On-load tap changer coordination control system and method for transformer variable turn ratio regulation

Abstract

The application is suitable for the technical field of on-load tap coordination control, and provides an on-load tap coordination control system and method for transformer turn ratio adjustment, which comprises a mechanical execution unit, a fixedly installed insulation cylinder, a driving unit, an intelligent control unit and an oil circuit cooling unit. The mechanical execution unit comprises a first main shaft structure, a second main shaft structure and an isolation ring coaxially arranged between the first main shaft structure and the second main shaft structure. The fixedly installed insulation cylinder is provided with a plurality of tap changers. The driving unit comprises a first driving chain and a second driving chain. The intelligent control unit is electrically connected with the driving unit and the oil circuit cooling unit, and is internally provided with a coordinated control algorithm, a two-dimensional voltage regulation mapping model and three dynamic control modes. The system adopts the two-dimensional voltage regulation mapping model to construct rich gear combinations and expand the number of gear combinations, so as to realize fine voltage regulation and rapid turn ratio adjustment, improve voltage stability precision and better adapt to complex load fluctuation scenarios.

Description

Technical Field

[0001] This invention relates to the field of on-load tap changer coordination control technology, and more specifically, to an on-load tap changer coordination control system and method for transformer turns ratio adjustment. Background Technology

[0002] On-load tap changers are the core devices for adjusting the turns ratio and stabilizing the output voltage of transformers. Traditional on-load tap changers mostly adopt a single-spindle, single-contact assembly design. A drive chain drives the moving contact to contact the tap on the insulating cylinder, thereby changing the turns ratio of the winding to achieve voltage regulation.

[0003] However, the number of tap positions in a single-path voltage regulator is limited, making it impossible to achieve precise voltage adjustment. It lacks flexibility in responding to complex load fluctuations, and the voltage stability accuracy is difficult to improve. At the same time, a single contact assembly bears the voltage regulation operation task for a long time, and the high frequency of tap switching will cause local overheating of the contacts and accelerate the wear rate, resulting in a shortened overall service life of the switch and high equipment maintenance costs. Therefore, an on-load tap changer coordinated control system and method for transformer turns ratio regulation is proposed to improve the existing problems. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an on-load tap changer coordinated control system and method for transformer turns ratio adjustment.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The on-load tap changer coordination control system for transformer turns ratio adjustment includes: a mechanical actuator, a fixedly installed insulating cylinder, a drive unit, an intelligent control unit, and an oil cooling unit.

[0006] The mechanical actuator includes a first spindle structure, a second spindle structure, and an isolation ring coaxially disposed between the first spindle structure and the second spindle structure. A first moving contact assembly is mounted on the first spindle structure, and a second moving contact assembly is mounted on the second spindle structure.

[0007] A fixedly installed insulating cylinder is provided with a multi-component connector. The first moving contact assembly and the second moving contact assembly are respectively provided with contacts that are compatible with the corresponding taps and make electrical contact, forming two independent voltage regulating paths.

[0008] The drive unit includes a first drive chain and a second drive chain, which are two independent drive mechanisms.

[0009] The oil cooling unit is used for volume compensation of insulating oil, active circulation heat dissipation, and maintenance of insulation performance.

[0010] The intelligent control unit is electrically connected to the drive unit and oil circuit cooling unit, and has built-in collaborative control algorithm, two-dimensional voltage regulation mapping model, and three dynamic control modes: fine-tuning mode, contact equalization mode, and tracking mode.

[0011] The present invention is further configured such that: the first drive chain and the second drive chain are respectively used to drive the first spindle structure and the second spindle structure, so as to realize the independent rotation and coordinated linkage of the first spindle structure and the second spindle structure.

[0012] The first drive chain is provided with a first mating block, and the second drive chain is provided with a second mating block. The first mating block is connected to the first main shaft structure in a transmission connection, and the second mating block is connected to the second main shaft structure in a transmission connection.

[0013] The first spindle structure includes a first spindle body and a first meshing block fixed to its end. The second spindle structure includes a second spindle body, a connecting pipe, and a second meshing block fixed to the end of the connecting pipe. The first meshing block and the first mating block are coupled by a three-tooth gear and a toothed groove insertion meshing method. The second meshing block and the second mating block are coupled by a three-tooth gear and a toothed groove insertion meshing method.

[0014] The isolation ring is fixed between the mating surfaces of the first spindle body and the second spindle body.

[0015] The present invention is further configured such that: a sucker rod is coaxially disposed inside the second main shaft structure, and a mechanical seal structure is provided between the sucker rod and the second main shaft structure; the sucker rod is fixed relative to the second main shaft structure and does not rotate with it.

[0016] The first spindle body is coaxially sleeved on the outside of the connecting tube via a bearing, and the first spindle body and the connecting tube can rotate relative to each other.

[0017] The oil cooling unit is in sealed connection with the sucker rod.

[0018] The present invention is further configured such that the intelligent control unit includes: an information processing module, a prediction module, a decision-making module, and a synchronization control module.

[0019] The signal processing module is used to calculate the real-time voltage deviation based on the real-time acquired voltage signal and the preset voltage setting value.

[0020] The prediction module is used to predict voltage change trends and voltage deviations based on historical operating data, and to trigger preventive voltage regulation when the predicted voltage deviation exceeds a preset threshold.

[0021] The decision module is used to dynamically select between fine-tuning mode, tracking mode, and contact balancing mode based on the real-time voltage deviation and the candidate gear combination information calculated by calling the two-dimensional voltage regulation mapping model, and generate corresponding drive commands.

[0022] The synchronous control module is used to synchronously send control signals to the oil circuit cooling unit when generating the pressure regulation command.

[0023] The present invention is further configured such that: the two-dimensional voltage regulation mapping model is a discrete mapping function, and the expression of the discrete mapping function is: Where K is the real-time transformer ratio, i is the gear index of the first moving contact assembly corresponding to the first main shaft structure (1), and j is the gear index of the second moving contact assembly corresponding to the second main shaft structure (2).

[0024] The two-dimensional voltage regulation mapping model was obtained through multi-condition experimental calibration and stored in the memory of the intelligent control unit in the form of a lookup table.

[0025] The present invention is further configured such that the trigger condition for the fine-tuning mode is: |real-time voltage deviation| < fine-tuning threshold. In this mode, the intelligent control unit selects from the candidate gear combinations a combination that requires adjustment of only a single spindle in the first spindle structure or the second spindle structure. If multiple such combinations exist, the combination with the smallest increase in the overall workload of the contacts is selected for execution.

[0026] The triggering condition for the contact equalization mode is: the fine-tuning threshold ≤ |real-time voltage deviation| ≤ tracking threshold, and the number of candidate gear combinations calculated based on the two-dimensional voltage regulation mapping model is greater than one. In this mode, the intelligent control unit selects the combination with the smallest total cumulative workload of the involved contacts from multiple candidate gear combinations as the target gear combination to be executed.

[0027] The trigger condition for the tracking mode is: |Real-time voltage deviation| When tracking the threshold, in this mode, the target gear combination is selected according to a preset rapid adjustment strategy. The rapid adjustment strategy prioritizes the combination with the shortest estimated adjustment time. The intelligent control unit controls the drive unit to drive the first and second spindle structures synchronously to switch to the target gear combination.

