A distribution transformer control circuit

Abstract

The present invention relates to the technical field of power distribution transformer equipment, and in particular to a power distribution transformer control circuit, comprising a current monitoring module, a voltage monitoring module, a smoke sensing module, a temperature and humidity detection module, a power carrier communication module and an MCU main control module, wherein the MCU main control module is electrically connected to the current monitoring module, the smoke sensing module, the temperature and humidity detection module and the power carrier communication module respectively, and the power carrier communication module sends a control signal to the power carrier module corresponding to the bottom electric meter, and a current monitoring module is provided to realize current monitoring of indoor cables of the transformer; a voltage monitoring module is provided to realize voltage monitoring of indoor cables of the transformer; a power carrier communication module is provided to realize data collection and aggregation of each sub-meter in a bottom cable branch box and an electric meter box, and realize precise positioning; and accurate monitoring of the distribution transformer is realized by coordinating the current monitoring module, the smoke sensing module, the temperature and humidity detection module, the power carrier communication module and the MCU main control module.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution transformer equipment, and in particular to a power distribution transformer control circuit. Background Art

[0002] The existing technology is mainly used to monitor the operating conditions of distribution transformers, including operating parameters such as voltage, current, power, frequency, electricity, harmonics, and power outages. It can only monitor the electric energy meter data in the transformer room on-site, and cannot monitor the electric meters in the bottom cable branch box and meter box, etc., and manage the electric meter data within the range; it is unable to monitor the changes in ambient temperature and humidity in the transformer room, resulting in the inability to provide moisture-proof warnings under high temperature and high humidity; it is unable to monitor the smoke situation in the transformer room, resulting in the inability to provide fire smoke alarms; if transmission is carried out through a GPRS module, the cost of laying the overall network is too high, and it is not suitable for power distribution transformation. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a distribution transformer control circuit to achieve accurate monitoring of the distribution transformer.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A distribution transformer control circuit comprises a current monitoring module, a voltage monitoring module, a smoke sensing module, a temperature and humidity detection module, a power carrier communication module and an MCU main control module. The MCU main control module is electrically connected to the current monitoring module, the smoke sensing module, the temperature and humidity detection module and the power carrier communication module respectively. The power carrier communication module sends a control signal to the power carrier module corresponding to the bottom electric meter.

[0006] The beneficial effects of the present invention are:

[0007] A current monitoring module is set up to realize current monitoring of the indoor cables of the transformer; a voltage monitoring module is set up to realize voltage monitoring of the indoor cables of the transformer; a smoke sensor module is set up to realize monitoring of the smoke alarm in the transformer room; a temperature and humidity detection module is set up to realize monitoring of the indoor environmental temperature and humidity of the transformer; a power carrier communication module is set up and the power carrier communication module sends a control signal to the corresponding power carrier module of the bottom meter to realize data collection and aggregation of each sub-meter in the bottom cable branch box and the meter box, and realize precise positioning; an MCU main control module is set up to realize data interaction and control of the entire system operation; this scheme realizes precise monitoring of the distribution transformer through the coordination between the current monitoring module, the smoke sensor module, the temperature and humidity detection module, the power carrier communication module and the MCU main control module. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A connection block diagram of a distribution transformer control circuit according to the present invention;

[0009] Figure 2 A circuit schematic diagram of a power carrier communication module of a distribution transformer control circuit according to the present invention;

[0010] Figure 3 A circuit schematic diagram of a current monitoring module of a distribution transformer control circuit according to the present invention;

[0011] Figure 4 A circuit schematic diagram of a voltage monitoring module of a distribution transformer control circuit according to the present invention;

[0012] Figure 5 A circuit schematic diagram of a smoke sensor module of a distribution transformer control circuit according to the present invention;

[0013] Figure 6 A circuit schematic diagram of a temperature and humidity detection module of a distribution transformer control circuit according to the present invention;

[0014] Figure 7 A circuit schematic diagram of an RS485 communication module of a distribution transformer control circuit according to the present invention;

[0015] Figure 8 A circuit schematic diagram of a remote signaling module of a distribution transformer control circuit according to the present invention;

[0016] Fig. 9 A circuit schematic diagram of a power conversion module of a distribution transformer control circuit according to the present invention;

[0017] Fig.10 A circuit schematic diagram of an external expansion FLASH module of a distribution transformer control circuit according to the present invention;

[0018] Fig.11 A circuit schematic diagram of an MCU main control module of a distribution transformer control circuit according to the present invention;

[0019] Fig.12 A circuit schematic diagram of a liquid crystal display module of a distribution transformer control circuit according to the present invention;

[0020] Fig.13 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0021] Fig.14 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0022] Fig.15A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0023] Fig.16 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0024] Fig.17 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0025] Fig.18 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0026] Fig.19 A circuit schematic diagram of a 4G communication module of a distribution transformer control circuit according to the present invention;

[0027] Description of labels:

[0028] 1. Current monitoring module; 2. Voltage monitoring module; 3. Smoke sensor module; 4. Temperature and humidity detection module; 5. Power carrier communication module; 6. MCU main control module; 7. RS485 communication module; 8. Remote signal module; 9. Power conversion module; 10. External FLASH module; 11. LCD display module; 12. 4G communication module. DETAILED DESCRIPTION

[0029] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0030] Please refer to Figure 1 , the technical solution provided by the present invention:

[0031] A distribution transformer control circuit comprises a current monitoring module, a voltage monitoring module, a smoke sensing module, a temperature and humidity detection module, a power carrier communication module and an MCU main control module. The MCU main control module is electrically connected to the current monitoring module, the smoke sensing module, the temperature and humidity detection module and the power carrier communication module respectively. The power carrier communication module sends a control signal to the power carrier module corresponding to the bottom electric meter.

[0032] From the above description, it can be seen that the beneficial effects of the present invention are:

[0033] A current monitoring module is set up to realize current monitoring of the indoor cables of the transformer; a voltage monitoring module is set up to realize voltage monitoring of the indoor cables of the transformer; a smoke sensor module is set up to realize monitoring of the smoke alarm in the transformer room; a temperature and humidity detection module is set up to realize monitoring of the indoor environmental temperature and humidity of the transformer; a power carrier communication module is set up and the power carrier communication module sends a control signal to the corresponding power carrier module of the bottom meter to realize data collection and aggregation of each sub-meter in the bottom cable branch box and the meter box, and realize precise positioning; an MCU main control module is set up to realize data interaction and control of the entire system operation; this scheme realizes precise monitoring of the distribution transformer through the coordination between the current monitoring module, the smoke sensor module, the temperature and humidity detection module, the power carrier communication module and the MCU main control module.

[0034] Furthermore, the power carrier communication module includes a chip U7, the model of the chip U7 is LM1893, and the fifth pin of the chip U7, the twelfth pin of the chip U7 and the seventeenth pin of the chip U7 are electrically connected to the MCU main control module respectively.

