航空发电机容性负载自激励条件分析

Self-excitation analysis of aeronautical generator with capacitive load

多电飞机使用电能取代传统飞机的液压能和气压能,导致供电系统的非线性负载增加,常采用电容滤波改善非线性负载对供电质量的影响,形成电网的容性负载.本论文研究容性负载可能导致的发电机自激励问题.首先研究了导致航空发电机自激励的容性负载的条件,然后分析了转子的凸极结构对自激励特性的影响.通过推导得到了以负载阻抗和负载容量表示的发电机的自激励条件,并且分别从负载阻抗、负载容量以及电网功率因数的角度给出了防止发电机自激励的判据.最后,通过典型航空发电机系统的仿真以及样机原理性试验,验证了自激励条件的准确性.

More-electric aircraft use electricity to replace the traditional aircraft’s hydraulic and pneumatic energy,results increasing of nonlinear load in power supply system.The capacitive filtering are often used to improve the nonlinear power supply quality,thus forming the capacitive load on the grid.This paper investigates the problem of self-excitation of generators caused by capacitive loads.First,the conditions of the capacitive load that lead the aero-generators turn into self-excitation are analyzed.Then,the influence of salient pole structure of the rotor on the self-excitation characteristics is analyzed.Third,the self-excitation conditions of the generator which are expressed by load impedance and load capacity,are obtained by derivation.The criteria for preventing self-excitation of the generator are given respectively from the aspects of load impedance,load capacity and power factor.Finally,the accuracy of the self-excitation condition is verified by the simulation of a typical aeronautical generator system and prototype test