[0028] If the triggering conditions of multiple modes are met simultaneously, the decision will be made according to the following hierarchy: tracking mode takes precedence over touch balance mode, and touch balance mode takes precedence over fine-tuning mode.

[0029] The present invention is further configured such that: the cumulative workload is quantified and statistically analyzed by the status table maintained by the intelligent control unit for each contact point. The status table records the cumulative number of operations, cumulative current carrying time, and peak load current of a single operation for the corresponding contact point, and calculates the comprehensive workload value of the contact point using a weighted algorithm based on the preset weight of the contact point material.

[0030] A method for an on-load tap changer coordination control system for transformer turns ratio regulation, using the on-load tap changer coordination control system for transformer turns ratio regulation as described above, includes the following steps: S1. Real-time acquisition of transformer output voltage signal, combined with preset voltage setting value, to calculate real-time voltage deviation.

[0031] S2. Call up historical operating data to predict voltage change trends and voltage deviations.

[0032] S3. Based on the target voltage to be achieved, call the pre-stored two-dimensional voltage regulation mapping model to calculate the candidate gear combination that meets the requirements.

[0033] S4. Compare the real-time voltage deviation with the preset fine-tuning threshold, equalization threshold, and tracking threshold.

[0034] S5. Based on the threshold comparison results and the number of candidate gear combinations, dynamically select and execute one of the following control strategies: fine-tuning mode, tracking mode, and contact point balancing mode.

[0035] S6. Generate drive instructions corresponding to the selected strategy, control the first spindle structure and the second spindle structure to perform coordinated pressure regulation actions, and synchronously control the oil circuit cooling unit.

[0036] S7. Update system status records.

[0037] The present invention is further configured such that: in step S5, when the intelligent control unit selects to enter the fine-tuning mode according to the threshold comparison result, the intelligent control unit calculates the incremental comprehensive workload of the contacts involved in the candidate gear combination based on the contact status table, and selects the gear combination with the smallest incremental comprehensive workload of the contacts for execution.

[0038] When the system selects to enter the contact balancing mode based on the threshold comparison result, the intelligent control unit queries the contact status table to obtain the total cumulative workload of the contacts involved in the candidate gear combination, and selects the gear combination with the smallest total cumulative workload of the contacts to execute.

[0039] The contact status table is updated in real time after each voltage regulation action, recording the cumulative number of operations and cumulative current carrying time of each contact, and using a weighted algorithm to calculate the comprehensive workload value. The weighting coefficient is preset according to the contact material and working characteristics.

[0040] The present invention is further configured such that: the two-dimensional voltage regulation mapping model is obtained through multi-condition experimental calibration, covering the correspondence between the transformer ratio and the gear position under different loads and different ambient temperatures, stored in the form of an encrypted lookup table, and supports dynamic correction and update based on real-time operating data.

[0041] In summary, this application includes at least one of the following beneficial technical effects: (1) This system adopts a dual-spindle structure with dual-moving contact components to form two independent voltage regulation paths on the insulating cylinder. It also constructs a rich range of voltage regulation combinations by combining a two-dimensional voltage regulation mapping model. Compared with the limited range of traditional single-spindle single-path, this solution expands the number of range combinations, realizes fine voltage regulation and rapid adjustment of turns ratio, improves voltage stability accuracy, and can better adapt to complex load fluctuation scenarios.

[0042] (2) Based on the voltage deviation threshold, three control modes are divided: fine adjustment, contact equalization and tracking. Clear priority decision logic is set. For small deviation scenarios, a single-axis fine adjustment strategy is adopted; for medium deviation scenarios, a contact load equalization strategy is adopted; and for large deviation scenarios, a dual-axis synchronous linkage fast adjustment strategy is adopted. The optimal voltage regulation path can be selected as needed to improve the flexibility and timeliness of voltage regulation response.

[0043] (3) The contact status table is maintained by the intelligent control unit, the cumulative number of contact operations, current carrying time and current peak are quantitatively counted, and the weighted algorithm is used to calculate the comprehensive workload. In the contact balancing mode, the system prioritizes the combination of gears with the smallest total load to perform voltage regulation, reducing the possibility of local overheating caused by long-term high-frequency operation of a single contact, balancing the contact workload, reducing the contact wear rate, and extending the service life of the equipment. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of the on-load tap changer coordinated control system for transformer turns ratio adjustment in this invention.

[0045] Figure 2 for Figure 1 A magnified structural diagram of area A in the middle.

[0046] Figure 3 This is a schematic diagram of the cooperation structure between the first spindle structure and the second spindle structure in this invention.

[0047] Figure 4 for Figure 3 A magnified structural diagram of area B in the middle.

[0048] Figure 5 This is a flowchart of the on-load tap changer coordination control system for transformer turns ratio adjustment in this invention.

[0049] Figure 6This is a block diagram of the intelligent control unit in this invention.

[0050] Figure 7 This is a flowchart of the intelligent control unit in this invention.

[0051] Explanation of reference numerals in the attached drawings: 1. First spindle structure; 2. Second spindle structure; 3. First drive chain; 4. Second drive chain; 5. First mating block; 6. First meshing block; 7. Isolation ring; 8. Second mating block; 9. Second meshing block. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0054] Please see Figures 1-7 The present invention provides the following technical solutions: Example 1: The on-load tap changer coordination control system for transformer turns ratio adjustment includes: a mechanical actuator, a fixedly installed insulating cylinder, a drive unit, and an intelligent control unit.

[0055] This system forms two independent voltage regulation paths on the insulating cylinder by setting up two independent spindle structures and moving contact assemblies. The two independent drive chains of the drive unit can drive the corresponding spindle structures through their mating blocks to achieve independent, synchronous, or coordinated rotational movements, thereby changing the contact position between the moving contact assembly and the tap on the insulating cylinder to adjust the transformer turns ratio. The intelligent control unit coordinates the actions of the drive unit according to algorithms and models, and simultaneously manages the operation of the oil cooling unit, so that the performance of the insulating oil remains stable during voltage regulation. Its core lies in providing more flexible and reliable gear adjustment capabilities through the coordination of the two mechanical actuators.

[0056] See Figure 3 The specific structure of the mechanical actuator is as follows: The mechanical actuator includes a first spindle structure 1, a second spindle structure 2, and an isolation ring 7 coaxially disposed between the first spindle structure 1 and the second spindle structure 2; a first moving contact assembly is mounted on the first spindle structure 1, and a second moving contact assembly is mounted on the second spindle structure 2.

[0057] See Figure 4The first spindle structure 1 includes a first spindle body and a first engagement block 6 fixed to its end. The second spindle structure 2 includes a second spindle body, a connecting pipe and a second engagement block 9 fixed to the end of the connecting pipe. The isolation ring 7 is fixed between the mating surfaces of the first spindle body and the second spindle body.

[0058] The insulating cylinder is fixedly installed and has multiple component connectors. The first moving contact assembly and the second moving contact assembly are respectively provided with contacts that are compatible with the corresponding taps and make electrical contact, forming two independent voltage regulating paths.

[0059] The insulating cylinder is fixedly installed on the inner wall of the transformer tank. Multiple sets of taps are distributed along the circumference of the cylinder wall. The contacts of the first moving contact assembly and the second moving contact assembly can rotate with their respective main shafts and selectively contact the taps in the corresponding areas, thereby forming two parallel and insulated voltage regulating paths.

