METHOD FOR ESTIMATING VOLTAGE AND REACTANCE OF ELECTRIC POWER SYSTEM

PURPOSE:To obtain easily and exactly the voltage and reactance of an electric power system by changing deliberately the operating conditions of a generator then returning the same to the original conditions and detecting the information on the operation of the generator during this time. CONSTITUTION:A generator terminal voltage VG1, generator output (available power) P1 and generator current I1 are detected while the generator is under operation in the 1st state. The generator is successively operated in the 2nd state under the deliberately changed operating conditions and the similar parameters VG2, P2, I2 are detected. The operating conditions are returned to the original conditions and the generator is operated in the 3rd state. The parameters VG3, P3, I3 are then detected. The restoration to the original state is when I1=I3 holds on condition of VG1=VG3, P1=P3. A vector diagram is drawn from these detected values and the infinite generator voltage VB and reactance Xe are determined. Then the easy and exact determination of the voltage and reactance of even the intricate power system is made possible.