CN207301219U - Electrical energy measurement verification current loop open circuit warning device - Google Patents

Abstract

The utility model discloses an open-circuit alarm device for electric energy measurement verification current loop, comprising: a sampling module and a monitoring module; the sampling module includes: a current data sampler for measuring three-phase current data; the monitoring module includes: a single-chip microcomputer, an alarm unit and a display unit; the current data sampler, the alarm unit and the display unit are respectively connected with the single chip microcomputer. The utility model has beneficial effects: the current clamp with a small volume and an induction coil is used for three-phase current sampling, and the principle of electromagnetic induction can be used to accurately collect the current in the case of a small current open circuit; at the same time, it is convenient for electric energy measurement and calibration current The connection between the circuit open circuit alarm device and the line.

Description

Electric energy measurement calibration current loop open circuit alarm device

technical field

The utility model relates to the technical field of electric energy measurement, in particular to an open circuit alarm device for electric energy measurement verification current loop.

Background technique

When working in the current secondary circuit, the loose current test terminal should be placed slowly and gently. If the operation error causes an open circuit, the open circuit current will slowly decrease. Some users with small loads will find it difficult to find the open circuit if they do not pay attention. If the load rises, it will be difficult to control. In order to avoid the open circuit of the current loop due to the negligence of equipment and personnel, the magnetic flux saturation magnetic density of the metering and relay protection transformer will increase, and the excitation breakdown insulation will cause casualties and equipment damage.

Utility model content

The purpose of this utility model is to solve the above problems, and proposes an electric energy measurement verification current loop open circuit alarm device, which can accurately and effectively monitor small current open circuits.

In order to achieve the above object, the utility model adopts the following technical solutions:

An open circuit alarm device for electric energy metering and verification current loop, comprising: a sampling module and a monitoring module;

The sampling module includes: a current data sampler for measuring three-phase current data;

The monitoring module includes: a single-chip microcomputer, an alarm unit and a display unit;

The current data sampler, the alarm unit and the display unit are respectively connected with the single chip microcomputer.

The three-phase current data is collected by the current data sampler and transmitted to the monitoring module, and the monitoring module performs display and leakage alarm after processing the data.

Further, it also includes: a communication unit; the communication unit is connected to a single-chip microcomputer; and the communication unit is connected to an external video monitoring device. The communication unit transmits the collected current data to the external video monitoring device in real time, and the external video monitoring device receives the current data to form a real-time monitoring video of the open circuit current.

Further, the current data sampler includes: clamp heads with induction coils for collecting ABC three-phase currents respectively, and a sampling signal processing circuit connected with the induction coils.

Further, the sampling signal processing circuit includes: a sampling resistor, a signal amplifying circuit, an AC effective value measuring circuit and an A/D converter connected in sequence. A current clamp with a small size is used to reduce the secondary side current by a certain multiple and then pass through the sampling resistor to generate a voltage drop on the sampling resistor. The generated voltage drop is amplified by the signal amplification circuit and then converted to the AC voltage signal by the AC RMS measurement circuit. It is a DC signal, which enters the microcontroller after passing through the A/D.

Further, the alarm unit includes: LED lights and/or buzzers.

Beneficial effects of the utility model:

a) A small current clamp with an induction coil is used for three-phase current sampling, and the principle of electromagnetic induction can accurately collect the current in the case of a small current open circuit; at the same time, it is convenient for electric energy metering and verification of the current loop open circuit alarm device connection to the line.

b) The SPI port of the 8-bit single-chip microcomputer is used to collect the current sampling data of the sampling module and transmit it to the display unit in real time, so as to realize the collection, processing and real-time display of the three current data.

Description of drawings

Fig. 1 is a structural schematic diagram of the electric energy metering verification current loop open circuit alarm device of the utility model;

Fig. 2 is a working diagram of the power components of the electric energy metering verification current loop open circuit alarm device of the utility model.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is further described.

