Intelligent monitoring type transformer maintenance-free respirator

Abstract

The application discloses a kind of intelligent monitoring type transformer maintenance-free respirator, belong to transformer accessory technical field, solve the density, granularity difference of silica gel filling in silica gel tank, there is inadaptable contradiction with the symmetrical control logic of device solidification, leading to the silica gel tank of more optimal performance is accelerated thermal aging due to heavier adsorption load but only obtains the same regeneration energy with other tank and further causes airflow distribution imbalance and vicious cycle of performance attenuation, and the device lacks adsorption efficiency direct online monitoring capability, self-checking can only verify whether the local humidity in tank after regeneration is reduced to threshold value, cannot perceive the slow decay of overall dehumidification efficiency.The application perceives silica gel body moisture content and aging state in real time, discards fixed time length symmetrical regeneration logic, allocates differentiated regeneration energy dynamically according to actual adsorption load and performance decay degree of each tank, to ensure that silica gel tank is fully regenerated, to avoid accelerated aging due to insufficient regeneration.

Description

Technical Field

[0001] This invention relates to the field of transformer accessories technology, and in particular to an intelligent monitoring type maintenance-free transformer breather. Background Technology

[0002] The maintenance-free transformer breather is an intelligent transformer protection device that connects to the end of the transformer oil conservator's breathing pipe via a flange. It employs a multi-silicone canister design, controlled by a solenoid valve to ensure that one canister is always connected to the oil conservator for moisture absorption, while the others are isolated and heated for regeneration, thus achieving continuous and efficient drying of the breathing air. The device incorporates temperature and humidity sensors, an air pump, and a control unit, enabling the switching and regeneration cycles of the silica canisters. It aims to replace traditional breathers that require manual silica gel replacement, achieving maintenance-free operation.

[0003] For example, the dual-tank maintenance-free breather device and transformer with application number CN202121695393.4, the key technical points of which are: including: a housing, which is connected to the end of the pipe communicating with the oil tank and air of the transformer via a flange; a pipeline, one end of which is connected to the flange and the other end of which is connected to a solenoid valve for switching on and off; a first silica gel tank, which is connected to the pipeline via the solenoid valve, the first silica gel tank including: a first temperature and humidity sensor configured to measure first temperature and humidity data in the first silica gel tank; a first heater chamber assembly, which heats and dries the silica gel in the first silica gel tank based on the temperature and humidity data; and a second silica gel tank, which is connected to the pipeline via an electric... The solenoid valve can switch the pipeline on and off. The second silicone tank includes: a second temperature and humidity sensor configured to measure second temperature and humidity data inside the second silicone tank; a second heater chamber assembly that heats and dries the silicone in the second silicone tank based on the second temperature and humidity data; a solenoid valve that switches on and off to keep the pipeline connected to one of the first and second silicone tanks; an air pump located inside the housing and pumping air to the first or second silicone tank; a power supply located inside the housing and electrically connected to the solenoid valve, the air pump, the first and second silicone tanks; and a control unit electrically connected to the power supply, the solenoid valve, the air pump, the first and second silicone tanks.

[0004] The aforementioned technical solution enables the switching and regeneration cycle of silica gel tanks, achieving maintenance-free operation. However, within each silica gel tank, there are inherent differences in density and particle size among the silica gel filling materials. These differences create an irreconcilable contradiction with the device's solidified symmetrical control logic. Consequently, the silica gel tank with superior performance, despite its heavier adsorption load, receives only the same regeneration energy as other tanks, leading to accelerated thermal aging. This, in turn, triggers a vicious cycle of unbalanced airflow distribution and performance degradation. Furthermore, the device lacks direct online monitoring capabilities for adsorption efficiency. Its self-checking mechanism can only verify whether the local humidity inside the tank has dropped to the threshold after regeneration, but it cannot detect the slow decline in overall dehumidification efficiency. This results in "functional silent failure," meaning that the dehumidification efficiency has severely decreased without any alarm. The consequence is that the transformer insulating oil continuously absorbs moisture unnoticed, causing chronic damage to the solid insulation and significantly accelerating insulation aging. This greatly increases the risk of internal insulation breakdown accidents when the transformer is subjected to overvoltage or load surges in the future, and severely shortens its service life.

[0005] Therefore, an intelligent monitoring transformer maintenance-free breather is proposed to solve or alleviate the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing an intelligent monitoring transformer maintenance-free breather.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A smart monitoring transformer maintenance-free breather includes a housing, a first silicone tank and a second silicone tank installed at the bottom of the housing, a flange installed at the top of the housing, and a three-way pipe connecting the flange, the first silicone tank, and the second silicone tank and located inside the housing. The connection between the three-way pipe and the first and second silicone tanks is switchable. An air pump is installed inside the housing, and the air pump is connected via an air path to the switchable connection between the three-way pipe and the first and second silicone tanks. The first and second silicone tanks are respectively equipped with a first heater and a second heater. The device also includes a silicone condition monitoring and regeneration control circuit. The silicone condition monitoring and regeneration control circuit collects radio frequency and optical sensor data from the first and second silicone tanks simultaneously, fuses and analyzes the data, calculates the silicone moisture content and aging status, and uses this data to open and close solenoid valves, adjust heaters, and start and stop the air pump to control the injection of regeneration energy and continuously track performance trends to issue early warnings before degradation.

[0008] Preferably, the first solenoid valve and the second solenoid valve are two-position three-way solenoid valves, and both are electrically connected to the main control module in the silicone condition monitoring and regeneration control circuit.

