Summary
Power quality refers to how adequate the electrical energy a facility receives is for its equipment to function correctly. An installation can have available voltage and still present problems that affect processes, equipment and operational continuity.
What is power quality
Power quality analyzes electrical phenomena that can alter the normal operation of equipment. It is not always a complete interruption. Sometimes there is energy, but with distortion, momentary drops, transients, fluctuations or imbalance.
In industries, critical buildings, hospitals, data centers, solar plants and automated processes, these phenomena can generate failures that are difficult to explain.
Harmonics
Harmonics are distortions of the electrical waveform. They are mainly produced by non-linear loads such as variable frequency drives, UPS, rectifiers, chargers, ovens, solar inverters and BESS.
They can cause heating in transformers, nuisance trips, additional losses, resonances, measurement errors and reduction in equipment useful life.
Sags or voltage drops
A sag is a momentary decrease in tension. It can be caused by starting large motors, network failures, maneuvering or connecting heavy loads.
Sags can stop drives, restart PLCs, affect contactors or interrupt processes.
Swells or temporary overvoltages
A swell is a temporary increase in tension. It can occur due to large load shedding, single-phase faults, poor regulation, or grid events.
Although they usually do not last long, they can affect sensitive equipment.
Flicker
Flicker is a voltage fluctuation that can generate visible flickering in luminaires or discomfort in certain equipment. It is usually associated with variable loads, ovens, welders, large motors or processes with fluctuating demand.
Transients
Transients are rapid surge events. They can be caused by maneuvers, atmospheric discharges, capacitor banks or opening and closing of switches.
They can damage electronic sources, control cards, drives or communication systems.
Imbalance
Imbalance occurs when the voltages between phases are not equal. This especially affects three-phase motors, generating heating, vibration, loss of efficiency and reduced useful life.
Typical symptoms
Some symptoms that may indicate power quality problems are:
- Variators that fail without clear cause.
- PLCs being reset.
- Protections that trip without apparent overload.
- Hot transformers.
- Damaged capacitors.
- Flashing lights.
- Motors with noise or vibration.
- Electronic equipment with reduced useful life.
- Processes that stop randomly.
How it is diagnosed
Diagnosis begins with measurements. Many problems are rapid or intermittent, so a one-time measurement is not enough. Power quality analyzers are used that record voltage, current, harmonics, events, transients, flicker and unbalance during a defined period.
The events are then correlated with the actual operation of the plant.
common mistake
A common mistake is to immediately blame the distributor or a specific piece of equipment without sufficient measurements. The cause may be in the external network, but also in internal loads, reactive compensation, resonances, wiring, transformers, protections or power electronics.
Conclusion
Power quality affects the reliability, safety and efficiency of a facility. Measuring and analyzing these phenomena allows us to move from suspicion to technical diagnosis.
Power quality often explains failures that seem isolated. Measuring and analyzing allows you to find patterns before they become operational losses.
If you need to diagnose disturbances, intermittent failures or operational continuity problems, check out our service. power quality and power analysis.