The utility model discloses an open-circuit alarm device for electric energy measurement verification current loop, as shown in Fig. 1, comprising: a sampling module and a monitoring module;

Among them, the sampling module includes a current data sampler for measuring three-phase current data; the current data sampler is based on the principle of electromagnetic induction and a lithium battery as a power source, and uses a special clamp head with an induction coil to collect current signals, and the sampling at the back end of the induction coil The signal processing circuit converts the sampled signal into corresponding data according to its strength.

The sampling signal processing circuit specifically includes: a sequentially connected sampling resistor, a signal amplifying circuit, an AC effective value measuring circuit and an A/D converter.

A current clamp with a smaller volume is used to reduce the secondary side current by a certain multiple and then pass through the sampling resistor to generate a voltage drop on the sampling resistor. The voltage drop generated on the sampling resistor by the current output from the current acquisition clamp head is detected by the signal amplification circuit. After amplifying, the amplified signal is converted into a DC signal by the AC effective value measurement circuit, and then converted into a digital signal by the A/D converter to enter the single-chip microcomputer.

In this embodiment, the signal amplifying circuit adopts INA282 instrumentation amplifier, which can be checked and amplified, and the magnification factor is 50 times, and the power supply is +5V. The AC RMS measurement circuit adopts the special RMS calculation unit of AD637, powered by positive and negative 5V dual power supplies, and adopts a single-pole working mode to further reduce the output ripple. The AD conversion module adopts high-precision 16-bit ADS1115 with four-channel analog input, and the reference voltage and sampling rate can be changed as required.

The monitoring module includes: a single-chip microcomputer, and an alarm unit, a display unit and a communication unit respectively connected to the single-chip microcomputer; the alarm unit and the display unit are used to alarm and display the open circuit current; the communication unit transmits the open circuit current data to an external video monitoring device in real time, Form the open circuit current video.

As a preferred implementation mode, MSP430F5529 single-chip microcomputer is used as the main control unit of the system. MSP430F5529 single-chip microcomputer is a high-performance low-power 16-bit single-chip microcomputer launched by American TI Company. It has rich off-chip resources, including clock module, capture/comparison module, Flash module, watchdog timer module, timer module, 8-channel AD module, serial communication module and general I/O port module.

As a preferred embodiment, the display unit is a serial LCD, which is a high-performance, low-power, and easy-to-use display, and can be directly connected to an MCU or FPGA with a serial interface.

When the detected open-circuit current value is lower than the set threshold (generally 0.05A), the single-chip microcomputer controls the alarm unit to give an alarm. When an alarm event occurs, an alarm will be given through LED light or buzzer or a combination of both.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (5)

1. An electric energy metering verification current loop open circuit alarm device is characterized in that, comprising: a sampling module and a monitoring module; The sampling module includes: a current data sampler for measuring three-phase current data; The monitoring module includes: a single-chip microcomputer, an alarm unit and a display unit; The current data sampler, the alarm unit and the display unit are respectively connected with the single chip microcomputer. 2 . The electric energy metering verification current loop open circuit alarm device according to claim 1 , further comprising: a communication unit; the communication unit is connected to a single-chip microcomputer; and the communication unit is connected to an external video monitoring device. 3. A kind of electric energy metering checking current loop open-circuit alarm device as claimed in claim 1, is characterized in that, described current data sampler comprises: respectively collects the pincer head with induction coil of ABC three-phase current and with induction coil The sampling signal processing circuit connected to the coil. 4. A kind of electric energy metering verification current loop open circuit alarm device as claimed in claim 3, is characterized in that, described sampling signal processing circuit comprises: sequentially connected sampling resistance, signal amplifying circuit, AC RMS measuring circuit and A /D converter. 5 . The electric energy metering verification current loop open circuit alarm device according to claim 1 , wherein the alarm unit comprises: an LED lamp and/or a buzzer.