A Branch-and-cut Method for Computing Load Restoration Plan Considering Transmission Network and Discrete Load Increment

This paper proposes an optimization model to compute optimal load restoration plan for the transmission network. The objective of this model is to maximize the load pickup subject to power flow constraints and discrete load increment constraints. This mix-integer optimal power flow model (MIOPF) is solved via a branch-and-cut (B&C) framework. The nodes in the B&C tree are solved by the interior point method. In particular, three cutting planes, namely, the Gomory rounding cut, the knapsack cover cut, and the fixing variable cut, are incorporated into each node of the B&C tree to reduce the scale of the sub-tree. This model can be used to aid the system operators to conduct load restoration actions or draw up a restoration plan. The load restoration plan is obtained by solving a number of co-related MIOPF models till all load increments are restored. The RTS 24-bus test case with 170 load increments (i.e., with 170 binary variables) is used to illustrate complexity of the proposed model and the computational efficiency improvement stemming from the cutting planes.