On-load voltage regulation method and device based on existing transformer and storage medium

Abstract

The invention relates to the technical field of transformers, and discloses an on-load voltage regulation method and device based on an existing transformer and a storage medium, according to the method, a transient overvoltage suppression device is arranged on a switch, one end of the transient overvoltage suppression device is connected with an action end, the other end of the transient overvoltage suppression device is connected with a contact end corresponding to middle gear voltage, and the break-over voltage of the transient overvoltage suppression device is larger than the maximum voltage difference value between the action end and the contact end. And the action end is connected with a phase correction capacitor and then is connected with a primary side sleeve through the capacitor. Each contact end is correspondingly connected with a current-limiting reactor and is connected to taps with different turns of a primary side winding of the transformer through the current-limiting reactor, and the other tap of the winding is connected with another primary side sleeve. Detecting the secondary side voltage value of the transformer, and driving the action end to be connected with the contact end which is positively correlated with the secondary voltage value according to the secondary side voltage value; according to the method, the existing transformer can realize on-load voltage regulation, and the power supply voltage stability is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to an on-load voltage regulation method, device and storage medium based on an existing transformer. Background Art

[0002] With the development of new energy, distribution transformers need to undertake a large number of new energy reverse transmission tasks, so the voltage on the low-voltage side varies greatly. No-load voltage regulation and on-load voltage regulation are the two main ways of transformer voltage regulation. No-load voltage regulation refers to the situation where both the primary and secondary sides of the transformer are disconnected from the power supply, by changing the tap of the high-voltage side winding of the transformer to change the turns ratio of the winding, thereby adjusting the output voltage. For example, a 10kV / 0.4kV three-speed transformer, by adjusting the tap switch to connect different taps, changes the number of turns of the primary winding, and changes the secondary output voltage when the primary power supply voltage remains unchanged. On-load voltage regulation refers to the use of the on-load tap changer to switch from one tap to another without cutting off the load current, and change the transformer transformation ratio by changing the effective number of turns of the winding, thereby adjusting the output voltage. During the switching process, the transition resistor will be used to limit the current between the two gears to ensure that the transformer does not lose power.

[0003] At present, most of the existing transformers are off-load voltage regulators, and it is difficult to adjust the voltage when the voltage changes greatly, resulting in the problem of unqualified power quality due to the voltage fluctuations of users. However, on-load voltage regulators require the purchase of new transformers, which is very expensive. Therefore, it is very important to improve the existing off-load voltage regulators locally so that they have the ability to regulate voltage on-load. Summary of the invention

[0004] In order to enable an existing off-load voltage regulating transformer to perform on-load voltage regulating, the present application provides an on-load voltage regulating method, device and storage medium based on an existing transformer.

[0005] In a first aspect, the present application provides an on-load voltage regulation method based on an existing transformer, which adopts the following technical solution: A on-load voltage regulation method based on an existing transformer, which is based on an off-load voltage regulating tap changer connected to the transformer, includes the following steps: A transient overvoltage suppression device is arranged on the off-load voltage regulating tap changer. One end of the transient overvoltage suppression device is connected to the operating end of the off-load voltage regulating tap changer, and the other end is connected to the contact end corresponding to the voltage of the middle gear in the off-load voltage regulating tap changer. The conduction voltage of the transient overvoltage suppression device is greater than the positive and negative maximum voltage gear voltage difference between the operating end and the contact end corresponding to the voltage of the middle gear; the operating end is connected with a phase correction capacitor and is connected to a primary bushing through the phase correction capacitor; each contact end is correspondingly connected with a current-limiting reactor, and different contact ends are connected to taps with different turns on the primary winding of the transformer through the corresponding current-limiting reactors; the tap of the primary side coil of the transformer far from the contact end is connected to another primary bushing; the secondary voltage value of the transformer secondary side is detected; according to the secondary voltage value, the contact end connected to the operating end is driven to be positively correlated with the secondary voltage value.

[0006] Optionally, if the secondary voltage value is low, the operating end is driven to be connected to the contact end that reduces the number of turns of the primary winding; if the secondary voltage value is high, it is connected to the contact end that can increase the number of turns of the primary winding.

[0007] By adopting the above technical solutions, the contact end connected to the operating end of the off-load voltage regulating tap changer is adjusted by detecting the secondary voltage value of the transformer, so as to adjust the number of turns of the primary winding in real time, stabilize the secondary side output voltage, solve the problem of unstable power supply caused by voltage fluctuation, and ensure the normal operation of the user's electrical equipment; a transient overvoltage suppression device is arranged on the off-load voltage regulating tap changer, which can prevent the transient overvoltage during the operation of the tap changer from damaging the equipment, protect relevant electrical equipment such as transformers and tap changers, and improve the reliability of system operation; the phase correction capacitor connected to the operating end can improve the circuit phase relationship, improve the power factor, reduce the reactive power loss, and improve the power transmission efficiency; the current-limiting reactor connected to each contact end can limit the circulating current between windings, ensuring the safety and stability of the on-load voltage regulation process; accurately driving the operating end to be connected to different contact ends realizes the fine adjustment of the output voltage of the transformer, improves the power supply quality, and reduces the risk of damage to electrical equipment due to excessive voltage deviation.

[0008] Optionally, the method further includes the following steps: The transient overvoltage suppression device includes a plurality of silicon bilateral diodes connected in parallel, and each silicon bilateral diode is connected in series with a conduction device; In the most recent time period, calculate the secondary fluctuation voltage value of the secondary voltage value; Judge the voltage fluctuation range to which the secondary fluctuation voltage value belongs; Match a corresponding conduction device according to the voltage fluctuation range; Turn on the matched conduction device.

[0009] By adopting the above technical solution, the transient overvoltage suppression device is composed of multiple silicon bilateral diodes connected in parallel and each series-connected with a conducting device. The conducting device is matched according to the secondary fluctuation voltage value calculated from the secondary voltage value. It can enable the branch with a lower conducting voltage to accurately suppress the transient overvoltage when the voltage fluctuation is small, and enable the branch with a higher conducting voltage when the voltage fluctuation is large, so as to adapt to different degrees of voltage fluctuation, ensure reliable on-load voltage regulation, improve the adaptability and stability of the voltage regulation system; at the same time, accurately matching the conducting device can reduce the impact of voltage fluctuation on power quality, ensure the normal operation of electrical equipment, improve the user's power consumption experience, and also reduce the electrical impact on the equipment, reduce the failure rate, extend the service life of the equipment, improve the economy of the power system, and this automatic matching control according to the secondary fluctuation voltage value reflects the intelligence of the voltage regulation system, meeting the development needs of automation and intelligence in modern power systems.

[0010] Optionally, the method further includes the following steps: The transient overvoltage suppression device includes multiple silicon bilateral diodes connected in parallel, and each silicon bilateral diode is series-connected with a conducting device; Calculate the secondary fluctuation frequency value of the secondary voltage value in the most recent time period; Judge the frequency range to which the secondary fluctuation frequency value belongs, and match the corresponding conducting device for conduction according to the frequency range; If in the most recent time period, the secondary fluctuation frequency value repeatedly jumps horizontally between adjacent frequency ranges, and the number of horizontal jumps is greater than a preset threshold, then adjust the action period of the action end in positive correlation with the number of horizontal jumps; The larger the number of horizontal jumps, the longer the action period; the smaller the number of horizontal jumps, the shorter the action period.

[0011] By adopting the above technical solution, the transient overvoltage suppression device uses multiple silicon bilateral diodes connected in parallel and each series-connected with a conducting device, and matches the conducting device according to the frequency range to which the secondary fluctuation frequency value belongs, accurately suppressing transient overvoltages of different frequencies and ensuring the safe and stable operation of the equipment; when the secondary fluctuation frequency value repeatedly jumps horizontally between adjacent frequency ranges and the number of jumps exceeds the preset threshold, adjust the action period of the action end in positive correlation with the number of horizontal jumps, optimize the action strategy, extend the service life of the equipment and improve the voltage regulation efficiency; accurately suppressing transient overvoltages and reasonably adjusting the action period reduce system interference and unstable factors, improve the operation stability and power supply reliability of the on-load voltage regulation system; this system is automatically controlled according to the secondary fluctuation frequency value and the number of horizontal jumps, enhancing the adaptability and intelligence level, conforming to the development trend of intelligence in modern power systems, and improving the overall performance.

