With Rectifier Load Induction Generator

The induction generator with a rectifier load is characterized by hard and simplestructure, high reliability, low cost, high power density. It represents the developmenttendency of the power generation block in DC supply power system. In view of theinduction generator carrying a rectifier bridge, the overall system becomes multi-loop,non-linear, variable-topology; It is of great difficulty and complexity to analysis in loopcurrent directly. The equivalent circuit of induction generators is mathematically modeledby referring the stator and rotor voltage equation to the base frequency respectively. Thisarticle introduces the power balance method, with the induction generator equivalentcircuit and relationship between DC and AC, which builds the whole system'smathematical analysis model. Using this model the analysis process is not only simple,but also accuracy. This method's validity is confirmed by the experiment.The excited capacitors of the induction generator is the base to keep the rectifysystem output voltage constant, and the capacitors value is key to keep the DC voltageinvariable. In order to determine the capacitor values under the different loads andmaintain the DC side voltage constant, A direct search method presented by Hooke-Jeevesand variable alternating approach are utilized to solve constrained optimization problemthat offers the advantages over those of Newton-Raphson's method in stability andflexibility. With the calculated capacitance, a given load terminal voltage is build up.In the view of the problem that too many harmonics exists in the circuit in theinduction generator with a rectifier system, FFT algorithm is used to calculate the ACcurrent and voltage's base values and high harmonic value in order to determine theinfluence of the DC filter inductance, and a simple RC wave-filtering analysis method isalso presented based on the traditional technique of harmonic analysis in this paper. Onthe basis of ignoring more than three harmonic, the voltage-current relationship betweenDC and AC sides and its harmonic calculating formula are utilized to construct acomplete mathematical model for analyzing the DC-AC harmonic, and the model caneffectively determine the parameter scope of the AC-side filter.