Exciter

Definition

An exciter is a device used to supply the necessary field current to the rotor windings of a synchronous machine, ensuring proper magnetization and stable operation. It plays a crucial role in regulating voltage and power output, influencing the overall performance and reliability of the machine. By controlling the excitation level, the exciter helps maintain system stability and responds to varying load conditions.

5 Must Know Facts For Your Next Test

1. There are different types of exciters, including static and rotary exciters, each with unique methods for supplying field current.
2. The exciter can be part of an automatic voltage regulator (AVR) system, which continuously monitors and adjusts excitation levels based on load changes.
3. Proper excitation is essential for maintaining synchronous operation, as insufficient excitation can lead to loss of synchronism and instability.
4. Exciters also play a key role during transient conditions, helping to quickly stabilize the system after disturbances.
5. In modern power systems, exciters contribute to power system stability by enabling dynamic control over reactive power generation.

Review Questions

• How does the exciter influence the performance of synchronous machines?
  • The exciter directly influences the performance of synchronous machines by supplying field current necessary for rotor magnetization. This magnetization is essential for maintaining stable operation and allows the machine to produce consistent voltage levels. Without adequate excitation, a synchronous machine may experience instability, leading to poor voltage regulation and potential loss of synchronism during varying load conditions.
• Discuss the relationship between exciters and automatic voltage regulators in maintaining voltage levels.
  • Exciters work closely with automatic voltage regulators (AVRs) to ensure that voltage levels remain stable despite fluctuations in load. The AVR monitors output voltage and adjusts the excitation supplied by the exciter accordingly. This dynamic control helps prevent voltage drops or surges, ensuring that electrical systems operate efficiently and reliably under varying conditions.
• Evaluate the role of exciters in enhancing power system stability during disturbances.
  • Exciters play a critical role in enhancing power system stability during disturbances by enabling quick adjustments in excitation levels. When unexpected load changes or faults occur, exciters can rapidly respond by increasing or decreasing field current to stabilize voltage levels and maintain synchronous operation. This capability not only aids in recovering from transient conditions but also supports overall system reliability by reducing the likelihood of cascading failures across interconnected grids.

Related terms

Synchronous Machine: A type of electrical machine that operates at a constant speed in synchrony with the frequency of the supply current, typically used for generating or converting electrical energy.

Voltage Regulation:

The ability of a power system to maintain a constant voltage level despite changes in load or operating conditions.

Automatic Voltage Regulator (AVR):

A system that automatically adjusts the excitation of a generator to maintain output voltage within specified limits.