[0035] Furthermore, the current monitoring module includes a resistor R50, a resistor R56, a resistor R59, a resistor R62, a capacitor C38, a capacitor C43 and a current transformer U12, a first pin of the current transformer U12 being electrically connected to one end of the resistor R50 and one end of the resistor R56, respectively, the other end of the resistor R50 being electrically connected to one end of the capacitor C38, the other end of the capacitor C38 being electrically connected to the other end of the resistor R56 and the MCU main control module, a second pin of the current transformer U12 being electrically connected to one end of the resistor R59 and one end of the resistor R62, respectively, the other end of the resistor R59 being electrically connected to one end of the capacitor C43 and the MCU main control module, the other end of the resistor R62 being electrically connected to the other end of the capacitor C43, and the other end of the resistor R62 and the other end of the capacitor C43 are both grounded.

[0036] From the above description, it can be seen that the function of this module is to monitor the current value in the secondary cable of the transformer. Here, phase A monitoring is taken as an example (the same applies to phases B and C). The current transformer U12 is an open-type current transformer, which can convert the current on the primary cable side into a secondary current through a transformation ratio. Here, the current transformer U12 is a 3000:1 current transformer, that is, if the current on the primary side is 30A, the output current on the secondary side (i+ pin and i- pin of the current transformer U12) is 10mA; resistor R50 and resistor R62 are boost resistors to ground, which can convert the secondary current converted by the current transformer U12 into a voltage output, that is, U1=i+*R50; resistor R56 and resistor R59 are current limiting resistors to prevent the voltage after the current transformer conversion from being too high and breaking through the IO port of the MCU main control module; capacitor C38 and capacitor C43 are filter capacitors, which filter the converted voltage more smoothly to ensure that the data is accurate when the MCU main control module performs ADC sampling. The module will monitor the changes in the three-phase cable current in real time and output the data to the MCU main control module for data processing.

[0037] Further, the voltage monitoring module includes a resistor R48, a resistor R51, a resistor R52, a resistor R53, a resistor R54, a resistor R55, a resistor R57, a resistor R58, a resistor R60, a capacitor C36, a capacitor C42 and a voltage transformer U11, a first pin of the voltage transformer U11 is electrically connected to one end of the resistor R55, the other end of the resistor R55 is electrically connected to the resistor R54, the resistor R53, the resistor R52 and the resistor R57 in sequence, a second pin of the voltage transformer U11 is electrically connected to one end of the resistor R57, and a third pin of the voltage transformer U11 is electrically connected to one end of the resistor R48 and One end of the resistor R51 is electrically connected, and the other end of the resistor R51 is electrically connected to one end of the capacitor C36 and the MCU main control module respectively, the other end of the capacitor C36 is electrically connected to the other end of the resistor R48, and the other end of the capacitor C36 and the other end of the resistor R48 are both grounded, the fourth pin of the voltage transformer U11 is electrically connected to one end of the resistor R60 and one end of the resistor R58 respectively, the other end of the resistor R60 is electrically connected to one end of the capacitor C42, and the other end of the resistor R60 and one end of the capacitor C42 are both grounded, and the other end of the resistor R58 is electrically connected to the other end of the capacitor C42 and the MCU main control module respectively.

[0038] From the above description, it can be seen that the function of this module is to monitor the voltage value in the secondary cable of the transformer. Here, phase A monitoring is taken as an example (the same applies to phases B and C). In a three-phase system, Ua represents the voltage input of phase A, Un represents the neutral line input, and resistor R57 is a varistor voltage, the purpose of which is to prevent lightning strikes from damaging the line; resistors R52, R53, R54 and R55 are current limiting resistors, which convert the voltage of Ua into current input, that is, (I+) = Ua / (R52+R53+R54+R55). When the line operates normally, Ua = 220V, then (I+) = 73.33mA; voltage transformer U11 is a voltage transformer, which can convert the current on the primary cable side into a secondary proportional current through a transformation ratio. Here, voltage transformer U11 is a 1:1 voltage transformer, that is, if the current on the primary side is 1 0mA, the output current of the secondary side (i+ pin and i- pin of voltage transformer U11) is 10mA; resistor R48 and resistor R60 are boost resistors to ground, which can convert the secondary current converted by voltage transformer U11 into voltage output, that is, U=(i+)*R48; resistor R51 and resistor R58 are current limiting resistors, in order to prevent the voltage after voltage transformer conversion from being too high to break through the IO port of MCU main control module; capacitor C36 and capacitor C42 are filter capacitors, which filter the converted voltage more smoothly to ensure the accuracy of data when MCU main control module performs ADC sampling; this module will monitor the voltage changes of three-phase cables in real time, and output the data to the MCU main control module for data processing.

[0039] Further, the smoke sensing module includes a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a diode D2, a diode D3, a switch S1, a transistor Q1 and a chip U3, a first pin of the chip U3 is electrically connected to one end of the resistor R9, the other end of the resistor R9 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is grounded, a second pin of the chip U3 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to the anode of the diode D3, the cathode of the diode D3 is grounded, and a third pin of the chip U3 is electrically connected to one end of the switch S1. The fourth pin of the chip U3 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is electrically connected to one end of the resistor R13 and the base of the transistor Q1 respectively. The emitter of the transistor Q1 is electrically connected to the other end of the resistor R13, and the collector of the transistor Q1 is electrically connected to one end of the resistor R7 and the MCU main control module respectively. The other end of the resistor R7 is connected to the 3.3V power supply. The fifth pin of the chip U3 is grounded, and the twelfth pin of the chip U3 is grounded through the resistor R11.

[0040] From the above description, it can be seen that the function of this module is to monitor whether there is smoke in the transformer room and play a role in fire alarm. If fire smoke is detected, the smoke alarm information data will be transmitted to the MCU main control module and uploaded to the background for alarm. Chip U3 is a smoke sensor module that can detect smoke particles in the air in real time; capacitor C8 is a filter capacitor to ensure that the working power supply of the smoke sensor module U3 is in a stable state. Resistor R11 is a current limiting resistor to protect the module from overcurrent. When there is no smoke in the air, the first pin of chip U3 outputs a high level. At this time, diode D2 is turned on and is in a light-emitting state, indicating that it is currently in a normal state; the second pin of U3 outputs a low level. At this time, diode D2 is not turned on and is not in a light-emitting state, indicating that it is currently in a normal state; the fourth pin of chip U3 outputs a low level and cannot drive transistor Q1 to work, then the voltage at the YGBJ point is at a high level. When the MCU main control module detects that the voltage at the YGBJ point is high, it indicates that it is currently in a normal state;

[0041] When there is smoke in the air, the first pin of chip U3 outputs a low level. At this time, diode D2 is not turned on and is not in a light-emitting state, indicating that it is currently in a smoke alarm state; the second pin of chip U3 outputs a high level. At this time, diode D2 is turned on and is in a light-emitting state, indicating that it is currently in a smoke alarm state; the fourth pin of chip U3 outputs a high level, and through resistor R12 (current-limiting resistor), a small current can be generated to drive the switching transistor Q1 to work, then the voltage at point YGBJ is at a low level. When the MCU main control module detects a low voltage at point YGBJ, it indicates that it is currently in a smoke alarm state. Resistor R13 is a ground discharge resistor to prevent the level of the fourth pin of chip U3 from changing too much and breaking through transistor Q1, thereby protecting transistor Q1. Resistor R7 is a current-limiting resistor. When transistor Q1 is turned on, it ensures that VCC3.3V will not be directly pulled down to the ground level, causing system voltage abnormality.

