凸极永磁同步发电机内阻抗特性对电压调整率的影响分析

Analysis for the Impacts of Internal Impedance Characteristic on Voltage Regulation Rate in a Salient-pole Permanent Magnet Synchronous Machine

通过相量法建立起永磁同步发电机的内阻抗数学模型,研究了内阻抗特性及其对电压调整率的影响。研究结果表明,发电机内阻抗具有电流和功率因数角负反馈特性,使得电压调整率在一定程度上得到改善。感性负载下的改善更多受益于发电机内阻抗的功率因数角负反馈。中、低功率因数下电压调整率的改善效果主要取决于直轴反应电抗,阻性和近阻性负载下取决于交轴反应电抗。根据数值计算和分析确定了获得最佳电压调整率时电枢反应电抗的变化范围。实验测量表明,电枢反应电抗处于最佳区域内可使电压调整率得到明显改善。

The internal impedance characteristic analysis of the permanent magnet synchronous machine is presented,especially used to analyzing the voltage regulation rate of the machine.An internal impedance mathematic model of the machine is built with phasor analysis method for studying the relationship between voltage regulation rate and armature reactance by numerical calculation.The research results demonstrate that the internal impedance of machine has both current and power factor angle feedback characteristic,which makes the voltage regulation rate be improved to a certain extent.The improvement of voltage regulation rate more benefits from power factor angle feedback under condition of inductive load and the improved effect mainly lying in d-axis armature reactance in the condition of middle and low power factor,and lying in q-axis armature reactance under resistive load.Additionally,an optimal variation range of the armature reactance in which there is less voltage regulation rate is put forward with numerical calculation and analysis.Experimental results with a downhole turbine-alternator show that the voltage regulation rate could be improved obviously when the armature reactance is in the range of optimal area.