[0012] Optionally, the action end is linked with a driving motor, and the method includes the following steps: Adjust the operating speed of the drive motor in inverse correlation with the secondary voltage value; The greater the voltage value on the secondary side, the smaller the operating speed of the drive motor; the smaller the voltage value on the secondary side, the greater the operating speed of the drive motor.

[0013] By adopting the above technical solution, when the secondary side voltage value is low, the drive motor operates quickly, and the contact end connecting to reduce the number of turns of the primary side winding is lifted to increase the secondary voltage. When the voltage value is high, the motor operation slows down, and the contact end connecting to increase the number of turns of the primary side winding is used to avoid excessive adjustment. This method of adjusting the operating speed of the drive motor in real-time inverse correlation with the voltage value improves the voltage regulation efficiency and accuracy, ensures the stability of the output voltage, and guarantees the normal operation of the electrical equipment. At the same time, it can also avoid unnecessary high-speed operation of the motor, reduce equipment wear, mechanical loss and energy consumption, extend the service life of the equipment, reduce the maintenance cost, and improve the economy of the on-load tap-changer system. Moreover, it can adaptively adjust the motor speed during voltage fluctuations, make the voltage regulation process smooth, prevent unstable problems such as system oscillation, improve the reliability and stability of the on-load tap-changer system, and reduce the interference to other parts of the power system.

[0014] Optionally, a lightning arrester is connected in parallel with the phase correction capacitor.

[0015] By adopting the above technical solution, during the operation of the power system, lightning strikes, operations, etc. can cause overvoltage. The lightning arrester can quickly conduct when overvoltage appears and introduce the charge into the ground to limit the voltage amplitude. The phase correction capacitor is crucial for improving the circuit phase relationship and power factor. After connecting the lightning arrester in parallel, the lightning arrester acts preferentially during overvoltage to protect the phase correction capacitor from being damaged, ensure its continuous and stable operation, maintain the normal operation of the system, reduce system failures caused by phase problems, and improve the reliability of the power system. At the same time, the lightning arrester reduces the damage probability of the phase correction capacitor, reduces the equipment repair and replacement frequency, saves costs, and effectively controls the maintenance cost of the on-load tap-changer system. In addition, the parallel connection of the lightning arrester and the phase correction capacitor also reduces the risk of electrical accidents caused by overvoltage, and guarantees the safety of equipment and personnel.

[0016] Optionally, the inductance values of each current-limiting reactor are equal, and its inductive reactance is equal to the capacitive reactance of the phase correction capacitor. The circulating current of each current-limiting reactor under the tap voltage of adjacent taps of the existing transformer is less than 1% of the rated current; the operating end can be selected to stay at a position between two taps and supply power to the circuits of both taps simultaneously.

[0017] By adopting the above technical solution, the no-load tap-changer position is adjusted by driving a stepper motor, a current-limiting reactor is used to suppress the circulating current, and a phase-correcting capacitor cancels its reactance to the load current, avoiding complex technologies to achieve on-load voltage regulation. At the same time, a silicon bilateral diode is used to suppress transient overvoltage, and the impedance matching characteristic of the inductive-capacitive three-port circuit can be used to realize simultaneous power supply of two taps, constructing a tap position multiplication effect to achieve smooth voltage regulation at a ratio of 1.25%.

[0018] Optionally, the method further includes the following steps: When an action is performed at the action end, magnetic field change data on the primary side is acquired; The magnetic field change data is subjected to spectral analysis to obtain magnetic field change data in the frequency domain signal; The amplitude and phase of the magnetic field change data in the frequency domain signal are calculated; Spectral features are extracted according to the amplitude and phase, and the spectral features include a peak frequency band and a frequency band energy distribution; The spectral features are normalized to obtain corresponding eigenvalue; The corresponding silicon bilateral diode is turned on according to the eigenvalue matching;

[0019] By adopting the above technical solution, when an action is performed at the action end, magnetic field change data on the primary side is acquired in real time and spectral analysis is performed, converting the time-domain signal into a frequency-domain signal, which can clearly present the change characteristics of different frequency components. The amplitude and phase are calculated, spectral features are extracted and normalized to obtain eigenvalues, and the silicon bilateral diode is turned on by matching, which can accurately suppress transient overvoltage, improve the pertinence and effectiveness of suppression. This method can quickly respond to transient overvoltage, timely discharge the overvoltage energy, protect the equipment insulation and normal operation, has an adaptive protection ability, and can comprehensively and reliably protect the equipment. Accurately suppressing transient overvoltage can reduce the interference to the power system, ensure the stable operation of the system, improve the power quality, enhance the reliability of the power system, reduce the power outage risk, and meet the user's demand for continuous and stable power supply.

[0020] Optionally, after calculating the amplitude and phase of the magnetic field change data in the frequency domain signal, the method further includes the following steps: The signal within the first characteristic frequency band range is extracted from the magnetic field change data in the frequency domain signal; The discrete degree of the amplitudes of all frequency points within the first characteristic frequency band range is calculated as the first discrete coefficient; If the first discrete coefficient is greater than a preset first threshold, the execution speed of the action end is adjusted in an anti-correlation manner according to the first discrete coefficient; The signal within the second characteristic frequency band range is extracted from the magnetic field change data in the frequency domain signal; Calculate the discrete degree of the amplitude of all frequency points within the second characteristic frequency band as a second discrete coefficient; If the second discrete coefficient is greater than a preset second threshold, adjusting the execution speed of the action end according to the positive correlation of the second discrete coefficient; Among them, the values ​​within the first characteristic frequency band are all greater than the values ​​within the second characteristic frequency band.

[0021] By adopting the above technical solution, the solution realizes adaptive adjustment of the execution speed of the action end by monitoring and analyzing the characteristics of magnetic field changes in different frequency bands. When the amplitude discreteness of the first characteristic frequency band (high frequency band) exceeds the first threshold, it indicates that the magnetic field changes violently and unstable, which may be caused by high-frequency interference sources. At this time, the anti-correlation reduces the execution speed to avoid malfunction and equipment damage; when the amplitude discreteness of the second characteristic frequency band (low frequency band) exceeds the second threshold, it means that the magnetic field fluctuates greatly, which may be related to low-frequency oscillations, etc. At this time, the positive correlation increases the execution speed to prevent the low-frequency oscillation from intensifying. This adaptive adjustment makes the action end action more in line with the actual system, improves the voltage regulation efficiency and accuracy, reduces the adjustment error, reduces the system loss, enhances the anti-interference ability, and ensures the stable operation of the system.

[0022] In a second aspect, the present application provides an on-load voltage regulating device based on an existing transformer, which adopts the following technical solution: An on-load voltage regulation device based on an existing transformer comprises a processor, wherein the processor executes the steps of the on-load voltage regulation method based on an existing transformer as described in any one of the above.

[0023] In a third aspect, the present application provides a storage medium, which adopts the following technical solution: A storage medium stores a program, and when the program is executed by a processor, the steps of any one of the above-mentioned on-load voltage regulation methods based on an existing transformer are implemented.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: A voltage regulation execution controller is added to drive the stepper motor, detect the voltage at the output end of the transformer, and realize closed-loop regulation of the voltage position of the existing no-load tap changer, thus solving the problem of frequent voltage regulation under power. The high reactance rate of the current limiting reactor is used to limit the current and suppress the circulating current during the gear shifting process. At the same time, a phase correction capacitor is connected in series to offset the reactance of the current limiting reactor to the load current, so that it can suppress the circulating current at a high ratio and the reactance to the load current is zero, avoiding the complex transition resistor multi-group contact technology, and realizing live voltage regulation by relying on a simple no-load voltage regulating tap changer. Through silicon bidirectional diode protection, transient overvoltage during the gear shifting process can be effectively suppressed to ensure safe operation of the equipment. By virtue of the impedance matching characteristic of the inductance-capacitance three-port circuit, the operating end can stay between two gears, enabling simultaneous power supply to two taps, constructing a tapping gear multiplication effect, and achieving smooth voltage regulation at a ratio of 1.25% for each gear. Description of the Drawings

[0025] Figure 1 It is a on-load tap-changer circuit diagram based on an existing transformer.

