Anti-overheating automatic protection ammeter

Abstract

The utility model discloses an anti-overheating automatic protection ammeter, which comprises a flip cover, a general packet radio service (GPRS) module, an upper cover, an ammeter printed circuit board assembly (PCBA) mainboard, an electric energy meter terminal seat, a terminal cover, an ammeter bottom shell, a relay and a temperature detection unit, the GPRS module is sealed in the upper cover by the flip cover, and the ammeter PCBA mainboard, the electric energy meter terminal seat and the relay are sealed in the ammeter bottom shell by the upper cover. A temperature detection unit is arranged below the electric energy meter terminal base, a terminal cover is installed outside the electric energy meter terminal base, the electric energy meter terminal base is located on one side of the electric meter PCBA main board, and the relay is located below the electric meter PCBA main board. The temperature detection unit is arranged below the terminal base of the electric energy meter, when the electric energy meter detects that the temperature of the terminal is too high, the relay in the electric energy meter is cut off, high-power electricity utilization is forced to stop, then the electric energy meter is prevented from being burnt out due to the too high temperature of the terminal, and the electric energy meter can monitor electric energy parameters and equipment temperature in real time; and safe and stable operation of a power system is ensured.

Description

Technical Field

[0001] This utility model relates to an electricity meter, specifically an electricity meter with automatic overheat protection. Background Technology

[0002] Traditional electricity meters do not have automatic overheat protection, and are very easy to burn out under high current and overload conditions. Electricity meter wiring requires screws to be tightened. If the screws are not tightened securely, it will cause increased contact resistance and generate excessive heat under overcurrent conditions.

[0003] The screws installed on the internal terminals of the meter are used to fix the sampling manganese copper or current transformer. However, during the production process, there are always cases where the screws are not tightened properly. The external wiring of the meter to the user end is secured by two screws installed on the meter terminals. However, in actual operation, there are always cases where the electrician does not tighten them properly. At the meter installation site, there are often cases where the meter burns out. The proportion of accidents caused by the failure to tighten the above two types of screws is over 60%. If the screws are not tightened properly, there will be contact resistance. When the actual screws are not tightened, the resistance between the incoming and outgoing lines is tested. The resistance between the incoming and outgoing lines is 0.5Ω. If the screws are loosened further, the resistance will become larger. The current specification of the conventional meter is 5 (60)A. The maximum current at the user end can reach 60A. According to the power calculation formula P = I 2 R, at this time the heating power is 1.8kW. Such a large power is used to generate heat, the heat generation is very serious, and it will cause the terminal block to overheat and melt within a few minutes.

[0004] The safe use of smart meters is not only related to the normal operation of the power system, but also to the safety of people's lives and property. Overheat-proof meters greatly reduce the accident rate and reduce accidents caused by overheating of the meter terminals, which can lead to fires in severe cases. Therefore, it is urgent to design a power meter that can solve the problem of overheating and burning of the meter terminals. Utility Model Content

[0005] To address the problem of overheating terminals causing meter burnout, this invention provides an electric meter with automatic overheat protection.

[0006] This utility model provides the following technical solution:

[0007] An overheat-resistant automatic protection electricity meter includes a flip cover, a GPRS module, a top cover, a meter PCBA main board, an electricity meter terminal block, a terminal cover, a meter bottom shell, a relay, and a temperature detection unit. The flip cover encloses the GPRS module inside the top cover, and the top cover encloses the meter PCBA main board, the electricity meter terminal block, and the relay inside the meter bottom shell. A temperature detection unit is located below the electricity meter terminal block, and a terminal cover is installed outside the electricity meter terminal block. The electricity meter terminal block is located on one side of the electricity meter PCBA main board, and the relay is located below the electricity meter PCBA main board.

[0008] Furthermore, the mainboard of the electricity meter PCBA includes a microcontroller unit and a metering and detection unit.

[0009] Furthermore, the temperature detection unit monitors the terminal temperature in real time, and disconnects the energy meter relay when the temperature exceeds the limit; the temperature detection unit uses multiple DS18B20 sensors.

[0010] Furthermore, the metering and testing unit includes a voltage sampling circuit and a current sampling circuit.

[0011] Furthermore, the input terminals of the temperature detection unit and the metering detection unit are connected to the terminal block of the energy meter and the relay, and the output terminals of the temperature detection unit and the metering detection unit are connected to the microcontroller unit. The microcontroller unit determines whether to control the relay to open or close based on the received temperature and metering information.

[0012] Furthermore, the microcontroller unit uses an STM32 series chip.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] The electricity meter of this application has a temperature detection unit located below the terminal block. When the meter detects that the terminal temperature is too high, it cuts off the internal relay of the meter, forcing the high-power power consumption to stop, thereby preventing the meter from burning out due to excessive terminal temperature. The microcontroller unit determines whether to control the relay to open or close based on the received temperature and metering information, thereby realizing the control and protection of power output. The meter can monitor power parameters and equipment temperature in real time, ensuring the safe and stable operation of the power system. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the present utility model;

[0016] Figure 2 This is a schematic diagram of the present invention;

[0017] Figure 3 This is the temperature detection unit of this utility model.

