- The electrical equipment of power plants and substations is divided into one-time equipment and two-time equipment.
- A device (also called a main device) is the main component of an electric power system. It is a device that directly produces, transfers, and distributes power, including generators, power transformers, circuit breakers, isolating switches, power busbars, power cables, and transmission lines.
- A secondary device is a device that controls, adjusts, protects, and monitors a single device. It includes control appliances, relay protection and automatic devices, measurement instruments, and signal appliances.
- The secondary device is connected to the primary device through a voltage transformer and a current transformer.
- A device and its connected circuit are called a circuit.
- The electrical circuit that connects the secondary device according to certain rules to meet certain technical requirements is called the secondary circuit.
- The content of the secondary circuit includes the control, adjustment, relay protection and automatic device, measurement and signal circuit, and operating power system of the power plant and substation. Zone 1, zone 2, and Zone 3
Zone 1 is the most important part. It directly contacts the switch quantity of the device, and has an important control signal, such as adjusting the value. Zone 2 and Zone 3 are the areas where some poorly-organized information systems are located. They are like this: signal, different control values are divided into different zones to prevent human error. At the same time, the update speed of important areas is also different.
