Patent ID: 7509596

Claim:
A power distribution network simulation method comprising: (a) reducing an original circuit by using a variable reduction method; (b) analyzing the reduced circuit by using a linear equation analysis method; and (c) restoring states of nodes of the original circuit by using the variable reduction method based on the analysis, wherein (a) comprises: (a1) dividing nodes of the original circuit into eliminated nodes and maintained nodes; (a2) generating a reduction operator in a form of matrix; and (a3) reducing the original circuit with a linear transformation using the reduction operator, wherein (c) comprises: (c1) calculating voltages of the maintained nodes of the reduced circuit; (c2) generating a restoring operator; and (c3) restoring voltages of the eliminated nodes by using the reduction operator and the restoring operator, and wherein reducing the original circuit includes repetitively performing (a1), (a2), and (a3), and wherein restoring the states of nodes of the original circuit includes repetitively performing (c1), (c2), and (c3).