Intelligent electric energy metering box

Abstract

The invention discloses an intelligent electric energy metering box, and the box comprises a power conversion module which is used for converting 380V into a 12V power supply and a 3.3 V power supply; the electric energy metering module is electrically connected with the power supply conversion module and is used for metering the electricity consumption of the user and processing data; the WIFI radio frequency module is electrically connected with the electric energy metering module and is used for transmitting data of the electric energy metering module to an external main controller; and the system module is electrically connected with the power supply conversion module and is used for realizing heat dissipation and condensation retarding in the electric energy metering box under specified temperature and humidity conditions. The intelligent electric energy metering box has the beneficial effects that the use reliability can be improved, the service life of equipment is prolonged, and safe and stable operation of an electric energy metering system is ensured.

Description

Technical Field

[0001] The invention relates to the field of electric energy metering, and in particular to an intelligent electric energy metering box. Background Art

[0002] As an important metering equipment protection device in the power system, the electric energy meter box is mainly used to install and protect metering devices such as electric energy meters and circuit breakers. With the advancement of smart grid construction, modern electric energy meter boxes must not only meet basic protection requirements, but also adapt to the installation requirements of intelligent equipment. At present, the electric energy meter boxes on the market are generally made of metal (galvanized iron, stainless steel), non-metal (PC, ABS, gold-containing plastic PC + ABS, SMC glass fiber reinforced unsaturated polyester molding compound) and other materials, and have certain waterproof, dustproof and corrosion-resistant properties.

[0003] Traditional energy meter boxes usually adopt a fully enclosed structure design, and the heat inside the box is mainly dissipated by natural convection. In general, a small number of ventilation holes are set at the bottom or side of the box for air circulation. Although this design meets the requirements of the protection level to a certain extent, there are two prominent problems in actual use: unsatisfactory heat dissipation effect and condensation water formation.

[0004] In terms of heat dissipation, especially in hot summer weather or when the equipment load is heavy, the heat generated inside the box increases significantly. Equipment such as energy meters and circuit breakers generate a lot of heat during operation, which is difficult to dissipate in time in a closed space. Due to the limited effect of natural convection and the restrictions on the number and size of ventilation holes, the temperature inside the box continues to rise. High temperature environment will accelerate the aging of electronic components, reduce the accuracy of metering devices, and may even affect the normal operation of equipment.

[0005] Another serious problem is the formation of condensed water. When the ambient temperature is low (especially in spring and autumn when the temperature difference between day and night is large), the temperature difference between the inside and outside of the box will cause water vapor to condense into water droplets on the inner wall of the box and the surface of components. This phenomenon mainly occurs in the following situations: 1. The temperature drops sharply at night, and the moisture in the air inside the box condenses during the cooling process; 2. When the temperature rises in the early morning, the moist outside air enters the cooler interior of the cabinet and condenses; 3. The temperature drops sharply after rain, and the humid air in the box condenses when it gets cold.

[0006] These condensed water will bring a series of problems: first, the presence of water droplets will increase the risk of short circuit in electrical equipment and threaten the safety of electricity use; second, long-term condensation of water vapor will accelerate the rust of metal parts and shorten the service life of equipment; third, humid environment is prone to breed mold and affect the normal operation of the metering device.

[0007] In addition, the existing energy metering box is not well designed to cope with temperature changes. The temperature difference between the inside and outside of the box will cause changes in air pressure. If the seal is not tight, it is easy to cause the invasion of external humid air, aggravating the condensation problem. At the same time, the traditional ventilation and heat dissipation structure often cannot effectively balance the heat dissipation needs and the requirements for slowing condensation. These two goals often restrict each other.

[0008] Therefore, it is of great significance to develop an energy meter box that can solve the heat dissipation and slow down the condensation problem at the same time. This design not only ensures the effective heat dissipation inside the box, but also takes measures to slow down the formation of condensed water, which can significantly improve the reliability of the energy meter box, extend the service life of the equipment, and ensure the safe and stable operation of the energy metering system. Summary of the invention

[0009] The purpose of the present invention is to provide an intelligent electric energy metering box, which can improve the reliability of use, extend the service life of the equipment, and ensure the safe and stable operation of the electric energy metering system.