[0042] Furthermore, the temperature and humidity detection module includes a resistor R43, a resistor R44, a capacitor C41 and a chip U10, the first pin of the chip U10 is electrically connected to the resistor R43 and the MCU main control module respectively, the second pin of the chip U10 is grounded, the fifth pin of the chip U10 is electrically connected to one end of the capacitor C41, and the fifth pin of the chip U10 and one end of the capacitor C41 are respectively connected to a 3.3V power supply, the other end of the capacitor C41 is grounded, the sixth pin of the chip U10 is electrically connected to one end of the resistor R44 and the MCU main control module respectively, the other end of the resistor R44 is electrically connected to the other end of the resistor R43, and the other end of the resistor R44 and the other end of the resistor R43 are both connected to a 3.3V power supply.

[0043] From the above description, it can be seen that the function of the module is to monitor the ambient temperature and humidity in the transformer room, detect whether the operating environment of the equipment is healthy, and ensure that the system equipment is not in harsh conditions such as high temperature and high humidity. If high temperature and high humidity occur, this abnormal situation must be reported to the background alarm. Chip U10 is a digital temperature and humidity sensor chip that can automatically detect the temperature and humidity values ​​in the air in real time, and transmit data through the first pin and the sixth pin of the chip U10 and the MCU main control module through the IIC protocol. Resistors R43 and R44 are pull-up resistors that can provide load capacity and ensure stable data transmission. Capacitor C41 is a filter capacitor to ensure that the working power supply of chip U10 is in a stable state.

[0044] Furthermore, it also includes an RS485 communication module, which is electrically connected to the MCU main control module. The RS485 communication module includes resistor R85, resistor R87, resistor R90, resistor R92, resistor R95, resistor R98, resistor R105, resistor R107, capacitor C48, capacitor C50, diode D15, diode D17, voltage regulator VP1, connector J3 and chip U16. The first pin of the chip U16 is electrically connected to one end of the resistor R87, and the other end of the resistor R87 is electrically connected to the MCU main control module. The second pin of the chip U16 is electrically connected to the third pin of the chip U16 and one end of the resistor R92 respectively, and the other end of the resistor R92 is connected to a 3.3V power supply. The fourth pin of the chip U16 is electrically connected to the MCU main control module through the resistor R107, and the fifth pin of the chip U16 is grounded. The sixth pin of the chip U16 is electrically connected to one end of the resistor R95 and one end of the resistor R105 respectively, the other end of the resistor R105 is connected to a 3.3V power supply, the other end of the resistor R95 is electrically connected to the cathode of the diode D17 and one end of the voltage regulator VP1, one end of the resistor R98 and the second pin of the connector J3 respectively, the anode of the diode D17 is grounded, the seventh pin of the chip U16 is electrically connected to one end of the resistor R85 and one end of the resistor R90 respectively, the other end of the resistor R90 is electrically connected to the cathode of the diode D15, the other end of the voltage regulator VP1, the other end of the resistor R98 and the first pin of the connector J3 respectively, the anode of the diode D15 is grounded, the capacitor C50 is connected in parallel with the capacitor C48, one end of the capacitor C50 and the capacitor C48 after being connected in parallel is grounded, and the other end of the capacitor C50 and the capacitor C48 after being connected in parallel is connected to a 3.3V power supply.

[0045] From the above description, it can be seen that the function of this module is to communicate data processed by the MCU main control module with the outside through RS485 communication. Among them, chip U16 is an RS485 communication chip, and resistors R87 and R107 are current limiting resistors to protect the connection between the IO port of the MCU main control module and chip U16. Resistors R92, R85 and R105 are pull-up resistors to increase the driving capacity on the line. Resistors R90 and R95 are current limiting resistors to prevent overcurrent from breaking through chip U16 during external signal transmission. The voltage regulator VP1 is a bidirectional suppression diode to prevent the voltage difference between the AB lines from breaking through chip U16. Diodes D15 and D17 are single-phase suppression diodes for A and B, respectively, to protect A and B; resistor R98 is a matching resistor between AB, in order to match the impedance when communicating with external RS485. Capacitors C50 and C48 are filter capacitors for chip U16 to ensure a stable power supply voltage.

[0046] Furthermore, it also includes a remote signal module, which is electrically connected to the MCU main control module. The remote signal module includes a resistor R46, a resistor R49 and a photocoupler IC1. The first pin of the photocoupler IC1 is electrically connected to one end of the resistor R49, the second pin of the photocoupler IC1 and the third pin of the photocoupler IC1 are respectively grounded, the fourth pin of the photocoupler IC1 is respectively electrically connected to one end of the resistor R46 and the MCU main control module, and the other end of the resistor R46 is connected to a 3.3V power supply.

[0047] From the above description, it can be seen that this module can realize external telemetry signal monitoring. When the external telemetry signal alarms, the alarm information can be uploaded to the background; resistor R49 is a current limiting resistor, and resistor R46 is a pull-up resistor. When there is no external telemetry fault signal, IN1=0V, which is a low level, and the photocoupler IC1 is not turned on, then NET_IN1=3.3V, the MCU main control module detects a high level, and the system does not alarm; when there is an external telemetry fault signal, IN1=3.3V, which is a high level, and the photocoupler IC1 is turned on, then NET_IN1=0V, the MCU main control module detects a low level, and the system alarms.

[0048] Furthermore, it also includes a power conversion module, which is electrically connected to the MCU main control module. The power conversion module includes capacitor C34, capacitor C35, capacitor C37, diode D10, diode D12 and chip U9. The first pin of the chip U9 is grounded, and the second pin of the chip U9 is electrically connected to one end of the capacitor C34, one end of the capacitor C35 and the anode of the diode D10 respectively. The other end of the capacitor C34 is electrically connected to the other end of the capacitor C35, and the other end of the capacitor C34 and the other end of the capacitor C35 are both grounded. The cathode of the diode D10 is electrically connected to the cathode of the diode D12, and the cathode of the diode D10 and the cathode of the diode D12 are respectively connected to a 3.3V power supply, and the anode of the diode D12 is connected to a 3.6V power supply. The third pin of the chip U9 is electrically connected to one end of the capacitor C37, and the third pin of the chip U9 and one end of the capacitor C37 are respectively connected to a 5V power supply, and the other end of the capacitor C37 is grounded.

