Capacitor Buffer Unit

Overview

A Capacitor Buffer Unit (CBU), also called a Power Capacitor Shelf (PCS), is a component deployed alongside 50 V data center power systems to absorb the high-dynamic load jumps generated by GPU computation. During AI inference and training bursts, GPUs draw power in sharp transients that would otherwise appear as large spikes on the AC grid. The capacitor shelf stores and releases energy locally to smooth these transients, preventing undesirable power spikes visible to the energy provider and protecting upstream power distribution equipment.