| 2007 |
| Johnny Kennedy DT021 yr2 Group B 08/06/2011
Investigation of the equivalent circuit of an induction machine |
Investigation of the equivalent circuit of an Induction Machine
The objective of this experiment is to investigate the equivalent circuit of an Induction Machine (3φ AC Induction Motor), deduce the reactive and resistive elements that comprise the equivalent circuit from performing 2 tests (No Load & Locked Rotor), calculate the Stator Current, 3φ Power and Torque of the Induction Machine when it is drawing rated current and compare these values to their respective measured values.
The 3-phase AC (3φ) Induction Motor has 2 main components these being the stationery Stator and the Rotor which revolves. The Induction Machine takes in Electrical energy, this Electrical energy is used to set up an alternating Electro-magnetic field which turns the rotor and the rotor produces mechanical energy, the output energy is less than the input energy due to losses. There is no physical electrical connection between the 2 components because the Induction Machine operates by Electro Magnetic Induction, the Induction Machine shares this principle of operation with the Transformer and therefore both Electrical devices share many of the same characteristics and their respective equivalent circuits are almost identical, the equivalent circuits of both devices can be deduced by performing 2 tests on each device, the 2 tests performed on the Induction Machine are the No Load Test and the Locked Rotor Test (the No Load Test is equivalent to the Open circuit Test performed on a Transformer and the Locked Rotor Test is equivalent to the Short Circuit test performed on a Transformer).
No Load Test: The No Load Test on an Induction machine is run at the Rated Voltage of the Induction Machine. The values measured, recorded and used in the following calculations are |VNL |, |INL|,...