Study On UPS Based On Delta-Conversion Technology

With the development of power electronics, a new kind of UPS topology based on Delta-conversion technology appears. Because the UPS's have the good virtues of the traditional dual conversion UPS's and their shortcomings are conquered, they are paid high attentioned to recently. In order to promote the development of the technology, a deep research on the Delta-conversion technology UPS's is performed theoretically.In this dissertation, the analysis of the theory of Delta conversion UPS is firstly made. Based on which, this kind of Delta conversion UPS are divided into two parts: Delta inverter and main inverter functionally and structurally. an emphasis is put on the analysis and design of Delta inverter, a comparison of several kinds of control method is made explorectically, a practical control method is filtered out optimally, and a reseach on the dectection technique of the harmonic and reactive power is done. An implementation of the real-time detection of harmonic and reactive current is given based on three-phase instantaneous reactive power theory. By d-q conversion and compsrison, the instruction signal is obtained of modulation-wave voltage in which variation of harmonic wave and fundamental wave voltage is reflected.An implementation of the control of the current loop of Delta inverter and the voltage loop of the main inverter is performed by ultilizing MATLAB/Simulink as the simulation tool.