Experiment No.1 THE WOUND ROTOR INDUCTION MOTOR OBJECTIVE To examine the construction of the three-phase wound-rotor induction motor. EQUIPMENT REQUIRED: Power Supply Wound rotor Induction Machine, Electrodynamometer, AC Ammeter and AC Voltmeter Connection leads PROCEDURE: CAUTION! High voltages are present in this Experiment! Do not make any connections with the power on! The power should be turned off after completing each individual measurement! 1. Examine the construction of the Three-Phase Wound-Rotor Induction Motor, paying particular attention to the motor, slip rings, connection terminals and the wiring. 2.Viewing the motor from the rear of the module: a. Identify the three rotor slip rings and brushes. b. Can the brushes be moved? (Yes/No) c. Note that the three rotor windings are brought out to the pering the rotor shaft. via a slot in d. Identify the stator windings. Note that they consist of many turns of small diameter wire evenly spaced around the stator. e. Identify the rotor windings. Note that they consist of many turns of slightly larger diameter wire evenly spaced around the rotor. f. Note the spacing of the air gap between the rotor and the stator. 3. Viewing the front face of the module: EEL 3003 ELECTRICAL MACHINES 1 a. The three separate stator windings are connected to terminals. Sand and b. What is the rated current of the stator windings? 0.7 c. What is the rated voltage of the stator windings? 240 d. The three rotor windings are (wye, delta) connected. e. They are connected to terminals, 7,8,9 and f. What is the rated voltage of the rotor windings? 120 V g. What is the rated current of the rotor windings? IA h. What is the rated speed and mechanical output power of the rotor? Speed= 1315 r/min 175 W 14 a and 2 cover obj Theor Analysis concl Power= Review questions: 1. Knowing that the voltage induced in the rotor winding is zero when it is turning at synchronous speed, what is the synchronous speed of your motor? P= 120f hs MME Synchronous speed = r/min. Fe = NP 50 Hz nsx 4 120 120 ns= 1500 VPS 2. Knowing that the equation for synchronous speed is: S= ns-hr N₁ = 120f/P where: Ns synchronous speed (r/min) f power line frequency (Hz) hy P = number of stator poles determine the number of poles in your motor. EEL 3003 ELECTRICAL MACHINES