Power Quality in AC Drive Performance and Maintenance
AC drives are vital in industrial automation, but their performance and lifespan are heavily impacted by power quality issues like voltage fluctuations, harmonic distortions, and transient disturbances. Poor power quality can lead to frequent faults, reduced efficiency, and premature failure. By actively managing power quality — using filters, proper grounding, and voltage monitoring — organizations can optimize system performance, reduce downtime, lower maintenance costs, and extend the life of their AC drives, ensuring maximum return on investment.
What is power quality?
Power quality is the degree to which the voltage, frequency, and waveform of electrical power conform to certain specifications. In an ideal world, the electrical supply would be a perfect sine wave, free from distortions and interruptions. But there are quite a few factors that can impact power quality:
- Voltage fluctuations
- Harmonic distortion
- Frequency variations
- Power factor issues
- Transients and surges
Poor power quality can significantly affect AC drives in various ways. For instance, harmonics and voltage imbalances lead to increased heat generation in drive components. Meanwhile, voltage sags or transients can trigger protective features, resulting in unexpected shutdowns (nuisance tripping). Power factor issues and harmonic distortion can decrease the efficiency of the drive system as a whole.
These aren’t one-off issues. Consistent exposure to poor power quality can accelerate component wear, reducing the drive’s operational life. Harmonics can also create electromagnetic interference that affects sensitive control circuits in the drive. Put simply: Poor power quality takes a heavy toll over time.
Strategies for mitigating power quality issues
Poor power quality is a problem that needs to be addressed as soon as it’s discovered. Thankfully, there are several strategies that can mitigate harmonic distortion and improve power quality to the drive:
- Implement continuous power-quality monitoring. Regular monitoring helps detect power quality issues in real time, allowing for proactive measures to prevent drive damage or inefficiency.
- Install harmonic filters to reduce distortion. Harmonic filters mitigate the effects of harmonic distortion, which can lead to overheating and stress on AC drives, improving overall performance.
- Use capacitor banks or active frontend drives for power factor correction. Capacitor banks and active frontend drives help correct poor power factor, reducing reactive power and improving energy efficiency.
- Employ voltage regulators or UPS for stable voltage. Voltage regulators or uninterruptible power supplies (UPS) stabilize input voltage, protecting AC drives from voltage sags or surges that can cause faults.
- Ensure robust grounding to minimize transients and interference. Proper grounding reduces electrical noise and transients, preventing potential disruptions or damage to sensitive drive components.
- Install line reactors to mitigate voltage fluctuations. Line reactors smooth out voltage spikes and fluctuations, providing a more stable voltage supply to the AC drive and extending its lifespan.
Staying on top of power quality issues
Maintaining good power quality is an ongoing process and needs to be integrated into regular servicing routines. Consider adding the following practices to scheduled maintenance:
- Conduct periodic inspections of drive components.
- Perform comprehensive power quality audits.
- Use thermal cameras to detect hotspots.
- Regularly analyze harmonic levels.
- Train techs on symptoms of poor power quality.
Remember: Better power quality leads to fewer unexpected shutdowns and better reliability. Addressing power issues proactively can reduce the frequency and severity of equipment failures, leading to lower maintenance costs over time.
Are power quality issues taking a toll on your AC drives?
Throughout October, GES is offering 10% off any single drive repair or 15% off three or more repairs on AC drives. Let us help you reverse the effects of poor power quality — once and for all.
Give your drives the power they need!
Poor power quality will manifest at the expense of your drives and the equipment they power. Meanwhile, improved power factor and reduced harmonic distortion often result in lower energy consumption and costs, as well as reduced stress on AC drives and motors. Take power quality into account as part of your approach to AC drive maintenance.
