4G monitoring unit and medium and low voltage distribution line real-time monitoring system

Abstract

The utility model relates to a 4G monitoring unit and a medium and low voltage distribution line real-time monitoring system, which are used for directly uploading monitoring data of local key equipment to a master station in a 4G transmission mode and comprise an MCU module. The power supply module, the metering module, the data storage module, the clock module, the safety module, the remote signaling module, the RS485 communication module, the temperature detection module and the 4G communication module are connected with the MCU module. The power supply module adopts an ACDC switching power supply to convert 220V alternating current into 12V direct current power supply, and then the 12V direct current power supply is converted into the power supply required by each module; the MCU module is used for data acquisition; the metering module is used for monitoring metering data; the remote signaling module is used for remote signaling control and state feedback; the temperature detection module is used for temperature abnormity alarm and abnormity report judgment; and the 4G communication module is used for performing data unvarnished transmission through 4G communication. According to the utility model, faster response speed and larger data volume can be obtained through 4G high-speed communication, no influence is caused to field equipment, and the system can operate independently.

Description

Technical Field

[0001] The utility model belongs to the technical field of medium and low voltage distribution line monitoring, and particularly relates to a 4G monitoring unit and a real-time monitoring system for medium and low voltage distribution lines. Background Technique

[0002] With the gradual full coverage of the automation scope of medium voltage distribution lines and the further extension of distribution automation to low voltage distribution networks, it is necessary to monitor the power information such as voltage, current, and power at each branch node on site. The traditional monitoring node devices are electric energy meters and concentrators or TTUs (distribution Transformer supervisory Terminal Units), which have the capabilities of electric energy monitoring and remote communication. The existing medium and low voltage distribution systems realize real-time monitoring and risk management of medium and low voltage distribution lines by obtaining the electrical parameters of each branch node.

[0003] The main monitoring terminals in the prior art are electric energy meters and concentrators or TTUs, which carry out networking communication through carrier communication to complete the monitoring and metering of branch nodes. Due to the diverse on-site environments, some environments have fewer nodes and are not suitable for networking communication through carrier communication. Therefore, a solution using wireless technology to achieve single-point remote monitoring is needed. Content of the Utility Model

[0004] The purpose of the utility model is to provide a 4G monitoring unit and a real-time monitoring system for medium and low voltage distribution lines. The 4G monitoring unit is directly connected to the master station to reduce the construction cost of intermediate devices such as TTUs and is applicable to single nodes with fewer nodes.

[0005] The utility model provides a 4G monitoring unit for directly uploading the monitoring data of local key devices to the master station through 4G transmission mode, including an MCU module, and a power supply module, a metering module, a data storage module, a clock module, a security module, a tele-signal module, an RS485 communication module, a temperature detection module, and a 4G communication module connected to the MCU module;

[0006] The power supply module uses an ACDC switching power supply to convert AC 220V into DC 12V power, and then converts 12V into the power required by each module;

[0007] The MCU module is used for data acquisition;

[0008] The metering module is used for monitoring metering data, including voltage, current, and power factor;

[0009] The data storage module is used for data storage;

[0010] The clock module is used to provide clock information;

[0011] The described security module is used for data interaction security protection;

[0012] The described telemetry signal module is used for telemetry signal control and status feedback;

[0013] The described RS485 communication module is powered by a separate power supply isolation, and the signal transmission adopts the optocoupler isolation method;

[0014] The described temperature detection module is used for temperature anomaly alarm and anomaly reporting judgment;

[0015] The described 4G communication module is used for data transparent transmission through 4G communication.

[0016] Furthermore, the described local key device is an ordinary circuit breaker.

[0017] Furthermore, the described MCU module uses HC32F460KETA as the main chip.

[0018] Furthermore, the described metering module uses RN8306 as the metering chip.

[0019] Furthermore, the peripheral circuit of the described metering module uses an 8.192MHz crystal oscillator as the external clock circuit of the metering chip, and uses a sampling resistor with low resistance value, high precision and high power.