[0026] Figure 2 It is a circuit diagram of a transient overvoltage suppression device including multiple silicon bilateral diodes connected in parallel.

[0027] Reference Signs: 1. Existing transformer; 2. Off-load tap-changer; 3. Transient overvoltage suppression device; 4. Phase correction capacitor; 5. Current-limiting reactor; 6. Contact end; 7. Primary side bushing; 8. Conductive device; 9. Driving motor; 10. Tap-changing execution controller; 11. Lightning arrester. Detailed Embodiments

[0028] The following describes in detail the embodiments of the present application, and the examples of the embodiments are shown in the drawings.

[0029] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0030] The embodiments of the present application disclose a on-load tap-changing method based on an existing transformer. Referring to Figure 1 , based on the off-load tap-changer 2 connected to the transformer, it includes the following steps: A transient overvoltage suppression device 3 is provided on the off-load tap-changer 2. One end of the transient overvoltage suppression device 3 is connected to the operating end of the off-load tap-changer 2, and the other end is connected to the contact terminal 6 corresponding to the voltage of the intermediate gear in the off-load tap-changer 2. Among them, the conduction voltage of the transient overvoltage suppression device 3 is greater than the voltage difference between the positive and negative maximum voltage gears between the operating end and the contact terminal 6 corresponding to the voltage of the intermediate gear. Thus, it is ensured that within the normal voltage fluctuation range, the transient overvoltage suppression device 3 will not conduct randomly, thereby avoiding unnecessary interference to the normal operation of the system. And once a transient overvoltage situation occurs and the voltage difference exceeds the voltage difference between the positive and negative maximum voltage gears between the operating end and the contact terminal 6 corresponding to the voltage of the intermediate gear, the transient overvoltage suppression device 3 will be quickly activated to effectively divert the energy generated by the overvoltage, thereby protecting the electrical equipment in the entire system from the impact and damage of the transient overvoltage.

[0031] The operating end is connected with a phase correction capacitor 4 and is connected to a primary bushing 7 through the phase correction capacitor 4. The phase correction capacitor 4 can improve the power factor of the system, reduce the reactive power loss, and further improve the operating efficiency of the entire power system by adjusting the phase relationship between the current and the voltage. And the operating end is connected to a primary bushing 7 through the phase correction capacitor 4, further constructing a complete electrical path to ensure the stable transmission and distribution of electric energy on the primary side.

[0032] Each contact terminal 6 is correspondingly connected with a current-limiting reactor 5 one by one. Different contact terminals 6 are connected to taps with different turns on the winding of the primary side of the transformer through the corresponding current-limiting reactors 5. The tap of the primary side coil of the transformer far from the contact terminal 6 is connected to another primary bushing 7. Since the taps with different turns on the transformer winding correspond to different voltage outputs, through this connection method, the appropriate tap can be accurately selected according to the actual voltage regulation requirements to achieve precise regulation of the output voltage of the transformer. And the tap of the primary side coil of the transformer far from the contact terminal 6 is connected to another primary bushing 7, which further improves the circuit structure of the primary side of the transformer to ensure the stable flow of current and the effective output of voltage on the primary side.

[0033] The number of static contacts of the off-load switching switch is the same as the number of tap-changer taps of the existing transformer 1. Each winding tap contact terminal 6 is connected to the tap-changer taps of the existing transformer 1 in sequence according to the voltage level.

[0034] Detect the secondary voltage value of the transformer secondary side.

[0035] Drive the contact terminal 6 to which the operating end is connected according to the secondary voltage value, which is positively correlated with the secondary voltage value.

[0036] When the secondary voltage value is low, the system will automatically control the moving end to connect to the contact end 6 that can reduce the number of turns of the primary winding. According to the voltage transformation ratio principle of the transformer, this can increase the output voltage of the secondary side. Conversely, when the secondary voltage value is high, the moving end will be connected to the contact end 6 that can increase the number of turns of the primary winding, thereby reducing the output voltage of the secondary side, so as to achieve dynamic and precise adjustment of the output voltage of the transformer, ensure that the output voltage is always stable within a reasonable range, and meet the normal operation requirements of various electrical equipment.

[0037] Suppose a transformer tap changer has 5 taps, corresponding to different numbers of turns of the primary winding respectively. From tap 1 to tap 5, the number of turns increases in sequence.

[0038] At a certain moment, the secondary voltage value of the transformer secondary side is detected to be 370V, which is lower than the normal operating voltage range (usually the industrial electricity standard voltage is 380V - 400V). At this time, according to the above voltage regulation method, the system detects that the secondary voltage value is low and will automatically control the moving end to connect to the contact end 6 that can reduce the number of turns of the primary winding. Suppose the current moving end is connected to tap 3, and the corresponding number of turns of the primary winding is N3. In order to increase the secondary voltage, the system switches the moving end to tap 2, and the corresponding number of turns of the primary winding of tap 2 is N2, and N2 < N3.

[0039] According to the voltage transformation ratio principle of the transformer, the voltage transformation ratio formula is K = U2 / U1 = N2 / N1, where U1 is the primary side voltage, U2 is the secondary side voltage, N1 is the number of turns of the primary winding, and N2 is the number of turns of the secondary winding. When the primary side voltage U1 remains unchanged, when the number of turns of the primary winding decreases from N3 to N2, the secondary side voltage U2 will increase accordingly. After actual measurement, the secondary side voltage rises to 385V after switching, meeting the normal operating voltage requirements of most industrial equipment.

[0040] After a period of time, due to the shutdown of large industrial equipment, the power consumption load drops significantly, and the secondary voltage value rises to 410V. The system detects the voltage anomaly again and judges that the secondary voltage value is high. At this time, the moving end will switch from the currently connected tap 2 to tap 3 that can increase the number of turns of the primary winding. By increasing the number of turns of the primary winding, according to the voltage transformation ratio principle, the secondary side voltage will decrease. Measuring the secondary voltage again, it is found that it drops to 390V, returning to the reasonable voltage range again, ensuring the stable operation of industrial equipment and avoiding potential damage to the equipment caused by excessive voltage.

[0041] By detecting the voltage value on the secondary side of the transformer and adjusting the contact terminal 6 connected to the operating terminal of the off-load tap-changer 2 accordingly, the number of turns of the primary side winding can be adjusted in real time, thereby stabilizing the output voltage on the secondary side. When the secondary voltage is low, the number of turns of the primary side winding is reduced, and the secondary voltage is increased according to the transformer voltage transformation ratio principle; when the secondary voltage is high, the number of turns of the primary side is increased to reduce the secondary voltage, so that the output voltage is maintained within a reasonable range, effectively solving the problem of unstable power supply caused by voltage fluctuations and ensuring the normal operation of the user's electrical equipment. The transient overvoltage suppression device 3 provided on the off-load tap-changer 2 can prevent the transient overvoltage generated during the operation of the tap-changer from damaging the equipment. Its conduction voltage is greater than the voltage difference between the positive and negative maximum voltage levels between the operating terminal and the corresponding intermediate voltage contact terminal 6, and it will only conduct when a transient overvoltage occurs, limiting the overvoltage within a safe range, protecting the transformer, tap-changer and other related electrical equipment, extending the service life of the equipment, and improving the reliability of the system operation. The phase correction capacitor 4 connected to the operating terminal can improve the phase relationship of the circuit. During the operation of the transformer, by adjusting the phase of the current and voltage, the power factor can be improved, the reactive power loss can be reduced, the power transmission efficiency can be increased, and the operation of the entire power system can be made more economical and efficient. The current-limiting reactor 5 connected to each contact terminal 6 can effectively limit the circulating current between the windings when different contact terminals 6 are connected to different turn taps of the primary side winding of the transformer. The circulating current will increase the equipment loss and affect the equipment life. The current-limiting reactor 5 controls the circulating current at a safe level through its own reactance characteristics, reducing the adverse impact of the circulating current on the equipment and ensuring the safety and stability of the on-load tap-changing process. Driving the operating terminal to connect different contact terminals 6 accurately according to the secondary voltage value realizes the refined adjustment of the output voltage of the transformer. This voltage regulation method can be flexibly adjusted according to the actual voltage demand. Compared with the traditional voltage regulation method, it can more accurately meet the voltage requirements of different users and electrical equipment, improve the power supply quality, and reduce the risk of damage to electrical equipment caused by excessive voltage deviation.

