Adaptive control of uninterruptible power supply based on AC/AC Power Converter

This work deals with the problems of uninterruptible power supplies “UPS” based on the converter AC/AC built in two stages: an input stage AC/DC and an output stage DC/AC. The two blocks are joined by a continuous intermediate bus, such as power factor correction “PFC”, regulating the DC bus voltage and generating a sinusoidal output voltage. These problems have three levels of difficulty: (i) the input source alternative network side is not available, (ii) the states of the model are not all accessible to measurement, (iii) the load is unknown. The solution developed in this paper consists of three controllers one of them is adaptive. The first controller consists of a Kalman observer and control law developed by the backstepping technique from the model observed, the second controller consists of three components: (i) an observer estimating online the state of output current of the inverter which is not accessible to measurement, (ii) a control law developed by the backstepping technique from the model observed, (iii) a robust adaptation law made through a parametric projection. This robustness is necessary to deal with state estimation errors in the model.