[0010] The above technical objectives of the present invention are achieved through the following technical solutions: An intelligent electric energy metering box comprises: a power conversion module, used for converting 380V into 12V and 3.3V power; an electric energy metering module, electrically connected to the power conversion module, used for metering and data processing of user power consumption; a WIFI radio frequency module, electrically connected to the electric energy metering module, used for transmitting data of the electric energy metering module to an external main controller; and a system module, electrically connected to the power conversion module, used for heat dissipation and condensation alleviation inside the electric energy metering box under specified temperature and humidity conditions.

[0011] The present invention is further configured as follows: the power conversion module includes: a first step-down conversion circuit, including an MP150GJ-Z controller, whose input end is connected to a 380V power supply via a 20Ω current limiting resistor, and whose output end is connected to a 4.7μF output capacitor via a 1mH power inductor, an ES1J freewheeling diode, a 1N4007W diode, to form a 12V output; a second step-down conversion circuit, including an AMS1117S-3.3 linear regulator, whose input end is connected to the 12V output end of the first step-down conversion circuit, and is connected to the VIN pin of the regulator after a 0.1μF decoupling capacitor, and the output end VOUT pin outputs a 3.3V voltage.

[0012] The present invention is further configured as follows: the electric energy metering module includes: a CSE7761 chip, having two sets of differential input terminals, V1P / V1N and V2P / V2N; a first signal conditioning circuit, including a 5Ω precision resistor, a 100Ω resistor and a 330pF capacitor connected in series, connected to the V1P / V1N differential input terminal; a second signal conditioning circuit, including a 5Ω precision resistor, a 100Ω resistor and a 330pF capacitor connected in series, connected to the V2P / V2N differential input terminal; a high-voltage voltage divider network, consisting of four 250kΩ resistors connected in series and a 1kΩ resistor and a 33pF capacitor connected in parallel.

[0013] The present invention is further configured as follows: the WIFI radio frequency module includes: an ESP8266EX chip; a PCB antenna, connected to an RF radio frequency switch through a 5.8pF coupling capacitor; the RF radio frequency switch is connected to the radio frequency input terminal of the ESP8266EX chip through a 5.8pF capacitor; and a 26MHz crystal oscillator is connected to the clock input terminal of the ESP8266EX chip.

[0014] The present invention is further configured as follows: the system module includes: a first temperature control circuit, including a 1kΩ / 20W NTC thermistor and a first fan connected in series, connected to the 12V output end of the power conversion module; a second temperature control circuit, including a 10kΩ / 20W NTC thermistor connected in series and a second and a third fan connected in parallel, connected to the 12V output end of the power conversion module; an environmental monitoring circuit, including a magnetoresistor and a humidity resistor connected in series and a reversely excited permanent magnet, connected to the 3.3V output end of the power conversion module, and the spacing between the magnetoresistor and the permanent magnet is 2-3mm.

[0015] The present invention is further configured as follows: the first step-down conversion circuit also includes a multi-stage filtering network: the first stage filtering is composed of a 1mH inductor and a 2.2μF capacitor; the second stage filtering is composed of a 1nF capacitor; the third stage filtering is composed of a 220nF capacitor; the fourth stage filtering is composed of a 220μF electrolytic capacitor; the input end of the multi-stage filtering network is connected to the output end of the MP150GJ-Z controller, and the output end is connected to the 12V output end.

[0016] The present invention is further configured as follows: the second step-down conversion circuit also includes an output filter network: a 1μF capacitor, a 0.1μF capacitor and a 4.7μF / 16V aluminum electrolytic capacitor are connected in parallel; the input end of the output filter network is connected to the VOUT pin of the AMS1117S-3.3 linear regulator, and the output end forms a 3.3V regulated output.

[0017] The present invention is further configured as follows: a first fan is arranged at the bottom of the electric energy metering box and is started when the temperature exceeds 35°C.

