Power quality - why is it important and how to address it?

In today's energy systems, it's not just about how much energy you have, but also about how good the quality of that energy is. Power quality problems can cause outages, equipment failures, lower efficiency or even damage to technology.

Power quality
Power Quality (PQ) refers to the quality of the electricity that is supplied to the equipment. The EN 50160 standard (explaining what parameters the voltage on the distribution network should have) and IEEE 1159 (describing how to monitor and evaluate PQ problems) describe what is "normal" and when the network is no longer functioning properly.

The most common power quality problems:

• Voltage fluctuations - either too low (undervoltage) or too high (overvoltage).
• Flicker - rapid voltage changes that cause lights to flicker
• sags/spikes - short-term dips or spikes in voltage
• Frequency fluctuations - deviations from 50 Hz
• Harmonic distortion - distortion of the voltage wave due to non-linear loads
• Uneven loading between phases - called unbalance
• Transients - sudden voltage jumps
• Interruptions

How are these problems solved?

• Network monitoring: The first step is to measure the power quality - special analysers are used to show exactly where the problems are.
• Voltage and frequency stabilisation: Voltage regulators, UPS systems or frequency converters are used to stabilise the grid.
• Harmonic filters: reduce harmonic distortion that causes overheating of cables and reduces the life of equipment.
• Phase load balancing: In three-phase systems, each phase may be loaded differently. Technology that can supply or receive power as needed by each phase separately helps.
• Battery Energy Storage Systems (BESS): Modern battery systems ensure grid stability, balance voltage and frequency, and serve as a backup power source during outages.

Addressing power quality issues is key to reliable and efficient operation of the technology. Whether it's a manufacturing plant, data center, or renewable microgrid, a stable, high-quality power supply is essential.