Devise And Realization Of The Parallel Converter On Series-Parallel Compensated UPS

With the development of information technology, UPS is gradually being used in realms of bank, security, military, medical service, navigation and etc. As the bound of application extend, the demand for UPS is increasingly higher. A new set of high performance UPS is called out. Series-parallel compensated UPS, which could be able to research separately. This dissertation aims to do some research on parallel part of this new kind of UPS, exploring some valuable and new characteristic.Firstly, the paper introduces the configuration of series-parallel compensated UPS, and put forward a direct current scheme to control the parallel compensated inverter a sinusoidal voltage source.Secondly, at the third chapter, the mathematical model of three-phase inverter in abc coordinate,αβcoordinate and dq coordinate are derived too. It is addressed that according to the coordinate transformation, the model of three-phase inverter in abc coordinates can be transformed into a phaseαinverter andαphaseβinverter which are both in the same form. The coupling of the three-phase inverter in abccoordinates is eliminated and the design of controller is simplified.Based on direct current scheme, the dissertation uncovers the rules on active power flow and on active power balance. In order to insure that the parallel compensated part could output a excellent sinusoidal voltage waveform which has the same phase as the net, we select and ascertain the dual-loop with repetitive function as the final control method. Then, follow this way, we adopt pole-placement means to devise the control system of the parallel compensated inverter.Finally, simulation and experiment are made to verify that with this composite method of control, the parallel compensated inverter owns wonderful performance even if in worst condition.