[0009] Preferably, the three-way pipeline includes a three-way connector connecting the first solenoid valve and the second solenoid valve, a pipe connected to the three-way connector, a temporary storage tank connected to the pipe, an end solenoid valve connected to the pipe, and a flange connecting pipe connecting the temporary storage tank and the flange. A humidity sensor is installed inside the temporary storage tank. The humidity sensor and the end solenoid valve are electrically connected to the main control module in the silica gel status monitoring and regeneration control circuit. The temporary storage tank is connected to an exhaust pipe that penetrates the box to the outside. A one-way valve for venting air outward is installed inside the exhaust pipe.

[0010] Preferably, the air path includes a three-way connecting pipe connecting the first solenoid valve and the second solenoid valve, and a connecting air pipe connecting the air pump and the three-way connecting pipe. The air pump is connected to an air inlet pipe that passes through the housing to the outside. The air pump is electrically connected to the main control module in the silicone status monitoring and regeneration control circuit.

[0011] Preferably, the silicone state monitoring and regeneration control circuit includes an optical fiber sensing module, an radio frequency sensing module, a main control module, a power control module, and a communication module. The detection ends of the optical fiber sensing module and the radio frequency sensing module are disposed inside the first silicone tank and the second silicone tank. The data output interface of the radio frequency sensing module is connected to the first data input interface of the main control module, the control input interface of the radio frequency sensing module is connected to the first control output interface of the main control module, the data output interface of the optical fiber sensing module is connected to the second data input interface of the main control module, the control input interface of the optical fiber sensing module is connected to the second control output interface of the main control module, the power control output interface of the main control module is connected to the control input interface of the power control module, the current feedback output interface of the power control module is connected to the feedback input interface of the main control module, the power output interface of the power control module is used to connect the first heater and the second heater, and the communication interface of the main control module is connected to the communication module.

[0012] Preferably, the RF sensing module includes several patch antennas, a direct digital frequency synthesizer AD9959, a power amplifier PE15A4002, a circulator, a high-frequency switching matrix PE4259, a quadrature demodulator ADL5391, a first operational amplifier OPA657, a second operational amplifier OPA657, and a first analog-to-digital converter ADS9220. The patch antennas are mounted on the inner wall of a silicone container, and are located at different horizontal heights. The direct digital frequency synthesizer AD9959 has a serial clock pin, a serial... The line data input / output pins and chip select pins are connected to the first control output interface of the main control module via a serial peripheral interface bus. The differential sine wave positive and negative output pins of the direct digital frequency synthesizer AD9959 are connected to the signal input terminal of the power amplifier PE15A4002 via a first balun. The signal output terminal of the power amplifier PE15A4002 is connected to the first port of the circulator. The second port of the circulator is connected to the common terminal of the high-frequency switching matrix PE4259. The multiple outputs of the high-frequency switching matrix PE4259... The output terminal is used to connect several patch antennas. The third port of the circulator is connected to the RF signal input pin of the quadrature demodulator ADL5391 through a first attenuator. The reference clock output pin of the direct digital frequency synthesizer AD9959 is connected to the local oscillator signal input pin of the quadrature demodulator ADL5391. The in-phase component output pin of the quadrature demodulator ADL5391 is connected to the in-phase input terminal of the first operational amplifier OPA657. The output terminal of the first operational amplifier OPA657 is connected to the first analog-to-digital converter ADS9220. The analog non-inverting input channel is provided. The quadrature component output pin of the quadrature demodulator ADL5391 is connected to the non-inverting input of the second operational amplifier OPA657. The output of the second operational amplifier OPA657 is connected to the second analog non-inverting input channel of the first analog-to-digital converter ADS9220. The data clock output pin, the first channel data output pin, the second channel data output pin, and the frame synchronization clock output pin of the first analog-to-digital converter ADS9220 are connected to the corresponding pins of the first data input interface of the main control module in low-voltage differential signal mode.

[0013] Preferably, the fiber optic sensing module includes a fiber optic grating sensor array, a laser driver ADN8835, a tunable laser, an optical circulator, a photodetector, a transimpedance amplifier OPA657, and a second analog-to-digital converter ADS1256. The fiber optic grating sensor array is embedded in silicone within a silicone container. The serial clock pin, serial data input pin, serial data output pin, and chip select pin of the laser driver ADN8835 are connected to the second control output interface of the main control module via a serial peripheral interface bus. The laser diode drive current output pin of the laser driver ADN8835 is connected to the anode of the tunable laser via a constant current source circuit. The positive output pin and negative output pin of the thermoelectric cooler of the laser driver ADN8835 are connected to... The tunable laser has an integrated thermoelectric cooler. The optical output pigtail of the tunable laser is connected to the first port of an optical circulator. The second port of the optical circulator is used to connect to an external fiber Bragg grating sensor array. The third port of the optical circulator is aligned with the photosensitive surface of a photodetector. The cathode of the photodetector is connected to the inverting input of a transimpedance amplifier OPA657, and the anode of the photodetector is connected to signal ground. The output of the transimpedance amplifier OPA657 is connected to the first analog input channel of a second analog-to-digital converter ADS1256 through a low-pass filter. The data-ready output pin, serial clock input pin, serial data input pin, and serial data output pin of the second analog-to-digital converter ADS1256 are connected to the corresponding pins of the second data input interface of the main control module.

[0014] Preferably, the main control module includes a SoC system-on-a-chip integrating an FPGA programmable logic unit and an ARM processor core, an NPN transistor, a relay, and a Darlington transistor array. The output terminal of the main control module is connected to the base of the NPN transistor through a first current-limiting resistor. The emitter of the NPN transistor is grounded. The collector of the NPN transistor is connected to one end of the relay coil. The other end of the relay coil is energized. The switching contacts of the relay are connected in series in the energizing circuit of the air pump. The output terminal of the numerical control module is connected to the input terminal of the Darlington transistor array. The output terminal of the Darlington transistor array is connected to the coils of the first solenoid valve, the second solenoid valve, and the final solenoid valve.

