Intelligent monitoring device for distribution transformer

Abstract

The utility model provides a distribution transformer intelligent monitoring device, which relates to the technical field of distribution transformer monitoring and comprises a sensor assembly and terminal equipment. The sensor assembly comprises a main mounting body, a pressure regulating plate for supplying power, a pressure relief valve mounted at one end of the main mounting body, and a first monitoring unit and a control circuit board which are hermetically fixed in the main mounting body; the control circuit board is connected with terminal equipment; the other end of the main mounting body penetrates through the distribution transformer oil tank; the first monitoring unit comprises a floater, a guide rod and at least one monitoring circuit board fixed to the control circuit board in a sealed mode. At least one monitoring circuit board penetrates through the floater in the first direction, the floater is fixed to the guide rod, the guide rod is in sliding fit with the main installation body in the first direction, the guide rod is connected with one monitoring circuit board, and the first direction is parallel to the axis direction of the main installation body. The intelligent monitoring device for the distribution transformer is small in size, high in integration level, short in monitoring information transmission path, convenient to install, small in installation space and low in comprehensive cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of distribution transformer monitoring, and particularly relates to a distribution transformer intelligent monitoring device. BACKGROUND

[0002] At present, the online monitoring technology of distribution transformer, namely, distribution transformer, has been facing many difficulties in the process of popularization, and it is difficult to realize effective wide-range application. Most distribution transformers are installed in outdoor environments, so they often face problems such as humid environment, aging, overload, and long-period operation. The operation and maintenance personnel mainly monitor the state of the transformer by periodic inspection and by using monitored voltage, current and other data. However, this monitoring method can only grasp the overload and overload of the transformer in real time, and cannot realize real-time monitoring of the insulation state inside the distribution transformer. Especially for the distribution transformer running for a long period, the monitoring of the insulation performance inside it is even more lacking in effective means. In addition, for the overloaded transformer, the current mainly relies on the experience of the operation and maintenance personnel to judge whether it needs to be replaced, but due to the lack of specific data support, the replacement period of the transformer lacks regularity. During this period, the transformer that has already appeared overload may cause safety hazards due to insufficient insulation performance.

[0003] For the existing monitoring means inside the distribution transformer tank, such as oil chromatographic analysis, partial discharge detection, infrared thermal imaging and video monitoring technology, the comprehensive cost is relatively high, and the monitoring equipment occupies a large space. In actual application, part of the technical means is difficult to discover the insulation defects inside the distribution transformer in the early stage in time, resulting in that the performance price ratio is not ideal. Specifically, although the oil chromatography and partial discharge monitoring technology can accurately discover the potential problems inside the transformer, due to the high cost of equipment purchase, installation and maintenance, it is not suitable to use these high-cost monitoring means for the distribution transformer with low cost itself. Therefore, how to reduce the comprehensive cost while ensuring the monitoring effect has become a key problem to be solved in the popularization and application of the online monitoring technology of distribution transformer. UTILITY MODEL CONTENTS

[0004] The utility model provides a distribution transformer intelligent monitoring device that is small in size, high in integration, short in monitoring information transmission path, convenient to install, small in installation space and low in comprehensive cost in view of the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the utility model is as follows: a distribution transformer intelligent monitoring device, comprising a sensor assembly and a terminal device; the sensor assembly comprises a main mounting body, a pressure release valve, a first monitoring unit, a control circuit board and a pressure regulating plate; the control circuit board is connected with the pressure regulating plate, and the control circuit board is connected with the terminal device;

[0006] The main installation body comprises a first end, a middle installation section and a second end, the control circuit board is fixedly sealed in the middle installation section, the first end is used for penetratingly connecting a distribution transformer oil tank, and the second end is used for installing the pressure release valve;

[0007] The first monitoring unit comprises a float, a guide rod and at least one monitoring circuit board, the at least one monitoring circuit board penetrates the first end, one end of the at least one monitoring circuit board is fixedly and sealingly connected with the control circuit board, the other end of the at least one monitoring circuit board penetrates the float in a first direction, the float is fixedly connected with one end of the guide rod, the other end of the guide rod is slidingly matched with the middle installation section in the first direction, and the guide rod is connected with one of the monitoring circuit boards; the first direction is parallel to the axial direction of the main installation body;

[0008] When the guide rod moves in the first direction, the float is at least partially withdrawn into the first end or at least partially extends out of the first end away from the second end.

[0009] The first monitoring unit and the control circuit board are integrated in the main installation body, the space in the main installation body is effectively utilized while the monitoring and information processing functions are realized, the monitoring circuit board and the control circuit board are fixedly and sealingly connected in the main installation body, the transmission path is shortened, the reliability of monitoring information and the timeliness of information processing are ensured, meanwhile, the main installation body can be installed on the existing transformer oil level, the design is reasonable and convenient for installation, the comprehensive cost is reduced, only the monitoring circuit board of the first monitoring unit and the control circuit board need to be integrated in the main installation body, and the guide rod can move in the first direction, the main installation body is small in size, and thus the installation space of the device on the distribution transformer is saved.

