New power-based control stabilizes data center UPS in weak grids
PLL-based rectifiers fail at SCR=2 – here's a fix that works.
Deep Dive
Researchers developed a power-based control strategy for centralized UPS systems that eliminates the need for PLL synchronization. In simulations, conventional PI-controlled rectifiers became unstable at a short-circuit ratio (SCR) of 2. The new approach directly regulates active and reactive power, restoring stability and improving system damping—critical as data centers face increasingly weak grid conditions.
Key Points
- Conventional PLL-based PI control for UPS rectifiers becomes unstable at a short-circuit ratio (SCR) of 2.
- The proposed power-based control eliminates dependence on PLL synchronization by directly regulating active and reactive power.
- Electromagnetic transient simulations show improved system damping and restored stability under weak-grid conditions.
Why It Matters
As grids weaken with renewable integration, data centers need control upgrades to avoid UPS instability and downtime.