[0015] Preferably, the power control module comprises two sets, which are respectively connected to the first heater and the second heater. Each power control module includes a digital PWM controller UCD3138, a half-bridge driver UCC27201A, an isolated modulator AMC1301, a first MOSFET, and a second MOSFET. The clock and data pins of the digital PWM controller UCD3138 are connected to the power control output interface of the main control module via a power management bus. The first pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the high-side input pin of the half-bridge driver UCC27201A, and the second pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the low-side input pin of the half-bridge driver UCC27201A. The high-side output pin of the half-bridge driver UCC27201A... The pin is connected to the gate of the first MOSFET through the first gate resistor. The low-side output pin of the half-bridge driver UCC27201A is connected to the gate of the second MOSFET through the second gate resistor. The drain of the first MOSFET is used for power connection. The connection point between the source of the first MOSFET and the drain of the second MOSFET forms a resonant power network to the heater. The digital PWM controller UCD3138 outputs current through the primary coil of the current transformer. The two ends of the secondary coil of the current transformer are connected to a sampling resistor. The positive analog input pin and the negative analog input pin of the isolated modulator AMC1301 are respectively connected to the two ends of the sampling resistor. The data clock output pin and the data output pin of the isolated modulator AMC1301 are respectively connected to the first fault detection pin and the second fault detection pin of the digital PWM controller UCD3138.

[0016] Preferably, the communication module includes an Ethernet physical layer chip and an RS-485 differential bus transceiver. The transmit data pin zero, receive data pin zero, transmit enable pin, and receive data valid pin of the main control module are connected to the corresponding media independent interface pins of the Ethernet physical layer chip. The serial port transmit data pin of the main control module is connected to the data input pin of the RS-485 differential bus transceiver, and the serial port receive data pin of the main control module is connected to the receive data output pin of the RS-485 differential bus transceiver.

[0017] The present invention has the following beneficial effects: This invention, by sensing the moisture content and aging status of the silica gel in real time, abandons the fixed-duration symmetrical regeneration logic and dynamically allocates differentiated regeneration energy according to the actual adsorption load and efficiency decay of each tank, ensuring that the silica gel tank is fully regenerated and avoiding accelerated aging caused by insufficient regeneration. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the internal structure of the present invention; Figure 4 This is a block diagram of the silicone state monitoring and regeneration control circuit in this invention.

[0020] In the diagram: 1. Housing; 2. Flange; 3. Flange connecting pipe; 4. Temporary storage tank; 5. Terminal solenoid valve; 6. Pipe; 7. T-connector; 8. Connecting air pipe; 9. Air pump; 10. First solenoid valve; 11. Second solenoid valve; 12. Inlet pipe; 13. First silica gel tank; 14. Second silica gel tank; 15. Humidity sensor; 16. Fiber optic sensing module; 17. Radio frequency sensing module; 18. Main control module; 19. Power control module; 20. First heater; 21. Second heater; 22. Communication module; 23. Power supply; 24. T-connector; 25. Inlet pipe; 26. Outlet pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0026] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] A smart monitoring transformer maintenance-free breather, such as Figures 1 to 3As shown, the system includes a housing 1, a first silicone tank 13 and a second silicone tank 14 installed at the bottom of the housing 1, a flange 2 installed at the top of the housing 1, and a three-way pipe connecting the flange 2, the first silicone tank 13, and the second silicone tank 14 and located inside the housing 1. A power supply is installed inside the housing 1 for power supply. The connection between the three-way pipe and the first silicone tank 13 and the second silicone tank 14 is switchable. An air pump 9 is installed inside the housing 1, and the air pump 9 is connected via an air path to the switchable connection between the three-way pipe and the first silicone tank 13 and the second silicone tank 14. A first heater 20 and a second heater 21 are respectively installed inside the first silicone tank 13 and the second silicone tank 14. The first solenoid valve 10 and the second solenoid valve 11 are two-position three-way solenoid valves, and both are electrically connected to the main control module 18 in the silicone status monitoring and regeneration control circuit. The three-way pipe includes a connecting... The first solenoid valve 10 and the second solenoid valve 11 are connected by a three-way connector 7, a pipe 6 connected to the three-way connector 7, a temporary storage tank 4 connected to the pipe 6, an end solenoid valve 5 connected to the pipe 6, and a flange connecting pipe 3 connecting the temporary storage tank 4 and the flange 2. A humidity sensor 15 is installed inside the temporary storage tank 4. The humidity sensor 15 and the end solenoid valve 5 are electrically connected to the main control module 18 in the silica gel status monitoring and regeneration control circuit. The temporary storage tank 4 is connected to an air outlet pipe 26 that runs through the housing 1 to the outside. A one-way valve for one-way exhaust is installed inside the air outlet pipe 26. The air path includes a three-way connecting pipe 24 that connects the first solenoid valve 10 and the second solenoid valve 11, and a connecting pipe 8 that connects the air pump 9 and the three-way connecting pipe 24. The air pump 9 is connected to an air inlet pipe 25 that runs through the housing 1 to the outside. The air pump 9 is electrically connected to the main control module 18 in the silica gel status monitoring and regeneration control circuit.

