Simply put, power quality is a measure of an ideal power supply system. In general, power quality as a concept is no different from the notion of quality for goods or services of all kinds. But while quality is a general concept that includes subjective attributes like personal likeability, taste or gut-feel, power quality is an objective, measurable and clear metric that tells us about the state of the power being supplied.
Broadly, PQ may be defined as a provision of voltages and a system design so that the user of electric power can utilise electric energy from the distribution system successfully, without interference on interruption.
Power Quality is defined in the Institute of Electrical and Electronics Engineers (IEEE) 100 Authoritative Dictionary of IEEE Standard Terms as “the concept of powering and grounding electronic equipment in a manner that is suitable to the operation of that equipment and compatible with the premise wiring system and other connected equipment.” Utilities may want to define power quality as reliability.
PQ is an important issue for electricity consumers at all levels of usage, particularly industries and the services sector. We extensively use sensitive power electronic equipment and non-linear loads these days in industry, commercial and domestic applications. In such an environment, problems like power surges/sags, poor voltage and frequency regulation, harmonics, switching transients, electrical noise and the Electro-Magnetic Interference effect are frequently encountered. This leads to damage of capital-intensive appliances, safety concerns, loss of reliability and above all a huge economic loss.
Consequent to the enactment of Indian Electricity Act 2003, Power Quality is becoming a priority among power supply utilities. Regulated entities, are expected to observe ‘Quality of Service’ regulations. Industry needs to gear up for a better understanding of this issue and adopt a long term approach to mitigating the issues involved.