《《[Useful]Sensorless double-inverter-fed wound-rotor induction-machine drive》.pdfVIP

86 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 1, FEBRUARY 2006 Sensorless Double-Inverter-Fed Wound-Rotor Induction-Machine Drive Gautam Poddar and V. T. Ranganathan, Senior Member, IEEE Abstract—The basic operation of a wound-rotor induction- I. INTRODUCTION motor drive fed by inverters on the stator as well as the rotor side is discussed. Different modes of operations are defined and HE wound-rotor induction motor offers the possibility of explained based on power flow on both the sides of the machine. Tfull control on both the sides (stator and rotor) of the The sensorless motor control scheme consists of V /f -type direct machine to an equal extent. This is an important feature because frequency control on one side, with either vector control or direct it gives more freedom of operation as an electric drive. torque and flux control on the other side. The machine operates up to twice the rated speed in either direction, with full flux and The configuration of a grid-connected wound-rotor torque, thereby producing up to twice the rated power. Novel induction-motor drive that is popular today is shown in frequency profiles are proposed, which ensure that the frequency Fig. 1. In this configuration, the stator side is directly on either side never drops below a minimum value (set at 12 Hz connected to the grid and the rotor side is connected to the in this work). Therefore, the estimation of flux can be simply and back-to-back insulated gate bipolar transistor (IGBT) inverters reliably carried ou