Generator means of voltage regulation controls the output voltage . The three-phase voltage regulator the output voltage , the voltage of its average value is compared with the set . Regulator to obtain energy from the internal auxiliary power generator , usually coaxial with the main generator of small generators, DC power transmitted to the generator rotor magnetic field excitation coil. Coil current up or down to control the magnetic field generator stator coils ( called electromotive force or NMF size.
Current induced by the stator coil voltage drop I × Z represents the voltage vector . It is actually the two voltage vectors and the smaller , the two voltage vectors with the I -phase and the voltage drop with the resistance 90 ° ahead of the inductive voltage drop . bsfs-3k because the force must be equal to the voltage drop across the internal resistance of the generator and the output voltage and that is equal to the vector d and I × Z and a vector . Generator stator coil resistance, because the assumption is purely inductive load , the amount of current in phase I hysteresis voltage inch just 90 ° electrical phase angle.
For with the same force watt inductive load capacitive load is generated when the generator output voltage inches high , the voltage regulator must significantly reduce the magnetic field of the stator coils. In fact , the voltage regulator may not have sufficient range of adjustment to regulate the output voltage. Because the rotor of the generator comprises a permanent magnetic field of the permanent magnetic field in one direction continuously , even if the voltage regulator is fully closed , the rotor electromotive force generated by the permanent magnetic field remain continuous enough to charge the capacitive load .
     When the diesel generators with a non-linear loads ( including leading or lagging power factor of the load , as well as with higher input harmonic current load ) , the work will harm the stability of diesel generators . In the distribution system , the load parameter adjustment of this nature have AC voltage regulator , UPS and speed motor with a rectifier filter input and so on. This is a typical R, L, C series circuit , the nature of the load and load variation during the series resonance is likely to occur , resulting in substantial changes periodically diesel generator output voltage and frequency.