Analytic computation for steady states of loaded self-excited induction generators

Abstract

Based on the state-space mathematic model obtained from the transient equivalent circuits in two-phase stationary reference frame of the loaded self-excited induction generator, a holistic analysis approach using Lyapunov stability theory was proposed for the whole of transient and steady state process of self-excitation buildup. According to the approach, it was obtained the steady-state conditions for self-excitation buildup represented by the transient mathematic model. The limit cycle condition was solved to get analytic formulas of the stator frequency and rotor speed, as well as the load ranges and analytic relationship of the magnetizing inductance for self-excitation buildup. In order to solve the steady-state operating point condition, an equivalent transformation method based on the physical occasion was presented to analytically compute all the points. The example analysis tested and confirmed only a set of analytic formulas. Good agreement between measured and computed results verified correctness, scientificalness and high validity of the steady-state conditions analytic formulas, showing universality and referenced value in engineering. It was solved the problem of the transient and steady state operating performance of induction generators unable to be analytically computed for a long time. The approach could be applicable to performance analysis of other power systems of dynamics.