[0028] like Figure 4As shown, it also includes a silica gel condition monitoring and regeneration control circuit. This circuit synchronously collects and analyzes radio frequency and optical sensor data from the first silica gel tank 13 and the second silica gel tank 14, calculating the silica gel moisture content and aging status. This data is used to control the injection of regeneration energy by opening and closing the solenoid valve, adjusting the heater, and starting and stopping the air pump 9. It also continuously tracks performance trends to issue early warnings before degradation. The silica gel condition monitoring and regeneration control circuit includes a fiber optic sensing module 16, a radio frequency sensing module 17, a main control module 18, a power control module 19, and a communication module 22. The detection ends of the fiber optic sensing module 16 and the radio frequency sensing module 17 are located inside the first silica gel tank 13 and the second silica gel tank 14. The data output interface of the radio frequency sensing module 17... The first data input interface of the main control module 18 is connected to the first data input interface of the main control module 18, the control input interface of the RF sensing module 17 is connected to the first control output interface of the main control module 18, the data output interface of the fiber optic sensing module 16 is connected to the second data input interface of the main control module 18, the control input interface of the fiber optic sensing module 16 is connected to the second control output interface of the main control module 18, the power control output interface of the main control module 18 is connected to the control input interface of the power control module 19, the current feedback output interface of the power control module 19 is connected to the feedback input interface of the main control module 18, the power output interface of the power control module 19 is used to connect the first heater 20 and the second heater 21, and the communication interface of the main control module 18 is connected to the communication module 22.

[0029] The RF sensing module 17 includes several patch antennas, a direct digital frequency synthesizer AD9959, a power amplifier PE15A4002, a circulator, a high-frequency switching matrix PE4259, a quadrature demodulator ADL5391, a first operational amplifier OPA657, a second operational amplifier OPA657, and a first analog-to-digital converter ADS9220. The patch antennas are mounted on the inner wall of a silicone container at different horizontal heights. The direct digital frequency synthesizer AD9959 has a serial clock pin and a serial data pin. The input / output pins and chip select pins are connected to the first control output interface of the main control module 18 via a serial peripheral interface bus. The differential sine wave in-phase and in-phase output pins of the direct digital frequency synthesizer AD9959 are connected to the signal input terminal of the power amplifier PE15A4002 via the first balun. The signal output terminal of the power amplifier PE15A4002 is connected to the first port of the circulator. The second port of the circulator is connected to the common terminal of the high-frequency switching matrix PE4259. The multiple output terminals of the high-frequency switching matrix PE4259... Used to connect several patch antennas, the third port of the circulator is connected to the RF signal input pin of the quadrature demodulator ADL5391 through the first attenuator. The reference clock output pin of the direct digital frequency synthesizer AD9959 is connected to the local oscillator signal input pin of the quadrature demodulator ADL5391. The in-phase component output pin of the quadrature demodulator ADL5391 is connected to the in-phase input of the first operational amplifier OPA657. The output of the first operational amplifier OPA657 is connected to the first analog in-phase input channel of the first analog-to-digital converter ADS9220. The quadrature component output pin of the quadrature demodulator ADL5391 is connected to the in-phase input of the second operational amplifier OPA657. The output of the second operational amplifier OPA657 is connected to the second analog in-phase input channel of the first analog-to-digital converter ADS9220. The data clock output pin, the first channel data output pin, the second channel data output pin, and the frame synchronization clock output pin of the first analog-to-digital converter ADS9220 are connected to the corresponding pins of the first data input interface of the main control module 18 in low-voltage differential signal mode.

[0030] The fiber optic sensing module 16 includes a fiber optic grating sensor array, a laser driver ADN8835, a tunable laser, an optical circulator, a photodetector, a transimpedance amplifier OPA657, and a second analog-to-digital converter ADS1256. The fiber optic grating sensor array is embedded in silicone within a silicone container. The serial clock pin, serial data input pin, serial data output pin, and chip select pin of the laser driver ADN8835 are connected to the second control output interface of the main control module 18 via a serial peripheral interface bus. The laser diode drive current output pin of the laser driver ADN8835 is connected to the anode of the tunable laser via a constant current source circuit. The positive output pin and negative output pin of the thermoelectric cooler of the laser driver ADN8835 are connected to... The tunable laser is connected to an integrated thermoelectric cooler. The optical output pigtail of the tunable laser is connected to the first port of the optical circulator. The second port of the optical circulator is used to connect to an external fiber Bragg grating sensor array. The third port of the optical circulator is aligned with the photosensitive surface of the photodetector. The cathode of the photodetector is connected to the inverting input of the transimpedance amplifier OPA657. The anode of the photodetector is connected to the signal ground. The output of the transimpedance amplifier OPA657 is connected to the first analog input channel of the second analog-to-digital converter ADS1256 through a low-pass filter. The data-ready output pin, serial clock input pin, serial data input pin, and serial data output pin of the second analog-to-digital converter ADS1256 are connected to the corresponding pins of the second data input interface of the main control module 18.

[0031] The main control module 18 includes a SoC system-on-a-chip integrating an FPGA programmable logic unit and an ARM processor core, an NPN transistor, a relay, and a Darlington transistor array. The output terminal of the main control module 18 is connected to the base of the NPN transistor through a first current-limiting resistor. The emitter of the NPN transistor is grounded. The collector of the NPN transistor is connected to one end of the relay coil. The other end of the relay coil is energized. The switch contacts of the relay are connected in series in the energizing circuit of the air pump 9. The output terminal of the numerical control module is connected to the input terminal of the Darlington transistor array. The output terminal of the Darlington transistor array is connected to the coils of the first solenoid valve 10, the second solenoid valve 11, and the end solenoid valve 5.

