Parallel algorithm of dynamic reactive power optimization and its implementation

When a dynamic reactive power optimization problem in next 24 hours is solved by nonlinear primal-dual interior-point algorithm incorporating discretization penalty, the reduced correction equation's dimension increases rapidly with enlargement of system size because the limits for switching operations of capacitors and transformer load tap changers should be considered. But it is found easily that the coefficient matrix of the reduced correction equation has block bordered diagonal structure and hence the correction equation can be accurately decomposed into 25 sets of low-dimension linear equations. Therefore, a coarse-grained parallel algorithm is proposed and implemented under message passing interface (MPI) based parallel environment. Numerical results on a real 14-bus and IEEE 118-bus systems demonstrate that the proposed algorithm can accelerate computational process obviously and has application potential in large-scale power system.