For the system in the diagram D. The line current at startup. Use this per-phase equivalent circuit: Apply Ohm's law, note that slip is equal to 1 at startup and the resulting current is complex. Show the current in polar form. E. The starting torque. For each phase, Tstart = Pin/ധs , and the input power is the "line current squared times the equivalent rotor resistance given as 0.25/slip with slip = 1 at startup." F. Find the full-load current with a star starter and the power factor. Use Ifl = VL/Zeq, VL from the above circuit, and Zeq must include the slip calculated in problem 4. Show the complex current in polar form G. Determine the full-load torque. The suitable formula for the full-load torque is derived as: Tfl = (per phase x 3) Ifl2 x Req / (ധs x slip). Req is the sum of all the resistive impedances from the above circuit. Get the synchronous speed, and slip from problem 4. Note: From Problem 4: Synchronous Speed Ns = 1800 rpm Slip s = 2.5%
For the system in the diagram
D. The line current at startup. Use this per-phase equivalent circuit:
Apply Ohm's law, note that slip is equal to 1 at startup and the resulting current is complex. Show the current in polar form.
E. The starting torque. For each phase, Tstart = Pin/ധs , and the input power is the "line current squared times the equivalent rotor resistance given as 0.25/slip with slip = 1 at startup."
F. Find the full-load current with a star starter and the power factor. Use Ifl = VL/Zeq, VL from the above circuit, and Zeq must include the slip calculated in problem 4. Show the complex current in polar form
G. Determine the full-load torque. The suitable formula for the full-load torque is derived as:
Tfl = (per phase x 3) Ifl2 x Req / (ധs x slip). Req is the sum of all the resistive impedances from the above circuit. Get the synchronous speed, and slip from problem 4.
Note: From Problem 4:
Synchronous Speed Ns = 1800 rpm
Slip s = 2.5%
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