High-Voltage Ring Main Unit
Product Overview
A high-voltage ring main unit is equipment used to improve power supply reliability. By connecting the power supply network into a ring shape, it enables users to obtain power from two directions. This type of equipment usually consists of a set of high-voltage switchgears, installed in a steel metal enclosure or fabricated as assembled sectional ring power supply units. Its core components adopt load switches and fuses, featuring advantages such as simple structure, small size, low cost, improved power supply parameters and performance, and enhanced power supply safety.
Control Types
Load Switch Control: The load switch is one of the core parts of the ring main unit, used for making and breaking load current, interrupting short-circuit current and transformer no-load current. Load switch cabinets can be applied in scenarios such as ring power supply, tapping from medium-voltage boundary rooms, and power supply for medium-voltage terminal transformer rooms.
Vacuum Contactor Control: In high-voltage ring main units, vacuum contactor control is also a common control method, which is widely used especially in systems with small load capacity.
Circuit Breaker Control: Some load switch cabinets can be fitted with special vacuum circuit breakers or SF6 circuit breakers to enhance their short-circuit breaking capacity.
Application Scenarios, Advantages and Disadvantages of Different Control Modes:
Load Switch Control: It has a simple structure, small size and low cost, suitable for systems with small load capacity. However, its protection performance is relatively weak and it usually needs to be used together with fuses.
Vacuum Contactor Control: Suitable for systems with small load capacity, it features high reliability and convenient maintenance.
Circuit Breaker Control: Despite its high cost, its short-circuit breaking capacity is close to or reaches the level of switch cabinets, making it applicable to systems requiring high reliability and large load capacity.
Specific Application Examples of Different Control Modes in High-Voltage Ring Main Units:
Load Switch plus Fuse: This is the most common combination, used in ring power supply systems, with the merits of simple structure, small size and low cost.
Vacuum Circuit Breaker: In some high-end applications, vacuum circuit breakers can increase the short-circuit breaking capacity of ring main units, suitable for occasions demanding high reliability and large load capacity.
