Power Quality Explained

What Is Power Quality & Why Is It Important?

With recent increases in energy prices and the continuing shift towards environmental sustainability, there has never been a better time for businesses to consider their energy efficiency. One of the more significant components of energy efficiency is power quality, with poor power quality often resulting in increased energy and repair costs. Below, we’ve included a comprehensive overview of power quality, how it can be measured and why and how you can make improvements.

Power quality establishes the suitability of electrical power supplying electrical installations and the components, switchgear and equipment connected therein. A well balanced, synchronised electrical supply will allow an installation to function in its intended manner without significant loss of performance, or causing damage to equipment installed such as motors and machinery.

Research shows that whilst almost a quarter of all power disturbances occur within the distribution network outside of a customer’s premises*, over three quarters of disturbances are being generated within the consumer’s installation itself. Within consumer premises, potential power problems include inrush currents caused by machinery starting up or shutting down, imbalanced phases, overloaded circuits or poor power harmonics, and this is where power quality analysis can be hugely beneficial.

*External disturbances can be caused by a wide variety of occurrences such as adverse weather conditions, failure of electrical equipment, animal interference, human error and even cyber attacks

UK Regulatory Requirements

Climate Change Levy, commonly known as "CCL", is a tax on UK business energy consumption introduced to help achieve reduced non-domestic energy consumption. It is charged at a specific unit rate depending on the energy source and is collected at the time of supply as a separate line item on the energy suppliers invoice. CCL was introduced to encourage larger businesses to reduce their energy consumption, promote energy efficiency and purchase of energy from renewable source. Through proper power consumption analysis, businesses can ensure they minimise any cost incurred through CCL, in addition to helping to minimise their environmental footprint.

Minimising Energy Consumption In-House

There are many ways in which companies can reduce their power consumption. The most popular remedies include power factor correction on certain items of equipment, and retrofitting new and improved energy-efficient equipment. Other power disturbances that affect power-quality could be:

Harmonics - harmonic voltages and currents in an electric power system are a result of non-linear electric loads and can generate increased heat in equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors.

Transients - (voltage spikes) can lead to tripped circuit breakers, short circuits and power outages which can all cause damage to equipment, or immediate failure of operation.

Minimising Risk

A power quality analyser is an instrument which is connected to an electrical supply with the use of current transformer (CT) clamps and voltage connections, with the intention of gathering power quality data across a specific duration of time. The unit is typically left in situ for the duration, with many models able to record hundreds of parameters simultaneously, including: voltage, current, voltage/current waveform peak, active power, reactive power, power factor, phase angle, frequency, current integration, power integration, efficiency, loss, voltage/current ripple factor, harmonics and electrical noise.

Some power quality analysers such as the Chauvin Arnoux CA8336 and Fluke 1777 feature live data streaming for many parameters, enabling the user to see exactly when a power problem may arise in real time. Most analysers also store data onto an internal memory card (typically SD format), so any power disturbances that aren't caught live can be stored for later analysis.

Other units such as the Chauvin Arnoux PEL series are used as data loggers. The PEL103 records data solely onto an internal memory format for download at a later date. Similar to the PEL103, the PEL104 and PEL106 feature small screens in order to display basic data including power consumption and power factor. Both units can be connected to a laptop or PC for live time analysis and can even be accessed from anywhere in the world should the unit be connected to a network via Ethernet.

Below we have included a 1 hour presentation from Megger, providing a deep dive on power quality and important concepts therein. You can view our full range of power quality analysers here. Alternatively, if you would like some additional advice or support, feel free to contact our expert technical advisors on 0113 248 9966 should you need any help in choosing the correct power quality analyser for purchase or hire.