With the rapid advancement of urban power grid transformation, industrial park construction, and new energy projects, power distribution systems are placing higher demands on equipment intelligence, environmental friendliness, and safety. Ring main unit (RMU), a key component of medium-voltage power distribution networks, boasts a compact structure, stable performance, and safe operation. It has been widely used in urban power distribution networks, wind and photovoltaic power integration, and electric vehicle charging stations.
Core Functions and Structure of a Ring Main Unit
A ring main unit is a medium-voltage switchgear used in 12kV or 24kV power distribution networks. Its main functions include:
Connection control for incoming and outgoing power lines
Short-circuit protection and cable branch management
Remote control of power distribution automation
Advantages
1. High Power Supply Reliability
Ring Network Structure: This system forms a closed loop, enabling dual or multiple power sources. If a line fault occurs on one side, the system quickly switches to the other power source, minimizing the scope and duration of the outage.
Fault Isolation: Built-in load switches and fuses quickly isolate the faulty section, preventing it from impacting the entire grid.
2. Space and Cost Savings
Compact Design: This system utilizes a modular, miniaturized structure, making it ideal for space-constrained locations such as urban areas and basements.
Reduced Cable Use: The ring network structure shortens power supply distances, reducing cable investment and installation costs.
3.Flexibility and Scalability
Modular Combination: Modules such as switches, transformers, and protection units can be flexibly configured to meet diverse network topologies.
Easy Expansion: When adding new loads, simply expand the ring main unit without having to restructure.
4. Easy Maintenance
Low-Maintenance Design: Typically utilizes SF6 gas insulation or vacuum arc extinguishing technology to minimize environmental impact and extend maintenance cycles.
Live Indication and Measurement and Control Functions: Integrated voltage/current indication and remote monitoring (e.g., DTU) facilitate fault diagnosis and status monitoring.
5. High Safety
Fully Enclosed Structure: High protection rating (e.g., IP67) protects against dust, moisture, and electric shock, making it suitable for harsh environments.
Automated Protection: Supports relay protection, automatic reclosing, and other functions to enhance operational safety.
6. Adaptability to Various Scenarios
Distributed Power Generation Integration: Compatible with grid-connected renewable energy sources such as photovoltaic and wind power, supporting bidirectional power flow.
Urban Distribution and Industrial Applications: Widely used for medium-voltage power distribution (e.g., 10kV and 20kV systems) in residential areas, commercial centers, and industrial parks.
7. Energy Saving and Environmental Protection
Low Loss: Optimized electrical design reduces energy loss, and some models use environmentally friendly gases (such as dry air) instead of SF6.
Typical application scenarios
| Application Scenarios | Recommended Product Configuration | Description |
|---|---|---|
| Urban residential areas | HXGN-12 load switch + circuit breaker combination | Space-saving, stable power supply, and flexible networking with cable branch boxes. |
| Industrial park distribution stations | Ring main unit with intelligent FTU module | Supports remote control, quickly locates fault areas, and reduces power outages. |
| New energy grid-connected projects | Ring main unit + metering module + isolation module | Facilitates grid connection for photovoltaic and wind power generation, with automatic switching and protection functions. |
| Underground substations | Fully sealed and fully insulated ring main unit | High protection rating, suitable for harsh environments such as humid and dusty environments. |
Selection Recommendations
When selecting a ring main unit (RMU), we recommend focusing on the following parameters:
Rated voltage (kV): Commonly 12kV and 24kV are recommended, and should be matched to the system voltage level;
Rated current and short-circuit breaking capacity: Consider load capacity and future expansion requirements;
Installation environment: Are there any special climate, altitude, humidity, or other restrictions?
Intelligent requirements: Whether a monitoring system or remote control system is required?
Module combination: Whether the combination of load switches, circuit breakers, and disconnectors meets the on-site functional requirements.
Shaanxi Huadian ring main unit products are widely used in State Grid projects, municipal engineering, industrial and mining enterprises, and new energy stations. We provide customized power distribution solutions, support smart terminal access, and help customers build safe, efficient, and intelligent medium-voltage power distribution systems. Please contact us for technical information and engineering support.
Email:pannie@hdswitchgear.com
Whatsapp/Wechat:+8618789455087