[0018] In the diagram: 1. Flip cover; 2. GPRS module; 3. Top cover; 4. Electricity meter PCBA main board; 5. Electricity meter terminal block; 6. Terminal cover; 7. Electricity meter bottom case; 8. Relay;

[0019] 100. Temperature detection unit; 200. Measurement and detection unit; 300. Microcontroller unit. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Figure 1 As shown, the present invention provides an overheat protection automatic electricity meter, including a flip cover 1, a GPRS module 2, an upper cover 3, an electricity meter PCBA main board 4, an electricity meter terminal block 5, a terminal cover 6, an electricity meter bottom shell 7, a relay 8, and a temperature detection unit. The flip cover 1 encloses the GPRS module 2 inside the upper cover 3. The upper cover 3 encloses the electricity meter PCBA main board 4, the electricity meter terminal block 5, and the relay 8 inside the electricity meter bottom shell 7. A temperature detection unit 100 is provided below the electricity meter terminal block 5. The terminal cover 6 is installed on the outside of the electricity meter terminal block 5. The electricity meter terminal block 5 is located on one side of the electricity meter PCBA main board 4, and the relay 8 is located below the electricity meter PCBA main board 4.

[0022] The main board 4 of the electricity meter PCBA includes a microcontroller unit 300 and a metering and detection unit 200.

[0023] The microcontroller unit 300 uses STM32 series chips, which are highly integrated and have low power consumption.

[0024] Temperature detection unit 100 detects terminal temperature in real time. When the temperature exceeds the limit, the energy meter relay is disconnected.

[0025] Figure 3 This circuit is primarily used for temperature measurement. The microcontroller unit 300 communicates with multiple DS18B20 sensors via I / O ports, reading the temperature data measured by each sensor. The DS18B20 sensors convert temperature signals into digital signals, which are directly transmitted to the microcontroller unit via the data line DQ. After processing, the microcontroller unit 300 can display the temperature value in real time.

[0026] The metering and detection unit 200 includes a voltage sampling circuit and a current sampling circuit.

[0027] A voltage sampling circuit consists of two or more resistors connected in series. The power supply voltage is applied across the series resistors. Based on the voltage divider principle of series resistors, a voltage signal proportional to the power supply voltage is extracted across one of the resistors. This signal can be used as the sampling voltage. This circuit structure is simple, but its accuracy depends on the accuracy and stability of the resistors.

[0028] The current sampling circuit consists of the primary winding of a current transformer connected in series with the circuit containing the current being measured. When the current being measured flows through the primary winding, an induced current proportional to the primary current is generated in the secondary winding. This induced current is converted into a voltage signal through a load resistor, thereby achieving current sampling. Current transformers can transform and isolate large currents and are widely used in high-current measurement applications such as power systems.

[0029] The input terminals of the temperature detection unit 100 and the metering detection unit 200 are connected to the terminal block of the energy meter and the relay. The output terminals of the temperature detection unit 100 and the metering detection unit 200 are connected to the microcontroller unit 300. The microcontroller unit 300 determines whether to control the relay to open or close based on the received temperature and metering information.

[0030] Figure 2 As shown, the electricity meter terminal block and relay serve as the system's input and output interfaces. On the one hand, they receive the current from the input line "lin", and on the other hand, they output the current to "lout".

[0031] During operation, the electricity meter terminal block and relay collect temperature signals and voltage and current signals, which are then transmitted to the temperature detection unit and the metering detection unit, respectively.

[0032] The temperature detection unit processes the temperature signal and sends the result to the microcontroller unit; the metering detection unit processes and measures the voltage and current signals and also sends the result to the microcontroller unit.

[0033] The microcontroller unit determines whether to control the relay to open or close based on the received temperature and metering information, thereby achieving control and protection of electrical energy output.

[0034] This meter can monitor electrical parameters and equipment temperature in real time, ensuring the safe and stable operation of the power system.

[0035] To address the issue of meter burnout due to overheating of the terminal block, this application cuts off the internal relay of the meter when it detects that the terminal temperature is too high, forcing the termination of high-power power consumption and thus preventing the meter from burning out due to excessive terminal temperature. This detection uses a dedicated temperature sensing integrated circuit, designed as an independent PCB, placed below the terminal block. It can uniformly detect any terminal overheating and promptly cut off the relay when severe overheating is detected, avoiding burnout or fire caused by meter overheating, thus ensuring high safety performance.

Claims

1. An electric meter with automatic overheat protection, characterized in that: The device includes a flip cover (1), a GPRS module (2), a top cover (3), a meter PCBA main board (4), a meter terminal block (5), a terminal cover (6), a meter bottom shell (7), and a relay (8). The flip cover (1) encloses the GPRS module (2) inside the top cover (3). The top cover (3) encloses the meter PCBA main board (4), the meter terminal block (5), and the relay (8) inside the meter bottom shell (7). A temperature detection unit (100) is provided below the meter terminal block (5). The terminal cover (6) is installed outside the meter terminal block (5). The meter terminal block (5) is located on one side of the meter PCBA main board (4), and the relay (8) is located below the meter PCBA main board (4).

2. The electric meter with automatic overheat protection according to claim 1, characterized in that: The main board (4) of the electricity meter PCBA includes a microcontroller unit (300) and a metering and detection unit (200).

3. The electric meter with automatic overheat protection according to claim 1, characterized in that: The temperature detection unit (100) detects the terminal temperature in real time. When the temperature exceeds the limit, it disconnects the power meter relay. The temperature detection unit (100) uses multiple DS18B20 sensors.

4. The electric meter with automatic overheat protection according to claim 2, characterized in that: The metering and detection unit (200) includes a voltage sampling circuit and a current sampling circuit.

5. An electric meter with automatic overheat protection according to claim 2, characterized in that: The input terminals of the temperature detection unit (100) and the metering detection unit (200) are connected to the terminal block of the energy meter and the relay. The output terminals of the temperature detection unit (100) and the metering detection unit (200) are connected to the microcontroller unit (300). The microcontroller unit (300) determines whether it is necessary to control the relay to open or close based on the received temperature and metering information.

6. The electric meter with automatic overheat protection according to claim 2, characterized in that: The The microcontroller unit uses an STM32 series chip.

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