What is Power Quality?

Power quality refers to how closely the electricity supplied in a power system matches the ideal conditions necessary for efficient and reliable operation. In an ideal scenario, electricity in a network would be a perfectly balanced, pure, and undistorted three-phase sinusoidal waveform, with a specified and stable frequency and amplitude. Deviations from this ideal—such as imbalances between phases, waveform distortions in voltage or current, variations in amplitude or frequency, outages, fluctuations, harmonics, transients, and other disturbances—are indicators of degraded power quality.

The significance of power quality has grown with the increasing complexity of modern power systems. Factors like the expansion of consumer demand, the rise of sensitive electronic loads, the development of distributed generation sources, and the interconnection of power grids have all made power quality a critical concern. Maintaining power quality is a shared responsibility between network service providers and consumers, especially industrial users with high power consumption and non-linear loads.

From the perspective of a network or service provider, power quality is primarily about voltage quality—ensuring that the voltage delivered to consumers meets established standards. Conversely, consumers are responsible for maintaining current quality by ensuring their consumption patterns and types of loads do not adversely affect the power grid.

For service providers, power quality is achieved when the voltage remains within standard limits concerning amplitude, frequency, waveform, balance, and stability. For consumers, it is achieved when the current they draw from the network, in terms of waveform distortion, load fluctuations, and phase alignment with voltage, stays within acceptable limits.