[0018] The present invention is further configured as follows: the second and third fans are arranged at the bottom or side of the electric energy meter box and are started when the temperature exceeds 45°C.

[0019] In summary, the present invention has the following beneficial effects: The smart energy meter box adopts a hierarchical power conversion solution, using the MP150GJ-Z controller to achieve efficient step-down conversion from 380V to 12V, and further converting it to 3.3V power using the AMS1117S-3.3 linear regulator, providing stable and reliable working power for each functional module. The design of the multi-stage filter network significantly improves the power quality, effectively suppresses the power ripple, and ensures the stable operation of the system.

[0020] Based on the dual-channel differential input design of the CSE7761 chip, with precision shunt resistors and RC low-pass filter circuits, high-precision voltage and current detection is achieved. The metering data output through the serial communication interface can be transmitted remotely and monitored in real time through the WIFI radio frequency module built with the ESP8266EX chip, greatly improving the intelligence level and ease of use of the system.

[0021] The temperature and humidity control system uses three independent temperature detection and control loops, and controls the start and stop of multiple fans through NTC thermistors with different thresholds, thus achieving graded heat dissipation. When the temperature exceeds 35°C, the first fan starts to perform basic heat dissipation; when the temperature reaches 45°C, the second and third fans start at the same time to form forced convection heat dissipation, effectively preventing the internal temperature of the box from being too high. At the same time, the composite control circuit composed of magnetic resistors and humidity resistors can be adaptively adjusted according to environmental conditions, effectively slowing down the formation of condensed water.

[0022] The intelligent temperature and humidity control solution not only solves the problem of insufficient heat dissipation in traditional electric energy meter boxes, but also effectively prevents the generation of condensed water, significantly extending the service life of the equipment. The overall design not only ensures the metering accuracy and data transmission reliability, but also improves the environmental adaptability of the system, achieving a significant improvement in the functionality, reliability and practicality of the intelligent electric energy meter box. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an intelligent electric energy metering box; Figure 2 It is a system flow chart of a smart electric energy metering box; Figure 3 This is the circuit diagram of the power conversion module 380V-12V conversion; Figure 4 This is the circuit diagram of 12V-3.3V conversion of the power conversion module; Figure 5 This is the circuit diagram of the electric energy metering module; Figure 6 This is the circuit diagram of the WIFI radio frequency module; Figure 7 This is the circuit diagram of the system module. DETAILED DESCRIPTION

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "page", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0026] In the description of the present invention, "multiple" means two or more than two, unless otherwise clearly defined. In the present invention, unless otherwise clearly defined and defined, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0028] like Figure 1 , Figure 2As shown, a smart electric energy meter box can be a single-phase 4, 6, 9, 12 meter box. This application takes a single-phase 6 meter as an example, which mainly includes a power conversion module. The power conversion module can be uniformly integrated and set in the main control circuit of the electric energy meter box. The power conversion module converts 380V into available 12V and 3.3V power supplies. The power conversion module is connected to the electric energy metering module. The electric energy metering modules are respectively arranged in each electric energy meter. Through the electric energy metering module, the electric energy used by the user can be measured and the data can be processed. The electric energy metering module and the power conversion module are connected to a WIFI radio frequency module. Among them, the electric energy metering module and the WIFI radio frequency module are existing electric energy meter functions, and the existing electric energy meter can be installed in the electric energy meter box. The WIFI radio frequency module summarizes and transmits the relevant data of the electric energy metering module to the external main controller, so as to summarize and process the electric power data. The power conversion module is also connected to a system module. The system module is used to achieve the purpose of heat dissipation and slowing down condensation inside the electric energy meter box at specified temperature and humidity.

[0029] like Figure 3 As shown, the power conversion module is a buck converter based on the MP150GJ-Z controller U2, which is set In the main control circuit of the electric energy meter box The 380V high voltage input passes through the 20Ω current limiting resistor R4 from the L end, which plays a role in current limiting protection and also suppresses the impact of surge current on the subsequent circuit. The input current passes through the 1N4007 diode D4, which can withstand 600V reverse voltage, ensuring the reliability of the circuit under large voltage fluctuations.