[0042] Refer to Figure 2 , the method further includes the following steps: The transient overvoltage suppression device 3 includes a plurality of silicon bilateral diodes connected in parallel, and each silicon bilateral diode is connected in series with a conduction device 8; the conduction device 8 is a switching device controlled by a background control system.

[0043] Calculate the secondary fluctuation voltage value of the secondary voltage value in the most recent time period; the secondary fluctuation voltage value reflects the change amplitude and trend of the voltage in this time period.

[0044] Determine the voltage fluctuation range to which the secondary fluctuation voltage value belongs; where the voltage fluctuation range is pre-divided into multiple different intervals, and each interval corresponds to a different degree of voltage change. For example, a slight fluctuation range, a moderate fluctuation range, and a severe fluctuation range may be set. By accurately determining the range in which the secondary fluctuation voltage value is located, the system can take corresponding measures more targeted.

[0045] Match a corresponding conducting device 8 according to the voltage fluctuation range and turn on the matched conducting device 8. According to the determined voltage fluctuation range, the system will match a corresponding one from multiple conducting devices 8. This matching process is based on pre-set rules and algorithms, aiming to ensure that the selected conducting device 8 can most effectively suppress the transient overvoltage under the current voltage fluctuation condition. Different voltage fluctuation ranges correspond to conducting devices 8 with different characteristics to achieve precise voltage control. The system will turn on the matched conducting device 8 to put it into the working state. Once turned on, the branch composed of the silicon bilateral diode and the conducting device 8 will start to function, quickly suppress the transient overvoltage, limit the overvoltage within a safe range, thereby protecting the transformer and other related electrical equipment from damage.

[0046] Suppose a transformer device using the above voltage regulation method is installed in the power supply system of a residential community. During the peak electricity consumption period of a certain day, due to a large number of residents using various electrical equipment at the same time, the voltage on the secondary side of the transformer fluctuates significantly. The system monitors and calculates the secondary voltage value within the recent 10 minutes and obtains that the secondary fluctuation voltage value is ±15V. After analysis and judgment, this secondary fluctuation voltage value is within the moderate fluctuation range. According to the pre-set rules, the moderate fluctuation range corresponds to the conducting device 8 numbered 3. Therefore, the background control system quickly issues an instruction to turn on the conducting device 8 numbered 3. The branch composed of the conducting device 8 and the corresponding silicon bilateral diode immediately starts to work, effectively suppressing the generation of transient overvoltage, making the secondary voltage value gradually return to stability, ensuring the normal operation of the electrical equipment in the residential community, and avoiding equipment damage or faults that may be caused by excessive voltage fluctuations.

[0047] The transient overvoltage suppression device 3 employs multiple silicon bilateral diodes connected in parallel, and each silicon bilateral diode is in series with a conduction device 8. Based on the secondary voltage fluctuation value calculated from the secondary voltage value, the corresponding conduction device 8 can be matched and made to conduct. This means that different silicon bilateral diodes can be flexibly enabled according to the actual situation of voltage fluctuation. When the voltage fluctuation is small, the silicon bilateral diode branch with a lower breakdown voltage is selected to operate, precisely suppressing the transient overvoltage, avoiding damage to equipment caused by excessive voltage, and protecting the safe and stable operation of the transformer and related equipment. By judging the voltage fluctuation range to which the secondary voltage fluctuation value belongs to match the conduction device 8, the voltage regulation method can better adapt to different degrees of voltage fluctuation. When the voltage fluctuation is large, the silicon bilateral diode branch with a higher breakdown voltage is enabled to ensure that the transient overvoltage suppression device 3 can effectively operate under various complex working conditions, ensuring reliable on-load voltage regulation under different voltage fluctuation conditions, and improving the adaptability and stability of the entire voltage regulation system. Precisely matching the conduction device 8 to suppress the transient overvoltage reduces the impact of voltage fluctuation on power quality. Problems such as voltage spikes and harmonics caused by transient overvoltage can be avoided, providing users with more stable and pure electric energy, reducing interference to sensitive electrical equipment, ensuring the normal operation of various electrical equipment, and enhancing the user's electricity consumption experience. Effectively suppressing the transient overvoltage can reduce the electrical impact on equipment such as transformers and tap changers, and reduce the failure rate of the equipment. Frequent voltage fluctuations and transient overvoltages will accelerate the insulation aging of the equipment and damage internal components, while precise transient overvoltage suppression can reduce the burden on the equipment, extend the service life of the equipment, reduce the equipment maintenance cost and replacement frequency, and improve the economy of the power system. Matching and controlling the conduction device 8 according to the secondary voltage fluctuation value reflects the intelligence of the voltage regulation system. This process is automatic and does not require manual intervention, can quickly respond to voltage changes, achieve intelligent regulation of transient overvoltage, make the operation of the entire on-load voltage regulation system more efficient and intelligent, and meet the requirements of the automation and intelligence development of modern power systems.

[0048] In other embodiments, the method further includes the following steps: The transient overvoltage suppression device 3 includes multiple silicon bilateral diodes connected in parallel, and each silicon bilateral diode is in series with a conduction device 8; the conduction device 8 is also a switching device controlled by the background control system.

[0049] Calculate the secondary voltage fluctuation frequency value of the secondary voltage value in the most recent time period; the secondary voltage fluctuation frequency value reflects the characteristics of voltage fluctuation in the frequency dimension during this period. For example, it may reveal whether the voltage fluctuates rapidly at a high frequency, slowly at a low frequency, or is in a certain complex frequency change pattern.

[0050] Determine the frequency range to which the secondary fluctuation frequency value belongs, and match the corresponding conducting device 8 for conduction according to the frequency range. These frequency ranges are pre-divided according to the operating characteristics of the system and different manifestations of transient overvoltage. Different frequency ranges correspond to different types of voltage fluctuation conditions, respectively representing voltage abnormalities caused by different reasons. For example, the high-frequency range may be related to the rapid switching actions of power electronic devices, and the low-frequency range may be related to voltage disturbances caused by the startup or shutdown of large equipment. The system accurately matches a corresponding one from numerous conducting devices 8 according to the judgment result and conducts it. This enables the silicon bilateral diode branch connected thereto to respond quickly and effectively suppress the transient overvoltage in a specific frequency range.

[0051] If within the most recent time period, the secondary fluctuation frequency value repeatedly jumps between adjacent frequency ranges, and the number of jumps is greater than the preset threshold, then adjust the action period of the action end in positive correlation with the number of jumps; the greater the number of jumps, the longer the action period; the smaller the number of jumps, the shorter the action period. The secondary fluctuation frequency value repeatedly jumping between adjacent frequency ranges indicates that the system is in an unstable voltage fluctuation state. At this time, the system adjusts the action period of the action end in positive correlation with the number of jumps. The greater the number of jumps, the higher the degree of voltage fluctuation instability. To avoid the action end acting frequently and unnecessarily, thereby causing additional impacts and losses to the system, the system will correspondingly extend the action period of the action end; conversely, the smaller the number of jumps, the relatively lower the degree of voltage fluctuation instability, and the action period of the action end will be shortened so as to be able to respond more promptly to relatively stable voltage changes.

[0052] Taking the power supply system of an industrial park as an example. There are a large number of different types of industrial equipment in the park, and their electricity consumption characteristics vary greatly. On the morning of a working day, due to the frequent startup and shutdown of some automated production lines, the voltage on the secondary side of the transformer fluctuated. The system began to calculate the secondary fluctuation frequency value. Within 15 minutes, it was found that the secondary fluctuation frequency value frequently jumped back and forth between 50 - 60 Hz (corresponding to a frequency range) and 60 - 70 Hz (adjacent frequency range) as many as 20 times, far exceeding the preset threshold of 10 times. Based on this, the system adjusted the action period of the action end in positive correlation with the number of jumps, extending the original short action period from 5 seconds to 15 seconds. In this way, the action end will not act frequently due to the frequent unstable voltage fluctuations, effectively reducing equipment wear and system interference. In the afternoon, with the adjustment of the production process, the voltage fluctuation tended to be stable, and the secondary fluctuation frequency value had only 3 jumps between adjacent frequency ranges within a certain period of time. The system then correspondingly shortened the action period to 8 seconds, enabling the action end to make necessary adjustments more quickly according to voltage changes, ensuring the stable operation of various equipment in the industrial park, and improving the reliability and stability of the power supply system.