[0032] There are two sets of power control modules 19, which are respectively connected to the first heater 20 and the second heater 21. Each power control module 19 includes a digital PWM controller UCD3138, a half-bridge driver UCC27201A, an isolated modulator AMC1301, a first MOSFET, and a second MOSFET. The clock and data pins of the digital PWM controller UCD3138 are connected to the power control output interface of the main control module 18 via a power management bus. The first pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the high-side input pin of the half-bridge driver UCC27201A, and the second pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the low-side input pin of the half-bridge driver UCC27201A. The low-side output pin of the half-bridge driver UCC27201A is connected to the gate of the first MOSFET through the first gate resistor. The low-side output pin of the half-bridge driver UCC27201A is connected to the gate of the second MOSFET through the second gate resistor. The drain of the first MOSFET is used for power connection. The connection point between the source of the first MOSFET and the drain of the second MOSFET forms a resonant power network to the heater. The digital PWM controller UCD3138 outputs current through the primary coil of the current transformer. A sampling resistor is connected to both ends of the secondary coil of the current transformer. The positive analog input pin and the negative analog input pin of the isolated modulator AMC1301 are respectively connected to both ends of the sampling resistor. The data clock output pin and the data output pin of the isolated modulator AMC1301 are respectively connected to the first fault detection pin and the second fault detection pin of the digital PWM controller UCD3138.

[0033] The communication module 22 includes an Ethernet physical layer chip and an RS-485 differential bus transceiver. The transmit data pin 0, receive data pin 0, transmit enable pin, and receive data valid pin of the main control module 18 are connected to the corresponding media independent interface pins of the Ethernet physical layer chip. The serial port transmit data pin of the main control module 18 is connected to the data input pin of the RS-485 differential bus transceiver, and the serial port receive data pin of the main control module 18 is connected to the receive data output pin of the RS-485 differential bus transceiver.

[0034] The silicone condition monitoring and regeneration control circuit also includes a clock module, which includes a temperature-controlled crystal oscillator and a clock buffer SI5338A. The output pin of the temperature-controlled crystal oscillator is connected to the first input pin of the clock buffer SI5338A. The first output pin of the clock buffer SI5338A is connected to the global clock input pin of the main control module 18. The second output pin of the clock buffer SI5338A is connected to the external clock input pin of the first analog-to-digital converter ADS9220 in the RF sensing module 17. The third output pin of the clock buffer SI5338A is connected to the reference clock input pin of the direct digital frequency synthesizer AD9959 in the RF sensing module 17.

[0035] When the intelligent monitoring transformer maintenance-free breather is working, the main control module 18 needs to perform the following steps, specifically including: S1: Control the radio frequency sensing module 17 and the fiber optic sensing module 16 to perform synchronous data acquisition; S11: The main control module 18 sends a synchronization trigger signal to the direct digital frequency synthesizer AD9959 in the radio frequency sensing module 17 and the laser driver ADN8835 in the fiber optic sensing module 16. S12: The main control module 18 reads the in-phase and quadrature component data pairs acquired at N frequency points from the first analog-to-digital converter ADS9220 in the RF sensing module 17; S13: The main control module 18 reads the center wavelength offset data of M fiber optic grating sensors from the second analog-to-digital converter ADS1256 in the fiber optic sensing module 16; S2: Process and fuse data from RF sensing module 17 and fiber optic sensing module 16 to calculate the current moisture content and aging state index of the silicone. S21: Calculate the amplitude and phase of the reflection coefficient of the radio frequency signal at each frequency point based on the data pairs of in-phase and quadrature components; S22: Based on the amplitude and phase of the reflection coefficient, calculate the complex dielectric constant of the silicone at each frequency point; S23: Based on the complex permittivity, the first moisture content value is calculated using a preset first calibration model. The first calibration model is a quadratic polynomial model. The first moisture content value is the result obtained by multiplying a value a by the square of the real part average of the complex permittivity, adding a value b by the real part average of the complex permittivity, and adding a value c. Among them, values ​​a, b, and c are calibration coefficients predetermined through experiments. S24: Perform temperature compensation decoupling on the center wavelength offset data to obtain the wavelength offset caused purely by strain; S25: Based on the wavelength shift caused purely by strain, the second moisture content value is calculated using a preset second calibration model. The second calibration model is a linear model, and the second moisture content value is the product of a strain moisture sensitivity coefficient and the wavelength shift caused purely by strain. The strain moisture sensitivity coefficient is a calibration coefficient determined in advance through experiments. S26: Based on Kalman filtering or weighted average algorithm, the first moisture content value and the second moisture content value are fused to obtain the final moisture content value; S27: Analyze the spectral variation characteristics of the complex permittivity and calculate the aging state index; S3: Based on the current moisture content and aging state index, calculate the energy required for regeneration and control the power control module 19 to inject energy into the heater; S31: Calculate the total mass of adsorbed water based on the final moisture content value and the total mass of silica gel; S32: Based on the total mass of adsorbed water and the aging state index, the required regeneration energy value is obtained through the energy calculation model. The calculation method of the energy calculation model is as follows: the required regeneration energy value is equal to the product of a first proportional coefficient and the total mass of adsorbed water, plus the product of a second proportional coefficient and the reciprocal of the aging state index. S33: Convert the required regenerative energy value into a control command and send it to the digital PWM controller UCD3138 in the power control module 19 via the power management bus; S34: The power control module 19 collects the load current in real time through its internal isolated modulator AMC1301 and integrates and calculates the injected energy to form a closed-loop control until the injected energy reaches the required regenerative energy value. S4: Track and record the long-term trend of silicone performance changes, and issue an early warning message through communication module 22 before the performance degrades to the threshold; S41: After each regeneration is completed, record the energy consumed in this regeneration process and the aging state index when the regeneration is completed; S42: Establish the historical energy consumption curve and health index curve for each silicone can; S43: Perform a linear fit on the historical curve of the health index and calculate its slope; S44: If the current health index is lower than the first preset threshold, or the slope is greater than the second preset threshold, it is determined that the performance of silicone has significantly deteriorated, and an early warning instruction is generated. S45: The control communication module 22 sends the warning command to the remote monitoring terminal.