[0030] The current enters the 1mH power inductor L2, which plays the role of storing and releasing energy during the switching process. When the internal power tube at the DRAIN end of the MP150GJ-Z controller is turned on, L2 stores energy; when the power tube is turned off, L2 releases energy through D4 to maintain the continuity of the load current. The 4.7μF output capacitor C6 receives the rectified power and filters the ripple to provide a stable DC voltage for the next stage.

[0031] In order to obtain a purer output, this application designs a multi-stage filtering network: 1mH inductor L1 cooperates with 2.2μF capacitor C1 to form the main LC filter, 1nF capacitor C2 is used for high-frequency interference, and 220nF capacitor C3 is used for mid-frequency filtering. 220μF large-capacity electrolytic capacitor C5 provides main energy storage and low-frequency filtering, and 0.1μF ceramic capacitor C4 handles high-frequency noise. The above multi-stage filtering combination can effectively suppress broadband electromagnetic interference.

[0032] ES1J freewheeling diode D2 and 1N4007W diode D3 form dual protection: D2 provides a freewheeling path for the load, and D3 prevents reverse connection. 4.7kΩ resistors R1 and R2 form a voltage divider network to feed back the output voltage information to the controller FB terminal to achieve dynamic voltage regulation.

[0033] Through the above settings, the high voltage of 380V is converted into a low voltage of 12V and output from the VCC terminal, thereby achieving the purpose of converting the high voltage power supply into a low voltage power supply.

[0034] like Figure 4 As shown, the power conversion module also includes a step-down circuit based on the AMS1117S-3.3 linear regulator U5. Voltage regulator circuit. The input voltage of the circuit is input from the VCC terminal through the VIN pin (pin 3) of the voltage regulator, and the internal voltage regulator circuit converts the higher input voltage into a stable 3.3V output voltage. A 0.1μF decoupling capacitor C7 is configured at the input end to filter out high-frequency interference and ripple of the input power supply and improve the anti-interference ability of the circuit. The output end VOUT (pin 2) of the voltage regulator is connected to a three-stage filter capacitor network, including a 1μF capacitor C8 for main filtering, a 0.1μF capacitor C9 to handle high-frequency noise, and a 4.7μF / 16V type A aluminum electrolytic capacitor C21 to provide large-capacity energy storage and low-frequency filtering. This ladder capacitor configuration can effectively suppress the full-band ripple from low frequency to high frequency, ensuring the stability of the output voltage. The GND pin (pin 1) is connected to the system ground to provide a stable reference potential.

[0035] The above-mentioned 12V voltage at the VCC end is converted into a low voltage of 3.3V through the low voltage drop characteristic of the AMS1117S-3.3 voltage regulator.

[0036] like Figure 5 As shown, the electric energy metering module includes an electric energy metering front-end circuit based on the CSE7761 chip U4. The existing electric energy meter is installed in the electric energy meter box and connected to the main control circuit for use. The input of the circuit introduces the measurement signal through the CN3 interface, using two sets of differential input channels. Each channel is equipped with a precise voltage divider and filter network: the input signal first passes through the 5Ω precision resistors (R25 / R12 and R15 / R24) for primary shunting, and then passes through 100Ω resistors (R10 / R11 and R13 / R14) and 330pF capacitors (C13 / C14 and C15 / C16) to form an RC low-pass filter circuit to suppress high-frequency interference. The signal is sent to the differential input terminals V1P / V1N and V2P / V2N of the CSE7761 chip.

[0037] At the high-voltage input end, a high-voltage voltage divider network consisting of 250kΩ resistors R18 / R19 / R20 / R21 in series is used, and a 1kΩ resistor R22 and a 33pF capacitor C19 form a voltage divider and filter circuit to adjust the high-voltage signal to an acceptable level range for the chip. The CSE7761 chip operates at a 3.3V operating voltage converted by the above power conversion module, and a 0.1μF decoupling capacitor C17 and a 1μF capacitor C18 are used to ensure stable power supply to the chip.

