Electric power secondary device.

Electric power secondary device is an auxiliary device that monitors, measures, controls, protects, and regulates primary equipment in the power system，which is not relate to electric energy directly.

Internal device:

1.Meters, such as voltmeters, ammeters, power meters, and energy meters, are used to measure electrical parameters in the circuit.

2.Insulation monitoring device.

3.Control and signaling devices.

4.Relay protection and automatic devices, such as relays, automatic devices, etc., are used to monitor the operating status of a system, quickly respond to abnormalities and accidents, and then act on circuit breakers to perform protection control.

5.DC power supply equipment, such as battery packs, DC generators, and silicon rectifiers, supplies DC power for control protection, DC load, and accident lighting.

6.High-frequency wave filter.

7.Prepare self-injection devices and so on.