Relay test

- Sep 20, 2018 -

Relay test

The relay is a key component in the intelligent prepaid energy meter. The life of the relay determines the life of the meter to a certain extent. The performance of the device is very important for the operation of the intelligent prepaid energy meter. There are many domestic and foreign relay manufacturers, the production scale is quite different, the technical level is very different, and the performance parameters vary widely. Therefore, the manufacturer of electric energy meter must have a complete set of detection devices in the selection of relays to ensure the quality of the meter. At the same time, the State Grid has also strengthened the sampling of the performance parameters of the relays in the smart energy meter. It also needs corresponding testing equipment to check the quality of the meters produced by different manufacturers. However, at present, the relay detection equipment not only has a single detection project, but the detection process cannot be automated. The detection data needs manual processing and analysis. The detection results have various randomness and artificiality, and the detection efficiency is low and the safety is not guaranteed. [1] .

In the past two years, the State Grid has gradually standardized the technical requirements of electric meters and formulated relevant industry standards and technical specifications. This has raised some technical difficulties for the detection of relay parameters, such as the load switching capability of relays and the testing of switching characteristics. Therefore, it is urgent to study a device to achieve comprehensive detection of relay performance parameters [1].

According to the test requirements of relay performance parameters, the test items can be divided into two categories, one is test items without load current, such as action value, contact contact resistance, mechanical life; the other is test items with load current, such as contacts Contact voltage, electrical life, and overload capacity.

The main test items are briefly described as follows: (1) Action values. The voltage value required for the relay to operate. (2) Contact contact resistance. The resistance between the two contacts when the electric shock is closed. (3) Mechanical life. The number of times the relay repeatedly switches and operates without damage to the mechanical part. (4) Contact contact voltage. When the electric shock is closed, a certain load current is applied to the electric shock circuit, and the voltage value between the contacts is used. (5) Electrical life. When the rated voltage is applied across the relay drive coil and the rated resistive load is applied in the contact circuit, the number of reliable operations of the relay is less than 300 cycles per hour and the duty ratio is 1:4. (6) Overload capability. When the rated voltage is applied across the relay drive coil and the rated load is 1.5 times in the contact circuit, the relay operates reliably under the condition of operating frequency (10±1) times/min [1].