A study of the optimization problem on the combination of sectionalizing switches in power grid with quantum annealing

Abstract

From the perspective of global warming, efficiency improvement of power grids is a pressing issue. Power grids have many switching devices to control the flow of electricity. Since there is a slight resistance in the wires and power consumption is proportional to the square of the current, the value of power loss on the wires changes depending on the combination of switch values that change the supply path of the current. The total number of switch combinations increases exponentially with the number of switches, and various algorithms have been studied to find the optimal combination of switch values. We propose a method to capture the switch combination problem in power grids as quadratic unconstrained binary optimization (QUBO) and derive an evaluation function to solve it using quantum annealing. The result is registered as a patent P6736787 at Japanese patent office.