EENG 105: Voltage Regulators & AVRs

The voltage that is desired to be maintained in the system, typically between 119V and 121V.

A device used to adjust the voltage in a power system, usually located at a substation.

The part of the regulator that senses the actual voltage on the power line.

The time delay built into the regulator before the voltage control action begins.

The ability to adjust for variations in voltage drop along the power line.

The part of the regulator that allows the voltage to be adjusted by changing the turns on the transformer.

The motor used to physically change the taps on the transformer, altering the voltage.

The part of the regulator that supplies the signal to the control system based on the line voltage.

The time delay feature prevents rapid tap changes, ensuring stability in the system. It allows for a delay before a new tap change can occur.

This mode aims to stabilize the voltage by averaging instantaneous readings and adjusting the tap accordingly. It helps to mitigate voltage fluctuations by taking a smoother approach.

In this mode, the system waits for the voltage to stay within the acceptable range for a period of 10 continuous seconds before resetting the timer. This avoids unnecessary tap adjustments caused by momentary voltage shifts.

A technique used in voltage regulation to ensure a smooth transition between tap adjustments. Instead of immediate changes, it gradually reduces the timer at a rate of 1.1 seconds per second passed, until it reaches zero.

Power flowing in the opposite direction from the intended flow, typically from the load to the source (e.g., a generator). This can be problematic for voltage regulation and may require adjustments.

Automatic Voltage Regulators (AVRs) increase the voltage at the output of a system, but not at the input.

AVRs are typically installed in various locations within an electrical system, including the primary side of a power transformer, the secondary of a power transformer, the main line of a feeder, the middle of a feeder, and at customer tapping points.

Pole-mounted AVRs are usually found on utility poles and are generally used for smaller applications.

Platform-mounted AVRs are often used in larger installations, such as substations, and are typically placed on a platform for easy access and maintenance.

An autotransformer can be set up as a step-up transformer, where the output voltage is higher than the input voltage, or as a step-down transformer, where the output voltage is lower than the input voltage.

A step voltage regulator is a type of transformer that uses tap-changing to adjust the output voltage based on the load demand.

Step voltage regulators use a tap changer mechanism to adjust the voltage by selecting different turns on the transformer winding.

The step voltage regulator uses a reversing switch to allow it to both raise (increase) and lower (decrease) the output voltage, providing flexibility.

The step voltage regulator's operation involves moving through a series of taps to adjust the output voltage according to load changes.

A step voltage regulator monitors the voltage at the load, compares it to a setpoint, and uses line drop compensation to determine the necessary tap adjustments to maintain a stable voltage.

A method of controlling an AVR where the voltage regulation is based on the source voltage (V2) even when power flow is reversed, but the AVR still maintains the original winding configuration.

The voltage regulation of an AVR is based on the voltage at the source winding (V1) even when power flow is reversed.

A method where the AVR adjusts its regulation based on the power flow direction, either normal or reverse, ensuring proper operation.

The voltage regulation of an AVR is based on the source voltage (V2) when power flow is normal (from Source A to Source B) or reversed.

The number of turns in the primary winding (T1) and the secondary winding (T2) of a transformer dictates the voltage transformation based on the relationship: V1/V2 = T1/T2.

A device that regulates the output voltage of a generator by adjusting the excitation current.

An electrical component that changes the voltage from one level to another based on the windings ratio.

The difference in voltage between the upper and lower voltage limits.

How much voltage drop on the line is compensated by the AVR control.

The amount of reactive power compensation that the AVR control can handle.

A component that signals when the voltage is outside the permitted range.

A switch that allows for manual control of the AVR to adjust voltage settings.

The ability of the AVR control to change taps sequentially or all at once.

A port that allows for electronic communication with the AVR control.

A special feature that allows the AVR control to be turned on and off externally.

A feature that prevents the output voltage from going above or below a specific range, protecting connected equipment.

Allows the regulator to lower the output voltage when the demand for power exceeds the available supply, preventing overloading.

A feature that limits the range of voltage adjustment when a certain current level is reached, enhancing system stability.

The ability of the AVR to operate at currents greater than the rated nameplate capacity when the voltage regulation range is restricted.

The ratio of maximum allowable current to rated current, depending on the desired regulation range.

A safety measure that protects the series winding from damage due to high currents.

Protects the system from lightning strikes by diverting the current to the ground.

A procedure that removes the regulator from service by bypassing it, requiring specific precautions to avoid damaging equipment.