Enhancing Data Center Low-Voltage Ride-Through
Yiheng Xie, Wenqi Cui, Adam Wierman
TL;DR
The paper addresses LVRT for large data-center loads by exploiting the data center's internal distribution network and designing voltage controllers to keep internal voltages within safe limits during external grid disturbances, using a Linear DistFlow model $\mathbf{v}=\mathbf{R}\mathbf{p}+\mathbf{X}\mathbf{q}+v_0\mathbf{1}$. It compares centralized and decentralized control strategies for coordinating IT loads, cooling, UPS, and on-site storage to achieve stay-online operation. Key contributions include a systematic LVRT analysis for data centers, the development of centralized and decentralized voltage-control laws, and an open-source integrated test system for grid-data-center dynamics. The results demonstrate effective LVRT enhancement with practical implications for grid stability and data-center reliability.
Abstract
Data center loads have expanded significantly in recent years. Compared to traditional loads, data centers are highly sensitive to voltage deviations and thus their protection mechanisms trip more proactively during voltage fluctuations. During a grid fault, simultaneous tripping of large-scale data centers can further destabilize the transmission system and even lead to cascading failures. In response, transmission system operators are imposing voltage ride-through (VRT) requirements for data centers. In this work, we enhance the VRT capability of data centers by designing voltage controllers for their internal power distribution network. We first systematically analyze VRT standards and the controllable resources related to data centers. These resources enable the design of voltage control strategies to regulate voltages internal to the data center, thereby allowing loads to remain online during voltage disturbances from the external transmission grid. We study and contrast both centralized and decentralized controllers that unify the control of heterogeneous flexible resources. Additionally, we construct an integrated test system that simulates both the transient fault response of the transmission system and the data center distribution network. Case studies demonstrate that the proposed voltage control mechanisms provide effective yet simple solutions to enhance data center low-voltage ride-through capability.
