1.On network model design, the system and the physical basis of the network between i nput and output were well considered. The network model was transformed from "bl ack box model" to "gray box model" to a certain degree.
9.Based on the structure,an ultra-low voltage operational amplifier is designed,which provides a rail-to-rail common-mode input voltage range and output voltage swing,as well as a high common mode rejection ratio(CMRR).
10.The results show that the proposed control scheme can stabilize the output 50 Hz sine wave well,is a costeffective wave for UPS invert control system.