[0049] From the above description, it can be seen that the function of this module is to convert the voltage into several working voltages required by the system to ensure the use of various sub-modules of the system; capacitor C37 is a filtering aluminum electrolytic capacitor, which makes the system voltage 5V output smoothly, chip U9 is an LDO chip, which can convert the system voltage 5V into 3.3V output, capacitor C34 and capacitor C35 are filtering capacitors, which makes the system voltage 3.3V output smoothly, diode D10 and diode D12 are Schottky diodes, single-phase conduction, which separates the 3.6V voltage provided by the battery from the voltage converted by chip U9 to ensure that they do not conflict with each other during use.

[0050] Furthermore, it also includes an external FLASH module, which is electrically connected to the MCU main control module. The external FLASH module includes a chip U13 and a capacitor C40. The first pin of the chip U13, the second pin of the chip U13, the fifth pin of the chip U13 and the sixth pin of the chip U13 are respectively electrically connected to the MCU main control module, the third pin of the chip U13, the seventh pin of the chip U13 and the eighth pin of the chip U13 are respectively connected to a 3.3V power supply, the fourth pin of the chip U13 is grounded, one end of the capacitor C40 is connected to a 3.3V power supply, and the other end of the capacitor C40 is grounded.

[0051] From the above description, it can be seen that this module is designed to ensure that when the data capacity is insufficient, data can be stored on the chip to ensure that the data can be permanently preserved. Capacitor C40 is a filter capacitor to ensure that the chip voltage works smoothly.

[0052] Please refer to Figures 1 to 19 , Embodiment 1 of the present invention is:

[0053] Please refer to Figure 1A distribution transformer control circuit includes a current monitoring module 1, a voltage monitoring module 2, a smoke sensor module 3, a temperature and humidity detection module 4, a power carrier communication module 5 and an MCU main control module 6. The MCU main control module 6 is electrically connected to the current monitoring module 1, the smoke sensor module 3, the temperature and humidity detection module 4 and the power carrier communication module 5 respectively. The power carrier communication module 5 sends a control signal to the corresponding power carrier module of the bottom meter.

[0054] Please refer to Figure 2 The power carrier communication module 5 includes a chip U7, the model of the chip U7 is LM1893, and the fifth pin of the chip U7, the twelfth pin of the chip U7 and the seventeenth pin of the chip U7 are electrically connected to the MCU main control module 6 respectively.

[0055] Please refer to Figure 2 The power carrier communication module 5 also includes a resistor R35 (resistance value is 6.2kΩ), a resistor R36 (resistance value is 33kΩ), a resistor R37 (resistance value is 10kΩ), a resistor R38 (resistance value is 10kΩ), a resistor R39 (resistance value is 33kΩ), a resistor R40 (resistance value is 510kΩ), a resistor R41 (resistance value is 4.7Ω), a capacitor C17 (capacitance value is 568pF), a capacitor C18 (capacitance value is 47nF), a capacitor C23 (capacitance value is 47nF), a capacitor C 30 (capacitance value is 100nF), capacitor C19 (capacitance value is 47nF), capacitor C22 (capacitance value is 47nF), capacitor C25 (capacitance value is 47μF), capacitor C28 (capacitance value is 33nF), capacitor C29 (capacitance value is 0.22μF), diode D7 (model ZM4756), diode D8 (model ZM4755), transformer T1 (model 220To05) and chip U22 (model MB10S). For the specific connection relationship between the components, please refer to Figure 2 ;

[0056] The function of the power carrier communication module 5 is to transmit the power quality information of all meters in the cable branch box and the meter box to the chip U6 on the distribution transformer for data processing through carrier communication. The distribution transformer can also send a control signal to the corresponding power carrier module of the bottom meter through the power carrier communication module 5 to realize the control of the meter.

[0057] Power line carrier communication uses existing power lines to transmit signals. Its working principle is briefly described as follows: data is modulated on a carrier frequency of tens to hundreds of kHz and sent out through the power line. The receiving end receives the carrier carrying the signal on the power line and demodulates it to restore the original data. The communication carrier is the existing power line. There is no need to re-lay the communication line like wired communication, nor does it require complex sending and receiving equipment to transmit information like wireless transmission. It does not require the construction of additional communication lines, nor does it occupy precious wireless spectrum resources. Therefore, it is very suitable for forming a local area network within a small group (generally between the same power transformers) to achieve the purpose of data or voice transmission.

[0058] LM1893 is a power line carrier communication integrated circuit developed by National Semiconductor. It integrates all functions of sending and receiving data, can realize half-duplex communication of serial data, and only requires a small number of external components to form a complete power line carrier communication system.

[0059] Resistor R40 is a varistor, which is used for lightning protection of power input. Capacitor C29 is a safety capacitor, which filters out the DC component in the power grid. Transformer T1 is an AC transformer, which can convert AC 220V into AC5V. Capacitor C28 is a filter capacitor, which can make the voltage at the output of transformer T1 more stable. Chip U22 with model MB10S is a rectifier bridge, which can convert AC voltage into DC voltage. Capacitor C25 is a filter capacitor, which makes the DC 5V output more stable; resistor R41 is a current limiting resistor, which separates the ground of transformer T1 from the ground of the internal circuit and acts as a fuse; diode D7 and diode D8 form a double protection tube to discharge leakage current in the circuit; capacitor C17, capacitor C49, capacitor C22 and capacitor C23 are matching capacitors of chip U7, capacitor C18 and resistor R36 and capacitor C30 and resistor R39 respectively form filter circuits, which can separate high-frequency components, resistor R37 and resistor R38 form a voltage divider circuit, and by detecting the voltage of the eleventh pin of chip U7, it can be determined whether chip U7 is in the sending stage or the receiving stage at this time.

[0060] When the fifth pin of chip U7 is at a high level, the data signal is input into the FSK modulator from the seventeenth pin of chip U7, forming a switch control current and driving the oscillator to generate a triangle wave with a frequency deviation of ±2.2%. The sinusoidal wave signal is output through the sinusoidal wave shaping circuit, and then transmitted to the power line through the coupling coil after power amplification.

[0061] When the fifth pin of chip U7 is at ground level, the circuit is in receiving mode, and the signal on the power line is input into the tenth pin of chip U7 through the coupling transformer, and enters the limiting amplifier for amplification, and the DC component and 50Hz / 100Hz industrial frequency signal in the signal are filtered out. The signal is then demodulated by the phase-locked loop circuit and the high-frequency component is filtered out by the RC filter circuit to output the data signal. In order to keep the data signal reliable, it is shaped by the comparator and filtered by the noise filter, and finally the complete data signal is output from the twelfth pin of chip U7.

