【作者】 李鹏；

【导师】 王成山；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2010， 博士

【摘要】 暂态仿真是认知分布式发电微网系统中快动态过程的重要手段,也是揭示系统中各种暂态相关问题的基础,实现分布式发电微网系统的暂态仿真具有十分重要的理论意义与工程应用价值。论文围绕仿真程序的建模能力、计算求解的数值精度及仿真计算的速度与效率三个方面开展工作,研究适用于分布式发电微网系统暂态仿真的相关模型与仿真方法,提出了基于节点分析的暂态仿真的基本框架,设计并实现了暂态仿真程序。论文具体工作如下:(1)结合系统的建模需求,提出了扩展暂态仿真程序建模能力的方法,包括:采用增广改进节点方程扩展了电气系统的建模能力;提出并实现了基于自动微分技术的静态非线性特性元件暂态仿真建模方法,特别适于各种具有复杂静态非线性特性的分布式电源及储能元件的建模。算例表明暂态仿真程序提供了充分的系统底层建模能力,能够满足分布式发电微网系统暂态仿真的建模需求。(2)研究了改善暂态仿真程序计算求解精度的方法,包括:实现了基于牛顿法的控制系统精确求解;提出了一种用于电力电子电路仿真的电气系统插值算法。仿真算例的研究表明,基于文中提出的各种算法,程序具有较高的仿真计算精度与较好的数值稳定性。(3)研究了提高暂态仿真程序计算速度与效率的方法,包括:采用伪牛顿法加快了控制系统的计算速度;提出了一种易于实现的电气系统与控制系统并行求解策略;提出了一种改进的电气系统与控制系统并行求解策略,改善了并行算法的计算精度;提出了基于自然解耦特性的控制系统并行求解策略,进一步加快了程序的计算求解速度。仿真算例表明,综合应用文中提出的各种算法,基于并行实现的程序计算速度相对于单线程的串行程序最多可提高2倍以上。(4)基于本文开发的暂态仿真程序,选取典型的分布式电源及相应的控制策略,实现了包括光伏发电系统、固体氧化物燃料电池发电系统及微型燃气轮机发电系统在内的各种分布式发电系统的建模与暂态仿真,考察了它们在并网和独立运行时出现环境条件改变、系统外部故障及功率输出变化等各种扰动时系统的暂态过程;在上述工作基础上,对含多种分布式电源的微网算例系统进行了仿真分析。通过与各种商业仿真工具的比较,验证了本文提出的各种算法的正确性和有效性。更多还原

【Abstract】 Transient simulation of the distributed energy resources powered micro-grid is the foundation to understand the fast dynamic characteristics and to reveal the various related transient problems in the system. The implementation of transient simulation is considered to be of great scientific and engineering significance. The models suitable for the transient simulation are studied. The algorithms for detailed transient simulation are studied repectively from modeling capability, accuracy improvement and simulation efficiency Nodal analysis based electromagnetic simulation methodology is employed to design the transient simulation program - TSDG. The work in this dissertation is summarized as follows:1) According to the modeling requirement of the transient simulation, methods to extend modeling capability of electrical system and control system are studied. Modified augmented nodal analysis is used to extend modeling capability of electrical system. Automatic differentiation is adopted to realize the modeling of static nonlinear element in control system, especially for complex nonlinear characteristics dominated DG and energy storage elements. Case studies show that TSDG provides sufficient low-level modeling capability, it can totally meet the requirement of the transient simulation.2) Algorithms on improving simulation accuracy are studied as well. Newton method is applied on obtaining precise solution of control system. An interpolation scheme of electrical system is presented for power electronic circuit simulation. Case studies show that TSDG is with highly accuracy and well numerical stability as the algorithms adopted.3) Methods for accelerating transient simulation are studied. Pseudo Newton method is applied on accelerating the speed of control system solving. A parallel solving strategy of electrical system and control system is proposed with the merit of easy-realization. An improved parallel solving strategy is presented to enhance the accuracy of the former algorithm. With the characteristics of naturally decoupling of DGs and its controller, a parallel solving strategy for control system is presented. Case studies show that the parallel version of TSDG can achieve at most two times faster than the series one in some cases as the algorithms adopted. 4) Transient simulation of typical DG systems, including PV generation system, fuel cell generation system and micro-turbine generation system, are realized with proper control strategies. Mostly encountered large signal disturbances are considered in the cases. Transient simulation of European LV micro-grid with multiple DGs is accomplished to validate the effectiveness of the methods presented. For all the cases, the results of TSDG are compared with that obtained from various electromagnetic transient simulation tools.更多还原