[0060] See Figure 1 The specific structure of the drive unit is as follows: The drive unit includes a first drive chain 3 and a second drive chain 4, which are two independent drive mechanisms.

[0061] The first drive chain 3 and the second drive chain 4 are both equipped with drive motors and transmission structures. The two sets of drive motors and transmission structures are mounted on a layered mounting frame, which provides installation space for the first drive chain 3 and the second drive chain 4.

[0062] The first drive chain 3 and the second drive chain 4 are used to drive the first spindle structure 1 and the second spindle structure 2 respectively, so as to realize the independent rotation and coordinated linkage of the first spindle structure 1 and the second spindle structure 2.

[0063] See Figure 2 The first drive chain 3 is provided with a first mating block 5, and the second drive chain 4 is provided with a second mating block 8. The first mating block 5 is connected to the first main shaft structure 1 in a transmission connection, and the second mating block 8 is connected to the second main shaft structure 2 in a transmission connection.

[0064] See Figure 2 The first meshing block 6 and the first mating block 5 are coupled by a three-tooth gear and a tooth groove insertion meshing method, and the second meshing block 9 and the second mating block 8 are coupled by a three-tooth gear and a tooth groove insertion meshing method.

[0065] The first meshing block 6 and the second meshing block 9 are both three-tooth trapezoidal gears, which are fixed to the end shoulders of the first spindle body and the second spindle body respectively by flat keys. The axial direction is limited by elastic retaining rings, and the spindles that are adapted to them rotate coaxially. The first mating block 5 and the second mating block 8 are respectively provided with three-tooth trapezoidal tooth grooves corresponding to the first meshing block 6 and the second meshing block 9. The first mating block 5 and the second mating block 8 are respectively connected to the first drive chain 3 and the second drive chain 4.

[0066] When the first drive chain 3 drives the first mating block 5 to rotate, the tooth groove of the first mating block 5 is embedded and connected with the tooth of the first meshing block 6, thus achieving rigid power transmission. The first mating block 5 and the first meshing block 6 adopt a backlash-free insertion meshing, which is different from the conventional tooth surface contact transmission. This insertion method can reduce the possibility of meshing slippage.

[0067] In this connection method, the meshing action of the first mating block 5 and the first meshing block 6 directly drives the first spindle to rotate, thereby driving the first moving contact assembly to switch the tap position; the connection method of the second meshing block 9 and the second mating block 8 is completely consistent with this structure, jointly supporting the independent or coordinated rotation function of the two spindles, and improving the stability of subsequent dual spindle switching.

[0068] The intelligent control unit can independently control the motors of the two drive chains, enabling the first spindle structure 1 and the second spindle structure 2 to rotate independently, rotate synchronously at the same angle, or coordinate with different angle differences.

[0069] A sucker rod is coaxially installed inside the second main shaft structure 2. A mechanical seal structure is provided between the sucker rod and the second main shaft structure 2. The sucker rod is fixed relative to the second main shaft structure 2 and does not rotate with it.

[0070] The first spindle body is coaxially sleeved on the outside of the connecting tube via a bearing, and the first spindle body and the connecting tube can rotate relative to each other.

[0071] The oil cooling unit is sealed and connected to the sucker rod. The oil cooling unit is used for volume compensation of insulating oil, active circulation heat dissipation, and maintenance of insulation performance.

[0072] The second main shaft structure 2 is installed inside the first main shaft structure 1, and the sucker rod is installed inside the second main shaft structure 2 of the first main shaft structure 1. Through the sequential arrangement of the sucker rod, the second main shaft structure 2, and the first main shaft structure 1, the movements of the sucker rod, the first main shaft structure 1, and the second main shaft structure 2 do not affect each other, and the first main shaft structure 1 and the second main shaft structure 2 can independently control the first moving contact assembly and the second moving contact assembly.

[0073] The sucker rod passes through the interior of the second main shaft structure 2 and is fixed by a mechanical seal structure, keeping it stationary when the second main shaft structure 2 rotates. This provides a stationary pipe interface for the stable delivery of insulating oil. The first main shaft body is mounted on the connecting pipe through bearings, realizing the relative rotational freedom between the first main shaft structure 1 and the second main shaft structure 2, allowing the two main shafts to rotate independently. The oil cooling unit is connected to the stationary sucker rod, enabling the circulation and cooling of insulating oil without interference from the rotation of the main shafts.

[0074] In addition, the sucker rod is connected to the oil cooling unit. The sucker rod can draw the insulating oil inside the first spindle structure 1 and the second spindle structure 2 into the oil cooling unit, and at the same time, it can transport the insulating oil in the oil cooling unit back to the first spindle structure 1 and the second spindle structure 2 to form an oil circulation. This helps to replace the oil inside the selector switch that has deteriorated due to the electric arc generated during tap switching in a timely manner, and maintain the reliable operation of the selector switch.

[0075] It adopts a dual-spindle independent voltage regulation path design. The first spindle structure 1 and the second spindle structure 2 are arranged coaxially and are insulated from each other by an isolation ring 7. They can rotate independently, synchronously or collaboratively, and can complete gear switching without complex transmission conversion, which greatly shortens the mechanical action link and realizes rapid adjustment of the turns ratio.

[0076] The intelligent control unit is electrically connected to the drive unit and oil circuit cooling unit, and has a built-in collaborative control algorithm and a two-dimensional voltage regulation mapping model.

[0077] The two-dimensional voltage regulation mapping model is a discrete mapping function, and the expression of the discrete mapping function is: Where K is the real-time transformer ratio, i is the gear index of the first moving contact assembly corresponding to the first main shaft structure 1, and j is the gear index of the second moving contact assembly corresponding to the second main shaft structure 2.

[0078] The two-dimensional voltage regulation mapping model was obtained through multi-condition experimental calibration and stored in the memory of the intelligent control unit in the form of a lookup table.

[0079] See Figure 6 The intelligent control unit includes: a signal processing module, a prediction module, a decision-making module, and a synchronization control module.

[0080] The signal processing module is used to calculate the real-time voltage deviation based on the real-time acquired voltage signal and the preset voltage setting value.

[0081] The prediction module is used to predict voltage change trends and voltage deviations based on historical operating data, and to trigger preventive voltage regulation when the predicted voltage deviation exceeds a preset threshold.

[0082] The decision module is used to dynamically select between fine-tuning mode, tracking mode, and contact balancing mode based on the real-time voltage deviation and the candidate gear combination information calculated by calling the two-dimensional voltage regulation mapping model, and generate corresponding drive instructions.

[0083] The synchronous control module is used to send control signals to the oil circuit cooling unit synchronously when generating the pressure regulation command.

[0084] System workflow description: After the system is powered on, the intelligent control unit continuously collects the output voltage signal and calculates the real-time deviation. It then uses historical data to predict the voltage trend over the next 5 seconds. If the prediction deviation exceeds the warning threshold... If so, preventative voltage regulation will be triggered in advance. The decision module will then... The control mode is dynamically selected based on the comparison result with the preset threshold and the number of candidate gear combinations. When the pressure adjustment command is executed, the synchronous control module starts the oil circuit cooling unit and adjusts the oil pump power to cope with possible heat load. After the pressure adjustment is completed, the contact status table and system log are updated.