[0020] Furthermore, the described clock module uses an 8025T clock chip as the clock chip.

[0021] Furthermore, the control pins of the described telemetry signal module adopt optocoupler output, the feedback signal is controlled by the on-off quantity, and a TVS tube is used for protection.

[0022] Furthermore, the described 4G communication module is equipped with a SIM card, the SIM card uses a nano card, the power supply of the SIM card is provided by the 4G communication module, and an anti-static tube should be installed at the SIM card slot interface.

[0023] The present invention also provides a real-time monitoring system for medium and low voltage distribution lines, including the described 4G monitoring unit, master station, TTU, frame switch, carrier monitoring unit, ordinary circuit breaker, miniature circuit breaker, and electric energy meter;

[0024] One path of the described master station is directly connected to the ordinary circuit breaker through the described 4G monitoring unit;

[0025] Another path of the described master station is sequentially connected to the TTU, frame switch, carrier monitoring unit, ordinary circuit breaker, miniature circuit breaker, and electric energy meter.

[0026] With the above solution, through the 4G monitoring unit and the real-time monitoring system of medium and low voltage distribution lines, faster response speed and larger data volume can be obtained through 4G high-speed communication, and there is no impact on on-site equipment, and it can operate independently.

[0027] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and implement it according to the content of the specification, the following describes in detail with reference to the preferred embodiments of the present invention and the accompanying drawings. Brief Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the 4G monitoring unit of the present invention;

[0029] Figure 2 It is a circuit diagram of the power supply module of the present invention;

[0030] Figure 3 It is a circuit diagram of 12V TO 5V of the present invention;

[0031] Figure 4 It is a circuit diagram of the metering module of the present invention;

[0032] Figure 5 It is a circuit diagram of the SIM interface of the present invention;

[0033] Figure 6 It is a schematic structural diagram of the real-time monitoring system of medium and low voltage distribution lines of the present invention. Detailed Description of the Preferred Embodiments

[0034] The following combines the accompanying drawings and embodiments to further describe in detail the specific implementation manners of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0035] Refer Figure 1 As shown, this embodiment provides a 4G monitoring unit for directly uploading the monitoring data of local key devices to the master station through 4G transmission mode, including an MCU module, and a power supply module, a metering module, a data storage module, a clock module, a security module, a telemetry module,

[0036] RS485 communication module, temperature detection module, 4G communication module connected to the MCU module; the power supply module uses an ACDC switching power supply to convert AC 220V into DC 12V power supply, and then converts 12V into the power supply required by each module; the MCU module is used for data acquisition; the metering module is used for monitoring metering data, including voltage, current, power factor; the data storage module is used for data storage; the clock module is used to provide clock information;

[0037] The security module is used for data interaction security protection; the tele-signal module is used for tele-signal control and status feedback;

[0038] The RS485 communication module is powered by a separate power supply isolation, and the signal transmission adopts an opto-coupler isolation method; the temperature detection module is used for temperature anomaly alarm and anomaly reporting judgment; the 4G communication module is used for data transparent transmission through 4G communication.

[0039] Through the 4G high-speed communication of this 4G monitoring unit, the monitoring data of local key devices can be directly uploaded to the master station, which can obtain a faster response speed and a larger data volume, and has no impact on on-site devices and can operate independently.

[0040] In this embodiment, the power supply module uses a single power supply for power supply and performs three-phase metering operations at the same time. To meet the power requirements in the circuit and output the supply voltage as required to ensure the normal operation of the device, the main power supply circuit design adopts a full-bridge rectification method, uses a large-capacity capacitor for ripple operation to ensure the normal supply voltage. Considering the power efficiency, an AC-DC switching power supply is used to convert the AC 220V into a DC 12V power supply, and then the 12V is converted into the power supplies of each module. Considering that isolation protection between strong and weak electricity needs to be realized for tele-signal, remote control, and 485 communication, the switching power supply outputs two isolated power supplies. The main circuit supplies the MCU and the metering module, and the secondary circuit supplies the 485 and the tele-signal remote control circuits. See Figure 2 as shown.