[0010] In some embodiments, the main installation body comprises a mounting seat, a first mounting member and a second mounting member;

[0011] The mounting seat comprises an inner cavity, the inner cavity comprises a first cavity, a second cavity and a third cavity, the first cavity is located at the first end, and the third cavity is located at the second end; the first cavity is in communication with the second cavity and the third cavity respectively, and the second cavity and the third cavity are mutually separated;

[0012] The first mounting member and the second mounting member are sealingly installed in the second cavity respectively, the first mounting member is close to the second end, the second mounting member is close to the first end, the control circuit board is sealingly installed on the first mounting member, and the at least one monitoring circuit board is sealingly installed on the second mounting member; the at least one monitoring circuit board penetrates the first cavity;

[0013] The pressure release valve is sealingly installed in the third cavity.

[0014] The main mounting body is provided as a detachable mounting seat, a first mounting member and a second mounting member. The mounting seat is fixedly connected with the transformer oil tank and generally requires certain connection strength and rigidity, and at the same time, forms mechanical protection and electromagnetic protection for the control circuit board and the first monitoring unit integrated in the main mounting body. Generally, metal materials are selected, which have high cost and large processing difficulty. The first mounting member and the second mounting member generally need to meet the bonding strength and chemical resistance, and generally, materials such as epoxy glue, acrylic glue, silicone glue or polyurethane glue are selected, which have low processing difficulty. According to the needs, different parts of the main mounting body are selected and processed, which can improve the installation and use performance, save production cost, and when the main mounting body is partially damaged, the whole does not need to be replaced, thereby reducing the maintenance cost.

[0015] In some embodiments, the mounting seat further comprises a first cylinder wall, a second cylinder wall and a third cylinder wall, a partition plate is arranged between the second cylinder wall and the third cylinder wall, the first cylinder wall surrounds the first cavity, the second cylinder wall and the partition plate surround the second cavity, and the third cylinder wall and the partition plate surround the third cavity; an oil guide hole is formed in the second cylinder wall, one end of the oil guide hole extends into the first cavity, and the other end of the oil guide hole penetrates through the partition plate and extends into the third cavity. When the oil quantity in the transformer oil tank is reduced, the mounting seat does not need to be removed, only the pressure release valve needs to be removed, oil is injected into the third cavity, and then the oil can be guided to the first cavity through the oil guide hole and flow into the transformer oil tank, which is convenient to operate, the second cavity and the third cavity are mutually isolated, the oil can be prevented from flowing into the second cavity during oil filling, the structure is simple, and the space utilization rate is high.

[0016] In some embodiments, the other end of the guide rod is slidably connected with the first mounting member and the second mounting member in the first direction, and the parts slidably connected with the guide rod are arranged on the first mounting member and the second mounting member which have small processing difficulty, so that low-cost maintenance is facilitated.

[0017] In some embodiments, the other end of the guide rod slides in the guide hole in the first direction, the guide hole comprises a first guide hole and a second guide hole, the first guide hole is formed in the first mounting member, the second guide hole is formed in the second mounting member, and the first guide hole and the second guide hole are in communication.

[0018] In some embodiments, at least one side of the second cylinder wall is provided with a mounting hole, the mounting hole is in communication with the second cavity, the mounting of the first mounting member, the second mounting member, the monitoring circuit board and the control circuit board is facilitated, a sealing cover is mounted on the mounting hole, and the second cavity after mounting is sealed.

[0019] In some embodiments, at least one of the covers is transparent, and a first through hole is formed in the first mounting member and faces the cover, and the first through hole is in communication with the first guide hole, so that the position of the guide rod can be directly observed through the cover from the first through hole, and the oil level can be further confirmed.

[0020] In some embodiments, the mounting holes are formed in opposite sides of the second cylinder wall, so that the mounting operation in the second cavity is further facilitated.

[0021] In some embodiments, a first through hole is formed in the first mounting member and faces one of the covers, and the first through hole is in communication with the first guide hole, and the cover facing the first through hole is transparent.

[0022] In some embodiments, a glue injection hole is formed in another cover, and the second cavity can be sealed by glue injection through the glue injection hole.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] 1、 the utility model discloses that first monitoring unit and control circuit board are integrated in main installation body, realize monitoring and information processing function while making the space in main installation body realize effective utilization, and monitoring circuit board and control circuit board are sealedly connected in one main installation body, shorten the transmission path of monitoring information between monitoring circuit board and control circuit board, guarantee the reliability of monitoring information and the timeliness of information processing;

[0025] 2、 the utility model discloses that main installation body can be installed on existing transformer oil level simultaneously, and reasonable design and convenient installation reduce comprehensive cost, and only need to integrate the monitoring circuit board of first monitoring unit and control circuit board in main installation body, and meet the movement of guide rod along first direction, and main installation body is small in size, thereby save the installation space of device on distribution transformer. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic view of the utility model intelligent monitoring device for distribution transformer;

[0027] Figure 2 It is an explosion view of main installation body of the utility model integrated first monitoring unit and control circuit board;

[0028] Figure 3 It is an appearance structure schematic of main installation body of the utility model integrated first monitoring unit and control circuit board Figure I ;

[0029] Figure 4The installation seat in the utility model is along B-B direction section view;

[0030] Figure 5 The installation seat in the utility model is along C-C direction section view;

[0031] Figure 6 The connection relation of the first installation piece, the second installation piece, the float and the guide rod in the utility model is the exploded view;

[0032] Figure 7 The connection relation of the first installation piece, the second installation piece, the float and the guide rod in the utility model is the schematic diagram;

[0033] Figure 8 The connection relation of the float and the guide rod in the utility model is the schematic diagram;

[0034] Figure 9 The connection relation of the first installation piece and the second installation piece in the utility model is the schematic diagram;

[0035] Figure 10 The appearance structure of the main installation body of the utility model is integrated with the first monitoring unit and the control circuit board Figure II ;

[0036] Figure 11 For Figure 1 The local amplification structure schematic diagram in A place in the utility model.

