What is Power Quality?
Power quality is often defined as the electrical network's or the grid's ability to supply a clean and stable power supply. In other words, power quality ideally creates a perfect power supply that is always available, has a pure noise-free sinusoidal wave shape, and is always within voltage and frequency tolerances. However, with increasing and varying energy demands from various industrial processes, many loads regularly impose disturbances on the grid, making deviations from these ideal conditions are frequent.
The Problem: Poor Power Quality
Poor power quality is a problem for a many industries, from data centers to offshore oil rigs. Low power quality contributes to high energy cost and rising energy and production disturbances—which is especially problematic for increasingly sensitive modern production equipment. Ironically, it is often the equipment itself that generates the disturbances.
Current Behaviors that Cause Losses and Disturbances
Unstable energy loads waste energy and cause electrical and production disturbances. They are a growing problem in the electrical environment.
Electrical current behaviors that create losses constitute reactive behavior (phase displacement due to electric or magnetic fields), harmonics (disturbances to production and/or the energy grid), and unbalance (uneven power distribution between the phases in the electrical network).
Current behaviors that create electrical disturbances include transients (fast disturbances, bursts of energy), voltage variations, flicker, and resonance (oscillations that cause instability and overloading).
The most common behaviors that waste energy significantly and contribute to electrical disturbances include:
|Reactive power: The phase angle between the current and voltage waveforms in an AC system. Used to develop magnetic field in motors, causes low power factor.||Voltage variations (dips, sags, swells, brown-outs): The line voltage is higher or lower than the nominal voltage for a shorter period. Caused by e.g. network faults, switching of capacitive loads, and excessive loading.|
|Harmonics: Multiples of the supply frequency, i.e. the fifth harmonic would be 250 Hz if the supply frequency is 50 Hz. Caused by e.g. power electronic loads such as variable speed drives and UPS systems.||Flicker: Random or repetitive variations in the voltage. Caused by e.g. mills, EAF operation (arc furnaces), welding equipment and shredders.|
|Network unbalance: Different line voltages. Caused by single-phase loads, phase to phase loads and unbalanced three-phase loads like welding equipment.||Oscillations (resonances): The flow of electrical energy, e.g. between the magnetic field of an inductor and the electric field of a capacitor, changes direction periodically.|
|Transients (fast disturbances): Rapid change in the sine wave that occurs in both voltage and current waveforms. Caused by switching devices, start- and stop of high power equipment.|
The Consequences of Poor Power Quality
When optimizing processes to mitigate interruptions to production or quality issues, power and power quality are often overlooked issues. Some common direct impacts of poor power quality are:
In addition to the direct impacts above, poor power quality often negatively impacts business costs. Such as with:
Achieve Power Quality with our Active Dynamic Filters
Traditionally, fixed electro-mechanical and semiconductor controlled filters and/or compensators have been used to limit behaviors that waste energy. They operate mainly on a fixed or stepped basis using passive elements. But these solutions have multiple disadvantages - they add losses, are installation-specific, and have no ability to adapt to dynamic load changes.
Active Filters, such as ADF Power Tuning, eliminate energy-wasting behaviors such as harmonics, flicker, voltage variations, and reactive energy using a highly dynamic, digitally controlled compensation and filtering approach. ADF Power Tuning restores the current waveform instantaneously, lowers the current consumption, and fully compensates changes in load or installation conditions at all times. Read more about ADF Technology.
ADF Power Tuning Product Range
Our Active Harmonic Filter product range consists of four main product families:
Each ADF unit targets different power levels in commercial and industrial applications in the low and medium voltage segments.
What are you Paying for Poor Power Quality?
Improving power quality reduces risk, raises throughput, decreases the cost of doing business, and improves your bottom line.
For support with making a decision for your facility, don’t hesitate to contact us.