[0041] Considering that the MCU module, the metering module, etc. are all 3V3 power supply systems, the 4G communication module uses a 3.8V voltage, and the 8025T and the battery require a voltage of 2.5 - 3.8V. This time, a DC-DC chip is used for power conversion. 12V to 5V provides a common power supply reference. 5V is converted to 3.8V through an LDO 29302 to provide a maximum supply current of 3A for the 4G communication module. 5V is converted to 3V3 through an LDO1117 to ensure the normal supply voltage and ripple of the MCU and the metering chip. To meet the requirements of the 4G communication module for a large input current, low ripple, and controllable power supply (the power supply can be turned off to achieve ultra-low power consumption), this embodiment uses a 29302 LDO. Considering that the 485 module requires a 5V supply voltage, this embodiment uses a 78L05 voltage regulator chip for power supply voltage regulation.

[0042] For 12V TO 5V, ETA8103 is selected. ETA8103 is a synchronous buck converter with a wide input voltage of 4V - 18V and a maximum output current of 3A. The circuit is simple and does not require an external diode. See Figure 3 as shown.

[0043] The power supply of the 4G remote communication module requires a relatively large current. The DC voltage is 4V ± 0.2V, the normal operating current is 500mA, the voltage ripple is less than 30mV; the maximum current is 2A and can last for 1ms. Selecting Spiex29302 has a maximum current output capacity of 3A.

[0044] In this embodiment, the local key device is an ordinary circuit breaker.

[0045] In this embodiment, the MCU module uses HC32F460KETA as the main chip, which meets the requirements of real-time data sampling and also includes functions such as temperature monitoring. HC32F460KETA is a -M4 core 32-bit RISC CPU, a high-performance MCU with a maximum operating frequency of 200MHz. At the same time, this chip integrates high-speed on-chip memory, including a maximum of 512KB of Flash and a maximum of 192KB of SRAM. The rich storage resources can be competent for the subsequent upgrade and transformation of program development.

[0046] In this embodiment, to implement the energy efficiency management function and meet the high-frequency sampling requirements, the monitoring unit needs to achieve accurate monitoring of metering data such as voltage, current, and power factor. The metering module uses RN8306 as the metering chip. RN8306 is a three-phase metering chip that provides full-wave and fundamental active energy, with a dynamic range of 10,000:1, a non-linear error < 0.1%, and meets the accuracy requirements of 0.5S and 0.2S class active energy meters. This chip has high metering accuracy and has multiple functions such as metering, measurement, power quality analysis, waveform output, temperature compensation, and anti-stealing electricity. It can be better competent for future function expansion. The peripheral circuit uses an 8.192MHz crystal oscillator as the external clock circuit of the metering chip. To ensure that the metering accuracy meets general requirements, low-resistance, high-precision, and high-power sampling resistors are used. See Figure 4 as shown.

[0047] Among them, voltage sampling uses a voltage transformer. The voltage transformer selects a 2mA:2mA current-type voltage transformer to obtain the voltage signal. Each phase consists of 4 resistors of 56k to form a current-limiting resistor. When the phase voltage is 220V, the input current is 0.982mA, and the output current is the same. The sampling resistors are two 49.9Ω resistors, with the middle common terminal grounded. The sampling voltage is 98.01mV, which meets the input requirements of RN8306. The subsequent resistors and capacitors form an RC low-pass filter circuit to suppress interference above 4kHz.

[0048] Current sampling uses a current transformer to obtain the current signal through a 5A / 2.5mA current transformer. When the input current is 5A, the output current is 2.5mA. The sampling resistors are two 10Ω resistors with the middle common terminal grounded. The sampling voltage is 50mV. After being amplified 4 times internally, 200mV meets the input requirements of RN8306. The subsequent resistors and capacitors form an RC low-pass filter circuit to suppress interference above 4kHz.