[0037] Wherein, the reference signs are: 100, main mounting body; 101, first end; 102, mounting middle section; 103, second end; 110, mounting seat; 111, first cavity; 112, second cavity; 1121, mounting hole; 113, third cavity; 114, oil guide hole; 115, barrel wall; 116, partition plate; 117, placing table; 120, first mounting piece; 121, first back plate; 122, first side plate; 123, top plate; 124, first through hole; 125, fixing seat; 126, first guide hole; 127, fourth through hole; 130, second mounting piece; 131, first sub mounting piece; 1311, second back plate; 1312, bottom plate; 1313, second side plate; 1314, third side plate; 1315, second through hole; 1316, clamping groove; 1317, third through hole; 1318, second guide hole; 132, second sub mounting piece; 1321, mounting groove; 133, first glue injection space; 134, second glue injection space; 140, first cover; 150, second cover; 151, glue injection hole; 160, limiting bolt; 170, first sealing gasket; 180, second sealing gasket; 200, pressure relief valve; 300, first monitoring unit; 310, oil level sensor; 311, float; 3111, sampling hole; 312, guide rod; 3121, oil level indication mark; 3122, limiting hole; 313, first monitoring circuit board; 320, second monitoring circuit board; 400, second monitoring unit; 500, control circuit board; 600, pressure regulating plate; 700, transformer oil tank; 710, oil surface; 800, terminal device. DETAILED DESCRIPTION

[0038] In order to solve the problems in the background art, it is necessary to develop and apply some more economical and efficient monitoring technologies that can detect internal insulation problems early. Currently, many research institutions and enterprises are actively exploring new monitoring methods in order to reduce overall costs and improve monitoring accuracy. For example, by using advanced sensor technology, real-time monitoring of transformer operating status can be achieved, and minor abnormal signals can be captured in time, so that appropriate maintenance measures can be taken at the initial stage of the problem. In addition, the application of artificial intelligence and big data technology can also predict and identify potential failure risks by analyzing a large amount of historical data, thereby improving the safety and reliability of transformer operation.

[0039] In order to clearly illustrate the technical features of the present application, the embodiments of the present application will be described in detail below with reference to the drawings and examples, so that the implementation process of how the present application applies technical means to solve technical problems and achieves corresponding technical effects can be fully understood and implemented. The embodiments of the present application and each feature in the examples can be combined with each other without conflict, and the formed technical solutions are all within the protection scope of the present application.

[0040] Reference Figure 1The utility model embodiment provides a kind of intelligent monitoring device of distribution transformer, including sensor component and terminal equipment 800;Sensor component includes main mounting body 100, pressure release valve 200, first monitoring unit 300, control circuit board 500 and pressure regulating plate 600;Control circuit board 500 is connected with pressure regulating plate 600, and pressure regulating plate 600 is used to power supply for control circuit board 500, and control circuit board 500 is connected with terminal equipment 800;The data transmission to control circuit board 500 generation monitoring data by first monitoring unit 300 acquisition, and control circuit board 500 transmits monitoring data to terminal equipment 800;

[0041] Main mounting body 100 includes first end 101, installation middle section 102 and second end 103, control circuit board 500 is sealed and fixed in installation middle section 102, first end 101 is used to penetrate connection distribution transformer oil tank 700, and the overall appearance of main mounting body 100 is similar to existing oil level gauge, and it can be replaced and installed in existing transformer oil level, transformer oil level is the oil level gauge installation place of existing distribution transformer oil tank 700, preferably, the outer dimensions of main mounting body 100 are as follows: diameter 69mm, height 350mm;Second end 103 installs pressure release valve 200, and pressure release valve 200 is standard pressure release valve on market, guarantees the adaptability of distribution transformer intelligent monitoring device and existing distribution transformer and parts;

[0042] First monitoring unit 300 includes float 311, guide rod 312 and at least one monitoring circuit board, float 311, guide rod 312 and at least one monitoring circuit board form at least oil level sensor 310, and the sampling circuit of oil level sensor 310 is integrated on monitoring circuit board;At least one monitoring circuit board penetrates first end 101, one end of at least one monitoring circuit board is sealingly fixedly connected with control circuit board 500, and the other end of at least one monitoring circuit board penetrates float 311 along first direction, when using, float 311 floats on oil surface 710 and rises and falls with oil surface 710 height, and the sensor integrated on monitoring circuit board can monitor the real-time state of the part close to oil surface 710 above float 311 and below oil surface 710 in all directions, float 311 is fixedly connected with one end of guide rod 312, the other end of guide rod 312 is slidingly fitted with installation middle section 102 along first direction, and guide rod 312 is connected with one of monitoring circuit board;First direction is parallel to the axial direction of main mounting body 100;

[0043] When guide rod 312 moves along first direction, float 311 is at least partially withdrawn into first end 101, or float 311 is at least partially extended to the direction away from second end 103 outside first end 101.

[0044] In use, the main mounting body 100 is fixed on the distribution transformer oil tank 700, the control circuit board 500 and the monitoring circuit board are both fixed in the mounting middle section 102, and the guide rod 312 fixedly connected with the float 311 is guided by the guide rod 312 when moving in the first direction, so that the float 311 does not affect the monitoring effect of the sensor integrated on the monitoring circuit board when the oil surface 710 rises and falls.

