中文摘要：

为实现并联UPS系统中负载电流的均分和环流的抑制，阐述了一种应用于模块化UPS并联系统的数字化控制均流技术。给出了并联系统的结构；通过分析并联系统环流、功率调节特性、并联系统数字功率检测技术，得到一种新型的功率检测方法；检测和分析并联系统的瞬时平均电流和各个UPS模块输出电流，再反馈调节分别控制输出电压幅值和相位以实现其均流控制。实验证明该环流抑制控制策略可获得良好的并联均流特性，方案简洁、实用。

英文摘要：

In order to share the load and restrain circumfluence, a digital current sharing control technique for modularized UPS parallel operation is investigated in detail, and the structure of parallel system is presented. The modularized UPS parallel operation uses the distributed-logical-control, where each parallel operating inverter is at equal position in the parallel system. So it has better reliability. Based on the analysis of circumfluence of paralleled system, characteristics of the power regulation and a novel digital power detection technique are deduced. With measur- ing and analyzing the instantaneous average current of all modules and the output current of each UPS module in the parallel system, both of current components are used to feedback control and regulate the amplitude and the phase of the output voltage with DSP controller. In this way, the control of current sharing in the modularized UPS paralleling system is realized. The proposed current sharing control technique and the good characteristic of restraining circumfluence were verified by the experimental results. The control strategy has advantages of simple, high practicality.