[0036] More specifically, When the intelligent monitoring transformer maintenance-free breather is working, it does not directly start the air pump 9 to draw in air and open the solenoid valve to let the processed air enter the transformer. Instead, the main control module 18 first performs a self-test and sends a configuration command to the direct digital frequency synthesizer AD9959 in the radio frequency sensing module 17 to generate a multi-frequency sine wave signal in the range of 1MHz to 50MHz. After the signal is converted by a balun, it is amplified by the power amplifier PE15A4002, transmitted through port one of the circulator to port two, and then radiated into the silicone by the patch antenna through the high-frequency switching matrix PE4259.

[0037] Meanwhile, the main control module 18 configures the laser driver ADN8835 in the fiber optic sensing module 16 via the SPI bus, so that it drives the tunable laser to emit a wavelength-tunable optical signal. The optical signal is transmitted through port one of the optical circulator to port two and enters the fiber grating sensor array embedded in silicone. Each FBG sensor reflects a specific wavelength of optical signal according to its inherent Bragg wavelength. These reflected lights carrying strain and temperature information are output to the photodetector through port three of the optical circulator.

[0038] On the RF side, the reflected electromagnetic wave signal from the silicone is output through the circulator port three. After the amplitude is adjusted by the attenuator, it is sent to the RF input pin of the quadrature demodulator. It is mixed with the reference signal provided by the direct digital frequency synthesizer AD9959 to generate in-phase and quadrature component outputs. These two components are conditioned by operational amplifiers and then converted into digital signals by the first analog-to-digital converter ADS9220.

[0039] On the fiber optic side, the photodetector converts the optical signal into an electrical signal, which is then processed by a transimpedance amplifier and a low-pass filter before being acquired as a digital signal by a second analog-to-digital converter, ADS1256. All of this data is kept synchronized through a precision clock distribution network to ensure time consistency.

[0040] Next, the main control module 18 executes the algorithm to process these data. For radio frequency data, it calculates the amplitude and phase of the reflection coefficient at each frequency point, obtains the complex dielectric constant spectrum of silicone through the inversion algorithm, and uses a preset quadratic polynomial calibration model to convert the average real part of the dielectric constant into the first moisture content value.

[0041] For fiber optic data, temperature compensation is performed to decouple the wavelength shift of each FBG sensor to obtain the wavelength shift caused by pure strain, and the second moisture content value is calculated through a linear model.

[0042] Then, a weighted average algorithm is used to fuse the two moisture content values ​​to obtain a final moisture content value with high confidence.

[0043] Simultaneously, the relaxation frequency and loss factor changes of the complex permittivity spectrum are analyzed to calculate a health index reflecting the degree of silicone aging.

[0044] Based on these analysis results, the circuit realizes asymmetric intelligent control. First, it calculates the total mass of adsorbed water based on the final moisture content and the total mass of silica gel. Then, it calculates the precise personalized regeneration energy demand by comprehensively considering the total amount of water and the reciprocal of the health index according to the energy calculation model. The energy setpoint is sent to the digital PWM controller UCD3138 through the PMBus bus.

[0045] The power control module 19 then starts the high-frequency resonant heating driver, which provides precise energy output to the heater in the silicone tank that needs to be regenerated through the LLC resonant network. The heater is actually an electric heating wire. At the same time, the load current is monitored in real time through the isolated modulator AMC1301, and the energy delivered is calculated by integration to achieve closed-loop control until the set value is reached.

[0046] Throughout the process, the system intelligently determines the switching timing by comparing the health index and moisture content of the two silica gel tanks. Then, it switches between the first solenoid valve 10 and the second solenoid valve 11 to ensure that the silica gel tank with better performance always undertakes the adsorption task. It also allocates additional regeneration energy quotas to the tank with a higher degree of aging, thus solving the problem of unfair regeneration caused by the microscopic differences in silica gel.

[0047] After leaving through the three-way pipe, the air will first enter the temporary storage tank 4, where it will be buffered. The humidity sensor 15 will then perform further humidity detection to ensure that there are no problems before the air is fed into the transformer. If there is a humidity problem, the end solenoid valve 5 can be closed to prevent subsequent humid air from entering the transformer. Excess air in the temporary storage tank 4 will leave through the air outlet pipe 26.

[0048] Secondly, the silica gel condition monitoring and regeneration control circuit establishes a performance degradation model by tracking the historical health index curve and unit regeneration energy consumption curve of each silica gel tube over a long period of time. When a continuous decline in the health index is detected or a significant increase in the energy required to reach the same degree of dryness is detected, an early warning of silica gel performance degradation will be generated even if the local humidity detection inside the tank is normal. The alarm will be sent to the remote monitoring center through the Ethernet physical layer chip and RS-485 transceiver, thereby completely eliminating the risk of "functional silent failure".

[0049] By employing a dual direct monitoring mechanism of radio frequency impedance spectroscopy analysis and fiber optic strain measurement, combined with an asymmetric energy distribution strategy and trend prediction based on historical data, accurate perception, intelligent management, and predictive maintenance of the silicone condition of transformer breathers are achieved, significantly improving the operational reliability and service life of the equipment.

[0050] The dielectric properties of silicone are directly measured by multi-band radio frequency impedance analysis. Its distributed patch antenna array can sense the dielectric information of different depth regions, overcoming the problem of unrepresentative local sampling. At the same time, the fiber optic grating sensor array directly measures the micro-strain caused by the moisture absorption and expansion of silicone. This mechanical measurement method is not affected by environmental factors. Furthermore, by connecting multiple FBG sensors with different center wavelengths in series, the distributed measurement of the overall strain distribution of the silicone bed is realized.

