中国建筑设计研究院 李炳华 王玉卿 王振声 李战赠 王烈 马名东

　　摘要：对于特级或一级体育场，应急电视转播需要应急电源为场地照明供电。我们通过对四种品牌2000W/380V金属卤化物投光灯的试验、测量、数据分析，得出场地照明用应急电源装置(EPF)必须具备的主要特性：第一，EPF的切换时间长短不能保证在电源转换时金属卤化物灯不熄灭，除非切换时间为零;第二，金属卤化物灯具有不大于2倍额定电流，启动时间长于2分钟的启动特性，EPF应能承受此冲击;第三，灯端电压变化对金属卤化物灯光输出有很大的影响;第四，EPF供电时间大于10分钟即可。据此，本文提出了场地照明应急电源装置EPF的参数要求。

　　关键词：EPF 场地照明 体育场 应急电源 金属卤化物灯 电源转换

　　The research on the characteristics of emergency power facility of the field lighting of stadiums

　　Li Binghua， Wang Yuqing， Wang Zhensheng， Li Zhanzeng， Wang Lie， Ma Mingdong

　　China Architecture Design & Research Group

　　Abstract[LiBH1] : For a A+ class or A class stadium, the emergency power supply required by emergency TV broadcasting should provide power for emergency lighting. Through our tests, measurement and data analysis of four brands of metal halide lamps with 2000W/380V, we get the main features of emergency power facility for field lighting (EPF) as follows: Firstly, the switching time of EPF cannot ensure the light continuity of metal halide lamp during the power switching, as long as the switching time can not reach zero. Secondly, metal halide lamps should be no more than twice of the rated current value and yet longer than 2 minutes of start time, which EPF should endure. Thirdly, the voltage variation of lamp has great influence on the light output of the metal halide lamp. Over 10 minutes of EPF power supply time should be acceptable. Based on this, we bring forward the working principle and parameter requirements of EPF. Fourthly, because EPF will only be applied during power switching and the switching time of power supply is only a few seconds, in principle, over 10 minutes of EPF power supply time should be acceptable. Based on this, we bring forward the working principle and parameter requirements of EPF.

　　Keywords: EPF，field lighting，stadium，emergency power supply，metal halide lamp，power switching

　　1 Analysis of common methods used for field lighting emergency power supply

　　For a A+ class or A class stadium, its field lighting is A class or the most important A class load respectively; therefore, the reliability and continuity of the power supply for its field lighting should be ensured. Except for city power and diesel generators, there should be other safeguard means, such as hot re-striker\UPS\EPS. Table 1 shows the characteristics of these three solutions.

　　From table1，UPS can ensure the continuity of field-lighting power supply, but UPS’ capacity lowered for usage here, because UPS is designed for computers and this kind of load is capacitive load, but most field lighting lamps are metal halide lamps which are inductive load and these two do not match. Switching time of EPS is too long, and the switching of city power to EPS power may cause metal halide lamps to extinguish, which cannot satisfy the requirement for reliability and continuity of power supply; but EPS has advantages in overload capability, environment requirement, efficiency, life, etc. Hot re-striker is more expensive, and every emergency start reduces the life of lamps and also affects color temperature of lamps, which goes against the TV broadcast requirement. At the same time, hot re-strikers requires short switch time, at which darkness arises, audience can be frightened, and possibility of accidents looms in. From the above, all these three have defects, new solution for field lighting power supply should be found.

　　2 Main characteristics of emergency power facility(EPF)

　　Through repeated tests, using 4 types of 2000W/380V metal halide lamps as shown in Table 2, we can get the characteristics of the newly developed EPF for field lighting:

　　2.1 Switching time of EPF

　　Figure 1 is the test using EF2000, whose switching time [1]τ1all is 1.5ms; many tests show that, during switching, some times the lamps extinguished, and other times they did not extinguish. Figure 1(a) shows the wave when lamps extinguished, and figure 1(b) shows the wave when lamps did not extinguish.

　　From figure 1 we can know, figure (b)’s switching timeτ2 is more than figure (a)’s，and the lamps did not always extinguish at long switching time, and also the lamps did not always continue on at short switching time.

　　Therefore, the switching time of metal halide lamps is not certain. The switching time of EPF should be 0，that is online EPF.

　　2.2 The start characteristic of EPF

　　The start curve in figure 2 is derived from tests. Black curve is National lamps’current —time curve, because there is not reactive power compensation in National lamps, and its start current is rather large, the maximum current arises 12~16s after start as 10.5A. About 2 and a half minutes (150s)later，operating current is apt to be stable, shown as 6.1A. Maximum/stable value=10.5/6.1=1.72 times.

　　The red curve is GE lamps’ current —time curve, because there is reactive power compensation in GE lamps, and its start current is rather low, the maximum current arises 12~70s after start, the maximum current lasts longer (about 1min), whose value is 7.7A. About 3 and a half minutes (210s)later，operating current is apt to be stable，whose value is 5.8A。Maximum/stable value =7.7/5.8=1.33 times.

　　Blue curve is Thorn lamps’current —time curve, the maximum current arises 19s after start as 6.1A. About 2 minutes (120s)later，operating current is apt to be stable，whose value is 5.2A。Maximum/stable =6.1/5.2=1.17times.

　　Therefore, different types of metal halide lamps have different start characteristic, the characteristic of EPF should match with those of lamps, that is, EPF should endure the impact of lamps at their start time when this period is no less than 4 mins and their maximum current is no less than 2 times of the rated current.

　　2.3 The overload capability of EPF

　　From figure 2, the overload capacity characteristic can be established, as detailed in table 3.

　　2.4 The voltage stability of EPF

　　From figure 3, we can know, the voltage has rather great effect on the light output of metal halide lamps, and power voltage changes linearly to illuminance approximately, when the voltage reduces 10%，illuminance reduces 14~24%;in reverse, when voltage increases 7.9%，illuminance increases 17~20%。

　　Therefore ，EPF should provide voltage stability to reduce the effects on illuminance from voltage.

　　2.5 The power supply time of EPF

　　Chinese design codes regulates that a A+ class or A class building must have two separate ways of power supply, therefore, EPF will only be used at power switch, and after the switch, EPF will not be used until the next switch. The switch time is only a few seconds, therefore in principle, 2 minutes of EPF power supply should be acceptable; considering storage battery’s self discharge and system reliability, the power supply time of EPF should be no less than 10 minutes.

　　3 Conclusion

　　EPF is designed according to the characteristics of metal halide lamps, its main specially is that the lamps will not extinguish during the power switch, and at the same time, it can match with the metal halide lamp in voltage stability and start impact resistance , all of which can ensure the continuity of the metal halide lamp.

　　Reference：

　　1 “体育场馆场地照明专用电源装置切换时间的研究”，李炳华 王振声 李战增 马名东 王烈，《建筑电气》2005年第6期

　　Research on Switch Time of Power Supply Facilities for Stadium Field Lighting, Li BingHua, Wang ZhenSheng, Li ZhanZeng, Ma MingDong，Wang Lie, Architectural Elec, the 6rd edition in 2005