I. Basic concepts

The high and low voltage of electric power are distinguished by the large and small rated voltage. The voltage classes of 1kV and above are medium voltage and high voltage, and the voltage classes of 1kV and below are low voltage.

Low-voltage power network refers to the power network composed of low-voltage side of distribution transformer or busbar of direct distribution generator, electrical appliances such as monitoring, control, protection, metering, etc. to the electrical equipment of each user. It mainly consists of distribution lines, distribution devices and electrical equipment.

Distribution device - refers to the equipment which is assembled by bus bar, switchgear, instrument and transformer according to certain technical requirements to receive, distribute and control electric energy.

Distribution equipment manufacturing - refers to the whole process of installation of electrical components, bus connection, secondary wiring, product debugging and product packaging on the already manufactured screen.

Classification

A low-voltage distribution system usually consists of a receiving cabinet (i.e. an incoming cabinet), a feeder cabinet (controlling functional units), a reactive power compensation cabinet, etc. When two sets of transformers supply power, a receiving cabinet and a bus cabinet are added accordingly, and the number of functional units (feeder cabinets) of control is increased accordingly.

The low-voltage distribution devices are divided into two categories according to their different structures: one is the drawer cabinet, such as GCK (GCL), GCS, MNS, etc. and the other is the fixed structure (i.e., the fixed distribution cabinet), such as GGD, PGL, etc.

The main switch of the receiving cabinet - distribution system controls the whole system from the low-voltage side of the transformer.

Feeder cabinet - directly to the user's receiving equipment, control each power unit.

Capacitance Compensation Cabinet - The input of shunt capacitor banks is automatically controlled according to the amount of inductive reactive power consumed by the load of the power grid, so that the reactive power consumption of the power grid can be kept to a minimum, thus improving the voltage quality of the power grid and reducing the loss of transmission system and transformer.