[0045] Beneficially, the first monitoring unit 300 and the control circuit board 500 are integrated in the main mounting body 100, the space in the main mounting body 100 is effectively utilized while realizing the monitoring and information processing functions, the monitoring circuit board and the control circuit board 500 are sealed and connected in the main mounting body 100, the transmission path is shortened, the reliability of the monitoring information and the timeliness of the information processing are ensured, the main mounting body 100 can be installed on the existing transformer oil level, the design is reasonable and convenient to install, the comprehensive cost is reduced, and only the monitoring circuit board and the control circuit board 500 integrated with the first monitoring unit 300 are needed in the main mounting body 100, and the guide rod 312 can move in the first direction, the main mounting body 100 is small in size, thereby saving the installation space of the device on the distribution transformer.

[0046] The first monitoring unit 300 comprises a gas sensor, an oil level sensor 310 and an oil temperature sensor;

[0047] The insulating oil medium used in the distribution transformer will inevitably gradually age in the long running process. This aging phenomenon can be caused by various factors, including a humid environment, overload operation, high temperature, high pressure and electric arc, etc. These factors will cause the properties of the insulating medium of the transformer, i.e. the transformer oil, to change, and then hydrogen gas is separated out. The generation of hydrogen gas not only significantly reduces the insulation protection strength of the transformer, thereby affecting the safe and stable operation of the power grid, but also poses a potential threat to personal safety; the gas sensor can detect the content of various gases separated out from the transformer oil, especially hydrogen gas, thereby evaluating the aging degree of the oil, in addition, hydrogen gas is the most primary characteristic gas when the distribution transformer fails, and the operation state of the distribution transformer can be effectively judged according to the concentration and gas production rate of hydrogen gas, when a failure occurs, the hydrogen gas separated out from the oil is monitored by installing the gas sensor, and the type of internal failure of the distribution transformer can be simply determined.

[0048] The oil level sensor 310 can be used to monitor the change of the oil level in real time, thereby ensuring the safe operation of the distribution transformer and prolonging the service life of the equipment;

[0049] The oil temperature sensor can be used to monitor the temperature of the oil in the distribution transformer in real time, thereby avoiding the rapid aging of the oil due to high temperature; preferably, the oil temperature sensor is a thermocouple sensor of MAX6675 type;

[0050] The gas sensor, the oil level sensor 310 and the oil temperature sensor can be integrated on the monitoring circuit board, and are preferably further integrated on the main mounting body 100. Preferably, the sampling circuit of the oil level sensor 310 and the guide rod 312 work by using the principle of magnetic coupling. If the oil level sensor 310 shares the circuit board with other sensors, the signal transmission may be unstable due to electromagnetic interference, which affects the measurement accuracy. In addition, after integrating multiple sensors, the difficulty of troubleshooting the circuit board is increased. Furthermore, when the size of the circuit board is limited, the sensor layout and heat dissipation design may be affected, which leads to a decrease in measurement accuracy or reliability. In order to solve the problems of measurement accuracy and high integration, the monitoring circuit board includes a first monitoring circuit board 313 and a second monitoring circuit board 320. The sampling circuit of the oil level sensor 310 is integrated on the first monitoring circuit board 313. The guide rod 312 is connected to the first monitoring circuit board 313. The gas sensor and the oil temperature sensor are integrated on the second monitoring circuit board 320. The first monitoring circuit board 313 and the second monitoring circuit board 320 are respectively and sealingly connected to the control circuit board 500. Further, the guide rod 312 is located on one side of the float 311. A sampling hole 3111 is formed in the middle of the float 311. The second monitoring circuit board 320 is movably and penetrably arranged in the sampling hole 3111. The first monitoring circuit board 313 is located between the guide rod 312 and the second monitoring circuit board 320, which facilitates the connection between the guide rod 312 and the first monitoring circuit board 313, and avoids the interference of the oil level sensor 310 on the sensors integrated on the second monitoring circuit board 320 during operation.

[0051] Preferably, the power distribution transformer intelligent monitoring device further comprises a second monitoring unit 400. The second monitoring unit 400 is located in the power distribution transformer tank 700 and above the oil surface 710. The second monitoring unit 400 is connected to the pressure regulating plate 600 and the control circuit board 500. The pressure regulating plate 600 supplies power to the second monitoring unit 400. The second monitoring unit 400 collects real-time conditions above the oil surface 710 in the power distribution transformer tank 700 and transmits the conditions to the control circuit board 500 in a wireless manner. The second monitoring unit 400 can further monitor the running environment in the power distribution transformer tank 700 in all directions, which provides strong technical support for the state evaluation and fault early warning of the power distribution transformer, significantly improves the accuracy of the power distribution transformer monitoring, effectively ensures the safe and stable operation of the power system, and reduces the comprehensive cost while ensuring the monitoring effect.

[0052] Preferably, the second monitoring unit 400 comprises an air pressure sensor and a temperature and humidity sensor.

[0053] The gas pressure sensor can detect the pressure and temperature of the gas above the oil surface 710, and the humidity sensor can monitor the humidity change in the transformer. It is worth noting that the fluctuation of temperature can significantly change the humidity state of the gas. Therefore, in order to ensure the accuracy and reliability of the data, the humidity sensor should work in a relatively stable temperature environment as much as possible. In this way, not only can the measurement error caused by temperature change be avoided, but also the accuracy and consistency of the overall measurement can be improved.