[0053] The transient overvoltage suppression device 3 adopts multiple silicon bilateral diodes connected in parallel, and each series conduction device 8 is matched according to the frequency range to which the secondary fluctuation frequency value belongs. Transient overvoltages of different frequencies may be generated by different reasons, such as switching on and off of different types of equipment and faults in the power system. In this way, the corresponding silicon bilateral diode branches can be accurately enabled for transient overvoltages of different frequencies, effectively suppressing the transient overvoltages, protecting the transformer and related equipment from the impact of overvoltages of different frequencies, and improving the safety and stability of equipment operation. When the secondary fluctuation frequency value repeatedly jumps between adjacent frequency intervals and the number of jumps is greater than the preset threshold, the action period of the action end is adjusted positively correlated with the number of jumps. This strategy fully considers the complex situation of voltage fluctuations. When the voltage fluctuates frequently but has not reached a stable state, it avoids frequent actions of the action end. Because frequent actions will not only increase equipment wear but also may trigger new transient problems. The action period is adaptively adjusted according to the number of jumps. The larger the number of jumps, the longer the action period, reducing unnecessary actions; the smaller the number of jumps, the shorter the action period, which can promptly respond to relatively stable voltage changes for voltage regulation, realizing the optimization of the action strategy of the action end, extending the service life of the equipment, and improving the voltage regulation efficiency at the same time. Precise transient overvoltage suppression and reasonable action period adjustment reduce the interference of transient overvoltages to the system and the unstable factors that may be brought by frequent actions of the action end. The entire on-load voltage regulation system can operate more stably in the face of complex voltage fluctuations, reducing the system failure risk, improving the power supply reliability, and ensuring the continuous and stable power supply of the power system to users. Corresponding control is carried out according to the secondary fluctuation frequency value and the number of jumps, enabling the system to automatically adapt to different voltage fluctuation conditions. Without frequent manual intervention, the system can make intelligent decisions according to the real-time situation, realizing the automatic adjustment of transient overvoltage suppression and the action period of the action end, enhancing the adaptability and intelligent level of the system, conforming to the trend of the intelligent development of modern power systems, and improving the overall performance of the power system.

[0054] The action end is linked with a driving motor 9, and the driving motor 9 is controlled by a voltage regulation execution controller 10. The method includes the following steps: The action speed of the driving motor 9 is adjusted inversely correlated with the secondary voltage value; the larger the voltage value on the secondary side, the smaller the action speed of the driving motor 9; the smaller the voltage value on the secondary side, the larger the action speed of the driving motor 9.

[0055] When the voltage value on the secondary side is at a relatively high level, it means that the output voltage of the current power system is relatively abundant. At this time, there is no need to drive the motor 9 to operate quickly to adjust the voltage. On the contrary, in order to avoid voltage instability caused by over-adjustment, the voltage regulation execution controller 10 will issue an instruction to slow down the action speed of the drive motor 9. This allows the action end to make adjustments at a relatively steady pace, ensuring that the voltage is slowly optimized within a suitable range and preventing large fluctuations in voltage caused by rapid actions.

[0056] Conversely, when the voltage value on the secondary side is low, it indicates that the output voltage of the power system fails to meet the actual demand, and it is urgent to quickly increase the voltage to ensure the normal operation of various electrical equipment. In this case, the voltage regulation execution controller 10 will respond quickly. Based on the monitored low-voltage data, it will issue an acceleration instruction to the drive motor 9, prompting a significant increase in the action speed of the drive motor 9. The drive motor 9 runs at a high speed, driving the action end to move quickly and connect quickly to the contact end 6 that can reduce the number of turns of the primary side winding. According to the transformer voltage transformation ratio principle, the output voltage on the secondary side is then quickly increased, enabling the voltage to quickly return to a reasonable working range.

[0057] Taking the power supply system of a commercial complex as an example, the complex includes various business forms such as shopping malls, office buildings, and hotels, with a large number of electrical equipment and complex and changeable electricity demands. During the lunchtime on weekdays, a large number of lighting equipment, air conditioning systems, and electrical equipment of catering merchants in the shopping mall operate simultaneously, resulting in a sharp increase in the power load, causing the voltage value on the secondary side of the transformer to drop to 360V, far lower than the standard range of 380V - 400V. The voltage regulation execution controller 10 quickly captures this voltage change and immediately increases the action speed of the drive motor 9 according to the preset inverse correlation adjustment rule. The drive motor 9 runs quickly, driving the action end to quickly switch to the appropriate contact end 6, reducing the number of turns of the primary side winding. After a short adjustment, the secondary side voltage quickly rises to 385V, meeting the normal electricity demands of various equipment in the commercial complex.

[0058] And late at night, most merchants and office areas stop operating and working, resulting in a significant reduction in the power load. The voltage value on the secondary side of the transformer rises to 405V. The voltage regulation execution controller 10 comes into play again. Based on the relatively high secondary voltage value at this time, it reduces the action speed of the drive motor 9. The drive motor 9 runs slowly, driving the action end to adjust slowly, increasing the number of turns of the primary side winding, making the secondary side voltage gradually stabilize at 390V, avoiding potential damage to equipment caused by excessive voltage, and at the same time ensuring the stable operation of the entire power supply system of the commercial complex, preparing for normal operation and work the next day.

[0059] When the secondary side voltage value is relatively low, the drive motor 9 operates quickly, causing the operating end to quickly connect to the contact end 6 that can reduce the number of turns of the primary side winding, thereby rapidly increasing the secondary side voltage. Conversely, when the secondary side voltage value is relatively high, the operating speed of the drive motor 9 slows down, allowing the operating end to slowly adjust to the contact end 6 that increases the number of turns of the primary side winding, avoiding excessive voltage regulation. This method of adjusting the operating speed in real time according to the voltage value enables the voltage regulation process to approach the target voltage value more quickly, reduces the voltage regulation time, and at the same time effectively prevents the voltage regulation amplitude from being too large or too small, significantly improving the efficiency and accuracy of voltage regulation, ensuring that the output voltage is stable within a reasonable range, and guaranteeing the normal operation of the user's electrical equipment. The operating speed of the drive motor 9 is inversely related to the secondary voltage value, which can prevent the motor from running at high speed when unnecessary. When the voltage deviation is small, the motor runs at a low speed, reducing the wear of the motor and related transmission components and lowering the mechanical losses of the equipment. At the same time, the reduction in the motor speed also means a decrease in energy consumption, which helps to extend the service life of the equipment, reduce the maintenance cost, and improve the economy of the entire on-load tap-changer system. When the voltage fluctuates greatly, the motor operates quickly to rapidly adjust the voltage; when the voltage approaches stability, the motor decelerates, making the voltage regulation process smoother. This helps to prevent the voltage from changing too rapidly due to the motor operating too quickly, causing system oscillations or other instability problems. Through this adaptive adjustment of the operating speed, the entire on-load tap-changer system can maintain stable operation under different voltage conditions, improving the reliability and stability of the system and reducing the interference to other parts of the power system.

[0060] The phase correction capacitor 4 is connected in parallel with a lightning arrester 11.

[0061] During the operation of the power system, various overvoltage situations may occur, such as lightning overvoltage, switching overvoltage, etc. The main function of the lightning arrester 11 is to conduct rapidly when overvoltage appears, introduce the charges generated by the overvoltage into the ground, thereby limiting the voltage amplitude. When the phase correction capacitor 4 is connected in parallel with the lightning arrester 11, once overvoltage occurs, the lightning arrester 11 acts preferentially to prevent the overvoltage from damaging the phase correction capacitor 4, prolongs the service life of the phase correction capacitor 4, ensures that it can continuously and stably improve the circuit phase relationship, and maintains the normal operation of the system. The phase correction capacitor 4 plays a key role in improving the circuit phase relationship and power factor. If the phase correction capacitor 4 is damaged due to overvoltage, the phase characteristics of the circuit will be affected, which may lead to problems such as reduced power factor and increased power loss. The parallel protection of the lightning arrester 11 can ensure the normal operation of the phase correction capacitor 4, thereby ensuring the stable operation of the entire circuit, reducing system failures caused by phase problems, and improving the reliability of the power system. Due to the protection of the lightning arrester 11, the damage probability of the phase correction capacitor 4 is reduced, and the maintenance and replacement frequency of the equipment are also reduced. This not only saves maintenance time and labor costs, but also reduces the material costs generated by equipment replacement, improves the economic efficiency of the power system operation, and effectively controls the maintenance costs of the entire on-load tap-changer system. Overvoltage may cause serious faults such as insulation breakdown and short circuit of electrical equipment, posing a threat to the safety of equipment and personnel. The parallel connection of the lightning arrester 11 and the phase correction capacitor 4 effectively limits the overvoltage, reduces the risk of electrical accidents caused by overvoltage, ensures the safe operation of the power system, and provides a more reliable safety guarantee for operators and surrounding equipment.