[0062] Please refer to Figure 3 The current monitoring module 1 includes a resistor R50 (resistance value is 7.5Ω), a resistor R56 (resistance value is 1.2kΩ), a resistor R59 (resistance value is 1.2kΩ), a resistor R62 (resistance value is 7.5Ω), a capacitor C38 (capacitance value is 0.1μF), a capacitor C43 (capacitance value is 0.1μF) and a current transformer U12 (model ZEMCTK04), wherein a first pin of the current transformer U12 is electrically connected to one end of the resistor R50 and one end of the resistor R56, respectively, and the resistor The other end of R50 is electrically connected to one end of capacitor C38, the other end of capacitor C38 is electrically connected to the other end of resistor R56 and MCU main control module 6 respectively, the second pin of current transformer U12 is electrically connected to one end of resistor R59 and one end of resistor R62 respectively, the other end of resistor R59 is electrically connected to one end of capacitor C43 and MCU main control module 6 respectively, the other end of resistor R62 is electrically connected to the other end of capacitor C43, and the other end of resistor R62 and the other end of capacitor C43 are both grounded.

[0063] Please refer to Figure 4The voltage monitoring module 2 includes a resistor R48 (resistance value is 150Ω), a resistor R51 (resistance value is 1.2kΩ), a resistor R52 (resistance value is 750kΩ), a resistor R53 (resistance value is 750kΩ), a resistor R54 (resistance value is 750kΩ), a resistor R55 (resistance value is 750kΩ), a resistor R57 (resistance value is 510kΩ), a resistor R58 (resistance value is 1.2kΩ), a resistor R60 (resistance value is 150Ω), a capacitor C36 (capacitance value is 0.1μF), a capacitor C42 (capacitance value is 0.1μF) and a voltage transformer U11 (model ZMPT107), a first pin of the voltage transformer U11 is electrically connected to one end of the resistor R55, and the other end of the resistor R55 is electrically connected to the resistors R54, R53, and R57 in sequence. 2 and resistor R57, the second pin of the voltage transformer U11 is electrically connected to one end of the resistor R57, the third pin of the voltage transformer U11 is electrically connected to one end of the resistor R48 and one end of the resistor R51 respectively, the other end of the resistor R51 is electrically connected to one end of the capacitor C36 and the MCU main control module 6 respectively, the other end of the capacitor C36 is electrically connected to the other end of the resistor R48, and the other end of the capacitor C36 and the other end of the resistor R48 are both grounded, the fourth pin of the voltage transformer U11 is electrically connected to one end of the resistor R60 and one end of the resistor R58 respectively, the other end of the resistor R60 is electrically connected to one end of the capacitor C42, and the other end of the resistor R60 and one end of the capacitor C42 are both grounded, and the other end of the resistor R58 is electrically connected to the other end of the capacitor C42 and the MCU main control module 6 respectively.

[0064] Please refer to Figure 5The smoke sensing module 3 includes a resistor R7 (resistance value is 10kΩ), a resistor R8 (resistance value is 2kΩ), a resistor R9 (resistance value is 2kΩ), a resistor R10 (resistance value is 0Ω), a resistor R11 (resistance value is 0Ω), a resistor R12 (resistance value is 2kΩ), a resistor R13 (resistance value is 10kΩ), a diode D2 (a light emitting diode), a diode D3 (a light emitting diode), a switch S1, a transistor Q1 (model SS8050) and a chip U3 (model SM100), a first pin of the chip U3 is electrically connected to one end of the resistor R9, the other end of the resistor R9 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is grounded, a second pin of the chip U3 is electrically connected to one end of the resistor R8, and the resistor R8 The other end of the chip U3 is electrically connected to the anode of the diode D3, and the cathode of the diode D3 is grounded. The third pin of the chip U3 is electrically connected to one end of the switch S1, and the other end of the switch S1 is electrically connected to one end of the resistor R10, and the other end of the resistor R10 is connected to a 3.3V power supply. The fourth pin of the chip U3 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is respectively electrically connected to one end of the resistor R13 and the base of the transistor Q1, the emitter of the transistor Q1 is electrically connected to the other end of the resistor R13, the collector of the transistor Q1 is respectively electrically connected to one end of the resistor R7 and the MCU main control module 6, and the other end of the resistor R7 is connected to a 3.3V power supply. The fifth pin of the chip U3 is grounded, and the twelfth pin of the chip U3 is grounded through the resistor R11.

[0065] Please refer to Figure 6 The temperature and humidity detection module 4 includes a resistor R43 (resistance value is 10kΩ), a resistor R44 (resistance value is 10kΩ), a capacitor C41 (capacitance value is 0.1μF) and a chip U10 (model SI7021). The first pin of the chip U10 is electrically connected to the resistor R43 and the MCU main control module 6 respectively, the second pin of the chip U10 is grounded, the fifth pin of the chip U10 is electrically connected to one end of the capacitor C41, and the fifth pin of the chip U10 and one end of the capacitor C41 are respectively connected to a 3.3V power supply, the other end of the capacitor C41 is grounded, the sixth pin of the chip U10 is electrically connected to one end of the resistor R44 and the MCU main control module 6 respectively, the other end of the resistor R44 is electrically connected to the other end of the resistor R43, and the other end of the resistor R44 and the other end of the resistor R43 are both connected to a 3.3V power supply.

[0066] Please refer to Figure 7, also includes an RS485 communication module 7, the RS485 communication module 7 is electrically connected to the MCU main control module 6, the RS485 communication module 7 includes a resistor R85 (resistance value is 1kΩ), a resistor R87 (resistance value is 120Ω), a resistor R90 (resistance value is 10Ω), a resistor R92 (resistance value is 1kΩ), a resistor R95 (resistance value is 10Ω), a resistor R98 (resistance value is 120Ω), a resistor R105 (resistance value is 1kΩ), a resistor R107 (resistance value is 120Ω), a capacitor C48 (capacitance value is 10μF ), capacitor C50 (capacitance value is 0.1μF), diode D15 (model SMBJ6.8A), diode D17 (model SMBJ6.8A), voltage regulator VP1 (model P6SMBJ6.8A), connector J3 (model KF127-2) and chip U16 (model SP3485EN-L / TR), the first pin of the chip U16 is electrically connected to one end of the resistor R87, the other end of the resistor R87 is electrically connected to the MCU main control module 6, and the second pin of the chip U16 is electrically connected to the first and second pins of the chip U16 respectively. The third pin is electrically connected to one end of the resistor R92, the other end of the resistor R92 is connected to a 3.3V power supply, the fourth pin of the chip U16 is electrically connected to the MCU main control module 6 through the resistor R107, the fifth pin of the chip U16 is grounded, the sixth pin of the chip U16 is electrically connected to one end of the resistor R95 and one end of the resistor R105 respectively, the other end of the resistor R105 is connected to a 3.3V power supply, the other end of the resistor R95 is electrically connected to the cathode of the diode D17 and one end of the voltage regulator VP1, one end of the resistor R98 and the second pin of the connector J3 respectively. The anode of the diode D17 is grounded, the seventh pin of the chip U16 is electrically connected to one end of the resistor R85 and one end of the resistor R90 respectively, the other end of the resistor R90 is electrically connected to the cathode of the diode D15, the other end of the voltage regulator VP1, the other end of the resistor R98 and the first pin of the connector J3 respectively, the anode of the diode D15 is grounded, the capacitor C50 is connected in parallel with the capacitor C48, one end of the capacitor C50 and the capacitor C48 after being connected in parallel is grounded, and the other end of the capacitor C50 and the capacitor C48 after being connected in parallel is connected to a 3.3V power supply.

