Advanced nonlinear control of three phase series active power filter

The problem of controlling three-phase series active power filter (TPSAPF) is addressed in this paper in presence of the perturbations in the voltages of the electrical supply network. The control objective of the TPSAPF is twofold: (i) compensation of all voltage perturbations (voltage harmonics, voltage unbalance and voltage sags), (ii) regulation of the DC bus voltage of the inverter. A controller formed by two nonlinear regulators is designed, using the Backstepping technique, to provide the above compensation. The regulation of the DC bus voltage of the inverter is ensured by the use of a diode bridge rectifier which its output is in parallel with the DC bus capacitor. The Analysis of controller performances is illustrated by numerical simulation in Matlab/Simulink environment

Adaptive nonlinear control of single-phase to three-phase UPS system

This work deals with the problems of uninterruptible power supplies (UPS) based on the single-phase to three-phase converters built in two stages: an input bridge rectifier and an output three phase inverter. The two blocks are joined by a continuous intermediate bus. The objective of control is threefold: i) power factor correction “PFC”, ii) generating a symmetrical three-phase system at the output even if the load is unknown, iii) regulating the DC bus voltage. The synthesis of controllers has been reached by two nonlinear techniques that are the sliding mode and adaptive backstepping control. The performances of regulators have been validated by numerical simulation in MATLAB / SIMULINK

Output-Feedback Nonlinear Adaptive Control Strategy of Three-phase AC/DC Boost Power Converter for On-line UPS Systems

International audienceIn this paper, the problem of controlling three-phase boost power converter is considered for charging the battery in uninterruptible power supply (UPS) systems. The control objective is twofold: (i) ensuring a satisfactory power factor correction (PFC) at the grid-UPS connection; (ii) guaranteeing a tight regulation of the DC output voltage despite of load uncertain. The considered control problem entails several difficulties including: (i) the numerous state variables that are inaccessible to measurements; (ii) the uncertainty that prevails on some system parameters. The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of the Lyapunov control design technique. The inner-loop ensures the PFC objective and involves an adaptive observer estimating the grid phase currents, the magnitude of the parameters grid phase voltages and the load resistance. The estimation is only based on the online measurements of DC output voltage. The outer-loop regulates the DC output voltage up to small size ripples