Automatic Voltage Regulators (AVR) Quiz

A device or system designed to automatically maintain a constant voltage output. It can use a simple feed-forward design or include negative feedback, and may utilize electromechanical mechanisms or electronic components.

A type of voltage regulator that utilizes a tap-changing autotransformer. It monitors its output voltage and automatically adjusts itself by changing taps until the desired voltage is reached.

The process of raising or lowering the voltage of a system using an AVR or Capacitor Bank.

A device that can raise or lower the voltage of a system, but only by being switched on or off.

AVRs solve voltage problems like undervoltage, overvoltage, and unbalanced voltage.

AVRs cannot solve voltage problems like voltage sags, voltage swells, and voltage flickers.

Capacitor Banks can raise the voltage of a system when placed on the source side.

A transformer connected to the secondary side of a voltage regulator. It provides a voltage proportional to the circuit voltage for controlling the tap-changing motor.

A device that compensates for voltage drops along a power line due to load current. It effectively raises the voltage output of the regulator at full load.

A sensitive gadget that measures the input voltage and compares it to a pre-set target voltage. It also has a tolerance range for normal variations. If the measured voltage goes outside the tolerance, the control system kicks in.

A feature of the regulator control that prevents it from reacting to brief and insignificant voltage fluctuations. The regulator only responds to voltage changes that last for a preset amount of time.

The difference between the highest and lowest voltage that the AVR can regulate effectively. This range determines how much the voltage can fluctuate before the AVR takes action.

The time required for the AVR to react to a voltage change and initiate adjustments. This delay helps avoid unnecessary adjustments due to brief voltage fluctuations.

A component that detects when the voltage reaches the upper or lower limit of the AVR's bandwidth. It helps the operator understand when the AVR is close to its limits.

A device that compensates for voltage drops along a power line due to load current. It effectively raises the voltage output of the regulator at full load.

The feature that allows the user to manually adjust the voltage output of the AVR, providing control over the voltage level outside of the automatic regulation process.

A device that automatically maintains a stable voltage output by changing taps on a transformer.

The voltage sensor monitors the output voltage and sends a signal to the control system when it deviates from the desired range.

The tap changer is an electromechanical device that alters the winding connection of a transformer to adjust the voltage. It uses a motor to reposition a contactor to select different taps on the transformer winding.

The control system uses a time delay to prevent rapid adjustments and ensure stability.

This compensates for the voltage drop that occurs over long distances due to line resistance.

It helps to provide a stable voltage regulation.

Voltage changes are a common occurrence in power systems and can cause problems for electrical equipment. AVRs help counteract these fluctuations and provide a reliable voltage supply.

The goal is to maintain the output voltage within a predefined acceptable range, even when the input voltage fluctuates.

They are used in various applications, including industrial, commercial, and residential power systems. AVRs ensure reliable operation of sensitive electrical equipment and protect against damage caused by voltage fluctuations.

The AVR will continue to adjust the tap changer until the output voltage is back within the acceptable range.

The flow of power from the Source A to the Source B, where Source B provides power and Source A receives power. This happens when the voltage at Source B is lower than the voltage at Source A, and the AVR is connected for normal regulation from Source A.

The ratio of turns in the secondary winding (T2) to the turns in the primary winding (T1) of a transformer. This ratio determines the voltage transformation between the two windings. In the case of reverse power flow, the voltage at Source A becomes the secondary voltage.

When the power flow is reversed, the AVR needs to adjust the voltage at Source A (now the load side) to maintain a stable voltage despite the change in the power flow direction. This requires a special control mode called 'Reverse Sensing Mode'.

A reverse sensing mode in which the AVR locks onto the voltage of Source A (the receiver) and maintains it regardless of voltage changes at Source B. This mode ensures a constant voltage for the receiving end even when the power source is reversed.

A reverse sensing mode in which the AVR locks onto the voltage of Source B (the source) and maintains it regardless of voltage changes at Source A. This mode ensures a constant voltage for the supplying end even when the power flow is reversed.

In Reverse Power Flow, the AVR is connected to the source that is providing power (Source B), but the voltage regulation occurs at the receiving end (Source A). This is opposite to the normal power flow scenario where the AVR is connected to the receiving end. To adjust the voltage at the receiving end, the AVR needs to control the voltage at the supplying end.

When the voltage at Source B (the new source) is low, the AVR tries to increase the voltage by raising the voltage on the secondary winding (T2). This change causes the relationship between T2 and V2 to shift, which then affects the voltage on the primary winding (V1) and its corresponding turns (T1).

When the AVR is connected for normal regulation from Source A, but is fed from Source B, the voltage at Source A will decrease. This is due to the change in the operating mode caused by reverse power flow, where the AVR regulates the supplying source (Source B) instead of the receiving source (Source A).

The AVR adjusts the voltage at Source B (now the source) based on the voltage reading at Source A (now the load). The AVR's feedback mechanism ensures a consistent voltage at Source A despite the reversed power flow. This effectively 'mirrors' the normal regulation operation.

Older AVR controls required an additional kit to detect reversed power flow and adjust the control accordingly. However, newer AVR controls now include this functionality as a standard feature. This advancement simplifies the setup and improves the overall reliability of the system.