[0038] The digital interface of the chip includes serial communication pins SDI / RX and SDO / TX, which are level matched through 1kΩ resistors R16 and R17. The clock circuit uses 3.579545MHz crystal oscillator X2, with 22pF load capacitors C22 and C23, to provide accurate time base signals.

[0039] The above-mentioned electric energy metering module is input into the chip U4 after voltage division through the L terminal (high voltage input terminal), and simultaneously uses a dual-channel sampling detection circuit to detect the voltage and current, so as to calculate the user's power consumption, and then outputs the corresponding data through the serial communication pins SDI / RX and SDO / TX and sends it to the external main controller for the purpose of aggregating power information.

[0040] like Figure 6 As shown, the WIFI radio frequency module includes a WiFi radio frequency circuit based on the ESP8266EX chip U1. The existing electric energy meter is installed in the electric energy meter box and connected to the main control circuit for use. The RF part of the circuit is input from the PCB antenna ANT1 and connected to the RF1 RF switch (HC-RF-IPEX0303-01) through a 5.8pF coupling capacitor C10. The RF switch couples the RF signal to the LNA (low noise amplifier) ​​input of the ESP8266EX through a matching network consisting of a 5.8pF capacitor C24 and a 1.5nH inductor L3. This ensures the best transmission efficiency and signal-to-noise ratio of the RF signal.

[0041] The clock circuit uses a 26MHz crystal oscillator X1 and forms an oscillator structure through two 5.6pF load capacitors C11 and C12 to provide an accurate reference clock signal for ESP8266EX.

[0042] Chip U1 uses a 3.3V regulated power supply converted by a power conversion module, decoupled by a 1μF capacitor C20, and pulls up the level of each functional module through multiple 12kΩ resistors (R5, R6, R7, R8, R9).

[0043] The GPIO interface of ESP8266EX is brought out through the 7-pin header CN2 for easy external connection. The serial communication interface (SD_CMD, SD_CLK) and debug interface (CSE_TXD, CSE_RXD) of chip U1 provide data communication function. Its working status indication uses LED1 (LED-0805_R) with resistor R23 for indication and judgment.

[0044] The matching network of the WIFI RF module above optimizes the signal transmission efficiency, making the WiFi signal transceiver performance optimal; the crystal oscillator circuit provides a stable clock source to ensure the accuracy of communication; the perfect decoupling and pull-up circuits ensure the stable operation of each functional module of the chip; its main function is that the serial communication pins SDI / RX and SDO / TX of the above-mentioned energy metering module are connected to the debugging interface CSE_TXD and CSE_RXD of the chip U1. The corresponding power consumption data is passed to the WIFI RF module. After that, the signal is transmitted to the external main controller through the chip U1, and then the corresponding user power consumption data is statistically processed.

[0045] like Figure 7 As shown, the system module includes a fan control circuit, which is arranged in the electric energy meter box. One side of the main control circuit is connected to the power conversion module. The circuit inputs 12V voltage from the VCC input terminal and performs reverse protection through the 1N4007 diode U1. A 100nF decoupling capacitor C25 is configured after the diode U1 to filter out high-frequency interference at the input terminal. The circuit contains three sets of temperature detection and control loops: The first circuit uses a 1kΩ / 20W NTC thermistor R01 to control the fan M1; when the temperature inside the energy meter box rises to more than 35°C, the resistance value of R01 decreases, and the current value passing through R01 increases, causing M1 to work and the fan to run to dissipate heat inside the energy meter box. The fan M1 is set at the bottom of the energy meter box.

[0046] The second circuit uses 10kΩ / 20W NTC thermistor R02 to control the parallel fans M2 and M3; when the temperature in the energy meter box exceeds 45°C, the resistance of R02 drops to a level that can reach the starting current of M2 and M3, so that M2 and M3 work. M2 and M3 are set at the bottom or side of the energy meter box, so that when M2 and M3 work, they cooperate with M1 to improve the heat dissipation efficiency.

