Research on a novel digital parallel current sharing control technique of modularized UPS

In order to share the load and restrain circumfluence, it is described that a digital current sharing control technique for modularized UPS parallel operation in detail in this paper, and the structure of parallel system is presented. Based on the analysis of circumfluence of paralleled system, characteristic of the power regulation, a novel digital power detection technique is deduced. With measuring and analyzing the instantaneous average current of all UPS modules and the output current of each module, both of current components are used to control and regulate the amplitude and the phase of the output voltage. In this way, the control of current sharing in the modularized UPS paralleling system is realized. The proposed control technique has been verified the good characteristic of restraining circumfluence by the results of the experiment. The control strategy has advantages of brevity, high practicality.