[0054] The gas pressure sensor adopts BMP180 gas pressure sensor, with a pressure range of 300 to 1100 hPa and a temperature range of -40 to 85 degrees Celsius, and an accuracy of ±1 degrees Celsius.

[0055] The humidity sensor is model SHT30, which can cover a relative humidity (RH) range of 0% to 100% and can control the error within ±3% RH in terms of measurement accuracy, achieving accurate measurement of environmental humidity.

[0056] In some embodiments, the control circuit board 500 includes a microcontroller, a voltage stabilizing module, and a communication module. The voltage regulating board 600 is connected to the voltage stabilizing module and the communication module, respectively. The voltage stabilizing module is connected to the microcontroller and the first monitoring module, respectively. The microcontroller is connected to the first monitoring module, the second monitoring module, and the communication module, respectively. The communication module is connected to the terminal device 800.

[0057] The microcontroller is selected as STM32, which has the characteristics of high performance, low power consumption, and strong reliability.

[0058] The voltage stabilizing module can enable the sensor assembly to function normally in an electromagnetic environment and not cause unacceptable electromagnetic interference to surrounding devices. Preferably, the voltage stabilizing module selects an EMC (Electromagnetic Compatibility) circuit, which can effectively prevent the circuit from being disturbed by external factors such as lightning overvoltage and electromagnetic wave interference, effectively ensuring the reliability of the sensor assembly in harsh working environments.

[0059] The standby current of the communication module is the average current of the DTU (Data Transfer Unit) when maintaining the server network connection and not sending data. The average current of 5V data transmission is about 30ma, and the average current of 12V data transmission is about 15ma. After data transmission is completed, it will automatically enter low power consumption after about 12 seconds. Preferably, the communication module selects a 4G communication module, which adopts 4G (LTE) technology and has the characteristics of wide coverage, high bandwidth, and low delay, can provide more stable connection for the sensor assembly, and avoid the high deployment cost of 5G.

[0060] The communication module communicates with the terminal device 800 through Lora (Long Range) technology, which can ensure low power consumption, strong anti-interference ability and long transmission distance in the transmission process. The strong anti-interference ability enables the intelligent monitoring device for power distribution transformers to stably transmit data in a noisy environment, ensuring the reliability of communication. The long transmission distance enables the intelligent monitoring device for power distribution transformers to cover several kilometers in urban environments and even dozens of kilometers in open rural areas, thereby reducing the number and cost of base stations.

[0061] Beneficially, the low-power microcontroller and communication module can enable the sensor assembly to be powered by a battery, with a battery life of several years, which is very suitable for power distribution transformer application scenarios that require long-term deployment and do not require frequent battery replacement. The high-reliability STM32, voltage stabilizing module, and communication module that communicates through Lora technology can effectively ensure the reliability of the sensor assembly in harsh working environments, and have a large coverage range and low deployment cost.

[0062] In some embodiments, the voltage regulating plate 600 includes a voltage regulating chip and a heat dissipation piece; the voltage regulating chip is laid on the heat dissipation piece to ensure stable operation of the voltage regulating chip;

[0063] Preferably, the heat dissipation piece is 2oz copper, and the 2oz copper is laid on the bottom of the voltage regulating chip and connected to the bottom layer of the heat dissipation pad through 4x0.3mm vias. A small aluminum heat sink can be added if necessary. The size of the small aluminum heat sink is 20mmx15mmx5mm, and the small aluminum heat sink is fixed using thermal conductive glue.

[0064] The voltage regulating chip includes a power input interface, a power conversion circuit, and a power output interface;

[0065] Preferably, the power input interface includes a first power input interface and a second power input interface, the first power input interface is connected to solar power supply, and the second power input interface is connected to DC power supply. The output voltage of the solar power supply and the DC power supply is 12V. The first power input interface uses a 5.08mm pitch 2P terminal, supports a maximum input voltage of 18V, and has a built-in anti-reverse connection diode. Preferably, the model of the anti-reverse connection diode is SS34 Schottky, and the parameter of the anti-reverse connection diode is a withstand voltage of 40V. The second power input interface uses the same specification terminal as the first power input interface. The second power input interface is connected in parallel with the first power input interface. The second power input interface realizes automatic switching through an ideal diode to avoid reverse current impact. Preferably, the model of the ideal diode is LM5050-1.

[0066] The power conversion circuit is connected with the power input interface and the power output interface respectively, and the power output interface is connected with the second monitoring unit 400, the voltage stabilizing module and the communication module respectively.

[0067] The power conversion circuit comprises an input protection circuit and a DC-DC conversion circuit. The first power input interface and the second power input interface are each equipped with a set of input protection circuits. The input protection circuit comprises a TVS tube and a self-resetting fuse. The TVS tube is used for surge suppression, and the self-resetting fuse is used for overcurrent protection. Preferably, the TVS tube is selected as SMBJ15CA. The DC-DC conversion circuit adopts a synchronous step-down chip, such as TPS54360, which can make the input range of the DC-DC conversion circuit reach 8V-36V, the output be 12V / 500mA, and the conversion efficiency be ≥92%. The output end of the DC-DC conversion circuit is configured with a low-ESR solid-state capacitor to reduce the ripple.

