Introduction
The excitation system of an alternating current(AC) generator is an important component in large scale power plants in industrial application. An accredited Automatic Voltage Regulator (AVR) is essential to maintain the voltage output of the generator within the acceptable limits. AVR failure may cause other related repairs on the generator, leading to loss of operational efficiency, hence finances.
Cause of AVR Failure
Despite the fact that the AVR can be an excellent stabilizer, it can become unstable if it is exposed to harsh working conditions. Examples of these conditions are temperature variations, electrical shocks, environmental issues, internal system malfunctions, insulation problems and power supply voltage issues. AVR failure can also be caused by natural disasters, lack of regular maintenance, incorrect operation or the use of the AVR with the wrong power supply.
Temperature variations can be a major cause of AVR failure. In some extreme cases, this may be due to the use of a generator that is not intended for extended operation in hotter climates. Temperature variations can also lead to a prolonged and very fast degradation of the AVRs insulation, making it unsafe.
Electrical shocks can be another factor as most AVRs are vulnerable to voltage surges and lightning strikes, so the proper precautions must be taken in order to protect the AVR from these surges.
Environmental issues can also cause AVR failure. Pollution from exhaust fumes can gather around the AVR and the generator, leading to a very slow but steady deterioration of the AVRs insulation. The contaminated air contains dust and can easily cause corrosion and slow down the operation of the AVR.
Internal system malfunctions can be caused by incorrect wiring of the AVR. An incorrect connection between the power supply and the AVR will cause a short circuit, leading to overheating and eventual failure of the AVR.
Insulation problems can also lead to AVR failure. The insulation between the power supply and the AVR need to be of the right thickness and quality to protect the AVR from electrical shocks and breakdowns. If the insulation is not of the right rating, then the AVR will be exposed to too much electrical shock and may fail as a result.
Power supply voltage issues can be another cause of AVR failure. In some cases, the voltage of the power supply may be too low, and the AVR may not be able to handle the load, leading to its failure. In some extreme cases, the voltage may be too high, causing a voltage spike that can damage the AVR.
Emergency Handling
The following steps may be taken to address the issue of AVR failure:
1. Ensure that detectors are placed at all strategic points to monitor temperature variations and other environmental conditions, ensuring that the AVR is not exposed to overloads and sudden power supply changes.
2. Ensure that all internal wiring and insulation are correct and in order, and that the output of the AVR is compatible with the power supply voltage.
3. Ensure that regular maintenance is performed on the AVR, including calibration and testing to ensure correct operation.
4. Ensure that the generator is intended for extended operation in the current environment, taking into account temperature fluctuations and other environmental considerations.
5. Implement quality planning and control procedures to ensure that the quality of the AVR remains in good operating condition at all times.
Conclusion
AVR failure can cause financial losses and reduce the efficiency of the generator. It is important to take the necessary preventive steps to guard against failure and address any potential issues as soon as they arise. By following the above guidance, and through quality planning, operators can ensure that the AVR continues to operate effectively and efficiently, allowing the generator to maintain stable output and prevent losses in productivity.
