An Evolutionary Pathway of Linear Power Flow Equation: Breaking of Empirical Assumptions

Abstract

Linearization of the power flow equation is widely-used in power system analysis to meet the computational efficiency demand of the power industry. However, existing linear power flow equations are proposed based on empirical assumptions. The optimality of these power flow equations cannot be proven. The evolutionary pathway of the linear power flow equation is not clear. In this paper, we review the widely-used linear power flow equation from the perspective of their zero-error assumption of linearization approximation. Then, the improvement of the linear power flow equation is revealed as constantly breaking the zero-error assumption. Finally, we propose an enhanced linear power flow equation based on the arithmetic-geometric mean inequality for optimal power flow (OPF) calculation. The performance is verified in IEEE 30, 118 and Polish 2383 test systems.