Voltage regulation is a measure of the change in voltage magnitude between the sending and receiving end of a component, such as a transmission or distribution line. It describes the ability of a system to provide near-constant voltage over a wide range of load conditions. Voltage regulation can refer to a passive property that results in more or less voltage drop under various load conditions, or to the active intervention with devices for the specific purpose of adjusting voltage. There are different types of voltage regulators, including electronic and electromechanical regulators.

The quality of a systems voltage regulation is described by three main parameters:

• Line regulation (Sv): the degree to which output voltage changes with input (supply) voltage changes
• Load regulation: the change in output voltage for a given change in load current
• Ripple rejection: the ability of a voltage regulator to suppress ripple and noise from the input voltage

Voltage regulation is important in electrical engineering, particularly power engineering, as it ensures that electrical devices receive a stable and consistent voltage supply. For example, a power transformers voltage regulation is the measure of how well it maintains a constant secondary voltage over a range of load currents. Voltage regulators are used in a variety of applications, including computer power supplies, automobile alternators, and central power station generator plants.