【作者】 鄂志君；

【导师】 房大中；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2008， 博士

【摘要】 随着大规模区域互联电网的逐步形成以及大量电力电子装置在电力系统中的应用,电力系统的运行与控制变得越来越复杂。在电力系统动态安全分析中采用精确仿真模型和快速仿真技术的需求越来越迫切。针对我国电力系统的发展要求,本论文重点研究了基于动态相量技术的电力系统元件建模和仿真以及电力系统混合仿真算法,其主要内容如下:推导了电力系统基本元件电感、电容和发电机的动态相量模型,结合三相分布参数线路的动态相量模型对实际系统进行了仿真。分析了基于梯形法的动态相量仿真的数值振荡问题,结合现有的算法和动态相量法的特点,讨论了基于临界阻尼调整法(CDA)的动态相量法。在现有模型的基础上,对三相分布参数线路的动态相量模型进行了改进,提出了考虑线路损耗的精确模型和大步长模型。通过与电磁暂态模型仿真结果的比较,验证了动态相量法能突破仿真步长的限制,用于仿真三相分布参数线路上的电磁暂态过程。使用动态相量建模原理,提出了一种晶闸管控制电抗器TCR的动态相量模型。该模型只考虑了对TCR动态特性影响较大的谐波分量,忽略了其余高阶分量,能快速准确地模拟器件的动态特性。使用开关函数模拟TCR的开关动作,能够反映TCR的非线性特性。并通过静止无功补偿器(SVC)和可控串补(TCSC)动态相量模型仿真验证了TCR模型的有效性。利用SVC动态相量模型,提出传统相量和动态相量模型的(TSP-DP)混合仿真算法,基于网络分割的思想,SVC使用动态相量进行电磁暂态仿真,并嵌入到外部网络的机电暂态仿真中来实现整体网络的机电暂态与动态相量混合仿真。通过实际系统上的仿真验证了算法的有效性。对动态相量模型和电磁暂态模型(DP-EMTP)混合仿真进行了初步研究,分析了混合仿真中的网络等效、曲线拟合和相位偏移等关键问题。在实际系统上进行了仿真,验证了DP-EMTP混合仿真能够准确地反映实际电力系统的快速暂态过程。更多还原

【Abstract】 With the gradual interconnection of large-scale regional power systems and application of electronic devices, the operation and control of power systems are becoming more and more complicated. There is an urgent need for a quick digital simulation technique with accurate models for power system dynamic stability assessment (DSA). This research was motivated by the progressing demand of power system. And the key research on the modelling and hybrid simulation of power system using dynamic phasors wae implemented in this dissertation. The main results of the dissertation are summarized as follows.The dynamic phasor models of basic devices such as conductor, capacitor, three-phase distribution parameter lines and generator are developed in this dissertation. The simulation of practical power systems is implemented with these models. The numerical oscillation of dynamic phasor simulation based on trapezoidal integrator is analyzed. In this dissertation, dynamic phasor method based on the critical damping adjustment (CDA) is developed to eliminate the numerical oscillation caused by the changes of the network configuration.Based on the former research, the dynamic phasor model of three-phase distribution parameter lines is improved in this dissertation. A novel large step size model which takes line loss into consideration is introduced to accelerate simulation speed further. By comparing with EMTP model, it is obvious that the new model can overcome the maximum step size constraint of regular transmission lines and be used to simulate the fast electromagnetic transient phenomena at a higher speed.As for the electronic device, the dissertation developed a new model of Thyristor-controlled reactor (TCR) using dynamic phasor modelling mthod. By truncating the less important higher order terms and keeping the significant ones, the dynamic phasor models of TCR can realistically simulate its nonlinear characteristic with fast speed and high accuracy. The operation of anti-parallel-connected thyristor pair is simulated by switching function which simplified the model deduction. Then based on the TCR dynamic phasor model, static VAR compensator (SVC) and thyristor-controlled series capacitor (TCSC) dynamic phasor models are implemented to valuate the TCR model.A hybrid simulation algorithm based on SVC dynamic phasor model proposed in this dissertation is implemented to effectively accelerate the simulation speed of power system including nonlinear devices. Based on network decomposition method, the external subsystem is represented with conventional quasi-steady state model. And SVC is simulated using DP model and interfaced into conventional transient stability program (TSP) as electromagnetic subsystem. Subsequently, the TSP-DP hybrid simulation of whole system is accomplished.The preliminary research on the hybrid simulation of dynamic phasor and electromagnetic transient program (DP-EMTP) was performed and implemented with the proposed DP models. The key problems during the hybrid simulation are discussed, which including the network equivalent, weighted curve-fitting and phase offset caused by frequency mismatch during the interactions. Case studies on the test systems were performed to assess the performance of the DP models and verify the effectiveness and efficiency of DP-EMTP hybrid simulation. By the comparison and analysis of simulation results, it is obvious that the DP-EMTP hybrid method can be practically used for fast trasnient simulation of power systems.更多还原