[0051] Two completely independent measurement methods are organically combined through a data fusion algorithm to mutually verify and compensate each other, greatly improving the accuracy and reliability of moisture content measurement. The predictive energy management strategy adopted completely changes the logic of traditional symmetrical control. It establishes an independent health record for each silica gel tank and dynamically calculates and allocates regeneration energy based on the actual adsorption contribution and material aging degree. Tanks with better performance and more adsorption of moisture will obtain more complete and thorough regeneration, thereby avoiding accelerated performance degradation caused by insufficient regeneration and breaking the vicious cycle.

[0052] The long-term performance tracking and trend analysis functions enable this intelligent monitoring transformer maintenance-free breather to have unprecedented early warning capabilities. It no longer only focuses on whether the instantaneous value exceeds the threshold, but also identifies early signs of degradation before the efficiency substantially declines by analyzing the long-term trend of performance parameters. This truly realizes predictive maintenance, transforming "silent failure" into "predictable explicit failure", providing sufficient time window for planned maintenance and fundamentally ensuring the insulation safety and operational reliability of the transformer.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A smart monitoring type transformer maintenance-free respirator, characterized by, The enclosure includes a housing (1), a first silicone canister (13) and a second silicone canister (14) installed at the bottom of the housing (1), a flange (2) installed at the top of the housing (1), and a three-way pipe connecting the flange (2), the first silicone canister (13), and the second silicone canister (14) and located inside the housing (1). The connection between the three-way pipe and the first silicone canister (13) and the second silicone canister (14) is switchable. An air pump (9) is installed inside the housing (1). The air pump (9) is connected to the three-way pipe and the first silicone canister (13), and the three-way pipe and the second silicone canister (14) through an air passage. The first silicone tank (13) and the second silicone tank (14) are respectively equipped with a first heater (20) and a second heater (21) at the connection point of the tank (14). The silicone tank (14) also includes a silicone state monitoring and regeneration control circuit. The silicone state monitoring and regeneration control circuit calculates the silicone moisture content and aging state by synchronously collecting radio frequency and optical sensor data in the first silicone tank (13) and the second silicone tank (14) and then fusing and analyzing the data. In this way, it opens and closes the solenoid valve, adjusts the heater, and starts and stops the air pump (9) to control the injection of regeneration energy and continuously track the performance trend to issue an early warning before degradation.

2. The smart monitoring type transformer maintenance-free respirator according to claim 1, characterized in that, The first solenoid valve (10) and the second solenoid valve (11) are two-position three-way solenoid valves, and both are electrically connected to the main control module (18) in the silicone status monitoring and regeneration control circuit.

3. The smart monitoring type transformer maintenance-free respirator according to claim 1, characterized in that, The three-way pipeline includes a three-way connector (7) connecting the first solenoid valve (10) and the second solenoid valve (11), a pipe (6) connected to the three-way connector (7), a temporary storage tank (4) connected to the pipe (6), an end solenoid valve (5) connected to the pipe (6), and a flange connecting pipe (3) connecting the temporary storage tank (4) and the flange (2). A humidity sensor (15) is installed inside the temporary storage tank (4). The humidity sensor (15) and the end solenoid valve (5) are electrically connected to the main control module (18) in the silica gel status monitoring and regeneration control circuit. The temporary storage tank (4) is connected to an exhaust pipe (26) that runs through the box (1) to the outside. A one-way valve for venting exhaust is installed inside the exhaust pipe (26).

4. The intelligent monitoring transformer maintenance-free breather according to claim 1, characterized in that, The air path includes a three-way connecting pipe (24) connecting the first solenoid valve (10) and the second solenoid valve (11), and a connecting air pipe (8) connecting the air pump (9) and the three-way connecting pipe (24). The air pump (9) is connected to an air inlet pipe (25) that passes through the housing (1) to the outside. The air pump (9) is electrically connected to the main control module (18) in the silicone status monitoring and regeneration control circuit.

5. The intelligent monitoring transformer maintenance-free breather according to claim 1, characterized in that, The silicone state monitoring and regeneration control circuit includes an optical fiber sensing module (16), an radio frequency sensing module (17), a main control module (18), a power control module (19), and a communication module (22). The detection ends of the optical fiber sensing module (16) and the radio frequency sensing module (17) are located inside the first silicone container (13) and the second silicone container (14). The data output interface of the radio frequency sensing module (17) is connected to the first data input interface of the main control module (18), and the control input interface of the radio frequency sensing module (17) is connected to the first control output interface of the main control module (18). The data of the optical fiber sensing module (16) is... The output interface is connected to the second data input interface of the main control module (18), the control input interface of the fiber optic sensing module (16) is connected to the second control output interface of the main control module (18), the power control output interface of the main control module (18) is connected to the control input interface of the power control module (19), the current feedback output interface of the power control module (19) is connected to the feedback input interface of the main control module (18), the power output interface of the power control module (19) is used to connect the first heater (20) and the second heater (21), and the communication interface of the main control module (18) is connected to the communication module (22).