[0062] The inductance values of each current-limiting reactor 5 are equal, its inductive reactance is equal to the capacitive reactance of the phase correction capacitor 4, and the circulating current of each current-limiting reactor 5 under the tap voltage of adjacent tap positions of the existing transformer 1 is less than 1% of the rated current; the action end can be selected to stay at the position between two tap positions and supply power to the circuits of two tap positions at the same time.

[0063] The on-load tap-changer tap position is adjusted by driving the stepping motor through the voltage regulation execution controller 10, the current-limiting reactor 5 is used to suppress the circulating current, and the phase correction capacitor 4 cancels its reactance to the load current, avoiding complex technologies to achieve on-load voltage regulation. At the same time, the transient overvoltage is suppressed by means of a silicon bilateral diode, and the impedance matching characteristic of the inductance-capacitance three-port circuit can be used to achieve simultaneous power supply of two taps, constructing a tap position multiplication effect to achieve smooth voltage regulation at a ratio of 1.25%.

[0064] The inductance values of each current-limiting reactor 5 are equal, and the circulating current generated by its inductive reactance under the tap voltages of adjacent positions of the existing transformer 1 is less than 1% of the rated current. During the voltage regulation process of the transformer, there is a potential difference between different taps, which is likely to generate a circulating current. Excessive circulating current will not only increase power loss but also may damage equipment. This design of the current-limiting reactor 5 can limit the circulating current to an extremely low level, ensuring the stability and safety of the transformer during the voltage regulation process and reducing the fault risk caused by the circulating current. The use of silicon bilateral diodes can effectively suppress transient overvoltage. During the voltage regulation process of the transformer, especially at the moment of tap change, transient overvoltage is likely to occur, which may damage the equipment. The silicon bilateral diode can conduct quickly when overvoltage appears, discharging the overvoltage energy and protecting the insulation performance of the transformer and related equipment, and prolonging the service life of the equipment.

[0065] The capacitive reactance of the phase correction capacitor 4 is equal to the inductive reactance of the current-limiting reactor 5, which can offset the reactance effect of the current-limiting reactor 5 on the load current. While suppressing the circulating current, the current-limiting reactor 5 will have a certain reactance effect on the load current, affecting the power transmission efficiency. The addition of the phase correction capacitor 4 optimizes the impedance characteristics of the circuit, improves the power factor, reduces the reactive power loss, and enhances the operation efficiency of the entire power system. Utilizing the impedance matching characteristics of the inductance-capacitance three-port circuit, it is possible to supply power simultaneously from two taps. This characteristic enables the operating end to stay between two taps and supply power to the circuits of the two taps simultaneously, achieving a more flexible voltage regulation method. Through reasonable impedance matching, the stability and balance during power supply from the two taps are ensured, avoiding equipment damage or voltage fluctuations caused by uneven power supply.

[0066] The operating end can stay between two taps and supply power to the circuits of the two taps simultaneously, creating the effect of multiplying the tap positions. The tap positions of traditional transformers are fixed, with a limited adjustment range. However, through this innovative method, this solution is equivalent to doubling the number of adjustment taps on the original basis, greatly expanding the voltage regulation range and being able to more precisely meet the voltage requirements of different loads. It achieves a smooth voltage regulation with a ratio of 1.25%. Compared with the relatively large voltage regulation step of traditional transformers, this solution can achieve more precise voltage regulation, making the voltage change smoother. This is of great significance for loads with high requirements for voltage stability, such as precision electronic equipment, etc., and can effectively reduce the impact of voltage fluctuations on the equipment, improving the operation stability and reliability of the equipment.

[0067] The inductive-capacitive three-port circuit includes inductors and capacitor components, and its impedance matching characteristics can enable the circuit to achieve an adapted state of impedance between different ports under specific conditions. In the voltage regulating device of the present invention, by carefully designing the parameters of the current-limiting reactor 5 (inductor) and the phase correction capacitor 4 (capacitor), the inductive-capacitive three-port circuit plays a crucial role in the transformer voltage regulation process. For example, the inductance values of each current-limiting reactor 5 are equal, and its inductive reactance is equal to the capacitive reactance of the phase correction capacitor 4. This parameter matching lays the foundation for realizing subsequent functions. When the traditional off-load tap-changer 2 switches gears, the moving terminal can only be connected to a fixed static contact, that is, only one tap participates in power supply at a certain moment. However, with the impedance matching characteristics of the inductive-capacitive three-port circuit, this situation has been changed. During the voltage regulation process, the moving terminal can stay at a position between the static contacts corresponding to two gears. At this time, the winding taps connected to these two static contacts achieve simultaneous power supply through the collaborative action of components such as the current-limiting reactor 5 and the phase correction capacitor 4. For example, when the moving terminal is between gear 1 and gear 2, the corresponding winding taps 1 and 2 can supply power to the circuit simultaneously. This power supply method breaks the traditional single-tap power supply mode. Since the moving terminal can stay between two gears and achieve simultaneous power supply from two taps, a new adjustable intermediate state is added between two adjacent gears (assuming that the voltage adjustment per gear is 2.5%). This is equivalent to doubling the number of gears on the basis of the original gear system. For example, originally there were only limited gears such as gear 1, gear 2, gear 3, etc. Now, adjustable intermediate gears are added between gear 1 and gear 2, between gear 2 and gear 3, etc., thus achieving the effect of doubling the tap positions. In the traditional tap-changer, the voltage adjustment amplitude per gear is 2.5%, which will cause large mutations during the voltage adjustment process, and users may notice phenomena such as lamp flickering. However, in the present invention, by doubling the tap positions, the original 2.5% voltage adjustment range is divided into two. For example, when the moving terminal is at the intermediate position between two gears, through the simultaneous power supply from two taps, a voltage adjustment of 1.25% can be achieved, making the voltage adjustment process smoother. Moreover, due to the regulation effect of the inductive-capacitive three-port circuit on current and voltage, when switching between different gears, it can effectively reduce voltage fluctuations and mutations, further improving the smoothness of voltage regulation, ensuring power quality, and reducing the user's perception of voltage changes during power consumption.

[0068] The method further includes the following steps: When an action is performed on the moving terminal, magnetic field change data of the primary side is obtained through a magnetic field detection device.

[0069] Perform spectral analysis on the magnetic field change data to obtain the magnetic field change data in the frequency domain signal; in the time domain, the magnetic field change data may show complex and disordered fluctuation patterns, but after spectral analysis, the proportion and role of different frequency components in the magnetic field change can be clearly seen.

[0070] Calculate the amplitude and phase of the magnetic field change data in the frequency domain; the amplitude reflects the intensity of each frequency component in the magnetic field change, while the phase represents the relative time relationship between different frequency components.

[0071] Extract spectral features based on the amplitude and phase. The spectral features include the peak frequency band and the frequency band energy distribution. The peak frequency band refers to the frequency interval with the largest amplitude in the spectrum, which often corresponds to the most significant frequency component in the magnetic field change and may be related to the operating state of specific electrical equipment or interference sources. The frequency band energy distribution describes the energy distribution within different frequency intervals. By analyzing the energy distribution, the importance and contribution of each frequency component in the magnetic field change can be understood.

[0072] Perform normalization processing on the spectral features to obtain the corresponding feature values; the normalization processing converts spectral features with different amplitudes and ranges into comparable feature values.

[0073] The system will match and conduct a corresponding one from multiple silicon bilateral diodes according to the feature values obtained after the normalization processing. Different feature values represent different magnetic field change situations, which also means that there may be different types of transient overvoltages. Each silicon bilateral diode has specific conduction characteristics and can effectively suppress different transient overvoltages. Through the precise matching of the feature values and the silicon bilateral diodes, the system can achieve targeted suppression of transient overvoltages, greatly improving the effect and efficiency of overvoltage suppression.