[0085] The transformer output voltage signal is acquired through the voltage transformer on the output side of the transformer. The sampling frequency is set to 100Hz. After the acquired data is filtered, it is compared with the preset voltage setting value to calculate the real-time voltage deviation.

[0086] Load current data is collected by a current sensor connected in series in the voltage regulation path, and the peak value of the load current in a single operation is recorded to provide a basis for calculating the working load of the contacts.

[0087] System status signals include hydraulic system pressure (acquired by hydraulic sensors), motor drive system voltage (acquired by voltage sensors), and controller communication status (detected by the built-in communication monitoring module of the intelligent control unit). Each signal is acquired in 50ms cycles to ensure timely fault detection.

[0088] Fault protection mechanism: If a drive chain motor fails, the system can switch to single-axis emergency pressure regulation mode; if the oil pressure or temperature is abnormal, an alarm will be triggered and pressure regulation will be suspended; if communication is interrupted, the system can continue to operate according to the locally stored threshold strategy.

[0089] Example 2: In this example, the mechanical structure and operating principle of the dual-axis control of the transformer are set. At the same time, the operation process of the intelligent control unit also needs to be set, including the data and judgment conditions of the signal processing module, prediction module, decision module and synchronization control module.

[0090] The intelligent control unit operates on a modular and collaborative principle. The signal processing module is responsible for calculating the deviation between the current voltage and the target value; the prediction module analyzes historical data to predict voltage fluctuation trends in advance and can initiate preventive adjustments; the decision module integrates multiple feasible gear combination schemes provided by the real-time deviation and the two-dimensional voltage regulation mapping model, dynamically selects the most suitable control mode according to the magnitude of the deviation, and generates specific drive commands; when the synchronous control module issues a voltage regulation command, the oil circuit cooling system can be activated or adjusted in coordination to cope with the heat that may be generated during voltage regulation.

[0091] See Figure 7 Based on the working principle of the intelligent control unit, the specific operation process of the intelligent control unit is as follows: First, the signal processing module acquires the voltage transformer signal on the output side of the transformer in real time, compares it with the preset voltage setpoint, and calculates the real-time voltage deviation. .

[0092] Second, the prediction module continuously analyzes historical voltage and load change data, and uses trend prediction algorithms to predict the voltage change trend and possible prediction deviations in the short term. When the prediction deviation exceeds the warning threshold, the prediction module can issue a preventive voltage adjustment suggestion to the decision module.

[0093] The specific implementation steps of the prediction module are as follows: Its specific implementation employs a lightweight algorithm that combines a scrolling window with trend extrapolation: Step 1: Set up the data window.

[0094] Select voltage and power timing data from the most recent period (e.g., 60 seconds).

[0095] Step 2: Trend Calculation and Forecasting.

[0096] Linear fitting is performed on the voltage data within the window to obtain the trend of change, and the predicted voltage for a short future time (e.g., 5 seconds) is extrapolated. .

[0097] Step 3: Warning Trigger.

[0098] Calculate the predicted voltage value Predicted voltage deviation from preset voltage setting value Set a preventative voltage regulation early warning threshold. (satisfy ), where the fine-tuning threshold Take 2% of the rated voltage, and set the tracking threshold. Take 5% of the rated voltage as the preventive voltage regulation early warning threshold. Take 3% of the rated voltage.

[0099] when At that time, the prediction module will generate forward-looking adjustment instructions containing prediction bias, intervene in the main decision-making process in advance, and enhance the system's proactive suppression capability.

[0100] Through this mechanism, the system can initiate voltage regulation operations in advance before the actual voltage deviation occurs, thereby achieving proactive suppression and preventive control of voltage fluctuations, significantly improving the stability of voltage quality and the system's forward-looking regulation capability, and realizing preventive rapid regulation.

[0101] Third, the decision-making module is the decision-making body. It integrates a gear-ratio relationship lookup table and a contact status table. The relationship lookup table stores the correspondence between all valid gear ratio and gear combinations. The contact status table maintains historical data such as the cumulative number of operations and current-carrying time for each physical contact, and calculates its comprehensive workload value using a weighted formula.

[0102] The two-dimensional voltage regulation mapping model is stored in the form of an encrypted lookup table, which is a lookup table of gear position and shift ratio relationship. The lookup table defines the correspondence between shift ratio K and the first main shaft gear i and the second main shaft gear j. .

[0103] When voltage regulation is required, the decision module calculates all candidate gear combinations (i, j) that meet the requirements from the model based on the target voltage or target turns ratio.

[0104] The two-dimensional voltage regulation mapping model is stored in the intelligent control unit in the form of an encrypted lookup table. The correspondence between the gear ratio and the dual main shaft gears is directly fixed in the table. When regulating the voltage, there is no need for complex real-time calculations. All candidate gear combinations that meet the target gear ratio can be quickly calculated by simply looking up the table in reverse, thus eliminating calculation delays from the decision-making end.

[0105] Meanwhile, the cumulative workload is quantified and statistically analyzed through the status table maintained by the intelligent control unit for each contact. The status table records the cumulative number of operations, cumulative current carrying time, and peak load current of a single operation for the corresponding contact, and uses a weighted algorithm to calculate the comprehensive workload value of the contact.

[0106] Specifically, the memory maintains a contact status table, which records the cumulative number of operations, cumulative current carrying time, historical load current peak value, etc. for each physical contact, and calculates a real-time updated comprehensive workload value for each contact through a preset weighted algorithm.

[0107] The status table records the cumulative number of operations N, the cumulative current carrying time T, and the historical peak load current I for each physical contact, and uses a weighted formula to calculate the comprehensive working load value W for each contact.

[0108]

[0109] Where W is the overall working load value of the contact, N is the cumulative number of operations, T is the cumulative current carrying time, I is the historical peak load current, and α, β, γ are preset weights.

[0110] For copper contacts, the weighting coefficients are α=0.3, β=0.5, and γ=0.2; for silver alloy contacts, the weighting coefficients are α=0.2, β=0.4, and γ=0.4. The weighting coefficients are preset based on the wear resistance and current carrying characteristics of the contact material.

[0111] The decision module uses the real-time absolute value of the voltage deviation sent by the signal processing module. Compare it with the preset fine-tuning threshold and tracking threshold , to compare, among which, The logic for dynamically selecting the control mode is as follows: The trigger conditions for fine-tuning mode, equalization mode, and tracking mode are as follows: The trigger condition for fine-tuning mode is: |real-time voltage deviation| < fine-tuning threshold; in this mode, the intelligent control unit selects from the candidate gear combinations that only require adjustment of a single spindle in the first spindle structure 1 or the second spindle structure 2. If there are multiple such combinations, the combination with the smallest increase in the overall workload of the contacts is selected for execution.

[0112] Specifically: If Entering the fine-tuning mode, the decision module prioritizes selecting the solution that requires only a single axis (i change or j change) action from the candidate combinations. If there are still multiple solutions, the solution with the smallest increase in the overall workload of the involved contacts is selected for execution. The aim is to complete the fine adjustment with the minimum mechanical action and slightly optimize the use of contacts.

