Modern factories rely heavily on automation – PLCs, VFDs, SCADA systems, servo drives, robotics and sensitive electronics. But many industries still ignore one silent productivity killer: power quality issues in industrial plants.
Power quality problems don’t just increase electricity bills – they cause machine trips, PLC faults, overheating motors and unexpected downtime. This article explains what power quality issues are, why they happen in industrial plants, and how to permanently solve them.
1. What are Power Quality Issues in Industrial Plants?
Power quality issues in industrial plants refer to any deviation in voltage, current, or frequency that results in the failure or misoperation of customer equipment.
In simple terms: It is a measure of how “clean” your electricity is. Think of it like fuel for a car; if the fuel is contaminated, the engine stutters. If your electrical sine wave is “dirty,” your automation hardware stutters.
Common Types of Power Quality Disturbances
- Voltage Sags (Dips): A brief decrease in voltage, often caused by starting heavy motors. In industrial environments, this stands as the primary culprit behind frequent PLC trips.
- Voltage Swells: A brief increase in voltage, usually when a large load is turned off, which can damage sensitive electronic components.
- Harmonics: Non-linear loads (like VFDs and LED lighting) “pollute” the electrical line, causing waves that interfere with the standard 50Hz frequency.
- Transients & Surges: Rapid, high-magnitude voltage spikes often resulting from atmospheric lightning or the activation of inductive loads, such as massive industrial transformers
- Unbalanced Loads: When power is not distributed evenly across the three phases, leading to excessive motor heat.
2. Real-World Industrial Causes
In our experience at Aknitech, we’ve seen that these problems rarely come from the utility provider alone. Most issues are generated inside the factory gates:
- VFDs and Soft Starters: While essential for energy saving, poorly filtered VFDs are major sources of harmonic distortion.
- Arc Welding & Induction Furnaces: These create massive “flicker” and voltage fluctuations that affect the entire internal grid.
- Old Capacitor Banks: Aging units can actually resonate with the system, amplifying harmonics rather than fixing them.
- Poor Earthing/Grounding: In many Indian plants, seasonal soil changes (especially in central India) affect earthing resistance, leading to “ghost” signals in communication cables (RS485/Ethernet).
3. The Cost of Poor Power: Effects on Automation
When power quality drops, your automation stack is the first to suffer.
Impact Table: Equipment vs. Failure Mode
| Component | Effect of Poor Power Quality | Resulting Cost |
| PLC/HMI | Logic resets or “freezing” | Unplanned production halts |
| AC/DC Motors | Overheating & insulation failure | Expensive motor rewinding |
| VFDs | Overvoltage or Undervoltage tripping | Process synchronization breaks |
| Sensors | False triggering due to noise | Product rejection/Scrap |
Expert Insight: A 10% voltage unbalance can reduce the life of a three-phase motor by nearly 50%. It isn’t just about the electricity bill; it’s about protecting your Capital Expenditure (CAPEX).
4. Practical Solutions Using Industrial Automation
Solving power quality isn’t just about adding a stabilizer; it requires an integrated automation approach.
A. Active & Passive Harmonic Filters
To neutralize the “noise” created by VFDs, we install harmonic filters. Active filters are particularly effective as they monitor the line in real-time and inject a compensating current to cancel out the distortion.
B. SCADA-Based Power Monitoring
You cannot fix what you cannot measure. Modern SCADA systems integrated with Energy Management Modules allow plant engineers to see real-time THD (Total Harmonic Distortion) levels and voltage trends on a central dashboard.
C. Advanced VFD & Soft Starter Optimization:
At Aknitech, our service goes beyond simple installation. We meticulously calibrate acceleration/deceleration curves and carrier frequencies to reduce the load pn your internal grid, effectively eliminating the voltage sags typically triggered by heavy motor start-ups.
D. Power Conditioning Panels
Using specialized MCC and PCC panels designed with high-quality switchgear and surge protection ensures that external grid spikes never reach your sensitive PLC racks.
5. How Aknitech Solves These Challenges
As a leading industrial automation company, Aknitech specializes in modernizing legacy plants and optimizing new installations.
- Site Audit: We analyze your current electrical drawings (AutoCAD/E-Plan) and measure actual line quality.
- System Integration: We bridge the gap between your power panels and your control room, providing IoT-enabled monitoring.
- Downtime Reduction: If your machines are tripping “randomly,” we identify the specific power quality culprit and install targeted protection.
6. FAQ (Featured Snippet Optimized)
Q: What is the most common cause of PLC failure in factories?
A: The most common cause is voltage sags. Even a millisecond drop in power can cause the PLC’s internal power supply to fail, triggering a CPU stop and halting the entire production line instantly.
Q: How do harmonics affect my electricity bill?
A: Harmonics cause “copper losses” and excess heat. This forces your equipment to draw more current for the same amount of work, increasing energy consumption and potentially leading to utility penalties for poor power factor.
Q: Can a VFD cause power quality issues?
A: Yes. VFDs are non-linear loads. Without proper input reactors or harmonic filters, they feedback “noise” into the system, which can cause other sensitive electronics on the same circuit to malfunction.
Q: Why is grounding (earthing) important for automation?
A: In automation, grounding isn’t just for safety; it provides a “clean” reference point. Without it, your PLC and HMI may experience communication errors or “flickering” data values due to high-frequency noise.
Q: How does an Energy Management System (EMS) improve power quality?
A: An EMS uses networked meters to provide a historical log. This allows engineers to pinpoint exactly which machine started up when a voltage dip occurred, enabling data-driven troubleshooting.
Conclusion
Power quality is the foundation of a digital, automated factory. Investing in high-quality PLC panels, harmonic filters, and SCADA monitoring isn’t just a technical upgrade-it’s an insurance policy against downtime.
Is your plant suffering from “mysterious” machine trips or frequent motor failures?
Visit Aknitech.in to explore our Power Management and Automation solutions.
