Detecting and Eliminating Mains Power Problems

Early Detection and Elimination of Mains Power Problems

At the latest since the beginning of the energy revolution in Germany, voltage quality in electrical distribution grids (so-called power quality) is becoming increasingly important. Ideally, voltage in electrical networks has a sinusoidal shape, which is determined by voltage level, frequency and waveform.

Due to interaction amongst changing grid conditions and increasing use of non-linear consumers and generators such as frequency converters, UPS systems, energy-saving lamps, PCs, copiers and filter circuits, phenomena are occurring more and more frequently which have an adverse effect on the sinusoidal shape of current and voltage, impair power quality and can result in problems with other consumers. These problems can generate additional costs for operators of electrical installations.

Typical examples of incidents resulting from poor power quality:

• Overheated motors
• Inadvertent shutdown triggered by residual current devices and fuses
• Flickering of fluorescent lamps and monitors
• Failure of electronic ballasts
• Impairment of the transmission of ripple control signals
• Impairment of, and false alarms generated by, wirelessly linked smoke detectors
• Increased reactive power demand and thus higher costs for electrical power

Consequently, poor power quality stresses and impairs electrical consumers and, at worst, may represent a hazard for people and property. Already in 2007, a study estimated that economic damage caused by grid phenomena amounts to €157 billion per year, with a strong upward trend. Power quality is by no means a new issue, but more and more attention has been focused on it in recent years due to our increasingly technologically advanced and vulnerable world. Observation of, and limits for, electrical phenomena are based on standardization for electromagnetic compatibility in accordance with IEC 61000-x-x.

How can mains power problems be detected?

Continuous monitoring of the network helps to detect grid phenomena at an early stage and prevent system failures. With modern heavy-current measuring instruments such as the certified class A LINAX PQ3000 from Swiss power quality specialists Camille Bauer of the GMC Instruments Group – to which GOSSEN METRAWATT also belongs – all common disturbance variables and voltage events such as harmonics, mains frequency changes and flicker can be reliably and permanently recorded, detected and evaluated. With the help of the integrated, highly detailed power quality reporting function (PQEasy-Report), experts can identify problems within the grid at a glance without the need for any expensive, additional software. Beyond this, it’s also possible to detect insulation faults by means of differential current measurement.

Threshold values can be used to generate a message when a critical value is exceeded. This makes it possible to plan and implement suitable countermeasures at an early stage and to avoid costly system failures.