti-slip function when the on-load tap changer body time relay fails.

[0048] 8. Clicking the "Emergency Stop" button can interrupt the current action and achieve an emergency stop of the on-load tap changer.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A remote tap changer adjustment device for on-load tap changers, comprising a conventional on-load tap changer, characterized in that: It also includes a control chip (1) electrically connected to the motor circuit and control circuit of the on-load tap changer; the M position of the control chip (1) can be used as several hard buttons or HMI virtual buttons to connect input devices; the Q position of the control chip (1) is several control interfaces, which serve as output units, and the operator can change the operating state of the corresponding relay on the Q position by controlling the input device of the M position; A relay a (2) is provided between the common terminal 1L and the Q.0 interface in the control chip (1). A pair of normally open contacts S1 of the relay a (2) are connected between two contacts of the on-load tap changer control circuit used for the upshift controller. A virtual button "upshift" is provided between the common terminal 1M and the M.0 interface on the M position as the control output. Q.0 is set as the output terminal of M.

0. A relay b (3) is provided between the common terminal 1L and the Q.1 interface in the control chip (1). A pair of normally open contacts S2 of the relay b (3) are connected between two contacts of the downshift controller in the control circuit. A virtual button "downshift" is set between the common terminal 1M of the M position and the M.1 interface as a control output, and Q.1 is set as the output terminal of M.

1. A virtual button "Continuous Upshift Starter" is set between the common terminal 1M and the M.2 interface of the M position as a control output. Q.0 of the Q position is set as the output terminal of M.

2. A virtual button "Stop / Reset" is set between the common terminal 1M and the M.5 interface as a control output. Q.3 of the Q position is set as the output terminal of M.

5. Clicking the "Continuous Upshift" button enables the continuous upshift function of the on-load tap changer. Clicking the "Stop / Reset" button stops the continuous upshift. A virtual button "Continuous Downshift Starter" is set between the common terminal 1M and the M.3 interface of the M position as the control output. The Q.1 of the Q position is set as the output terminal of M.

3. The continuous downshift function of the on-load tap changer can be realized by clicking the "Continuous Downshift" button, and the continuous downshift can be stopped by clicking the "Stop / Reset" button.

2. The on-load tap changer remote adjustment device according to claim 1, characterized in that: A virtual button "Set Gear" is set between the common terminal 1M and M.6 interfaces as a control output, setting Q.0 and Q.1 on the Q position as the output terminals of M6 on the M position; by clicking the "Set Gear" button, the tap changer can be adjusted to the corresponding gear.

3. The on-load tap changer remote adjustment device according to claim 1, characterized in that: A virtual button "Cyclic Up / Down Gears" is set between the common terminal 1M and the M.7 interface as a control output, and Q.0 and Q.1 on the Q position are set as the output terminals of M.

7.

4. The on-load tap changer remote adjustment device according to claim 1, characterized in that: A relay c (4) is provided between the common terminal 1L and the Q.2 interface in the control chip (1), and a pair of normally open contacts S5 of the relay c (4) are connected between the two contacts of the emergency stop controller on the control circuit. A virtual button "emergency stop controller" is set between the common terminal 1M and the M.4 interface as the control output, and Q.2 is set as the output terminal of M.4.

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