[0047] The third route is a composite circuit composed of a 1kΩ magnetic resistor MR-R04 and a 10kΩ humidity resistor RH-R03 connected in series. The third route uses the composite circuit to reduce the impact of water vapor condensation on the electric energy meter box when the temperature drops. The main points are as follows: When the temperature drops below 35°C, the resistance of R01 and R02 recovers and the current through M1, M2, and M3 is lower than the starting current. At this time, M1, M2, and M3 stop working, and YA-F is a reversely excited permanent magnet. Its magnetism decreases as the current increases. When the current through YA-F decreases, its magnetism increases.

[0048] Among them, the spacing between YA-F and the magnetoresistor R04 is 2-3mm, so that the magnetic field of the permanent magnet YA-F affects R04. When the magnetism of YA-F is enhanced, R04 is affected by the magnetic field strength of YA-F and the resistance value decreases. At this time, when the humidity inside the electric energy meter box increases, the resistance value of the humidity-sensitive resistor R03 decreases. When the humidity threshold is reached (the threshold is specifically set according to different regions), at this time, the current passing through R04 and R03 increases, reaching the starting current of M2 and M3, so that M2 and M3 are turned on and work, so that the air inside the electric energy meter box is accelerated to convect under low temperature conditions, thereby alleviating the influence of water vapor condensation under low temperature conditions. If necessary, a corresponding heating resistor can be set between R03 and R04, and the heating resistor can be set on M2 and M3, so that M2 and M3 can blow out wind higher than the condensation dew point temperature under low temperature conditions, thereby improving the effect of alleviating condensation.

[0049] Under the above settings, when the temperature rises, multiple fans are used to adjust the internal air convection to achieve the heat dissipation effect inside the electric energy meter box. When the temperature drops, the internal air convection can be adjusted by heating or non-heating fans to achieve the effect of slowing down condensation.

[0050] In addition, a 100nF capacitor C26 is configured at the output end of the circuit to suppress electromagnetic interference during the switching process.

[0051] The above circuit realizes precise regulation of the internal environment of the energy meter box through multi-stage temperature control and intelligent adjustment mechanism. When the temperature exceeds 35℃, the first-stage fan M1 automatically starts to dissipate heat; when the temperature continues to rise to 45℃, the second-stage parallel fans M2 and M3 work together to form a multi-stage heat dissipation mechanism, effectively preventing the internal components of the energy meter box from being damaged by high temperature. The system uses NTC thermistor as a temperature detection element, which has the characteristics of fast response and high sensitivity.

[0052] In low temperature environment, the series composite detection circuit of magnetoresistor R04 and humidity resistor R03, combined with the reverse excitation characteristics of permanent magnet YA-F, realizes intelligent monitoring of the humidity inside the box. When the temperature drops and condensation may occur, the system controls the fan to generate air convection, effectively suppresses the condensation of water vapor and protects the internal electronic components. The design ensures the accuracy of detection through reasonable component spacing (2-3mm between YA-F and R04).

[0053] The circuit uses a combination of 1N4007 diodes and decoupling capacitors for input protection and filtering, which significantly improves the system's anti-interference ability and stability. The 100nF capacitor C26 at the output end effectively suppresses electromagnetic interference during the switching process, making the system operation more reliable. The overall design realizes dual environmental regulation of temperature and humidity, and has the advantages of simple structure, precise control, and reliable function. It is particularly suitable for environmental control of electric energy metering equipment with strict requirements. In addition, since the chip inside the electric energy metering box itself has a large computing pressure, it often leads to signal interruption or poor signal connection. This application adopts the setting of thermistors and temperature-sensitive resistors, which achieves the goal of not having to process data and responses through the chip, reducing the computing pressure of the chip.

[0054] This design not only solves the heat dissipation problem of traditional electricity meter boxes under extreme temperatures, but also solves the hidden danger of condensation in low-temperature environments, significantly improving the service life and metering reliability of electricity metering equipment.

