基于网络分割的电力系统机电暂态仿真方法研究

发布时间：2018-07-25 07:20

【摘要】：随着电网规模的不断扩大,电力系统暂态仿真的难度也逐渐提高,因此,对基于网络分割方法的机电暂态仿真方法的研究对现代电力系统有着重要的意义。本文根据机网分割和网络区域分割两种方法,对基于恒阻抗负荷的电力系统机电暂态仿真的方法就进行了深入的研究和分析。基于发电机实用模型,利用梯形数值积分法,建立了用于电力系统机电暂态仿真的发电机组时域离散等值模型。模型变量由发电机机端电压和电流组成。在x-y轴坐标系中,该模型的导纳参数随发电机功角变化。这将导致电力系统的机电暂态仿真方程系数矩阵随各发电机功角而变化,加大了仿真的计算量。为此,提出了发电机组的近似等值模型,模型结构由导纳参数和电流源并联形式构成。该模型消除了发电机组等值模型导纳参数随功角变化的因素,减少了仿真的计算量。基于电力网络的恒阻抗负荷模型,研究了机网分割的电力系统机电暂态仿真算法。通过切割发电机组与电力网络的连接线路,将系统分解为发电机子系统和由恒阻抗负荷组成的电力网络子系统。利用线性网络等值方法建立了由恒阻抗负荷组成的电力网络等值建模。给出了由发电机等值模型和电力网络等值模型以及由发电机近似等值模型和电力网络等值模型组成的互联系统的计算方法。考虑电力系统的区域互联特性,利用分裂节点电位法将电力系统分解为若干个区域子系统。区域子系统由发电机和恒阻抗负荷组成。基于发电机组的等值模型和近似等值模型,研究了区域子系统等值模型的建立方法,并以此研究了由区域子系统等值模型组成的互联系统的计算方法。以新英格兰10机39节点系统为例,基于恒阻抗负荷,对提出的子系统等值模型和分裂算法进行了仿真验证。在不同的故障类型下,通过与PSASP仿真结果的对比,验证了提出的模型与方法是正确的,且具有较好的数值计算精度和稳定性。提出的电力系统机电暂态仿真方法易于实现并行计算。
[Abstract]:With the continuous expansion of power network scale, the difficulty of power system transient simulation is gradually increased. Therefore, the research of electromechanical transient simulation method based on network segmentation method is of great significance to modern power system. In this paper, the electromechanical transient simulation method of power system based on constant impedance load is deeply studied and analyzed according to the two methods of network segmentation and network area segmentation. Based on the practical generator model and the trapezoidal numerical integration method, the time-domain discrete equivalent model of generator set for electromechanical transient simulation of power system is established. The model variable consists of generator terminal voltage and current. In the x-y axis coordinate system, the admittance parameters of the model vary with the generator power angle. This will lead to the change of the coefficient matrix of the electromechanical transient simulation equation with the power angle of the generator, which increases the computational complexity of the simulation. In this paper, an approximate equivalent model of generator set is proposed. The model structure is composed of admittance parameters and current source in parallel. This model eliminates the factor that the admittance parameter of the equivalent model of generator sets varies with the power angle, and reduces the computational complexity of the simulation. Based on the constant impedance load model of power network, the electromechanical transient simulation algorithm of power system is studied. The system is decomposed into generator subsystem and power network subsystem composed of constant impedance load by cutting the connecting circuit between generator set and power network. The equivalent model of power network composed of constant impedance load is established by using linear network equivalence method. The calculation method of interconnected system composed of generator equivalent model, power network equivalent model and generator approximate equivalent model and power network equivalent model is presented. Considering the regional interconnection characteristics of power system, the split node potential method is used to decompose the power system into several regional subsystems. The area subsystem consists of generator and constant impedance load. Based on the equivalent model and approximate equivalent model of generator set, the method of establishing equivalent model of regional subsystem is studied, and the calculation method of interconnected system composed of equivalent model of regional subsystem is studied. Taking the New England 10-machine 39-bus system as an example, the equivalent model and splitting algorithm of the proposed subsystem are simulated and verified based on constant impedance load. Compared with the simulation results of PSASP, the proposed model and method are proved to be correct and have good numerical accuracy and stability under different fault types. The proposed power system electromechanical transient simulation method is easy to realize parallel computation.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM743

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