Power Quality - Voltage Disturbances

 

Voltage disturbances are the most common PQ problem causing effect ranging from minor annoyance through equipment failure to the shutdown of complete production processes.  The economic impact can be very large and can threaten the economic viability of a business.  This section of the Application Guide covers various aspects of voltage disturbances.

Standard EN 50160 defines the Voltage characteristic of electricity supplied by public supply networks.  The basic requirements are described in Standard EN 50160. 

Voltage dips are covered in four Application Notes, reflecting their economic importance.

Introduction to Voltage Dips discusses the nature of voltage dips and their origins within the installation or, more likely, in the network.  The sensitivity of equipment to voltage dips is discussed and compared with typical network performance.

Voltage Dip Mitigation discusses the principal traditional mitigation measures.  The discussion is continued in Considerations for choosing the appropriate voltage sag mitigation device in which some newer power electronic solutions are discussed, together with a methodology for selecting the most appropriate device.  Finally, Voltage Sags in Continuous Manufacturing describes a case study.

Voltage unbalance – often caused by unequal loading of the phases is discussed in Introduction to Unbalance.  Unbalance can have a serious effect on the performance of three-phase equipment.

This Application Note, Predictive Maintenance - The Key to Power Quality, proposes that, rather than simply responding to problems, PQ should be continuously monitored as part of a planned maintenance activity

Flicker is the impression of unsteadiness of visual sensation induced by cyclic variation in the intensity or spectral content of a light source due to fluctuation of the supply voltage.  It affects the concentration and productivity f people, but it does not have any effect on equipment.  Flicker introduces flicker and Flicker Measurement describes flicker-measurement in detail.