Under the guidance of the "dual carbon" strategy, urban rail transit is accelerating its transformation to green, intelligent and efficient. As a key link in the Ningbo rail transit line network, Ningbo Metro Line 7 will be officially opened for operation on August 29, 2025, the day of the traditional Chinese festival Qixi Festival!

The first operating vehicle entered the platform

Ningbo Metro Line 7 is the first 100km/h speed line of Ningbo rail transit, with a total length of 39.4 kilometers, 25 stations and 11 transfer stations, starting from Yunlong in Yinzhou and ending in Yufan, all of which are underground lines. The planned land area of the depot is about 600,000 square meters, the cover area is about 370,000 square meters, the total construction area is about 220,000 square meters, and more than 70 subway trains can be parked at the same time.

 All stations of Ningbo Metro Line 7

As a facility that needs to operate around the clock, there is a high demand for lighting. while traditional lighting systems operate for a long time and consume high energy, which is not conducive to energy conservation and emission reduction. Therefore, the normal lighting of the public area of the whole line, the normal lighting of the equipment area, the advertising lighting, the guide lighting, the section lighting, the lighting of the entrance and exit passages and other areas all adopt the Huiyeda intelligent lighting (DC) power supply system, which can automatically adjust the lighting brightness according to the train timetable and passenger flow changes, and realize the energy-saving mode of "the lights are on when the car is on, and the lights are dim when the car goes", which is about 20% more energy-saving than the traditional lighting system.

Huiyeda intelligent lighting power supply system    

In this project, a total of 33 sets of smart lighting power systems in the whole station use integrated AC and DC power supply devices, each set of AC and DC power supply devices are composed of AC screen, DC screen, battery screen (including battery online monitoring system), rectification module, monitoring unit, dimming module are independently developed and produced.

System features:   

● Adopt high-frequency switching power supply technology, modular design, N+1 thermal backup.

●Wide voltage input range and strong adaptability to the power grid.

● The rectifier module can be plugged and plugged with electricity, which is convenient and fast to maintain.

● There are reliable lightning protection and electrical insulation protection measures to ensure the safety of the system and people.

● Adopt a large screen touch screen to realize fully Chinese real-time display and operation.

● System parameter setting query, dimming lighting control can be carried out by clicking on the touch screen, the man-machine interface is friendly, and the operation is simple and convenient.

● Adopt a distributed monitoring system with microprocessor as the core, modular design, implement all-round monitoring and control of the lighting power system, and realize the "four remote" function and unattended.

The system adopts the advanced architecture of "centralized rectification and decentralized power supply", which converts 380V AC mains power into 200~300V low-voltage DC power at the front end, and then carries out secondary high-efficiency conversion through DC-DC modules. This architecture enables the comprehensive efficiency of the power supply system to reach more than 92%, eliminating the reactive power loss inherent in AC power supply, and achieving energy saving and efficiency increase of about 6% alone. On the basis of this hardware, the system deeply integrates intelligent control technology and supports four dimming modes: time period control, scene control, infrared induction control and illuminance control. The system can flexibly formulate dimming strategies according to operating hours, regional functions, real-time foot flow and ambient light intensity, and carry out circuit combination and manual/automatic settings to truly realize "on-demand lighting" and maximize the potential of energy saving.

Expected Results:      

 Safe operations

1. Improve the ability to ensure lighting safety in emergency situations and reduce safety risks.

2. Greatly reduce operational incidents caused by lighting failures through preventive maintenance.

 Economic cost reduction

1. Directly reduce the electricity cost of station lighting by 30%~50%, and the payback period is usually 2-4 years.

2. Reduce the labor cost of daily inspection and troubleshooting by about 50%, and optimize the inventory of spare parts.

 Management efficiency improvement

1. Realize the transformation of the lighting system from "manual on-site management" to "remote centralized intelligent control".

2. Provide strong data support and tools for the refined and digital operation and management of the station.

 Green brand

Significantly reduce the carbon footprint of stations and help owners achieve the goals of "green track" and "double carbon".

The successful opening of Ningbo Metro Line 7 and the comprehensive application of the smart lighting system not only bring a safer, more comfortable and more convenient travel experience to Ningbo citizens, but also achieve a double leap in energy utilization efficiency and lighting quality in the 39.4-kilometer underground space through the Huiye smart lighting power supply system. In the future, with the continuous optimization and data accumulation of this system in operation, its energy-saving potential will be further released.