[0049] Leakage current sampling obtains the current signal through a 1A / 0.5mA current transformer, and the input current is relatively small. To ensure the stability of the collected current identification, it is necessary to increase the resistance value of the sampling resistor. The leakage path uses a 5-fold gain of the phase current path.

[0050] In this embodiment, the data storage module (FLASH) is 16Mbits, and uses the SPI interface for data transmission, which can ensure that the data is not lost after power failure and can achieve long-term storage.

[0051] In this embodiment, the clock module uses the 8025T clock chip as the clock chip to ensure the normal operation of the chip and provide accurate clock information. The 8025T clock chip uses the I 2 C interface for data transmission. Since the power consumption of the clock chip is relatively low, the battery is used to supply power to the clock chip alone after the device loses power to ensure that the clock is correct after power restoration. At the same time, taking advantage of 4G communication, the network time synchronization function is used to supplement the application options of the clock circuit.

[0052] In this embodiment, the security module uses a security chip that meets the requirements of the State Grid to meet the requirements for data interaction security and conducts data interaction with the MCU through a standard SPI interface.

[0053] In this embodiment, the telecontrol signal module has telecontrol signal control function and status feedback function. The control pins use optocoupler output (dry contact), and the feedback signal is controlled by the switching quantity. To protect the device from interference such as static electricity, a TVS tube is used for protection. To enhance the output driving ability, a reasonable output resistance value needs to be calculated.

[0054] In this embodiment, the RS485 communication module uses a separate power supply for isolated power supply, and the signal transmission uses optocoupler isolation to isolate the main system from the RS485 circuit, preventing static electricity and withstand voltage tests from affecting the stability of the system. The standard requires that the RS485 interface circuit be isolated from the main system, and the highest communication rate is 9600bps.

[0055] In this embodiment, the temperature detection module is mainly used for alarm and abnormal reporting judgment. It is possible to collect the voltage on the resistance value of the thermistor using the ordinary ADC method. Pay attention to the protection of the external circuit to prevent the MCU from being directly damaged by static electricity.

[0056] In this embodiment, the 4G communication module only needs to support data transparent transmission, without the need for voice and short message functions. A low-cost 4G module 800k-CN CAT1 that supports the MQTT protocol can be used. The module requires an external power supply to provide a power supply of 3.6V - 4V. The SIM card uses a nano card, which reduces the installation volume of the SIM card and also reduces the installation cost. The power supply of the SIM card is provided by the 4G communication module. An anti-static tube should be installed at the SIM card slot interface, which can effectively avoid electrostatic damage to the internal circuit caused by manual plugging and unplugging. Refer Figure 5 as shown.

[0057] Refer Figure 6 As shown, this embodiment also provides a real-time monitoring system for medium and low voltage distribution lines, including the 4G monitoring unit, the master station, the TTU, the frame switch, the carrier monitoring unit, the ordinary circuit breaker, the miniature circuit breaker, and the electric energy meter; one path of the master station is directly connected to the ordinary circuit breaker through the 4G monitoring unit; the other path of the master station is sequentially connected to the TTU, the frame switch, the carrier monitoring unit, the ordinary circuit breaker, the miniature circuit breaker, and the electric energy meter. Among them, the carrier monitoring unit is responsible for collecting local communication devices such as ordinary circuit breakers, miniature circuit breakers, and electric energy meters, and after collecting the data, it transmits the data to the TTU through the broadband carrier method, and then the TTU transmits the data to the master station. The 4G monitoring unit is responsible for directly uploading local key devices to the master station through 4G.

[0058] The 4G monitoring unit has functions such as real-time monitoring of low-voltage lines, electrical parameter measurement, electric energy metering and statistics, temperature measurement, 4G communication, 485 communication, data storage, etc. The specific functions are as follows:

[0059] 1) It supports 4G Cat.1 communication for the uplink. The 4G communication module has an MQTT protocol stack and docks with the cloud platform;

[0060] 2) It supports 1-way RS485 communication for the downlink, which is used for local maintenance and connecting external peripheral small sensors; one path of Bluetooth communication is reserved.

