【作者】 陶大军；

【导师】 戈宝军；

【作者基本信息】 哈尔滨理工大学 ， 电机与电器， 2008， 硕士

【摘要】 能量变换器是一种新型高压发电机,采用高压交联聚乙烯(XLPE)电缆作为定子绕组,这种革新结构使其能够输出高电压,从而可以直接并网。因此,对能量变换器的运行进行系统地研究是极为必要的。本文针对能量变换器小值振荡和稳定性进行了深入地研究。本文首先介绍了能量变换器的发展背景和国内外的研究现状,详尽分析了研究大型同步发电机和能量变换器稳定性的意义。然后,本文对能量变换器静态稳定运行进行了分析,建立了能量变换器静态稳定运行时的数学模型,推导出了能量变换器静态稳定功率特性和静态稳定功率极限的表达式。并分析了励磁调节对能量变换器静态功率特性的影响,应用对比研究的方法,证明了能量变换器的静态稳定储备系数和静态稳定功率极限都比传统同步发电机高。本文同时结合能量变换器样机参数,系统分析了其稳态小值振荡的物理过程,推导了能量变换器小值振荡时的整步转矩系数、阻尼转矩系数和电流、转矩、电磁功率各微变量的表达式,并通过仿真分析,归纳出了不计定子电阻和线路阻抗时能量变换器相应微变量的变化规律。此外,本文对考虑励磁调节作用时小值振荡各微变量的变化进行了仿真研究,给出了此状态下相应微变量的变化规律。最后,本文对能量变换器系统在线路发生单相短路、相间短路和两相接地短路故障时的物理过程进行了分析,绘制了能量变换器正常运行和故障运行时的电气图与等值电路,结合等值电路推导了能量变换器相应故障状态下的功率表达式,并通过仿真分析与对比研究,给出了能量变换器系统在线路发生单相短路、相间短路和两相接地短路故障时的极限切除时间,得到了能量变换器的动态稳定极限。本文所得结论对能量变换器合理可靠的设计及运行提供了依据,具有一定的理论意义和实用价值。更多还原

【Abstract】 Powerformer, using XLPE (cross-linked polyethylene) as the stator windings, is a new kind of high voltage generator, this innovational structure enable it to generate high voltage and connect to the power grid directly. So, it is very necessary to study the operation of Powerformer systematically. In this paper, the small oscillation and stability of Powerformer is studied thoroughly.Firstly, the developing background and study state at home and abroad are introduced in this paper, and the significance of stability research for large synchronous generator and Powerformer is analyzed detailed.Then, the static operation state of Powerformer is analyzed, and the mathematical model of static operation state for Powerformer is built, the expressions of static power characteristic and static stability power limit for Powerformer are deduced. The influence of field regulation on the static power characteristic of Powerformer is analyzed, and it is proved that the static stability reserve factor and static stability power limit of Powerformer are all higher than that of conventional generator with comparative research method.At the same time, the physical process of steady small oscillation is analyzed systematically based on the parameters of the Powerformer model, some expressions of Powerformer are deduced such as synchronizing torque coefficient, damping torque coefficient and the small changes of current, torque, electromagnetic power, and the variable rule of the corresponding small changes variables of Powerformer is induced by simulation without the consideration of the stator resistance and the line reactance. Besides, the changes of small changes in volume of small oscillation are studied by simulation under the consideration of the function of field regulation in the paper, and the variable rule of the corresponding small changes in this state are presented. Finally, some physical processes of Powerformer system are analyzed respectively when the line breaks down because of one phase to ground fault, phase to phase fault and two phases to ground fault, the electric drawings and equivalent circuits are plotted when Powerformer runs in normal state and fault state, after that, the expressions of power are deduced based on the equivalent circuits when Powerformer system runs in fault state, and the circuit fault removal times of the one phase to ground fault, phase to phase fault and two phases to ground fault for Powerformer system are presented with simulation analyses and comparative study, with the studies above, the dynamic stability limit is obtained.The conclusion of this paper provides some basis for the reliable design and operation of Powerformer, having certain theoretical significance and practical value.更多还原