[0067] Please refer to Figure 8, also includes a remote signal module 8, the remote signal module 8 is electrically connected to the MCU main control module 6, the remote signal module 8 includes a resistor R46 (resistance value is 10kΩ), a resistor R49 (resistance value is 2.7kΩ) and a photoelectric coupler IC1 (model is PC817C), a first pin of the photoelectric coupler IC1 is electrically connected to one end of the resistor R49, a second pin of the photoelectric coupler IC1 and a third pin of the photoelectric coupler IC1 are respectively grounded, a fourth pin of the photoelectric coupler IC1 is respectively electrically connected to one end of the resistor R46 and the MCU main control module 6, and the other end of the resistor R46 is connected to a 3.3V power supply.

[0068] Please refer to Fig. 9 , and also includes a power conversion module 9, which is electrically connected to the MCU main control module 6, and the power conversion module 9 includes a capacitor C34 (capacitance value is 1μF), a capacitor C35 (capacitance value is 0.1μF), a capacitor C37 (capacitance value is 22μF), a diode D10 (model SS24), a diode D12 (model SS24) and a chip U9 (model BM1117-3.3), a first pin of the chip U9 is grounded, and a second pin of the chip U9 is respectively connected to one end of the capacitor C34, one end of the capacitor C35 and the diode D The anode of the diode D10 is electrically connected to the anode of the diode D10, the other end of the capacitor C34 is electrically connected to the other end of the capacitor C35, and the other end of the capacitor C34 and the other end of the capacitor C35 are grounded, the cathode of the diode D10 is electrically connected to the cathode of the diode D12, and the cathode of the diode D10 and the cathode of the diode D12 are respectively connected to a 3.3V power supply, the anode of the diode D12 is connected to a 3.6V power supply, the third pin of the chip U9 is electrically connected to one end of the capacitor C37, and the third pin of the chip U9 and one end of the capacitor C37 are respectively connected to a 5V power supply, and the other end of the capacitor C37 is grounded.

[0069] Please refer to Fig.10 , also includes an external FLASH module 10, the external FLASH module 10 is electrically connected to the MCU main control module 6, the external FLASH module 10 includes a chip U13 (model W25Q32SIG) and a capacitor C40 (capacitance value is 0.1μF), the first pin of the chip U13, the second pin of the chip U13, the fifth pin of the chip U13 and the sixth pin of the chip U13 are respectively electrically connected to the MCU main control module 6, the third pin of the chip U13, the seventh pin of the chip U13 and the eighth pin of the chip U13 are respectively connected to a 3.3V power supply, the fourth pin of the chip U13 is grounded, one end of the capacitor C40 is connected to a 3.3V power supply, and the other end of the capacitor C40 is grounded.

[0070] The MCU main control module 6 includes a resistor R33 (resistance value is 10MΩ), a resistor R34 (resistance value is 10kΩ), a capacitor C14 (capacitance value is 0.1μF), a capacitor C15 (capacitance value is 22pF), a capacitor C16 (capacitance value is 22pF), a capacitor C20 (capacitance value is 0.1μF), a capacitor C21 (capacitance value is 0.1μF), a capacitor C24 (capacitance value is 0.1μF), a capacitor C26 (capacitance value is 0.1μF), a capacitor C32 (capacitance value is 0.1μF), a crystal oscillator XT1 (frequency is 8MHz), a connector J2 and a chip U6 (model is STM32F103RCT6). For the specific connection relationship between the various components, please refer to Fig.11 ; This circuit is the main control circuit of the entire distribution transformer, which is connected to each sub-module circuit. Through the new product U6, each sub-module is controlled or read to realize the function of the whole system; among them, capacitor C21, capacitor C32, capacitor C26, capacitor C24 and capacitor C14 are filter capacitors to ensure the stable operation of chip U6.

[0071] Capacitor C15, capacitor C16, crystal oscillator XT1 and resistor R33 constitute the crystal oscillator circuit of the MCU, and resistor R34 and capacitor C20 constitute the reset circuit of the MCU, which is the general circuit connection method of chip U6.

[0072] The above-mentioned distribution transformer control circuit also includes a liquid crystal display module 11 and a 4G communication module 12, the liquid crystal display module 11 is electrically connected to the MCU main control module 6, and the 4G communication module 12 is electrically connected to the MCU main control module 6;

[0073] The liquid crystal display module 11 includes a resistor R42 (resistance value is 1 kΩ), a capacitor C27 (capacitance value is 0.1 μF), a capacitor C31 (capacitance value is 0.1 μF), a transistor Q6 (model S8050) and a chip U5 (model COG160160). For the specific connection relationship between the components, please refer to Fig.12 ;

[0074] The 4G communication module 12 includes a resistor R1 (resistance value is 0Ω), a resistor R2 (resistance value is 100kΩ), a resistor R3 (resistance value is 31.6kΩ), a resistor R4 (resistance value is 10kΩ), a resistor R5 (resistance value is 2.2kΩ), a resistor R6 (resistance value is 10kΩ), a resistor R15 (resistance value is 4.7kΩ), a resistor R29 (resistance value is 1kΩ), a resistor R31 (resistance value is 10kΩ), a resistor R16 (resistance value is 4.7kΩ), a resistor R30 (resistance value is 1kΩ), a resistor R32 (resistance value is 10kΩ), and a resistor R40 (resistance value is 10kΩ). Resistor R17 (resistance value is 4.7kΩ), resistor R18 (resistance value is 10kΩ), resistor R23 (resistance value is 47kΩ), resistor R24 ​​(resistance value is 4.7kΩ), resistor R19 (resistance value is 10kΩ), resistor R25 (resistance value is 47kΩ), resistor R26 (resistance value is 4.7kΩ), resistor R20 (resistance value is 1.5kΩ), resistor R14 (resistance value is 10kΩ), resistor R22 (resistance value is 22Ω), resistor R21 (resistance value is 10kΩ), resistor R27 (resistance value is 10kΩ), resistor R28 (resistance value is 10kΩ), resistor R30 (resistance value is 10kΩ), resistor R31 (resistance value is 10kΩ), resistor R32 (resistance value is 10kΩ), resistor R33 (resistance value is 10kΩ), resistor R34 (resistance value is 10kΩ), resistor R35 (resistance value is 10kΩ), resistor R36 (resistance value is 10kΩ), resistor R37 (resistance value is 10kΩ), resistor R38 (resistance value is 10kΩ) The resistance is 22Ω), capacitor C1 (capacitance value is 10μF), capacitor C2 (capacitance value is 100nF), capacitor C3 (capacitance value is 10nF), capacitor C4 (capacitance value is 100nF), capacitor C5 (capacitance value is 3nF), capacitor C6 (capacitance value is 47μF), capacitor C7 (capacitance value is 100nF), capacitor C9 (capacitance value is 100μF), capacitor C10 (capacitance value is 47pF), capacitor C11 (capacitance value is 47pF), capacitor C12 (capacitance value is 47pF), capacitor C13 (capacitance value is 33pF), inductor L1 (capacitance value is 47pF), capacitor C2 (capacitance value is 47p ...33pF), inductor L1 (capacitance value is 47pF), capacitor C3 (capacitance value is 33pF), inductor L2 (capacitance value is 47pF), capacitor C Inductance is 10μH), diode D1 (model IN4733), diode D4, diode D5, diode D6, transistor Q4, transistor Q5, transistor Q2 (model S9014), transistor Q3 (model S9014), connector X1 (model SIP12-2.54), connector X2 (model SIP12-2.54), chip U1A (model GM5), chip U1B (model GM5), chip J1 and chip U4 (model PESD5V0L5UV). For the specific connection relationship between the components, please refer to Figures 13 to 19 ;