[0074] Take the power supply system of a large factory as an example. There are a large number of power electronic devices in the factory, such as frequency converters, rectifiers, etc. These devices will generate complex electromagnetic interference during operation. When a large motor in the factory starts, the action terminal will correspondingly execute actions to adjust the output voltage of the transformer. At this time, the system starts to obtain the magnetic field change data on the primary side and performs spectral analysis. After analysis, it is found that in the frequency domain signal, the amplitude of the magnetic field change data shows an obvious peak in the 500Hz - 600Hz frequency band, and the energy distribution in this frequency band occupies a large proportion of the total energy. After the system calculates the amplitude and phase of this frequency band, it extracts the corresponding spectral features and performs normalization processing to obtain a specific feature value. According to the pre-set matching rules, the system quickly matches the corresponding silicon bilateral diode and conducts it. This silicon bilateral diode can effectively suppress the transient overvoltage in the 500Hz - 600Hz frequency band, protecting the electrical equipment in the factory from overvoltage damage and ensuring the normal progress of production.

[0075] When an action is performed at the action end, the magnetic field change data on the primary side is obtained in real time and spectral analysis is carried out. When the action end performs an action, it is often accompanied by changes in voltage and current, which may cause transient overvoltage. The magnetic field change data can reflect the dynamic changes of these electrical parameters. By converting the time-domain signal into a frequency-domain signal through spectral analysis, the change characteristics of different frequency components can be observed more clearly. Calculate the amplitude and phase of the magnetic field change data in the frequency-domain signal, extract the spectral characteristics including the peak frequency band and the frequency band energy distribution, and perform normalization processing to obtain the eigenvalue. Different types of transient overvoltages will exhibit different characteristics in the spectrum, such as specific peak frequency bands and energy distributions. By matching the corresponding silicon bilateral diode conduction through the eigenvalue, the appropriate silicon bilateral diode can be accurately selected according to the specific characteristics of the transient overvoltage to suppress it, improving the pertinence and effectiveness of transient overvoltage suppression.

[0076] This method can quickly respond to the transient overvoltage that may occur when the action end acts. Once the spectral characteristics of the magnetic field change data are detected, the corresponding silicon bilateral diode can be quickly matched and conducted according to the eigenvalue, and the overvoltage energy can be discharged in time to avoid damage to the transformer and related equipment caused by the overvoltage, effectively protecting the insulation performance and normal operation of the equipment and extending the service life of the equipment. Since the spectral characteristics can reflect the specific situation of the transient overvoltage, this method has the ability of adaptive protection. Regardless of the cause of the transient overvoltage (such as lightning strikes, operations, etc.) and how its frequency, amplitude and other characteristics change, the most suitable silicon bilateral diode can be found through spectral analysis and characteristic matching for conduction to achieve comprehensive and reliable protection of the equipment.

[0077] Precisely suppressing transient overvoltage can reduce the interference of overvoltage on the power system. Transient overvoltage may cause problems such as voltage fluctuations and harmonic increases, affecting the stability of the power system and the power quality. By effectively suppressing transient overvoltage, the impact of these interferences on the system can be reduced, ensuring the stable operation of the power system, improving the power quality, and providing better-quality power supply for users. The better protection of the equipment and the reduction of system operation interference both contribute to improving the reliability of the entire power system. Reducing equipment failures and system abnormalities caused by transient overvoltage reduces the power outage risk, improves the power supply reliability of the power system, and meets the user's demand for continuous and stable power supply.

[0078] After calculating the amplitude and phase of the magnetic field change data in the frequency-domain signal, the method further includes the following steps: Extract the signal within the first characteristic frequency band range from the magnetic field change data in the frequency-domain signal.

[0079] Calculate the degree of dispersion of the amplitudes of all frequency points within the first characteristic frequency band range as the first dispersion coefficient.

[0080] If the first discrete coefficient is greater than a preset first threshold, the execution speed of the action end is adjusted in anti-correlation according to the first discrete coefficient.

[0081] When the degree of dispersion (first dispersion coefficient) of the amplitude of all frequency points in the first characteristic frequency band (high frequency band) is greater than the preset first threshold, it means that the magnetic field in the high frequency band changes violently and is unstable. That is, when the spectrum analysis shows that the high frequency band changes greatly, it usually means that there are more high-frequency harmonics in the power grid, which may be caused by some rapidly changing loads (such as power electronic equipment, switching power supplies, etc.). High-frequency harmonics can cause rapid fluctuations in voltage and current, causing impacts on transformers and tap changers. At this time, the execution speed of the action end should be appropriately reduced. A slower execution speed can reduce the mutual influence of high-frequency harmonics when the tap changer is in action, reduce the amplitude of transient overvoltage and inrush current caused by rapid switching, and protect the equipment from damage. For example, in some industrial plants, a large number of equipment such as frequency converters will generate high-frequency harmonics. At this time, the tap changer action speed can be set to a lower gear to avoid abnormalities during the switching process.

[0082] A signal within a second characteristic frequency band is extracted from the magnetic field change data under the frequency domain signal.

[0083] The discrete degree of the amplitude of all frequency points within the second characteristic frequency band is calculated as the second discrete coefficient.

[0084] If the second discrete coefficient is greater than a preset second threshold, the execution speed of the action end is adjusted according to the positive correlation of the second discrete coefficient; wherein the values ​​within the first characteristic frequency band are greater than the values ​​within the second characteristic frequency band.

[0085] When the degree of dispersion (second dispersion coefficient) of the amplitude of all frequency points in the second characteristic frequency band (low frequency band) is greater than the preset second threshold, it indicates that the magnetic field change in the low frequency band has large fluctuations. That is, when the spectrum analysis shows that the low frequency band changes greatly, it may be related to the low-frequency oscillation of the power grid or the input and removal of large loads. Low-frequency oscillations can cause periodic changes in the voltage and power of the power grid. If the action end executes too fast, it may switch at an unfavorable moment of voltage fluctuation, resulting in poor voltage regulation or damage to the equipment. The execution speed of the action end can be appropriately increased. Rapid action can enable the tap changer to adapt to the low-frequency changes of the power grid as soon as possible, adjust the transformer ratio in time, and stabilize the output voltage. For example, when a large motor is started, it will cause a low-frequency drop in the power grid voltage. At this time, the rapid action of the tap changer can increase the voltage in time to ensure the power supply quality.

[0086] This solution can adaptively adjust the execution speed of the action end according to the magnetic field change characteristics of different frequency bands. When it is unstable in the high-frequency band, the speed is reduced to avoid excessive adjustment; when there is an anomaly in the low-frequency band, the speed is increased to accelerate the adjustment process. This adaptive adjustment method makes the actions of the action end more in line with the actual operating conditions of the system, can regulate the voltage of the system more accurately, improves the efficiency and accuracy of voltage regulation, and ensures the stability and reliability of the system output voltage. By separately processing and specifically adjusting different frequency bands, the change information of the system can be captured more accurately, and the adjustment error caused by frequency band interference can be reduced. Different adjustment strategies are adopted in the high-frequency band and the low-frequency band respectively, which can avoid the problem of inaccurate adjustment caused by the inability of a single adjustment method to adapt to complex frequency band changes, and make the voltage regulation effect of the system more ideal. Reasonably adjusting the execution speed of the action end can reduce the losses of the system. When there is an anomaly in the high-frequency band, the speed is reduced, which reduces the unnecessary rapid actions of the action end, and reduces the mechanical wear and energy consumption of the equipment; when there is an anomaly in the low-frequency band, the speed is increased, which can quickly stabilize the system and reduce the energy loss caused by low-frequency oscillation. By optimizing the execution speed, the energy utilization efficiency of the system is improved, and the operating cost of the system is reduced. This solution monitors and adjusts the magnetic field changes of different frequency bands, enhancing the anti-interference ability of the system. Whether it is high-frequency interference or low-frequency interference, the system can timely adjust the execution speed of the action end according to the frequency band characteristics, effectively suppress the influence of interference on the system, improve the reliability and stability of the system, and enable the system to operate normally in a complex electromagnetic environment.

