Power Quality

What is Power Quality?

The concept of power quality has often been misunderstood. In this day and age of sophisticated electronics, monitoring power quality has become too important to ignore. The widespread use of high-tech devices has complicated every aspect of electrical power. Not only are these devices more sensitive to the effects of power quality, they can also impact it negatively. Poor power quality can result in lost productivity, lost and corrupt data, damaged equipment and poor power efficiency.

‘Power Quality’ is a broad term used to describe the measurement of electrical power performance. It can be broken down into three key areas, as detailed below.

Power Factor.
Harmonics.
Disturbances.

Sources of Poor Power Quality

Power quality problems can be tracked to three origins, as detailed below.

Supply This is the initial source of power from the utility company such as the main transformer of a commercial building. This is where power coming into the consumers facility can be monitored.
Internal Distribution 80% of all power quality problems occur in a consumers distribution and earthing systems. Corroded connections, defective electrical devices, improper wiring and earthing are just some of the obstacles to be dealt with.
Internal Loads Typical loads such as variable speed drives, P.C’s and high frequency lighting can contriobute to the quality of the electrical power in a circuit. Internal loads can cause poor power factor, harmonics and disturbances.

Monitoring

Monitoring can be carried out to the relevant standard and level depending on the specific requirement of an existing or proposed installation.

State of the art equipment is utilised to record these values usually over a seven day period in order that a detailed profile can be captured across a typical period.

Recordable Values

VRMS – This facility allows us to capture voltage and current levels during the monitoring period.
Harmonics – These elements are often site generated by non-linear loads such as I.T equipment and high frequency lighting and can create issues both on your site and your neighbour's.
Flicker – This is the perceptible change in light intensity generally caused by small fluctuations in voltage.
Dips, Interrupts, Rapid Voltage Changes and Swells – The impact that these values have on the supply voltage are monitored in fine detail to detect unwanted instabilities.
Frequency and Unbalance – In this mode we are able to confirm the stability of the supply frequency (50HZ) and view any imbalance in the connected loads on site.
Power and Energy – We are able to accurately monitor the demand of an installation and record values such as KW, KVA, KVAR, Power Factor and current in all three phases. This data can subsequently be used to assist in future design or in the selection of engineering products.

Engineering Solutions

Following the monitoring period, the data is downloaded and analysed by our power quality team. As part of the service provided by TCS, our team can offer engineering solutions to any problems highlighted within the report.

Engineering solutions and mitigating equipment take many forms such as harmonic rejection transformers, active filters, voltage stabilisers, UPS and real time PFC’s.

Our Experience

During recent years TCS have been commissioned to investigate power quality issues for various customers across the UK. In this time we have successfully analysed and rectified various problems that were actively compromising the electrical installations in which they were present. As specialists in electrical testing TCS recognise the importance of power quality and consider the relationship between this and fixed wiring testing with increasing clarity.

For example, dealing with harmonic components just a few years ago was considered to be highly academic, almost mystic. The problems caused by harmonics are now much more relevant and can cause considerable damage to distribution systems and equipment connected to them. This is why an Electrician may meet the need to control harmonics in their every-day job.

TCS have therefore invested in the equipment and expertise in this field and can provide a comprehensive and competitive service covering a wide range of power quality and energy saving products and engineering solutions.

For further information on this service please direct your enquiry to our Middlesbrough Office