如何正确处理“1+1”UPS并机系统供电系统与备用发电机间的容量匹配问题(1)

Deal Properly with the Compatibility Between the Capability of the Generator and the Parallel-redundant UPS System

在空管系统用的供电系统中,常采用由"市电+发电机+电力稳压器+UPS并机系统"组成的供电系统的设计方案。在选用110kV·A的柴油发电机来向处于轻载运行条件下的80kV·A"1+1"UPS并机系统供电时,不但无法使发电机组进入正常的工作状态。还可能导致"1+1"UPS并机系统进入"输出停电"的故障状态。面对如何解决UPS并机供电系统与备用发电机之间的容量匹配问题时,常倾向于将由6脉冲整流型UPS所产生的电流谐波"污染"(THDI约为32%)归结为导致发电机的输出功率必须增大的惟一根源。为保险起见,在UPS供电系统的设计中、常采用"过份地"增大发电机输出功率的办法来解决此问题,从而导致机房建设成本不必要的增大。相关的统计和分析表明,可能导致发电机容量增大的因数有:①UPS所产生的电流谐波污染和电压谐波污染;②电力稳压器所产生的开机启动浪涌电流。相关的测试数据表明:导致这台发电机组"异常工作"的主要原因,是来自电力稳压器的"开机启动"浪涌电流,而不是来自UPS并机系统的输入电流/谐波电流。

The design scheme of the utility power supply＋generator＋automatic servo-control regulator ＋“ 1＋1＂type of the parallel-redundant UPS system is usually applied in the power supply system of the civil aviation system. In the past,The current harmonic pollution of controlled SCR rectifier of UPS（THDI〉32 %） is often attributed to the only cause for increasing the caloability of the generator. However, the related statistics and analysis show that it results from the following factors. （a） the current harmonics and voltage harmonics generated by UPS. （b）the surge current of automatic servo-control regulators during the start-up. It was found that major reason for abnormal operation of the generator results from the surge current of regulator, instead of the current harmonics of the paral- lel-redundant UPS system. In order to solve above-mentioned problem, the following technical measures are adopted, the decrease in time span of the start-up between two sets of the regulators; the increase in output voltage range of the regulators and a slight increase in the capability of generator.