6. The intelligent monitoring transformer maintenance-free breather according to claim 5, characterized in that, The radio frequency sensing module (17) includes several patch antennas, a direct digital frequency synthesizer AD9959, a power amplifier PE15A4002, a circulator, a high-frequency switching matrix PE4259, a quadrature demodulator ADL5391, a first operational amplifier OPA657, a second operational amplifier OPA657, and a first analog-to-digital converter ADS9220. The patch antennas are mounted on the inner wall of a silicone container, and are located at different horizontal heights. The direct digital frequency synthesizer AD9959 has a serial clock pin and a serial number pin... The input / output pins and chip select pins are connected to the first control output interface of the main control module (18) via a serial peripheral interface bus. The differential sine wave positive and negative output pins of the direct digital frequency synthesizer AD9959 are connected to the signal input terminal of the power amplifier PE15A4002 via a first balun. The signal output terminal of the power amplifier PE15A4002 is connected to the first port of the circulator. The second port of the circulator is connected to the common terminal of the high-frequency switching matrix PE4259. The multiple outputs of the high-frequency switching matrix PE4259 are connected to the first port of the circulator. The output terminal is used to connect several patch antennas. The third port of the circulator is connected to the RF signal input pin of the quadrature demodulator ADL5391 through a first attenuator. The reference clock output pin of the direct digital frequency synthesizer AD9959 is connected to the local oscillator signal input pin of the quadrature demodulator ADL5391. The in-phase component output pin of the quadrature demodulator ADL5391 is connected to the in-phase input terminal of the first operational amplifier OPA657. The output terminal of the first operational amplifier OPA657 is connected to the first analog input terminal of the first analog-to-digital converter ADS9220. The quadrature component output pin of the quadrature demodulator ADL5391 is connected to the non-inverting input of the second operational amplifier OPA657. The output of the second operational amplifier OPA657 is connected to the second analog non-inverting input channel of the first analog-to-digital converter ADS9220. The data clock output pin, the first channel data output pin, the second channel data output pin, and the frame synchronization clock output pin of the first analog-to-digital converter ADS9220 are connected to the corresponding pins of the first data input interface of the main control module (18) in low-voltage differential signal mode.

7. The intelligent monitoring transformer maintenance-free breather according to claim 5, characterized in that, The fiber optic sensing module (16) includes a fiber optic grating sensor array, a laser driver ADN8835, a tunable laser, an optical circulator, a photodetector, a transimpedance amplifier OPA657, and a second analog-to-digital converter ADS1256. The fiber optic grating sensor array is embedded in silicone within a silicone container. The serial clock pin, serial data input pin, serial data output pin, and chip select pin of the laser driver ADN8835 are connected to the second control output interface of the main control module (18) via a serial peripheral interface bus. The laser diode drive current output pin of the laser driver ADN8835 is connected to the anode of the tunable laser via a constant current source circuit. The positive output pin and negative output pin of the thermoelectric cooler of the laser driver ADN8835 are connected to... The tunable laser has an integrated thermoelectric cooler. The optical output pigtail of the tunable laser is connected to the first port of the optical circulator. The second port of the optical circulator is used to connect to an external fiber optic grating sensor array. The third port of the optical circulator is aligned with the photosensitive surface of the photodetector. The cathode of the photodetector is connected to the inverting input of the transimpedance amplifier OPA657. The anode of the photodetector is connected to the signal ground. The output of the transimpedance amplifier OPA657 is connected to the first analog input channel of the second analog-to-digital converter ADS1256 through a low-pass filter. The data ready output pin, serial clock input pin, serial data input pin, and serial data output pin of the second analog-to-digital converter ADS1256 are connected to the corresponding pins of the second data input interface of the main control module (18).

8. The intelligent monitoring transformer maintenance-free breather according to claim 5, characterized in that, The main control module (18) includes a SoC system-on-a-chip integrating an FPGA programmable logic unit and an ARM processor core, an NPN transistor, a relay, and a Darlington transistor array. The output terminal of the main control module (18) is connected to the base of the NPN transistor through a first current-limiting resistor. The emitter of the NPN transistor is grounded. The collector of the NPN transistor is connected to one end of the relay coil. The other end of the relay coil is energized. The switch contacts of the relay are connected in series in the energizing circuit of the air pump (9). The output terminal of the numerical control module is connected to the input terminal of the Darlington transistor array. The output terminal of the Darlington transistor array is connected to the coils of the first solenoid valve (10), the second solenoid valve (11), and the end solenoid valve (5).

9. The intelligent monitoring transformer maintenance-free breather according to claim 5, characterized in that, The power control modules (19) are in two sets, and the two sets of power control modules (19) are respectively connected to the first heater (20) and the second heater (21). The power control module (19) includes a digital PWM controller UCD3138, a half-bridge driver UCC27201A, an isolated modulator AMC1301, a first MOSFET, and a second MOSFET. The clock pin and data pin of the digital PWM controller UCD3138 are connected to the power control output interface of the main control module (18) through a power management bus. The first pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the high-side input pin of the half-bridge driver UCC27201A, and the second pulse width modulation output pin of the digital PWM controller UCD3138 is connected to the low-side input pin of the half-bridge driver UCC27201A. The half-bridge driver UCC27201A... The high-side output pin of the 201A is connected to the gate of the first MOSFET through a first gate resistor. The low-side output pin of the half-bridge driver UCC27201A is connected to the gate of the second MOSFET through a second gate resistor. The drain of the first MOSFET is used for power connection. The connection point between the source of the first MOSFET and the drain of the second MOSFET forms a resonant power network to the heater. The digital PWM controller UCD3138 outputs current through the primary coil of the current transformer. A sampling resistor is connected across the secondary coil of the current transformer. The non-inverting analog input pin and the inverting analog input pin of the isolated modulator AMC1301 are respectively connected across the sampling resistor. The data clock output pin and the data output pin of the isolated modulator AMC1301 are respectively connected to the first fault detection pin and the second fault detection pin of the digital PWM controller UCD3138.

10. The intelligent monitoring transformer maintenance-free breather according to claim 5, characterized in that, The communication module (22) includes an Ethernet physical layer chip and an RS-485 differential bus transceiver. The transmit data pin zero, receive data pin zero, transmit enable pin, and receive data valid pin of the main control module (18) are connected to the corresponding media independent interface pins of the Ethernet physical layer chip. The serial port transmit data pin of the main control module (18) is connected to the data input pin of the RS-485 differential bus transceiver. The serial port receive data pin of the main control module (18) is connected to the receive data output pin of the RS-485 differential bus transceiver.

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