Application analysis of high voltage DC power supply system (240V) in a test project

In recent years, with the rapid popularization of the computer network and the fast development of data service, the traditional UPS power supply mode reflect more and more problems in power supply reliability, safety and high energy consumption and other aspects. Higher Voltage DC (HVDC) Distribution System is becoming a new power supply mode of Data centers, because of its low investment, high reliability, low operating cost Advantages. A test for HVDC(240V) distribution system was conducted by China Unicom in Shaolin Road Telecommunication Building in Dengfeng city in 2011, intended to test the energy saving effect, the power supply reliability improvement to Information technology (IT) equipments, the comprehensive benefits of the technology in saving construction funds and reducing the cost of maintenance, and accumulate experience for large-scale application of the technology in the future. In the test, a set of HVDC(240V 200A) distribution system included 240-Vdc Output Rectifier and VRLA batteries was constructed, and a set of UPS distribution system was modified to adapt to the test. Some IT equipments of different type in operation were cut from a set of UPS distribution system to this modified UPS distribution system and then to the HVDC distribution system without power off. We measured and compared the Energy consumption and the stability of distribution system of the modified UPS distribution system and the HVDC distribution system. IT equipments of some types could not operate correctly in the HVDC distribution system for some reason, for example, some IT equipments could not be started unless voltage was reduced to a Specific level, some IT equipments could not work in the HVDC distribution system, and some Power Distribution facility gave an alarm before powered on. This paper describes the process and conclusion of the test,problems meeting in the process, and some methods to solve the problems. Based on the analysis of test results we get a conclusion that HVDC distribution system has many advantages comparison with traditional UPS distribution system, like higher reliability, better operation and maintenance, intelligent management, reduced the harmonic interference, higher safety, higher performance-price ratio, higher efficiency and energy saving, and can be widely used in the vast majority of communication or IT load. We think that HVDC distribution system can be widely used in China Unicom data center stage by stage in the future. With the rapid development of data communications service, due to the simplified equipment design, reduced cost, improved efficiency and reliability, the HVDC distribution system will be a very promising power supply mode. For the using of HVDC distribution system, communication industry reaches a consensus on HVDC power supply voltage level, current level, the key technical indicators, test method, inspection rules and other key issues and began to promote the use of HVDC distribution system. HVDC power supply technology will get more extensive commercial application in the communications industry, and make greater contribution to the network reliability in operation, energy saving and emission reduction.