Structural Emergency Control Paradigm

TL;DR

This paper introduces a novel structural emergency control method for power grids that stabilizes post-fault dynamics without load shedding, using discrete equilibrium relocation and convex optimization for scalability.

Contribution

It proposes a new control paradigm that stabilizes power grids after faults by relocating equilibrium points without continuous measurements or load shedding, scalable to large systems.

Findings

Control achieved through equilibrium relocation and stability region design.

Control scheme is scalable via convex optimization.

Implementation feasible with existing transmission infrastructure.

Abstract

Power grids normally operate at some stable operating condition where power supply and demand are balanced. In response to emergency situations, load shedding is a prevailing approach where local protective devices are activated to cut a suitable amount of load to quickly rebalance the supply demand and hopefully stabilize the system. This traditional emergency control results in interrupted service with severe economic damage to customers. Also, such control is usually less effective due to the lack of coordination among protective devices. In this paper, we propose a novel structural emergency control to render post-fault dynamics from the critical/emergency fault-cleared state to the stable equilibrium point. This is a new control paradigm that does not rely on any continuous measurement or load shedding, as in the classical setup. Instead, the grid is made stable by discretely relocating the equilibrium point and its stability region such that the system is consecutively attracted from the fault-cleared state back to the original equilibrium point. The proposed control is designed by solving linear and convex optimization problems, making it possibly scalable to large-scale power grids. Finally, this emergency control scheme can be implemented by exploiting transmission facilities available on the existing grids.