A simple DC bus voltage control method for self excited squirrel cage induction generators

With increasing rare earth prices and the claim for cost effectiveness of electrical drive trains especially induction generator solutions might turn into focus as preferable alternative to permanent magnet synchronous generators, even in spite of the lower power density. But an induction generator requires reactive power either provided by capacitors or by a self commutated power converter to ensure excitation. This article gives profound information on the fundamentals of the steady state operation of an induction machine operated by a voltage source power converter, VSC. Based on these fundamentals a very simple control law for the DC bus voltage of a power converter operated as active rectifier is proposed and validated by experiment. No vector calculus is needed and as it only requires the speed information (no current measurement is needed) this method can be considered as a contribution to robust drive control / condition monitoring with a common field oriented current control method possibly running in parallel.