I. Overview of the current situation of the industry
Expressway has high requirements for power supply reliability, and has the characteristics of wide application range, multiple load types, and complicated use environment. If some require redundant power supply mode, some require adaptation to its harsh environment, and some use centralized power supply. Or decentralized power supply. Therefore, to make a power solution, we must make a reasonable power distribution design for the actual demand situation, such as the use environment and equipment status.
Second, the industry environment, load characteristics description
UPS is mainly used in toll stations and tunnel lighting and tunnel ventilation in the expressway. The power demand is more than 10-30KVA, and the delay is generally about 2-4 hours.
Expressway application features:
1. Power quality
(1) Local electricity or even rural electricity is used along the expressway, and the power grid along the urban road is relatively bad.
(2) Located in remote rural areas, there are more lightning
2, environmental characteristics
(1) Dust and automobile exhaust
(2) alternating between hot and cold in the tunnel, easy to produce condensation
3, load characteristics
(1) It is mainly computer-based load, extremely sensitive to flashing, and requires high voltage accuracy.
(2) Tunnel lighting is high pressure sodium lamp, low power factor will reduce UPS load capacity
4, artificial features
The UPS at each site is basically unattended, and management and maintenance are not the same.
Third, technical solutions
In the equipment cavern inside the tunnel, the space is relatively limited, the humidity is large, and the exhaust and dust of the car are also large. At the same time, considering that many tunnels are located in the mountainous area, it is recommended to add a Class C lightning arrester at the UPS input point. The load is a tunnel lighting, and when the high-pressure sodium lamp with inductance ballast is used, a reactive power compensation device should be added, otherwise the power factor of the load is very low. , causing a great waste of UPS power. For areas with high humidity, in addition to the UPS itself to strengthen the chassis protection, circuit board coating, it is recommended that users configure the dehumidifier to ensure a better humidity environment in the equipment warehouse to improve the reliability of UPS operation.
Toll station equipment mainly includes: computers, printers, electric railings, lighting, monitoring, signal lights, sensing equipment, etc. The tunnel equipment mainly includes: high-pressure nano lamps, ventilation fans, and the like.
For the on-site characteristics of the expressway, after a comprehensive analysis, we provide corresponding solutions for toll stations and tunnel equipment, and UPS adopts a series of products of Chuangneng Hengdian.
1. The toll station adopts the power supply mode of mains and generator double backup: