异步发电机空载建压电容值的确定方法

Self-excited capacitance of induction generator for no-load operation

为使异步发电机建立数值给定的空载电压,采用了通过优化求取建压电容的新方法。以异步发电机基值频率所对应的等值电路为基础,令等值电路回路阻抗的实部与虚部分别为零作为异步发电机稳态运行的条件,并由此计算异步空载建压电容值。用Hooke-Jeeves提出的模式搜索法来求解有约束优化问题,从而克服了传统的Newton-Raphson法稳定性差与难于处理有约束条件之弱点。论文给出了空载时建立不同数值端电压所需的电容值,计算结果与实验结果的相互吻合说明了分析方法的正确性。计算结果同时验证了饱和程度对空载建压电容值的影响,表明随着饱和程度的增加,空载建压电容值的增加幅度越来越大。

A new approach was developed to optimize the self-excited capacitance and to calculate the related no-load terminal voltage. The loop impedance expression was derived from the induction generator equivalent circuit referred to the base frequency. Setting both the real and imaginary parts of the loop impedance to zero gives the steady state performance of the induction generator, which can be used to determine the self-excited capacitance. The direct search method used to solve the constrained optimization problem is more flexible and stable than the Newton-Raphson method. The calculated self-excited capacitances for various terminal voltages are in good agreement with experimental values. The calculated results also verify the effect of saturation on the no-load self-excited capacitances and show that the incremental increase of the self-excited capacitance is much greater than that of the saturation.