The increasing penetration of renewable and distributed energy resources in distribution networks calls for real-time and distributed voltage control. In this article, we investigate local Volt/VAR control with a gene...
详细信息
The increasing penetration of renewable and distributed energy resources in distribution networks calls for real-time and distributed voltage control. In this article, we investigate local Volt/VAR control with a general class of control functions, and show that the power system dynamics with nonincremental local voltage control can be seen as a distributed algorithm for solving a well-defined optimization problem (reverse engineering). The reverse engineering further reveals a fundamental limitation of the nonincremental voltage control: the convergence condition is restrictive and prevents better voltage regulation at equilibrium. This motivates us to design two incremental local voltage control schemes based on the subgradient and pseudo-gradient algorithms, respectively, for solving the same optimization problem (forward engineering). The new control schemes decouple the dynamical property from the equilibrium property, and have much less restrictive convergence conditions. This article presents another step toward developing a new foundation-network dynamics as optimization algorithms-for distributed real-time control and optimization of future power networks.
We lay out a general framework for reverse-engineering frequency dynamics with general primary frequency control and frequency response, by showing that it is a distributed algorithm to solve a well-defined optimizati...
详细信息
We lay out a general framework for reverse-engineering frequency dynamics with general primary frequency control and frequency response, by showing that it is a distributed algorithm to solve a well-defined optimization problem. We further characterize the role of deadband in control, and show that if the aggregated uncontrolled load deviation is nonzero the frequencies will be synchronized, and if however it is zero the frequencies may oscillate but within the deadband. The optimization based model does not only provide a way to characterize the equilibrium and establish the convergence of the frequency dynamics, but also suggests a principled way to engineer frequency control. By leveraging the optimization problem and insights from reverse engineering, we design a distributed realtime frequency control scheme that maintains the frequency to the nominal value while achieves economic efficiency. This work presents a further step towards developing a new foundation-network dynamics as optimization algorithms-for distributed realtime control and optimization of future power networks.
暂无评论