[0055] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An intelligent electric energy metering box, characterized in that: include: Power conversion module, used to convert 380V into 12V and 3.3V power; An electric energy metering module, electrically connected to the power conversion module, for metering and data processing of user power consumption; A WIFI radio frequency module is electrically connected to the electric energy metering module and is used to transmit data of the electric energy metering module to an external main controller; The system module is electrically connected to the power conversion module and is used to dissipate heat and slow down condensation inside the electric energy metering box under specified temperature and humidity conditions.

2. The intelligent electric energy meter box according to claim 1, characterized in that: The power conversion module comprises: The first step-down conversion circuit includes an MP150GJ-Z controller, whose input end is connected to a 380V power supply via a 20Ω current limiting resistor, and whose output end is connected to a 4.7μF output capacitor via a 1mH power inductor, an ES1J freewheeling diode, a 1N4007W diode, to form a 12V output; The second buck conversion circuit includes an AMS1117S-3.3 linear regulator, whose input end is connected to the 12V output end of the first buck conversion circuit, and is connected to the VIN pin of the regulator after a 0.1μF decoupling capacitor, and the output end VOUT pin outputs a 3.3V voltage.

3. The intelligent electric energy meter box according to claim 1, characterized in that: The electric energy metering module comprises: The CSE7761 chip has two sets of differential input terminals: V1P / V1N and V2P / V2N; A first signal conditioning circuit, including a 5Ω precision resistor, a 100Ω resistor and a 330pF capacitor connected in series, is connected to the V1P / V1N differential input terminal; A second signal conditioning circuit, including a 5Ω precision resistor, a 100Ω resistor and a 330pF capacitor connected in series, is connected to the V2P / V2N differential input terminal; The high-voltage divider network consists of four 250kΩ resistors in series and a 1kΩ resistor and a 33pF capacitor in parallel.

4. The intelligent electric energy meter box according to claim 1, characterized in that: The WIFI radio frequency module includes: ESP8266EX chip; PCB antenna, connected to the RF switch through a 5.8pF coupling capacitor; The RF switch is connected to the RF input terminal of the ESP8266EX chip through a 5.8pF capacitor; 26MHz crystal oscillator, connected to the clock input terminal of the ESP8266EX chip.

5. The intelligent electric energy meter box according to claim 1, characterized in that: The system modules include: A first temperature control circuit, comprising a 1kΩ / 20W NTC thermistor and a first fan connected in series, connected to a 12V output terminal of the power conversion module; A second temperature control circuit, comprising a 10kΩ / 20W NTC thermistor connected in series and a second and a third fan connected in parallel, is connected to the 12V output terminal of the power conversion module; The environment monitoring circuit includes a magnetoresistor and a humidity-sensitive resistor connected in series and a reversely excited permanent magnet, which is connected to the 3.3V output terminal of the power conversion module. The distance between the magnetoresistor and the permanent magnet is 2-3mm.

6. The intelligent electric energy meter box according to claim 2, characterized in that: The first step-down conversion circuit further includes a multi-stage filtering network: The first stage of filtering consists of a 1mH inductor and a 2.2μF capacitor; The second stage of filtering is composed of 1nF capacitors; The third stage of filtering is composed of 220nF capacitors; The fourth stage of filtering is composed of 220μF electrolytic capacitors; The input end of the multi-stage filter network is connected to the output end of the MP150GJ-Z controller, and the output end is connected to the 12V output end.

7. The intelligent electric energy meter box according to claim 2, characterized in that: The second buck converter circuit further includes an output filter network: A 1μF capacitor, a 0.1μF capacitor, and a 4.7μF / 16V aluminum electrolytic capacitor are connected in parallel; The input end of the output filter network is connected to the VOUT pin of the AMS1117S-3.3 linear regulator, and the output end forms a 3.3V regulated output.

8. The intelligent electric energy meter box according to claim 5, characterized in that: The first fan is arranged at the bottom of the electric energy meter box and starts when the temperature exceeds 35°C.

9. The intelligent electric energy meter box according to claim 5, characterized in that: The second and third fans are arranged at the bottom or side of the electric energy meter box and are started when the temperature exceeds 45°C.

Images