[0068] Further, the power conversion circuit is also used for power consumption optimization, i.e. in the standby mode, unnecessary peripherals such as the communication module are turned off, and the static current is <1mA. The dynamic load adjustment adopts a PFM mode, and the efficiency still remains above 85% under light load. The power conversion circuit realizes power consumption optimization, which is the prior art and will not be described here.

[0069] The power output interface adopts a 1×3P terminal with a 5.08mm pitch, which is used for providing an output voltage of 12V, and the maximum output current is 500mA. In addition, the power output interface also reserves an enable signal pin.

[0070] The power conversion circuit further comprises a state indication circuit and a debugging interface circuit. The state indication circuit comprises a double-color LED lamp, which usually comprises a red LED lamp and a green LED lamp. The power state is displayed through the control of the MCU, such as green indicating normal power supply and red indicating solar power supply and DC power supply switching. Usually, when the solar power supply is lower than the switching threshold, the DC power supply is automatically switched. The switching threshold can be adjusted by changing the resistance voltage division, which can be adapted to different batteries. Usually, the switching threshold is 8V. The debugging interface circuit adopts a SWD debugging interface, such as a 2.54mm pitch 4P pin, to support online firmware update and current monitoring.

[0071] Referring to Figure 2 In some embodiments, the main mounting body 100 comprises a mounting seat 110, a first mounting piece 120 and a second mounting piece 130.

[0072] Referring to Figure 4 , 5The mounting seat 110 comprises an inner cavity, the inner cavity comprises a first cavity 111, a second cavity 112 and a third cavity 113, the first cavity 111 is located at the first end 101, and the third cavity 113 is located at the second end 103; the first cavity 111 is in communication with the second cavity 112 and the third cavity 113 respectively, and the second cavity 112 and the third cavity 113 are mutually cut off; the first cavity 111 is in communication with the second cavity 112 to facilitate the connection between the control circuit board 500 and the monitoring circuit board, and the first cavity 111 is in communication with the third cavity 113 for discharging the gas in the distribution transformer oil tank 700 through the pressure relief valve 200 when necessary;

[0073] The first mounting member 120 and the second mounting member 130 are respectively sealingly mounted in the second cavity 112, the first mounting member 120 is close to the second end 103, and the second mounting member 130 is close to the first end 101; the control circuit board 500 is sealingly mounted on the first mounting member 120, and at least one monitoring circuit board is sealingly mounted on the second mounting member 130; the at least one monitoring circuit board penetrates the first cavity 111, such as the second monitoring circuit board 320 for integrating the oil temperature sensor and the gas sensor mentioned above;

[0074] The pressure relief valve 200 is sealingly mounted in the third cavity 113.

[0075] Beneficially, the main mounting body 100 is provided as a detachable mounting seat 110, a first mounting member 120 and a second mounting member 130, the mounting seat 110 is fixedly connected with the distribution transformer oil tank 700, and generally requires a certain connection strength and rigidity, and at the same time forms mechanical protection and electromagnetic protection for the control circuit board 500 and the first monitoring unit 300 integrated in the main mounting body 100, generally selected metal material, higher cost and difficult to process, and the first mounting member 120 and the second mounting member 130 generally need to meet the bonding strength and chemical resistance, generally selected epoxy glue, acrylic glue, silicone glue or polyurethane glue and the like material, low processing difficulty, according to the needs of the different components of the main mounting body 100, the material processing can improve the installation and use performance, at the same time saves the manufacturing cost, and when the main mounting body 100 is locally damaged, it does not need to be replaced as a whole, thereby reducing the maintenance cost.

[0076] Referring to Figure 5In some embodiments, the mounting base 110 further comprises a cylinder wall 115, the cylinder wall 115 comprising a first cylinder wall, a second cylinder wall and a third cylinder wall, a partition 116 being arranged between the second cylinder wall and the third cylinder wall in the cylinder wall 115, the first cylinder wall surrounding the first cavity 111, the second cylinder wall and the partition 116 surrounding the second cavity 112, and the third cylinder wall and the partition 116 surrounding the third cavity 113; an oil guide hole 114 is formed in the second cylinder wall, one end of the oil guide hole 114 extending into the first cavity 111, and the other end of the oil guide hole 114 extending into the third cavity 113 through the partition 116; when the oil amount in the transformer oil tank 700 is reduced, the mounting base 110 does not need to be removed, only the pressure relief valve 200 needs to be removed, and oil is injected into the third cavity 113, so that the oil can be guided to the first cavity 111 through the oil guide hole 114 and flow into the transformer oil tank 700, which is convenient to operate, and the second cavity 112 and the third cavity 113 are mutually isolated, which can prevent oil from flowing into the second cavity 112 during oil filling, and the structure is simple and the space utilization rate is high.

[0077] In some embodiments, the other end of the guide rod 312 is slidably connected with the first mounting member 120 and the second mounting member 130 along the first direction, and the positions slidably connected with the guide rod 312 are arranged on the first mounting member 120 and the second mounting member 130 which are less difficult to process, so that low-cost maintenance is facilitated, and the first mounting member 120 and the second mounting member 130 made of non-metallic material can avoid affecting the operation of the oil temperature sensor.