[0113] The goal of minimizing the incremental increase in the overall workload of the contacts is achieved based on the contact status table pre-stored in the intelligent control unit and the weighted incremental calculation model. The specific implementation steps are as follows: Step 1: Screening of candidate combinations for single-axis adjustment.

[0114] The intelligent control unit calls the two-dimensional voltage regulation mapping model. From all the calculated candidate gear combinations, select combinations that require only the adjustment of the first spindle structure 1 or the adjustment of the second spindle structure 2, and eliminate combinations that require the linkage of two spindles to form a list of single-axis adjustment candidate combinations.

[0115] Step 2: Candidate combination involves contact point extraction.

[0116] For each single-axis candidate combination in the list, match the tap contacts that the moving contact assembly corresponding to the combination needs to switch, and clarify all target contacts involved in each candidate combination; for example, a certain combination of the first main shaft structure 1 that is adjusted separately corresponds to one or more sets of contacts between the first moving contact assembly and the tap on the insulating cylinder.

[0117] Step 3: Calculation of the incremental workload of a single contact point.

[0118] For each target contact, based on the current data in the contact status table pre-stored in the intelligent control unit, the overall workload increment generated by this voltage regulation operation is calculated. The calculation formula is consistent with the formula for calculating the comprehensive working load value of the contacts:

[0119] in, This increment represents the number of contact operations resulting from this voltage regulation operation. The value is 1, indicating that the contact has completed one tap switching action. The estimated current-carrying time increment of the contact after this voltage adjustment is predicted by the intelligent control unit based on the current transformer load, which forecasts the continuous current-carrying time of the contact at the target tap. The difference between the peak load current of this voltage regulation and the historical peak load current of this contact. If the current peak value is greater than the historical peak value, Take the difference between the two values. If the current peak value is less than or equal to the historical peak value, Take 0.

[0120] α, β, and γ are preset weighting coefficients that match the contact material. For copper contacts, the weighting coefficients are α=0.3, β=0.5, and γ=0.2; for silver alloy contacts, the weighting coefficients are α=0.2, β=0.4, and γ=0.4. The weighting coefficients are preset according to the wear resistance and current carrying characteristics of the contact material.

[0121] Step 4: Sum the total increments of candidate combinations.

[0122] For each single-axis candidate combination, consider all target contacts involved. Summing is performed to obtain the total comprehensive workload increment for this candidate combination. .

[0123] Step 5: Optimal combination selection and execution.

[0124] The intelligent control unit compares all single-axis candidate combinations. The combination with the smallest total increment is selected as the final execution plan; if there are multiple candidate combinations... If they are the same, a preset priority rule is used to prioritize the combination of axes with fewer cumulative operations.

[0125] Step 6: The contact status table is updated in real time.

[0126] After the voltage regulation operation is completed, the intelligent control unit will calculate the voltage... , , The status table of the corresponding contact is synchronously written to update the cumulative number of operations, cumulative current carrying time, and historical load current peak value of the contact, providing an accurate data basis for the incremental calculation of the next voltage regulation.

[0127] The above steps enable the calculation and optimal selection of the overall workload increment of the contacts in the fine-tuning mode, effectively balancing the wear rate of each contact and extending the overall service life of the contacts.

[0128] The triggering condition for the contact equalization mode is: the fine-tuning threshold ≤ |real-time voltage deviation| ≤ tracking threshold, and the number of candidate gear combinations calculated based on the two-dimensional voltage regulation mapping model is greater than one; in this mode, the intelligent control unit selects the combination with the smallest total cumulative workload of the involved contacts from multiple candidate gear combinations as the target gear combination to be executed.

[0129] Specifically: If If there is more than one candidate gear combination, then the contact point balancing mode will be entered.

[0130] The decision module calculates the total current workload of all contacts involved in each candidate combination and selects the combination with the smallest total workload as the execution target.

[0131] This mode aims to take advantage of the non-uniqueness of gear combinations to actively allocate voltage regulation tasks to idle contacts with low historical workload, thereby achieving wear equalization.

[0132] The goal of minimizing the total cumulative workload of the contacts is achieved based on the contact status table pre-stored in the intelligent control unit and the cumulative load summation model. The specific implementation steps are as follows: Step 1: Extracting candidate combinations from multiple price levels.

[0133] The intelligent control unit calls the two-dimensional voltage regulation mapping model. Based on the target turns ratio corresponding to the current voltage deviation that needs to be corrected, the set of all candidate gear combinations that meet the voltage regulation requirements is calculated in reverse. And the number of candidate combinations n≥2.

[0134] Step 2: Matching the contact points corresponding to the candidate combinations.

[0135] For each candidate gear combination in the set Each is matched to the corresponding gear of the first spindle structure 1. The moving contact point and the corresponding gear position of the second spindle structure 2 The moving contact points are identified, and a complete list of all physical contacts involved in each candidate combination is determined.

[0136] Step 3: Retrieve the cumulative workload of a single contact.

[0137] The intelligent control unit queries the pre-stored contact status table and extracts the current cumulative workload value of each contact in the list. This value is calculated using a weighted formula based on historical operating data:

[0138] Where W is the overall working load value of the contact, N is the cumulative number of operations, T is the cumulative current carrying time, I is the historical peak load current, and α, β, γ are preset weights.

[0139] Step 4: Calculate the total load of candidate combinations.

[0140] For each candidate gear combination The total cumulative workload W of the combination is obtained by summing the cumulative workload values ​​W of all the contacts involved. The calculation formula is:

[0141] Where m is the total number of contacts involved in the candidate combination. This represents the cumulative workload value of the k-th contact.

[0142] Step 5: Optimal combination selection and execution.

[0143] The intelligent control unit compares the total cumulative workload of all candidate combinations. The combination with the smallest value is selected as the final target gear combination for execution; if multiple candidate combinations exist... If they are the same, a preset priority rule will be used to prioritize the combination with fewer touchpoints for execution.

[0144] Step 6: The contact status table is updated in real time.

[0145] After completing the voltage regulation operation, the intelligent control unit writes the contact action data of this operation, namely the operation increment ΔN=1, the estimated current carrying time increment ΔT, and the peak load current ΔI, into the status table of the corresponding contact, and updates the cumulative working load value W of the contact, so as to provide accurate data support for the next voltage regulation decision.

[0146] Through the above steps, the total load of each candidate combination can be accurately calculated and optimally selected in the contact balancing mode, the voltage regulation task can be actively distributed to low-load contacts, the wear rate of each contact can be balanced, and the overall service life of the on-load tap changer can be extended.

[0147] The trigger condition for tracking mode is: |real-time voltage deviation|>tracking threshold; in this mode, the target gear combination is selected according to the preset fast adjustment strategy; the fast adjustment strategy prioritizes the combination with the shortest estimated adjustment time, and the intelligent control unit controls the drive unit to drive the first spindle structure 1 and the second spindle structure 2 to move synchronously and switch to the target gear combination.

[0148] Specifically: If Then it enters tracking mode, in which the target gear combination is selected according to the preset quick adjustment strategy.

[0149] The core objective of the rapid adjustment strategy is to eliminate large voltage deviations in the shortest possible time. Its implementation relies on a two-dimensional voltage regulation mapping model, a single-axis adjustment time calculation model, and dual-spindle synchronous linkage control logic. Differentiated execution schemes are adopted for two practical application scenarios: one where the candidate gear combination calculated by the two-dimensional voltage regulation mapping model is unique, and the other where there are multiple candidate gear combinations. The details are as follows: Scenario 1: The two-dimensional voltage regulation mapping model calculates a unique candidate gear combination.

