ABSTRACT

The initialization problem of electromagnetic transient simulation is to calculate the steady-state solution of the differential equations describing the electromagnetic transients of power systems. Currently, the widely used initialization method in electromagnetic transient programs (EMTP) is the fixed-point iteration or the so-called EMTP-based approach where the steady-state periodic response is found for a given initial state by simply integrating the system equations until the response becomes periodic. In lightly damped systems, this type of method could extend over many periods making the computation costly. In this paper, the initialization is described as a two-point differential boundary value problem. On this basis, the differential quadrature method (DQM) is used to solve this problem, therefore, a new electromagnetic transient initialization method is derived. The proposed initialization method is a rigorous Newton algorithm and thus has better convergence than the fixed-point iterative method. In order to solve the problem that the Jacobian matrix involved in the DQM solution is very large, a block recursive solution method based on V-transformation is proposed. Case studies conducted on two typical networks have confirmed the effectiveness of the proposed method.

摘要

电磁暂态仿真的初始化问题是计算描述电力系统电磁暂态的微分方程的稳态解。目前，电磁暂态程序 (EMTP) 中广泛使用的初始化方法是定点迭代或所谓的基于 EMTP 的方法，其中通过简单地对系统方程进行积分，找到给定初始状态的稳态周期响应，直到响应变得周期性。在轻阻尼系统中，这种类型的方法可以扩展到许多周期，从而使计算成本高昂。在本文中，初始化被描述为一个两点微分边值问题。在此基础上，采用微分正交法（DQM）来解决这个问题，因此，推导出一种新的电磁暂态初始化方法。所提出的初始化方法是一种严格的牛顿算法，因此比定点迭代方法具有更好的收敛性。为了解决DQM求解中涉及的雅可比矩阵很大的问题，一种基于块递归求解的方法提出了V变换。在两个典型网络上进行的案例研究证实了所提出方法的有效性。