[0078] Figure 2 、 7 , 8, 10 show the connection relationship between the first mounting member 120 and the second mounting member 130;

[0079] The first mounting member 120 comprises a first back plate 121, a first side plate 122, a top plate 123 and a fixing seat 125, the first back plate 121 is rectangular, the fixing seat 125 is arranged on one side of the first back plate 121, the fixing seat 125 is used for fixing the control circuit board 500, the first side plate 122 and the top plate 123 are respectively arranged on two adjacent sides of the first back plate 121, and the first side plate 122 and the top plate 123 are respectively arranged on one side of the first back plate 121 on which the fixing seat 125 is arranged, the second mounting side is arranged on the side opposite to the top plate 123, and the side opposite to the first side plate 122 is used for the operation of connecting the monitoring circuit board and the control circuit board 500; during installation, the end face of the first back plate 121 away from the top plate 123 is connected with the second mounting member 130;

[0080] The second mounting member 130 comprises a first sub-mounting member 131 and a second sub-mounting member 132:

[0081] The first sub-mounting member 131 comprises a second back plate 1311, a bottom plate 1312, a second side plate 1313 and a third side plate 1314, the second back plate 1311 is fixedly connected with the bottom plate 1312 in an L shape, the second back plate 1311 is fixed with the second side plate 1313 and the third side plate 1314 on opposite sides respectively, the bottom plate 1312 is fixed between the second side plate 1313 and the third side plate 1314, and a rectangular groove is formed between the second back plate 1311, the second side plate 1313, the third side plate 1314 and the bottom plate 1312; a clamping groove 1316 is formed in the middle of the inner side of the second back plate 1311, the clamping groove 1316 is matched with the clamping protrusion on the back of the monitoring circuit board, a second through hole 1315 is formed in the middle of the bottom plate 1312, and a third through hole 1317 is formed on the bottom plate 1312 close to the third side plate 1314; during installation, the end face of the second back plate 1311 away from the bottom plate 1312 is connected with the first mounting member 120;

[0082] The second sub-mounting member 132 is rectangular, and an installation groove 1321 is formed on one side of the second sub-mounting member 132; during installation, the second sub-mounting member 132 is placed in the rectangular groove, the installation groove 1321 faces the clamping groove 1316, the size of the installation groove 1321 is determined according to the circuit design and sensor layout on the second monitoring circuit board 320, and a gap corresponding to the third through hole 1317 is left between the second sub-mounting member 132 and the third side plate 1314, and the size of the gap and the third through hole 1317 is determined according to the circuit design and sensor layout on the first monitoring circuit board 313;

[0083] During installation, the control circuit board 500 is fixed on the first mounting member 120 through the fixing seat 125; the end of the second monitoring circuit board 320 away from the clamping protrusion is penetrated through the second through hole 1315 from inside to outside, the clamping protrusion is matched with the clamping groove 1316 when the clamping protrusion is aligned with the clamping groove 1316, the second sub-mounting member 132 is placed in the rectangular groove, and the first sub-mounting member 131 and the second sub-mounting member 132 are fixed, a second glue injection space 134 is formed between the installation groove 1321 and the second monitoring circuit board 320, so as to realize the local sealing and stability of the second monitoring circuit board 320, meanwhile, the gap between the second sub-mounting member 132 and the third side plate 1314 forms a first glue injection space 133, so as to realize the local sealing and stability of the first monitoring circuit board 313, and preferably, the second sub-mounting member 132 is fixed on the second back plate 1311 by a bolt, so as to realize the fixing between the first sub-mounting member 131 and the second sub-mounting member 132;

[0084] In some embodiments, the guide rod 312 slides in the guide hole in the first direction at the other end, see Figure 11The guide holes include a first guide hole 126 and a second guide hole 1318. The first guide hole 126 is formed in the first mounting member 120 and the first side plate 122. One end of the first guide hole 126 penetrates through the end surface of the first side plate 122 away from the top plate 123. The second guide hole 1318 is formed in the second mounting member 130 and the third side plate 1314. The first guide hole 126 is in communication with the second guide hole 1318.

[0085] In some embodiments, at least one side of the second cylinder wall is provided with a mounting hole 1121 in communication with the second cavity 112, facilitating the installation of the first mounting member 120, the second mounting member 130, the monitoring circuit board and the control circuit board 500. A sealing cover is installed on the mounting hole 1121 to seal the second cavity 112 after installation.

[0086] In some embodiments, at least one cover is made of transparent material. A first through hole 124 is formed in the first side plate 122 of the first mounting member 120, facing the cover made of transparent material. The first through hole 124 is in communication with the first guide hole 126. An oil level indicating mark 3121 is provided on the guide rod 312. See Figure 3 , which facilitates direct observation of the oil level through the cover from the first through hole 124 during use.

[0087] See Figure 9 , preferably, a limiting hole 3122 is formed in the guide rod 312, and a fourth through hole 127 is formed in the first side plate 122 in communication with the first guide hole 126. See Figure 11 The limiting bolt 160 penetrates through the fourth through hole 127 and the limiting hole 3122 in sequence. The cooperation between the limiting bolt 160 and the limiting hole 3122 can limit the movement range of the float 311, preventing the float 311 from falling off when the oil level is low or the float 311 from interfering with the structure inside the main mounting body 100 when the oil level is high.