[0150] Step 1: Lock the target gear combination.

[0151] Based on the current voltage deviation that needs to be corrected, the intelligent control unit calculates the target turns ratio, calls the pre-stored two-dimensional voltage regulation mapping model, and reverse-engineers the unique candidate gear combination. The target gear that the first spindle structure 1 and the second spindle structure 2 need to reach is clearly defined.

[0152] Step 2: Calculation of single-axis adjustment time.

[0153] The intelligent control unit calculates the single-axis adjustment time of the dual spindles based on the inherent parameters of the drive unit, and obtains the current gear of the first spindle structure 1. and target gear Based on the gear difference, combined with the rated speed of the first drive chain and the gear meshing ratio, the single-axis adjustment time of the first main shaft structure 1 is calculated. The specific formula is as follows:

[0154] in, The gear difference between the current gear and the target gear in the first main shaft structure 1. This is the current gear position of the first spindle structure 1. The target gear for the first spindle structure 1; Adjustment time for the first spindle structure The rated speed of the first drive chain, This is the gear meshing transmission ratio of the first drive chain.

[0155] Get the current gear of the second spindle and target gear Based on the gear difference, combined with the rated speed of the second drive chain and the gear meshing ratio, the single-axis adjustment time t2 of the second main shaft is calculated. The specific formula is as follows:

[0156] in, The gear difference between the current gear and the target gear in the second main shaft structure 2. This is the current gear position of the second spindle structure 2. The target gear for the second main spindle structure 2; Adjustment time for the second spindle structure The rated speed of the second drive chain, This is the gear meshing transmission ratio of the second drive chain.

[0157] Step 3: Dual spindle synchronous linkage drive.

[0158] Pick and When the maximum value is used as the total estimated adjustment of the combination, this rule is to ensure that the two spindles reach the target gear synchronously and reduce the possibility of voltage regulation failure caused by asynchronous contact of the contacts.

[0159] The intelligent control unit sends synchronous start commands to the first and second drive chains, and dynamically adjusts the drive motor power based on the difference in single-axis adjustment time. like If the motor speed of the second drive chain is reduced or its transmission damping is increased, the second main shaft structure 2 will run at a matching speed. like If the motor speed of the first drive chain is reduced or its transmission damping is increased, the first main shaft structure 1 will run at a matching speed.

[0160] Scenario 2: The two-dimensional voltage regulation mapping model calculates multiple candidate gear combinations.

[0161] Step 1: Extract multiple candidate gear combinations.

[0162] The intelligent control unit calls the two-dimensional voltage regulation mapping model to calculate the set of all candidate gear combinations that meet the target gear ratio, and the number of combinations is greater than two.

[0163] Step 2: Calculate the total estimated adjustment time for each combination.

[0164] For each candidate gear combination within the set, repeat steps two and three of Case 1 to calculate the total estimated adjustment time for each combination.

[0165] Step 3: Optimal gear combination selection.

[0166] The intelligent control unit compares the total estimated adjustment time of all candidate combinations and selects the combination with the shortest total estimated adjustment time as the final target gear combination to be executed.

[0167] It should be noted that the core logic of the rapid adjustment strategy remains consistent in both cases: the shortest total estimated adjustment time is used as the selection criterion, and the synchronous linkage of the two main axes is used as the execution guarantee. There is no logical conflict between taking the maximum single-axis duration as the total duration and prioritizing the combination with the shortest adjustment time. The former is the execution rule to ensure the effectiveness of voltage regulation, and the latter is the selection rule to achieve the goal of rapid voltage regulation. Both serve the core requirement of the tracking mode to quickly eliminate large voltage deviations.

[0168] The logic for prioritizing the three modes and resolving conflicts is as follows: if the triggering conditions of multiple modes are met simultaneously, the resolution is made according to the hierarchy of tracking mode taking precedence over touch balance mode, and touch balance mode taking precedence over fine-tuning mode.

[0169] The triggering conditions of the three control modes may have critical overlap. To ensure the uniqueness and effectiveness of the system voltage regulation decision, a priority decision logic is set: the tracking mode takes precedence over the contact balancing mode, and the contact balancing mode takes precedence over the fine-tuning mode.

[0170] The design incorporates a tracking mode and sets it as the highest priority among all control modes (it is executed even when it overlaps with fine-tuning and balancing modes). The core of this design revolves around a rapid adjustment strategy to eliminate large deviations in the shortest possible time. If the candidate gear combination is unique, the dual spindle adjustment time is directly calculated and the speed is dynamically adjusted to achieve synchronous linkage, and the process is executed in one go.

[0171] If there are multiple candidate gear combinations, prioritize selecting the combination with the shortest total estimated adjustment time, and then execute dual-spindle synchronous linkage to avoid wasting time on ineffective gear selection.

[0172] In this mode, rapid adjustment is the core requirement, enabling rapid turns ratio adjustment under large deviations.

[0173] The decision-making logic is explained in detail, taking into account specific parameters and operating conditions.

[0174] Step 1: Setting basic parameters.

[0175] If the motor speed of the second drive chain is reduced or its transmission damping is increased, the second main shaft structure 2 will run at a matching speed. like If the motor speed of the first drive chain is reduced or its transmission damping is increased, the first main shaft structure 1 will run at a matching speed.

[0176] Scenario 2: The two-dimensional voltage regulation mapping model calculates multiple candidate gear combinations.

[0177] Step 1: Extract multiple candidate gear combinations.

[0178] The intelligent control unit calls the two-dimensional voltage regulation mapping model to calculate the set of all candidate gear combinations that meet the target gear ratio, and the number of combinations is greater than two.

[0179] Step 2: Calculate the total estimated adjustment time for each combination.

[0180] For each candidate gear combination within the set, repeat steps two and three of Case 1 to calculate the total estimated adjustment time for each combination.

[0181] Step 3: Optimal gear combination selection.

[0182] The intelligent control unit compares the total estimated adjustment time of all candidate combinations and selects the combination with the shortest total estimated adjustment time as the final target gear combination to be executed.

[0183] It should be noted that the core logic of the rapid adjustment strategy remains consistent in both cases: the shortest total estimated adjustment time is used as the selection criterion, and the synchronous linkage of the two main axes is used as the execution guarantee. There is no logical conflict between taking the maximum single-axis duration as the total duration and prioritizing the combination with the shortest adjustment time. The former is the execution rule to ensure the effectiveness of voltage regulation, and the latter is the selection rule to achieve the goal of rapid voltage regulation. Both serve the core requirement of the tracking mode to quickly eliminate large voltage deviations.

[0184] The logic for prioritizing the three modes and resolving conflicts is as follows: if the triggering conditions of multiple modes are met simultaneously, the resolution is made according to the hierarchy of tracking mode taking precedence over touch balance mode, and touch balance mode taking precedence over fine-tuning mode.

[0185] The triggering conditions of the three control modes may have critical overlap. To ensure the uniqueness and effectiveness of the system voltage regulation decision, a priority decision logic is set: the tracking mode takes precedence over the contact balancing mode, and the contact balancing mode takes precedence over the fine-tuning mode.