[0075] The function of this module is to package the data collected by the MCU main control module 6, upload it to the cloud platform via 4G, and display it on the cloud platform. At the same time, it can also issue instructions through the cloud platform to control the operation of the local distribution transformer after reaching the 4G communication module 12.

[0076] Chip U2 is a synchronous buck regulator. The second pin of chip U2 is the input terminal. Resistor R1 is a current limiting protection resistor to prevent overcurrent from breaking down chip U2. Capacitors C1 and C2 are bypass capacitors to absorb noise interference at the power input terminal. Resistor R2 is the enable terminal input and is set to a high level to ensure that chip U2 is always in the startup state. Capacitor C3 is a bypass capacitor, inductor L1 is a filter inductor to remove high-frequency interference on the line, and resistors R3 and R4 form a voltage divider circuit to reduce the system voltage to the voltage required by chip U1 (i.e., composed of chip U1A and chip U1B). The calculation formula is R3 / (R3+R4)*VCC=3.8V. Capacitors C6, C7 and C4 are filter capacitors, and capacitor C5 and resistor R5 form a low-pass filter circuit to remove interference on the horizon. Diode D1 is a voltage regulator diode to prevent the converted voltage from being too large and breaking down chip U1.

[0077] Resistors R22, R27 and R28 are current limiting resistors to protect the IO port between the SIM card chip and the MCU main control module 6. Resistor R21 is a pull-up resistor to improve the driving capability of the sixth pin of J1. Capacitor C12 is a filter capacitor, chip U4 is a SIM card slot, capacitors C10 and C11 are bypass capacitors, and the second pin, third pin and sixth pin of J1 communicate with the chip U1 via serial port.

[0078] Please refer to Fig.15 This circuit is a voltage divider circuit, which reduces the voltage of VCC=3.8V to 3.3V and is used for some chips in the 4G communication module 12.

[0079] Please refer to Fig.16 , this circuit is a level matching circuit. Since the power supply of chip U1 is 3.8V and the power supply of the IO port of MCU main control module 6 is 3.3V, the two are incompatible and need voltage matching. Resistor R18 and resistor R23 and resistor R19 and resistor R25 form a voltage divider circuit respectively, providing base current to drive transistor Q2 and transistor Q3 to work, so as to achieve level matching between the two. Resistor R24 ​​and resistor R26 are pull-up resistors to improve the driving capability of the IO port of MCU main control module 6, and capacitor C13 is a filter capacitor.

[0080] Please refer to Fig.17, diode D4, diode D5, and diode D6 are respectively the working indicator lights of the 4G communication module 12; wherein diode D6 is the power indicator light of the 4G communication module 12. When the system is powered by 3.8V, diode D6 is on, indicating that the module is working normally. Diode D4 is the working indicator light. When the system is working, WORK_LED outputs a high level, driving transistor Q4 to turn on, and diode D4 is on; diode D5 is a connection indicator light. When the 4G communication module 12 is connected to the platform, LINKA outputs a high level, driving the transistor to turn on, and diode D5 is on;

[0081] Chip U1 is a 4G module chip, and communicates with the MCU main control module 6 via a serial port.

[0082] In summary, the present invention provides a distribution transformer control circuit, which is provided with a current monitoring module to realize current monitoring of the indoor cable of the transformer; a voltage monitoring module is provided to realize voltage monitoring of the indoor cable of the transformer; a smoke sensing module is provided to realize monitoring of the smoke alarm in the transformer room; a temperature and humidity detection module is provided to realize monitoring of the indoor environmental temperature and humidity of the transformer; a power carrier communication module is provided and the power carrier communication module sends a control signal to the power carrier module corresponding to the bottom meter, so as to realize data collection and aggregation of each sub-meter in the bottom cable branch box and the meter box, and realize precise positioning; an MCU main control module is provided to realize data interaction and control of the operation of the entire system; this scheme realizes precise monitoring of the distribution transformer through the cooperation between the current monitoring module, the smoke sensing module, the temperature and humidity detection module, the power carrier communication module and the MCU main control module.

[0083] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A distribution transformer control circuit, characterized in that: It includes a current monitoring module, a voltage monitoring module, a smoke sensor module, a temperature and humidity detection module, a power carrier communication module and an MCU main control module. The MCU main control module is electrically connected to the current monitoring module, the smoke sensor module, the temperature and humidity detection module and the power carrier communication module respectively. The power carrier communication module sends a control signal to the corresponding power carrier module of the bottom meter; The voltage monitoring module includes a resistor R48, a resistor R51, a resistor R52, a resistor R53, a resistor R54, a resistor R55, a resistor R57, a resistor R58, a resistor R60, a capacitor C36, a capacitor C42 and a voltage transformer U11, wherein a first pin of the voltage transformer U11 is electrically connected to one end of the resistor R55, and the other end of the resistor R55 is electrically connected to the resistor R54, the resistor R53, the resistor R52 and the resistor R57 in sequence, a second pin of the voltage transformer U11 is electrically connected to one end of the resistor R57, and a third pin of the voltage transformer U11 is electrically connected to one end of the resistor R48 and the resistor R The fourth pin of the voltage transformer U11 is electrically connected to one end of the resistor R60 and one end of the resistor R58, the other end of the resistor R60 is electrically connected to one end of the capacitor C42, the other end of the resistor R60 and one end of the capacitor C42 are grounded, and the other end of the resistor R58 is electrically connected to the other end of the capacitor C42 and the MCU main control module.

2. The distribution transformer control circuit according to claim 1, characterized in that: The power carrier communication module includes a chip U7, the model of the chip U7 is LM1893, and the fifth pin of the chip U7, the twelfth pin of the chip U7 and the seventeenth pin of the chip U7 are electrically connected to the MCU main control module respectively.

