What is covered by the term power quality?
Power quality is a description of a power supply that is free of disturbance. Today, the greater part of all electrical equipment is built up of electronics that not only create disturbances on the power and transmission network but are also more sensitive to poorer power quality than traditional electrical apparatus.
Electrical disturbances occur at everything from planned to unplanned events on the power and transmission network. Examples of causes of power quality problems are; connections in the power and transmission network, connection and disconnection of electrical loads, lightning strikes, disturbing electrical apparatus (switched power supplies, frequency inverters, low energy light bulbs etc.), weak power and transmission networks and variable power production (renewable power production, wind power etc.)
The requirement for follow up and checking of power quality is increasing and a number of different national norms and regulations have been introduced to give guidance for what is to be considered good power quality.
Norm and regulation for good power quality EIFS 2013:1 (Swedish regulation).
Measurable energy and power quality problems
- Voltage variations
- Voltage sags
- Voltage swells