[0186] The design incorporates a tracking mode and sets it as the highest priority among all control modes (it is executed even when it overlaps with fine-tuning and balancing modes). The core of this design revolves around a rapid adjustment strategy to eliminate large deviations in the shortest possible time. If the candidate gear combination is unique, the dual spindle adjustment time is directly calculated and the speed is dynamically adjusted to achieve synchronous linkage, and the process is executed in one go.

[0187] If there are multiple candidate gear combinations, prioritize selecting the combination with the shortest total estimated adjustment time, and then execute dual-spindle synchronous linkage to avoid wasting time on ineffective gear selection.

[0188] In this mode, rapid adjustment is the core requirement, enabling rapid turns ratio adjustment under large deviations.

[0189] The decision-making logic is explained in detail, taking into account specific parameters and operating conditions.

[0190] Step 1: Setting basic parameters.

[0191] Set the transformer's rated voltage According to the preset threshold rule of the present invention, the following is determined: Fine-tuning threshold .

[0192] Tracking threshold .

[0193] Mode trigger conditions: Fine-tuning mode: .

[0194] Contact equalization mode: .

[0195] Tracking mode: .

[0196] Step 2: Specific Working Conditions and Execution Instructions.

[0197] Operating Condition 1: The triggering conditions of tracking mode and contact equalization mode overlap.

[0198] Real-time voltage deviation The intelligent control unit calls the two-dimensional voltage regulation mapping model to calculate three sets of candidate gear combinations that meet the target gear ratio.

[0199] Under this working condition The conditions for triggering the tracking mode are met, and the number of candidate gear combinations is greater than 1, which meets the combination quantity requirements of the contact balance mode.

[0200] Based on the priority decision-making logic, the system prioritizes the execution of the tracing mode.

[0201] Execution strategy: The intelligent control unit calculates the estimated adjustment time of the three candidate combinations, selects the combination with the shortest time, and controls the first spindle structure 1 and the second spindle structure 2 to work synchronously and quickly complete the voltage adjustment to eliminate the 600V voltage deviation.

[0202] Operating Condition 2: The triggering conditions of the contact equalization mode and the fine-tuning mode overlap.

[0203] Real-time voltage deviation The two-dimensional voltage regulation mapping model calculates two sets of candidate gear combinations, and one of the candidate combinations can be adjusted by adjusting only a single spindle to complete the voltage regulation.

[0204] Under this working condition Furthermore, the number of candidate gear combinations is greater than 1, which satisfies the triggering condition of the contact balance mode; at the same time, there are candidate combinations for single spindle adjustment, which conforms to the operation characteristics of the fine-tuning mode.

[0205] Based on the priority decision-making logic, the system prioritizes the execution of the contact point balancing mode.

[0206] Execution strategy: The intelligent control unit retrieves the contact status table, calculates the total cumulative workload of the contacts involved in the two candidate combinations, selects the combination with the smallest total load to perform voltage regulation, and achieves contact wear balance.

[0207] Condition 3: The triggering conditions of the three modes overlap simultaneously.

[0208] Real-time voltage deviation It is in the fine-tuning mode range, but the prediction module predicts based on historical data that the voltage deviation will rise rapidly to 550V within the next five seconds. At the same time, the two-dimensional voltage regulation mapping model calculates four sets of candidate gear combinations.

[0209] Under this working condition If the fine-tuning mode trigger conditions are met, the number of candidate gear combinations > 1 meets the requirements of the contact balance mode, and the prediction deviation exceeds the tracking threshold, the look-ahead condition for the tracking mode is triggered.

[0210] Based on the priority decision-making logic, the system prioritizes the execution of the tracing mode.

[0211] Execution strategy: The system does not adopt single-spindle fine-tuning or contact load balancing strategies. Instead, it directly follows the rapid adjustment rules, selects the combination with the shortest adjustment time, and controls the synchronous operation of the two spindles to suppress the risk of voltage deviation expansion in advance.

[0212] When the triggering conditions of multiple modes are met simultaneously, the system strictly follows the priority order of tracking mode, contact balancing mode, and fine-tuning mode, and only executes the voltage regulation strategy corresponding to the highest priority mode to ensure the balance between the timeliness, stability and equipment lifespan of voltage regulation action under different voltage deviation scenarios.

[0213] Fourth, after the decision module generates the final drive command, the synchronous control module will simultaneously send control signals to the oil circuit cooling unit, such as increasing the oil pump power to cope with the additional heat that may be generated due to the high current switching, and to ensure the insulation strength.

[0214] Example 3, see reference Figure 5 A method for an on-load tap changer coordination control system for transformer turns ratio regulation, using the on-load tap changer coordination control system for transformer turns ratio regulation as described above, includes the following steps: S1. Real-time acquisition of transformer output voltage signal, combined with preset voltage setting value, to calculate real-time voltage deviation.

[0215] S2. Call up historical operating data to predict voltage change trends and voltage deviations.

[0216] S3. Based on the target voltage to be achieved, call the pre-stored two-dimensional voltage regulation mapping model to calculate the candidate gear combination that meets the requirements.

[0217] S4. Compare the real-time voltage deviation with the preset fine-tuning threshold, equalization threshold, and tracking threshold.

[0218] S5. Based on the threshold comparison results and the number of candidate gear combinations, dynamically select and execute one of the following control strategies: fine-tuning mode, tracking mode, and contact point balancing mode.

[0219] S6. Generate drive instructions corresponding to the selected strategy, control the first spindle structure 1 and the second spindle structure 2 to perform coordinated pressure regulation actions, and synchronously control the oil circuit cooling unit.

[0220] S7. Update system status records.

[0221] In step S5, when the intelligent control unit selects to enter the fine-tuning mode based on the threshold comparison result, the intelligent control unit calculates the incremental increase of the total workload of the contacts involved in the candidate gear combination based on the contact status table, and selects the gear combination with the smallest incremental increase of the total workload of the contacts to execute.

[0222] When the system selects to enter the contact balancing mode based on the threshold comparison result, the intelligent control unit queries the contact status table to obtain the total cumulative workload of the contacts involved in the candidate gear combination, and selects the gear combination with the smallest total cumulative workload of the contacts to execute.

[0223] The contact status table is updated in real time after each voltage regulation action, recording the cumulative number of operations and cumulative current carrying time of each contact, and using a weighted algorithm to calculate the comprehensive workload value. The weighting coefficient is preset according to the contact material and working characteristics.

[0224] The two-dimensional voltage regulation mapping model was obtained through multi-condition experimental calibration. It covers the correspondence between the transformer ratio and the gear position under different loads and ambient temperatures. It is stored in the form of an encrypted lookup table and supports dynamic correction and updates based on real-time operating data.

