Induction Machine PLECS 1.5 Online Help Induction Machine Purpose Non-saturable induction machine with slip-ring rotor. Library Machines Description This model of a slip-ring induction machine can only be used with the continuous state-space method. If you want to use the discrete state-space method or if you need to take saturation into account, please use the Saturable Induction Machine. The machine model is based on a stationary reference frame (Clarke transformation). A sophisticated implementation of the Clarke transformation facilitates the connection of external inductances in series with the stator windings. However, external inductors cannot be connected to the rotor windings due to the current sources in the model. In this case, external inductors must be included in the leakage inductance of the rotor. The machine operates as a motor or generator; the sign of the mechanical torque determines the mode of operation (positive for motoring, negative for generating). All electrical variables and parameters are viewed from the stator side. In the component icon, phase a of the stator and rotor windings is marked with a dot. In order to inspect the implementation, please select the component in your circuit and choose Look under mask from the Edit menu. If you want to make changes, you must first choose Break library link and then Unprotect, both from the Edit menu. Electrical System The rotor flux is computed as The three-phase voltages and at the stator terminals are transformed into dq quantities: Likewise, the stator currents in the stationary reference frame are transformed back into three-phase currents: Similar equations apply to the voltages and currents at the rotor terminals with being the electrical rotor position: Electro-Mechanical System Electromagnetic torque: Mechanical System Mechanical rotor speed : Mechanical rotor angle : Parameters and Dialog Box Stator resistance Stator winding resistance in ohms (). Stator leakage inductance Stator leakage inductance in henries (H). Rotor resistance Rotor winding resistance in ohms (), referred to the stator side. Rotor leakage inductance Rotor leakage inductance in henries (H), referred to the stator side. Magnetizing inductance Magnetizing inductance in henries (H), referred to the stator side. Inertia Combined rotor and load inertia in Nms. Friction coefficient Viscous friction in Nms. Number of pole pairs Number of pole pairs . Initial rotor speed Initial mechanical rotor speed in s. Initial rotor position Initial mechanical rotor angle in radians. If is an integer multiple of the stator windings are aligned with the rotor windings at simulation start. Initial stator currents A two-element vector containing the initial stator currents and of phases a and b in amperes (A). Initial stator flux A two-element vector containing the initial stator flux and in the stationary reference frame in Vs. Inputs and Outputs Mechanical torque The input signal represents the mechanical torque at the rotor shaft, in Nm. The output vector "m" contains the following 3 signals: (1) Rotational speed The rotational speed of the rotor in radians per second (s). (2) Rotor position The mechanical rotor angle in radians. (3) Electrical torque The electrical torque of the machine in Nm. Probe Signals Stator phase currents The three-phase stator winding currents , and , in A. Currents flowing into the machine are considered positive. Rotor phase currents The three-phase rotor winding currents , and in A, referred to the stator side. Currents flowing into the machine are considered positive. Stator flux (dq) The stator flux linkages and in the stationary reference frame in Vs: Magnetizing flux (dq) The magnetizing flux linkages and in the stationary reference frame in Vs: Rotor flux (dq) The rotor flux linkages and in the stationary reference frame in Vs. Rotational speed The rotational speed of the rotor in radians per second (s). Rotor position The mechanical rotor angle in radians. Electrical torque The electrical torque of the machine in Nm.