摘要
为解释独立小容量供电系统中小容量同步发电机组带非线性负载能力差的原因,分析了谐波电流流过同步发电机的电枢绕组时其内部磁场的变化,用数学表达式描述了磁场的脉动情况并计算出该磁场的能量,从能量守恒的角度利用虚位移法推导出电磁转矩在电枢电流含有谐波时的解析式。给出一基于Matlab模型的算例,运用算例说明了谐波电流会给同步发电机的电磁转矩带来脉动分量,进而解释了同步发电机组带非线性负载能力差的原因和产生剧烈机械振动的机理。
In order to explain why the synchronous generator group with small and medium-capacity has a poor ability to support the non-linear load in the independent small-capacity power supply system,this paper analyzed how the harmonic current can influence the magnetic field inside the synchronous generator,and also gave a mathematical expression to depicte the pulsation of magnetic field and to calculate its energy.A formula which can describe the electromagnetic torque pulsation containing the harmonic currents was deduced from the energy conservation law by using virtual displacement method.An example based on Matlab model was given.The example shows that the harmonic current will bring pulsation to the electromagnetic torque and explain the mechanism of how synchronous generator with poor ability to support the non-linear load vibrates under the distortion of harmonic current.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2014年第1期67-71,共5页
Proceedings of the CSU-EPSA
关键词
谐波电流
同步发电机
电磁转矩
小容量电源
磁场
非线性负载
harmonic current
synchronous generator
electromagnetic torque
small-capacity power
magnetic field
non-linear load
