The Research On Parallel Asynchoronous Transient Stability Simulation Of Power System

The implementation of a national network makes real-time electromechanical transient simulation become more difficult. It is difficult to utilize serical simulation of a single computer to achieve this object, so we can only hope parallel computing.Firstly, Newton-GMRES method is used in this paper to solve large-scale nonlinear equations of transient stability calculation of power system. The outer iteration of this method is the classical Newton method, and the inner iteration is using GMRES to solve Jacobi equations inexactly. In each inner iterative step, finite difference is used to replace the product operation of jacobian matrix and vector, so there is no need to form jacobian matrix explicitly, and avoid storing Jacobian matrix. This method can save computer memory greatly, and improve computational efficiency. Before using GMRES to solve the linear equations in the inner iteration, sparse approximate inverse method is used to precondition the coefficient matrix of the linear equations, which can reduce the conditional number of the coefficient matrix, and accelerate the convergent speed of GMRES.Secondly, a new asynchronous parallel method based on equivalence is proposed for the parallel simulation of electromechanical transient. The general idea of this method is:The network is divided into several weak-coupling subsystems. In each simulation time step, each subsystem equivalence for each other, then utilizes the equivalent information from other subsystems to calculate independently until convergence. In the transferring process of equivalent information, the asynchronous strategy is used, that subsystems monitor that there is any new equivalent information coming from other subsystems or not at any time in the iterative process of calculation, which can update the equivalent information in time and speed up the convergence of iteration. The results of samples demonstrate that the new method not only has high equivalent accurancy, but also has a fast calculation speed. For some large-scale real systems, the on-line simulation will be realized. Communication and calculation to be carried out at the same time is the character of non-blocking communication, which is utilized to realize the asynchronous communication strategy in this thesis.The simulation in this paper is based on a small 6-node PC cluster created by myself. The achievements of this thesis enrich the parallel simulation methods of power system electromechanical transient and improve the utility progress of that.