A parallel algorithm on modification and equivalents of node impedance matrixes of bulk interconnected electric networks

Fast modification of node impedance matrix of an interconnected power network is pivotal to realize the real-time adaptive relay setting. Because the network has several adjacent networks, getting the boundary equivalents of each adjacent network is necessary to calculate the complete impedance matrix of the studied network for short circuit analysis. A parallel algorithm on blocking storage and modification of node impedance matrix based on PC cluster is proposed in this paper. The proposed parallel algorithm combines large grained blocking storage with message passing, it can fast deal with the network containing mutually coupled circuits. Moreover, the formula to calculate boundary equivalents based on node impedance matrix is derived. According to the boundary equivalents of the adjacent networks and the modified impedance matrix of the network-self, the complete impedance matrix of the studied network can be calculated. Furthermore, an optimization strategy on remote memory access (RMA) function is utilized to overlap the parallel computation and the communication between the scheduling processor and the sub-processors. The experimental results demonstrate the proposed parallel computing approaches on the modification and boundary equivalents of an interconnected network has obvious advantage in computation efficiency over traditional serial computing approaches. The proposed approaches are effective to meet the speed requirement of calculating adaptive relay settings for a large interconnected electric network.