3. The distribution transformer control circuit according to claim 1, characterized in that: The current monitoring module includes a resistor R50, a resistor R56, a resistor R59, a resistor R62, a capacitor C38, a capacitor C43 and a current transformer U12. The first pin of the current transformer U12 is electrically connected to one end of the resistor R50 and one end of the resistor R56, respectively. The other end of the resistor R50 is electrically connected to one end of the capacitor C38, and the other end of the capacitor C38 is electrically connected to the other end of the resistor R56 and the MCU main control module, respectively. The second pin of the current transformer U12 is electrically connected to one end of the resistor R59 and one end of the resistor R62, respectively. The other end of the resistor R59 is electrically connected to one end of the capacitor C43 and the MCU main control module, and the other end of the resistor R62 is electrically connected to the other end of the capacitor C43, and the other end of the resistor R62 and the other end of the capacitor C43 are both grounded.

4. The distribution transformer control circuit according to claim 1, characterized in that: The smoke sensing module includes a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a diode D2, a diode D3, a switch S1, a transistor Q1 and a chip U3. The first pin of the chip U3 is electrically connected to one end of the resistor R9, the other end of the resistor R9 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is grounded, the second pin of the chip U3 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to the anode of the diode D3, the cathode of the diode D3 is grounded, and the third pin of the chip U3 is electrically connected to one end of the switch S1. , the other end of the switch S1 is electrically connected to one end of the resistor R10, the other end of the resistor R10 is connected to a 3.3V power supply, the fourth pin of the chip U3 is electrically connected to one end of the resistor R12, the other end of the resistor R12 is electrically connected to one end of the resistor R13 and the base of the transistor Q1 respectively, the emitter of the transistor Q1 is electrically connected to the other end of the resistor R13, the collector of the transistor Q1 is electrically connected to one end of the resistor R7 and the MCU main control module respectively, the other end of the resistor R7 is connected to a 3.3V power supply, the fifth pin of the chip U3 is grounded, and the twelfth pin of the chip U3 is grounded through the resistor R11.

5. The distribution transformer control circuit according to claim 1, characterized in that: The temperature and humidity detection module includes a resistor R43, a resistor R44, a capacitor C41 and a chip U10. The first pin of the chip U10 is electrically connected to the resistor R43 and the MCU main control module respectively, the second pin of the chip U10 is grounded, the fifth pin of the chip U10 is electrically connected to one end of the capacitor C41, and the fifth pin of the chip U10 and one end of the capacitor C41 are respectively connected to a 3.3V power supply, the other end of the capacitor C41 is grounded, the sixth pin of the chip U10 is electrically connected to one end of the resistor R44 and the MCU main control module respectively, the other end of the resistor R44 is electrically connected to the other end of the resistor R43, and the other end of the resistor R44 and the other end of the resistor R43 are both connected to a 3.3V power supply.

6. The distribution transformer control circuit according to claim 1, characterized in that: It also includes an RS485 communication module, which is electrically connected to the MCU main control module. The RS485 communication module includes resistors R85, R87, R90, R92, R95, R98, R105, R107, capacitors C48, C50, diodes D15, D17, voltage regulator VP1, connector J3 and chip U16. The first pin of the chip U16 is electrically connected to one end of the resistor R87, and the other end of the resistor R87 is electrically connected to the MCU main control module. The second pin of the chip U16 is electrically connected to the third pin of the chip U16 and one end of the resistor R92 respectively, and the other end of the resistor R92 is connected to a 3.3V power supply. The fourth pin of the chip U16 is electrically connected to the MCU main control module through the resistor R107. The fifth pin of the chip U16 is grounded. The sixth pin of U16 is electrically connected to one end of the resistor R95 and one end of the resistor R105 respectively, the other end of the resistor R105 is connected to a 3.3V power supply, the other end of the resistor R95 is electrically connected to the cathode of the diode D17 and one end of the voltage regulator VP1, one end of the resistor R98 and the second pin of the connector J3 respectively, the anode of the diode D17 is grounded, the seventh pin of the chip U16 is electrically connected to one end of the resistor R85 and one end of the resistor R90 respectively, the other end of the resistor R90 is electrically connected to the cathode of the diode D15, the other end of the voltage regulator VP1, the other end of the resistor R98 and the first pin of the connector J3 respectively, the anode of the diode D15 is grounded, the capacitor C50 is connected in parallel with the capacitor C48, one end of the capacitor C50 and the capacitor C48 after being connected in parallel is grounded, and the other end of the capacitor C50 and the capacitor C48 after being connected in parallel is connected to a 3.3V power supply.

7. The distribution transformer control circuit according to claim 1, characterized in that: It also includes a remote signal module, which is electrically connected to the MCU main control module. The remote signal module includes a resistor R46, a resistor R49 and a photocoupler IC1. The first pin of the photocoupler IC1 is electrically connected to one end of the resistor R49, the second pin of the photocoupler IC1 and the third pin of the photocoupler IC1 are grounded respectively, the fourth pin of the photocoupler IC1 is electrically connected to one end of the resistor R46 and the MCU main control module respectively, and the other end of the resistor R46 is connected to a 3.3V power supply.

8. The distribution transformer control circuit according to claim 1, characterized in that: It also includes a power conversion module, which is electrically connected to the MCU main control module. The power conversion module includes a capacitor C34, a capacitor C35, a capacitor C37, a diode D10, a diode D12 and a chip U9. The first pin of the chip U9 is grounded, and the second pin of the chip U9 is electrically connected to one end of the capacitor C34, one end of the capacitor C35 and the anode of the diode D10 respectively. The other end of the capacitor C34 is electrically connected to the other end of the capacitor C35, and the other end of the capacitor C34 and the other end of the capacitor C35 are both grounded. The cathode of the diode D10 is electrically connected to the cathode of the diode D12, and the cathode of the diode D10 and the cathode of the diode D12 are respectively connected to a 3.3V power supply, and the anode of the diode D12 is connected to a 3.6V power supply. The third pin of the chip U9 is electrically connected to one end of the capacitor C37, and the third pin of the chip U9 and one end of the capacitor C37 are respectively connected to a 5V power supply, and the other end of the capacitor C37 is grounded.

9. The distribution transformer control circuit according to claim 1, characterized in that: It also includes an external FLASH module, which is electrically connected to the MCU main control module. The external FLASH module includes a chip U13 and a capacitor C40. The first pin of the chip U13, the second pin of the chip U13, the fifth pin of the chip U13 and the sixth pin of the chip U13 are respectively electrically connected to the MCU main control module, the third pin of the chip U13, the seventh pin of the chip U13 and the eighth pin of the chip U13 are respectively connected to a 3.3V power supply, the fourth pin of the chip U13 is grounded, one end of the capacitor C40 is connected to a 3.3V power supply, and the other end of the capacitor C40 is grounded.

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