Initialization of Electromagnetic Transient Simulation Using Differential Quadrature Method

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.