[0061] 3) It supports 4-way terminal temperature measurement interfaces; it is convenient to monitor the temperature of the line through the master station and report abnormal temperatures on site.

[0062] 4) It has functions such as remote signaling and remote measurement, supports 1-way DI interface and 1-way DO interface, and is used for joint control with other devices, and can be used in combination with switch devices such as circuit breakers.

[0063] 5) In terms of measurement functions, a three-phase metering chip method is adopted to sample the voltages and currents of phases A, B, and C, and 1-way leakage current sampling is satisfied.

[0064] 6) In terms of power supply and sampling, the product adopts the method of three-phase voltage access and single-phase power supply; for current sampling, an external current transformer is used. For a current transformer input current range of 1.5(5) A, an open structure form needs to be selected; if users have other current requirements, they need to purchase a current transformer by themselves for transformation.

[0065] 7) It adopts a rail-mounted structure and is suitable for indoor use, in distribution cabinets and other scenarios where waterproofing is not required. If there is a waterproof requirement, a waterproof shell needs to be additionally configured for use.

[0066] 8) It supports querying various event records during operation and querying electrical parameters.

[0067] 9) It has a fault detection function and can monitor and report faults such as overvoltage, undervoltage, open phase, missing zero, leakage (optional) and other information that appears in the circuit.

[0068] The above are only the preferred embodiments of the present invention and do not limit the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A 4G monitoring unit, characterized in that, It is used to upload the monitoring data of local key devices directly to the master station through 4G transmission mode, including an MCU module, a power supply module, a metering module, a data storage module, a clock module, a security module, a tele-signaling module, an RS485 communication module, a temperature detection module, and a 4G communication module connected to the MCU module; The power supply module uses an ACDC switching power supply to convert AC 220V into a DC 12V power supply, and then converts 12V into the power required by each module; The MCU module is used for data acquisition; The metering module is used for monitoring metering data, including voltage, current, and power factor; The data storage module is used for data storage; The clock module is used to provide clock information; The security module is used for data interaction security protection; The tele-signaling module is used for tele-signaling control and status feedback; The RS485 communication module is powered by a separate power supply isolation, and the signal transmission uses an opto-coupler isolation method; The temperature detection module is used for temperature anomaly alarm and anomaly reporting judgment; The 4G communication module is used for data transparent transmission through 4G communication.

2. The 4G monitoring unit according to claim 1, characterized in that, The local key device is an ordinary circuit breaker.

3. The 4G monitoring unit according to claim 2, characterized in that, The MCU module uses HC32F460KETA as the main chip.

4. The 4G monitoring unit according to claim 3, characterized in that, The metering module uses RN8306 as the metering chip.

5. The 4G monitoring unit according to claim 4, characterized in that, The peripheral circuit of the metering module uses an 8.192MHz crystal oscillator as the external clock circuit of the metering chip, and uses a sampling resistor with low resistance, high precision, and high power.

6. The 4G monitoring unit according to claim 5, wherein The clock module uses an 8025T clock chip as the clock chip.

7. The 4G monitoring unit according to claim 6, characterized in that, The control pins of the tele-signaling module use opto-coupler output, the feedback signal is controlled by an on-off quantity, and a TVS tube is used for protection.

8. The 4G monitoring unit according to claim 7, wherein The 4G communication module is equipped with a SIM card. The SIM card uses a nano card. The power supply of the SIM card is provided by the 4G communication module, and an anti-static tube should be installed at the SIM card slot interface.

9. A real-time monitoring system for medium and low voltage distribution lines, characterized in that, Including the 4G monitoring unit, master station, TTU, frame switch, carrier monitoring unit, ordinary circuit breaker, miniature circuit breaker, and electric energy meter according to any one of claims 1 to 8; One path of the master station is directly connected to the ordinary circuit breaker through the 4G monitoring unit; Another path of the master station is sequentially connected to the TTU, frame switch, carrier monitoring unit, ordinary circuit breaker, miniature circuit breaker, and electric energy meter.

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