Regenerative AC Drive System with the Three-phase Induction Machine

The three phase induction machine is the most used one in electrical drives. For the electrical drives with frequent starting, stopping or reversing regimes the consumed electrical energy is important and the overall efficiency of the system decreases significantly. Nowadays the worldwide manufactures in the power converters production area proposed as an alternative solution the regenerative electrical drives. The authors propose the modular regenerative electrical drive system with the three phase squirrel cage induction machine. During braking or reversing regime the recovered electrical energy is delivered into AC grid sources. The modular topology is formed by series AC active rectifier, DC link and three-phase power inverter. The integrated regenerative drive system assures both the power quality and improving efficiency. Moreover, the power balance control increase the speed response of the control loops, and decreases the size of the DC link capacitor. The vector control in synchronous reference frame is used for both power converters: the load side and the grid side. The boost inductor design is done such that the maximum 5% total harmonic distortion (THD) of the input current (at the rated power of the AC-AC converter) was ensured. The DC capacitor design is based on the maximum allowed value of the ripple in the DC link voltage. By using the Matlab/Simulink software environment the performances of the proposed regenerative drive system in motoring and regenerating operation modes are shown.