[0087] In addition, in other embodiments, during different power consumption periods, the voltage and load harmonic characteristics are different. To further optimize the voltage regulation timing, the voltage regulation timing is selected by combining the voltage and load harmonic period characteristics: Peak period: During the peak power consumption period, the power grid load is large, the voltage may drop, and the harmonics generated by the load are complex. Through spectrum analysis, if it is found that the changes in certain frequency bands are large and related to the voltage drop, the operation of the action end can be performed at a moment when the voltage fluctuation is relatively gentle. For example, if it is analyzed that the change in a certain low-frequency band is consistent with the voltage drop trend, the tap changer can be switched when the change in this frequency band is small, that is, at the moment when the voltage is relatively stable, to ensure the voltage regulation effect and equipment safety.

[0088] Valley period: During the valley power consumption period, the power grid load is light and the voltage may rise. At this time, the harmonic components in the spectrum are different from those in the peak period. If it is found that the changes in specific frequency bands are large and related to the voltage rise, the appropriate timing for action is also selected. For example, the high-frequency harmonics relatively decrease during the valley period, but there may be some low-frequency voltage fluctuations. The tap changer can be adjusted when the voltage rises to a certain extent and is about to stabilize, avoiding excessive voltage regulation and minimizing harmonic interference.

[0089] For example, a commercial area in a certain city contains numerous shopping malls, restaurants, and office buildings. During the peak period from 6 pm to 9 pm on weekdays, a large number of lighting, air conditioning, and catering equipment operate simultaneously, causing a sharp increase in the power grid load. Spectrum analysis shows that the second dispersion coefficient in the low-frequency band (5 - 20 Hz) is greater than the preset second threshold, indicating the existence of low-frequency oscillations and their correlation with voltage drops. Based on this situation, the system increases the execution speed of the action end, the tap changer operates quickly, adjusts the transformer turns ratio in a timely manner, stabilizes the voltage, and ensures the normal power consumption in the commercial area. At the same time, during this period, the first dispersion coefficient in the high-frequency band (500 - 1000 Hz) is also relatively large, and the system reduces the execution speed of the action end to avoid equipment damage caused by the interaction between high-frequency interference and rapid operation. While from 2 am to 5 am (valley period), the power consumption load drops significantly, and the voltage shows an upward trend. Spectrum analysis reveals some fluctuations in the low-frequency band (10 - 30 Hz). When the voltage rises to near the stable value, the system adjusts the tap changer to avoid overvoltage regulation, effectively maintains voltage stability, reduces harmonic interference, and ensures the efficient and stable operation of the entire commercial area power system.

[0090] An embodiment of the present application also discloses a on-load voltage regulating device based on an existing transformer, including a processor, and the processor executes the steps of the on-load voltage regulating method based on an existing transformer as described in any one of the above.

[0091] An embodiment of the present application also discloses a storage medium, in which a program is stored, and when the program is executed by the processor, it realizes the steps of the on-load voltage regulating method based on an existing transformer as described in any one of the above.

[0092] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A on-load voltage regulation method based on an existing transformer, characterized in that, It includes the following steps: A transient overvoltage suppression device (3) is provided on the off-load tap-changer (2). One end of the transient overvoltage suppression device (3) is connected to the operating end of the off-load tap-changer (2), and the other end is connected to the contact end (6) corresponding to the voltage of the middle gear in the off-load tap-changer (2). The conduction voltage of the transient overvoltage suppression device (3) is greater than the voltage difference between the positive and negative maximum voltage gears between the operating end and the contact end (6) corresponding to the voltage of the middle gear; the operating end is connected to the primary bushing (7) through a phase correction capacitor (4); each contact end (6) is correspondingly connected with a current-limiting reactor (5), and different contact ends (6) are connected to taps with different turns on the primary winding of the transformer; the tap of the primary side coil of the transformer far from the contact end (6) is connected to another primary bushing (7); the secondary voltage value of the secondary side of the transformer is detected; according to the secondary voltage value, the operating end is driven to be connected to the contact end (6) positively correlated with the secondary voltage value.

2. The on-load voltage regulation method based on an existing transformer according to claim 1, characterized in that, The method further includes the following steps: The transient overvoltage suppression device (3) includes a plurality of silicon bilateral diodes connected in parallel, and each silicon bilateral diode is connected in series with a conduction device (8); Within the most recent time period, calculate the secondary fluctuation voltage value of the secondary voltage value; Judge the voltage fluctuation range to which the secondary fluctuation voltage value belongs; Match a corresponding conduction device (8) according to the voltage fluctuation range; Turn on the matched conduction device (8).

3. The on-load voltage regulation method based on an existing transformer according to claim 1, characterized in that The method further includes the following steps: The transient overvoltage suppression device (3) includes a plurality of silicon bilateral diodes connected in parallel, and each silicon bilateral diode is connected in series with a conduction device (8); Within the most recent time period, calculate the secondary fluctuation frequency value of the secondary voltage value; Judge the frequency range to which the secondary fluctuation frequency value belongs, and turn on the corresponding conduction device (8) according to the frequency range; If within the most recent time period, the secondary fluctuation frequency value repeatedly jumps horizontally between adjacent frequency ranges, and the number of horizontal jumps is greater than a preset threshold, then adjust the action period of the operating end positively correlated according to the number of horizontal jumps; The greater the number of horizontal jumps, the longer the action period; the smaller the number of horizontal jumps, the shorter the action period.

4. The on-load voltage regulation method based on an existing transformer according to any one of claims 1-3, characterized in that The operating end is linked with a driving motor (9), and the method includes the following steps: Adjust the action speed of the driving motor (9) negatively correlated according to the secondary voltage value; The greater the voltage value of the secondary side, the smaller the action speed of the driving motor (9); the smaller the voltage value of the secondary side, the greater the action speed of the driving motor (9).

5. The on-load voltage regulation method based on an existing transformer according to claim 4, wherein A lightning arrester (11) is connected in parallel with the phase correction capacitor (4).

6. The on-load voltage regulation method based on an existing transformer according to claim 5, characterized in that, The inductance value of each current-limiting reactor (5) is equal, its inductive reactance is equal to the capacitive reactance of the phase correction capacitor (4), and the circulating current of each current-limiting reactor (5) under the gear voltage of adjacent gears of the existing transformer (1) is less than 1% of the rated current; the operating end can be selectively stopped at a position between two gears and supply power to the circuits of both gears at the same time.

7. The on-load voltage regulation method based on an existing transformer according to claim 1, characterized in that The method further includes the following steps: When the operating end performs an action, obtain the magnetic field change data of the primary side; Perform spectral analysis on the magnetic field change data to obtain the magnetic field change data in the frequency domain signal; Calculate the amplitude and phase of the magnetic field change data in the frequency domain signal; Extract spectral features based on the amplitude and phase, where the spectral features include the peak frequency band and the frequency band energy distribution; Perform normalization processing on the spectral features to obtain corresponding feature values; Match the corresponding silicon bilateral diode according to the feature values; Turn on the matched silicon bilateral diode.

8. The on-load voltage regulation method based on an existing transformer according to claim 7, characterized in that After calculating the amplitude and phase of the magnetic field change data in the frequency domain signal, the method further includes the following steps: Extract the signal within the first characteristic frequency band range from the magnetic field change data in the frequency domain signal; Calculate the discrete degree of the amplitudes of all frequency points within the first characteristic frequency band range as the first discrete coefficient; If the first discrete coefficient is greater than a preset first threshold, adjust the execution speed of the action end in inverse correlation according to the first discrete coefficient; Extract the signal within the second characteristic frequency band range from the magnetic field change data in the frequency domain signal; Calculate the discrete degree of the amplitudes of all frequency points within the second characteristic frequency band range as the second discrete coefficient; If the second discrete coefficient is greater than a preset second threshold, adjust the execution speed of the action end in positive correlation according to the second discrete coefficient; Wherein, the values within the first characteristic frequency band range are all greater than the values within the second characteristic frequency band range.

9. A on-load voltage regulating device based on an existing transformer, characterized in that, It includes a processor, and the processor executes the steps of the on-load voltage regulation method based on the existing transformer according to any one of claims 1-8.

10. A storage medium, characterized in that, A program is stored in the medium, and when the program is executed by the processor, the steps of the on-load voltage regulation method based on the existing transformer according to any one of claims 1-8 are implemented.

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