[0088] In some embodiments, the second cylinder wall is provided with mounting holes 1121 on opposite sides, the mounting holes 1121 are flush with the partition plate 116 at the top, and the mounting holes 1121 are provided with a placement table 117 at the bottom. The first mounting member 120 is provided with a first through hole 124, the first through hole 124 is connected with the first guide hole 126, and the first through hole 124 is directed to one of the covers, the cover directed by the first through hole 124 is made of transparent material, and the cover is recorded as a first cover 140, the other cover is recorded as a second cover 150, and the oil level can be directly observed from the first through hole 124 through the cover. During installation, the second mounting member 130 provided with the second monitoring circuit board 320 is placed into the second cavity 112 from the mounting hole 1121, the bottom plate 1312 is close to the first cavity 111 and away from the third cavity 113 during the placement process, the second monitoring circuit is penetrated into the first cavity 111 after the placement, the bottom plate 1312 or the second side plate 1313 and the third side plate 1314 on both sides of the bottom plate 1312 of the second mounting member 130 are placed on the placement table 117 to limit the second mounting member 130, and then the first mounting member 120 provided with the control circuit board 500 is placed between the second mounting member 130 and the partition plate 116, the top plate 123 of the first mounting member 120 is in contact with the partition plate 116, the space in the second cavity 112 can be more reasonably utilized, the mounting hole 1121 close to the first side plate 122 is sealed by the first sealing gasket 170 and the first cover 140, and after wiring is completed, the mounting hole 1121 away from the first side plate 122 is sealed by the second sealing gasket 180 and the second cover 150, and the first cover 140 is provided with a first through hole 141, and the second cover 150 is provided with a second through hole 151. Figure 6 The other cover, i.e., the second cover 150 is provided with a glue injection hole 151, and the second cavity 112 is sealed by glue injection from the glue injection hole 151, and it is worth noting that when external wiring is required in the main mounting body 100, the wiring can be connected first and then sealed by glue injection.

[0089] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application by ordinary skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A distribution transformer intelligent monitoring device, characterized in that, It includes a sensor assembly and a terminal device; the sensor assembly includes a main mounting body, a pressure relief valve, a first monitoring unit, a control circuit board, and a pressure regulating plate; the control circuit board is connected to the pressure regulating plate and the terminal device. The main mounting body includes a first end, a middle mounting section, and a second end. The control circuit board is sealed and fixed in the middle mounting section. The first end is used to connect through the distribution transformer oil tank, and the pressure relief valve is installed at the second end. The first monitoring unit includes a float, a guide rod, and at least one monitoring circuit board; the at least one monitoring circuit board extends through the first end, one end of the at least one monitoring circuit board is sealed and fixedly connected to the control circuit board, the other end of the at least one monitoring circuit board extends through the float along a first direction, the float is fixedly connected to one end of the guide rod, the other end of the guide rod is slidably engaged with the mounting section along the first direction, and the guide rod is connected to one of the monitoring circuit boards; the first direction is parallel to the axial direction of the main mounting body.

2. The intelligent monitoring device for distribution transformers according to claim 1, characterized in that, The main mounting body includes a mounting base, a first mounting component, and a second mounting component; The mounting base includes an inner cavity, which includes a first cavity, a second cavity, and a third cavity. The first cavity is located at a first end, and the third cavity is located at a second end. The first cavity is connected to the second cavity and the third cavity, respectively, and the second cavity and the third cavity are isolated from each other. The first mounting component and the second mounting component are respectively sealed and installed in the second cavity. The first mounting component is close to the second end, and the second mounting component is close to the first end. The control circuit board is sealed and installed on the first mounting component, and the at least one monitoring circuit board is sealed and installed on the second mounting component. At least one of the monitoring circuit boards penetrates the first cavity. The pressure relief valve is sealed and installed inside the third cavity.

3. The intelligent monitoring device for distribution transformers according to claim 2, characterized in that, The mounting base further includes a first cylindrical wall, a second cylindrical wall, and a third cylindrical wall. A partition is provided between the second cylindrical wall and the third cylindrical wall. The first cylindrical wall forms the first cavity, the second cylindrical wall and the partition form the second cavity, and the third cylindrical wall and the partition form the third cavity. An oil guide hole is provided in the second cylindrical wall. One end of the oil guide hole extends into the first cavity, and the other end of the oil guide hole passes through the partition and extends into the third cavity.

4. The intelligent monitoring device for distribution transformers according to claim 3, characterized in that, The other end of the guide rod is slidably engaged with the first mounting component and the second mounting component along the first direction.

5. The intelligent monitoring device for distribution transformers according to claim 4, characterized in that, The other end of the guide rod slides in the guide hole along a first direction. The guide hole includes a first guide hole and a second guide hole. The first guide hole is provided on the first mounting member, and the second guide hole is provided on the second mounting member. The first guide hole and the second guide hole are connected.

6. The intelligent monitoring device for distribution transformers according to claim 5, characterized in that, An installation hole is provided on at least one side of the second cylinder wall, the installation hole is connected to the second cavity, and a sealing cap is installed on the installation hole.

7. The intelligent monitoring device for distribution transformers according to claim 6, characterized in that, At least one of the caps is made of a transparent material, and a first through hole is formed on the first mounting member. The first through hole faces the transparent cap and is connected to the first guide hole.

8. The intelligent monitoring device for distribution transformers according to claim 6, characterized in that, The mounting holes are respectively opened on the opposite sides of the second cylinder wall.

9. The intelligent monitoring device for distribution transformers according to claim 8, characterized in that, The first mounting component has a first through hole facing one of the covers. The first through hole is connected to the first guide hole. The cover facing the first through hole is made of transparent material.

10. The intelligent monitoring device for distribution transformers according to claim 9, characterized in that, Another of the caps has an injection hole.

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