Single-phase Ups Inverter Interconnect Parallel

With the increasingly height requirement of UPS reliability and capacity, UPS connection in parallel redundancy technology becomes the important development direction of UPS. At present, UPS invert is still the most developed and widely applied UPS. Therefore, it is very important to do research on UPS invert connection in parallel technology. Invert non-interconnection line parallel technology has some advantages. For example, it smoothes out ordinary point fault because each invert is independent respectively, is more reliable, owns no complex connection line and saves more spaces etc.. It attracts more widely attentions and becomes the hottest research project at present.This thesis mainly puts forward optimization droop arithmetic based on traditional lop characteristics control method. This method could decrease the effects of flow equalization brought by link impedance inequivalence.The main content of this dissertation introduces the control tactics and connection in parallel method of invert, minutely constructs the model of UPS invert, LC output filter and each step of voltage and electric current hexagon control invert design method, chooses suitable parameters and use the simulations to prove the correctness of the chosen parameters. It has analyzed the effect of lop flow equalization control caused by link impedance inequivalence. Ordinary droop characteristics control method could only realize the agreement of output voltage phase position, but it could not make output voltage amplitude peak equal. In this case, the amplitude of system's active power and reactive power could not realize flow equalization. The optimization arithmetic of rectifying the amplitude droop parameter put forward by this thesis allow the amplitude lop parameters of paralleled operation invert outputting active and reactive power rectified according to the effective value of output voltage. It constructs the model of parallel system signals for the invert parallel operation and analyzes the system's stability by the small-signal transfer function.Finally, optimization tactics put forward and the designed parameters are feasible by prove of simulations. This tactics could make the system realize flow equalization better and dynamic state faster and output more stable.