[0225] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. An on-load tap changer coordination control system for transformer turns ratio adjustment, characterized in that: include: The mechanical actuator includes a first spindle structure (1), a second spindle structure (2), and an isolation ring (7) coaxially disposed between the first spindle structure (1) and the second spindle structure (2); a first moving contact assembly is mounted on the first spindle structure (1), and a second moving contact assembly is mounted on the second spindle structure (2); A fixedly installed insulating cylinder is provided with a multi-component connector. The first moving contact assembly and the second moving contact assembly are respectively provided with contacts that are compatible with the corresponding taps and make electrical contact, forming two independent voltage regulating paths. The drive unit includes a first drive chain (3) and a second drive chain (4), wherein the first drive chain (3) and the second drive chain (4) are two independent drive mechanisms; The oil cooling unit is used for volume compensation, active circulation heat dissipation, and insulation performance maintenance of insulating oil. The intelligent control unit is electrically connected to the drive unit and oil circuit cooling unit. It has a built-in collaborative control algorithm, a two-dimensional voltage regulation mapping model, and three dynamic control modes: fine-tuning mode, contact equalization mode, and tracking mode.

2. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 1, characterized in that: The first drive chain (3) and the second drive chain (4) are used to drive the first spindle structure (1) and the second spindle structure (2) respectively, so as to realize the independent rotation and coordinated linkage of the first spindle structure (1) and the second spindle structure (2); The first drive chain (3) is provided with a first mating block (5), and the second drive chain (4) is provided with a second mating block (8). The first mating block (5) is connected to the first main shaft structure (1) in a transmission manner, and the second mating block (8) is connected to the second main shaft structure (2) in a transmission manner. The first spindle structure (1) includes a first spindle body and a first meshing block (6) fixed to its end; the second spindle structure (2) includes a second spindle body, a connecting pipe and a second meshing block (9) fixed to the end of the connecting pipe; the first meshing block (6) and the first mating block (5) are coupled by a three-tooth gear and a tooth groove insertion meshing method; the second meshing block (9) and the second mating block (8) are coupled by a three-tooth gear and a tooth groove insertion meshing method. The isolation ring (7) is fixed between the mating surfaces of the first spindle body and the second spindle body.

3. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 2, characterized in that: The second main shaft structure (2) has a sucker rod coaxially running through it. A mechanical seal structure is provided between the sucker rod and the second main shaft structure (2). The sucker rod is fixed relative to the second main shaft structure (2) and does not rotate with it. The first spindle body is coaxially sleeved on the outside of the connecting tube via a bearing, and the first spindle body and the connecting tube can rotate relative to each other. The oil cooling unit is in sealed connection with the sucker rod.

4. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 1, characterized in that: The intelligent control unit includes: The signal processing module is used to calculate the real-time voltage deviation based on the real-time acquired voltage signal and the preset voltage setting value; The prediction module is used to predict voltage change trends and voltage deviations based on historical operating data, and to trigger preventive voltage regulation when the predicted voltage deviation exceeds a preset threshold. The decision module is used to dynamically select between fine-tuning mode, tracking mode, and contact balancing mode based on the real-time voltage deviation and the candidate gear combination information calculated by calling the two-dimensional voltage regulation mapping model, and generate corresponding drive commands. The synchronous control module is used to synchronously send control signals to the oil circuit cooling unit when generating the pressure regulation command.

5. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 4, characterized in that: The two-dimensional voltage regulation mapping model is a discrete mapping function, and the expression of the discrete mapping function is: Wherein, K is the real-time transformer ratio, i is the gear index of the first moving contact assembly corresponding to the first main shaft structure (1), and j is the gear index of the second moving contact assembly corresponding to the second main shaft structure (2). The two-dimensional voltage regulation mapping model was obtained through multi-condition experimental calibration and stored in the memory of the intelligent control unit in the form of a lookup table.

6. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 5, characterized in that: The trigger condition for the fine-tuning mode is: |real-time voltage deviation| < fine-tuning threshold; in this mode, the intelligent control unit selects from the candidate gear combination that only requires adjustment of a single spindle in the first spindle structure (1) and the second spindle structure (2). If there are multiple such combinations, the combination with the smallest increase in the overall workload of the contact points is selected for execution. The triggering condition for the contact equalization mode is: the fine-tuning threshold ≤ |real-time voltage deviation| ≤ tracking threshold, and the number of candidate gear combinations calculated based on the two-dimensional voltage regulation mapping model is greater than one; in this mode, the intelligent control unit selects the combination with the smallest total cumulative workload of the involved contacts from multiple candidate gear combinations as the target gear combination to be executed. The trigger condition for the tracking mode is: |Real-time voltage deviation| When tracking the threshold; in this mode, the target gear combination is selected according to the preset fast adjustment strategy; the fast adjustment strategy prioritizes the combination with the shortest estimated adjustment time, and the intelligent control unit controls the drive unit to drive the first spindle structure (1) and the second spindle structure (2) to move synchronously and switch to the target gear combination; If the triggering conditions of multiple modes are met simultaneously, the decision will be made according to the following hierarchy: tracking mode takes precedence over touch balance mode, and touch balance mode takes precedence over fine-tuning mode.

7. The on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 6, characterized in that: The cumulative workload is quantified and statistically analyzed by the status table maintained by the intelligent control unit for each contact. The status table records the cumulative number of operations, cumulative current carrying time, and peak load current of a single operation for the corresponding contact. The comprehensive workload value of the contact is calculated using a weighted algorithm based on the preset weight of the contact material.

8. A method for an on-load tap changer coordination control system for transformer turns ratio regulation, using the on-load tap changer coordination control system for transformer turns ratio regulation as described in any one of claims 1-7, characterized in that: Includes the following steps: S1. Real-time acquisition of transformer output voltage signal, combined with preset voltage setting value, to calculate real-time voltage deviation; S2. Retrieve historical operating data to predict voltage change trends and voltage deviations; S3. Based on the target voltage to be achieved, call the pre-stored two-dimensional voltage regulation mapping model to calculate the candidate gear combination that meets the requirements. S4. Compare the real-time voltage deviation with the preset fine-tuning threshold, equalization threshold, and tracking threshold; S5. Based on the threshold comparison results and the number of candidate gear combinations, dynamically select and execute one of the following control strategies: fine-tuning mode, tracking mode, and contact point balancing mode. S6. Generate drive instructions corresponding to the selected strategy, control the first spindle structure (1) and the second spindle structure (2) to perform coordinated pressure regulation, and synchronously control the oil circuit cooling unit; S7. Update system status records.

9. The method for on-load tap changer coordination control system for transformer turns ratio adjustment according to claim 8, characterized in that: In step S5, when the intelligent control unit selects to enter the fine-tuning mode based on the threshold comparison result, the intelligent control unit calculates the incremental increase of the total workload of the contacts involved in the candidate gear combination based on the contact status table, and selects the gear combination with the smallest incremental increase of the total workload of the contacts to execute. When the system selects to enter the contact balance mode based on the threshold comparison result, the intelligent control unit queries the contact status table to obtain the total cumulative workload of the contacts involved in the candidate gear combination, and selects the gear combination with the smallest total cumulative workload of contacts to execute. The contact status table is updated in real time after each voltage regulation action, recording the cumulative number of operations and cumulative current carrying time of each contact, and using a weighted algorithm to calculate the comprehensive workload value. The weighting coefficient is preset according to the contact material and working characteristics.

10. The method for an on-load tap changer coordinated control system for transformer turns ratio adjustment according to claim 8, characterized in that: The two-dimensional voltage regulation mapping model was obtained through multi-condition experimental calibration. It covers the correspondence between the transformer ratio and gear position under different loads and ambient temperatures. It is stored in the form of an encrypted lookup table and supports dynamic correction and updates based on real-time operating data.

Images