The electrical control system is generally called the two control circuit of the electrical equipment, the different equipment has different control loops, and the control mode of the high voltage electrical equipment and the low voltage electrical equipment is also different. The main function is to ensure the reliability and safety of the equipment operation. It needs a lot of auxiliary electrical equipment to serve it. It can realize the combination of some electrical components of a certain control function, which is called the control loop or the two circuit. These devices have the following functions:

　　1, automatic control function: the volume of high voltage and high current switching equipment is very large, usually uses the operating system to control and switch, especially when the equipment fails, it needs switch to cut off the circuit automatically, have a set of automatic control electric operation equipment, and control the power supply automatically.

　　2, protection function: electrical equipment and line will fail during operation, current (or voltage) will exceed the scope and limit of equipment and line, which requires a set of protective equipment to detect these fault signals and adjust the equipment and line automatically (disconnection, switching and so on).

　　3, monitoring function: electricity is invisible to the eye, a device is charged or power off, from the appearance can not be resolved, this needs to set all kinds of audio-visual signals, such as lighting and sound, and so on, the electrical monitoring of a device;

　　4, measurement function: light and sound signal can only qualitatively show the working state of the equipment (electricity or power break). If you want to know the working condition of the electrical equipment, there are various instrument measuring equipment to measure the parameters of the line, such as voltage, current, frequency and power.

　　In the operation and monitoring of equipment, traditional operating components, control appliances, instruments and signals can be replaced by computer control systems and electronic components, but there are still some applications in small equipment and local local control circuits. This is also the basis for the realization of microcomputer automation in circuits.

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  electrical system

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  Water system