PE3487
Electrical
- Apr 2, 2002
- 1
I would be grateful if anyone can point me to information on the derivation of the following formulae:
1.When a motor is being started, the alternator of the genset will experience a voltage dip, given by the formula, % voltage dip = (starting kVA of motor/rated kVA of alternator) x % transient reactance of alternator (xd)
2. After the 1st motor has been connected to the alternator, any subsequent starting of motors will cause a voltage dip and this voltage dip will be experienced by the 1st motor, and this motor will draw more current to maintain its output, hence increasing the voltage dip and the voltage dip is given by (1 + kVA1.Xd).kVA2.Xd
1.When a motor is being started, the alternator of the genset will experience a voltage dip, given by the formula, % voltage dip = (starting kVA of motor/rated kVA of alternator) x % transient reactance of alternator (xd)
2. After the 1st motor has been connected to the alternator, any subsequent starting of motors will cause a voltage dip and this voltage dip will be experienced by the 1st motor, and this motor will draw more current to maintain its output, hence increasing the voltage dip and the voltage dip is given by (1 + kVA1.Xd).kVA2.Xd