【作者】 戚庆茹；

【导师】 陈寿孙；

【作者基本信息】 清华大学 ， 电气工程， 2004， 博士

【摘要】 电力系统的区域间互联,各种新型电力电子设备在电力系统中的应用,使得电力系统日益庞大,其结构和运行方式越来越复杂,对电力系统建模和仿真技术提出了更高的要求。如何针对现代电力系统出现的新特点,对系统中的电力电子设备建立简单而又比较准确的数学模型;如何对大系统进行仿真,解决分别采用单独的电磁暂态仿真和机电暂态仿真引起的仿真精度和速度之间的矛盾,是现代电力系统数字仿真技术研究中的重大课题。本文的重点是研究含电力电子设备的现代电力系统的建模和仿真方法。把动态相量理论推广应用到了电力电子装置建模及仿真中。结合开关函数法,动态相量法能够对电力电子设备建立统一的、连续的模型;动态相量模型是介于准稳态模型和电磁暂态模型之间一种模型,在保证精度的同时,可以大大提高仿真的速度。本文中分别对三电平STATCOM、UPFC和HVDC系统进行了动态相量建模和仿真,并将仿真结果与精确的时域仿真结果进行了对比,结果表明,动态相量法是一种有效的建模和仿真方法,它的出现和应用可以填补电力电子装置简化模型与详细模型之间的空白。兼顾含电力电子设备的大系统仿真时的精度和速度,深入探讨了基于动态相量仿真和机电暂态仿真的混合仿真。根据研究需要,将系统划分为两个区域,分别用动态相量模型和机电暂态模型来描述。通过交替迭代法实现了动态相量模型和暂态稳定程序的接口,并且在进行交替迭代时,两种模型可以选用不同的仿真步长。这种混合仿真利用了动态相量模型的精确性和机电暂态仿真的快速性,适用于大规模电力系统的仿真和分析,为含电力电子设备的现代电力系统的稳定分析和研究提供了一种新的途径和手段。论文的另一项工作是建立了含三电平STATCOM的小型输电实验系统的仿真模型,提出并实现了一种改进的空间矢量脉宽调制控制方法,解决了中点钳位型三电平换流器直流侧电容电压的不平衡问题。更多还原

【Abstract】 With the power system interconnection and application of various power electronic devices, such as FACTS devices and HVDC, modern power systems are becoming more and more huge and complicated. Traditional technology for modeling and simulation is no longer appropriate. How to describe the power electronic devices with simple but accurate models? When simulating a large-scale power system including quick transients, how to solve the conflict between precision and speed using single electromagnetic transient simulation and electromechanical transient simulation? All these are the key problems in researching on digital simulation of modern power systems.The emphasis of this dissertation is put on the study of modeling and simulation method for modern power systems including power electronic devices.The dynamic phasor theory, which is based on time-varying Fourier coefficient series, is applied to modeling and simulation of power electronic devices. Combined with switching functions, dynamic phasor method can be used to build the general and continuous model for power electronic devices. In this dissertation, the dynamic models for a 3-level STATCOM, a UPFC, and a HVDC system with dynamic phasor method are presented. Computer simulation results verified the accuracy and efficiency of the dynamic phasor models. Dynamic phasor model can be viewed as an intermediate between quasi-steady static model and detailed electromagnetic transient model, which can describe the original system accurately and improve the simulation speed. It can fill the gap between the simplified and detailed models.Hybrid simulation based on dynamic phasor simulation and electromechanical transient simulation is implemented. The power system can be divided into two parts. One is described with dynamic phasor model and the other is described with electromechanical transient model. With the alternate iterative method, the dynamic phasor model can be interfaced with the transient stability program easily. During the iterative, the different simulation time steps can be chosen in the dynamic phasor <WP=6>simulation and the electromechanical transient simulation. This hybrid simulation approach can take account of both precision and speed, which fits for large-scale modern power systems.This dissertation also relates to a lab experimental system, which is tried to model a small-scale power transmission system including a 3-level STATCOM. An improved SVPWM control strategy is presented and implemented to balance the voltages on the two DC capacitors of the NPC 3-level converter.更多还原