What is voltage regulation in distribution systems and why is it important?

Voltage regulation maintains voltage within acceptable limits (typically plus/minus 5% of nominal) despite load variations. It is important because equipment is designed for specific voltage ranges - undervoltage reduces motor torque and dims lights, overvoltage shortens equipment life and wastes energy. Regulation is achieved through transformer tap changers, voltage regulators, capacitor banks, and static VAR compensators. ANSI C84.1 specifies voltage ranges.