The presence of harmonics in electrical systems has been an issue in power quality and efficiency. These are the voltage or current waveforms, which appear at frequencies that are integer multiples of the fundamental frequency. For example, if one considers Australia’s power grid as running at 50 Hz, the possible harmonics would include 100 Hz (2nd harmonic), 150 Hz (3rd harmonic), and so on. These deviated waveforms distort the ideal sinusoidal shape of electrical signals leading to a range of issues in power systems.
An easy-to-understand definition of harmonics is nonlinear loads, which draw current in abrupt pulses rather than in a smooth sinusoidal way. VFDs, switching power supplies, LED lighting, and UPS are among the common sources of harmonics. Since these are widely used devices, it is important to know how to detect these harmonics to maintain power quality and efficiency.
Harmonic detection requires advanced tools and methodologies that will determine distortions in electrical waveforms. The best tool for this purpose is the Power Quality Analyzer, or PQA. A PQA measures voltage, current, and power across various frequencies and provides detailed harmonic distortion analysis, including critical parameters like Total Harmonic Distortion and individual harmonic levels. It gives the engineer an overall view of the harmonic content in the system and where intervention is required.
Another detection method is the oscilloscope. The waveform distortions can be seen directly using an oscilloscope. Less advanced than a PQA, the devices are perfect for showing immediately if any anomaly exists in the waveforms. Digital relays are also gaining popularity these days for harmonic detection. Most of the modern relays have been equipped with this harmonic detection capability and are very suitable for real-time monitoring in industrial systems.
More theoretical analysis on electrical systems would include harmonic content modeled and analyzed through simulation software like MATLAB and ETAP. The design phase of electrical networks, in this regard, may prove particularly helpful for planning upgrades in existing systems. Through simulations of a few scenarios, it would be possible to predict what the potential harmonic issues are likely to be, hence designing the solution to mitigate these effectively.
A good starting point is the detection of harmonics, but equally important is knowing their source and mitigating the effects. It is with an investment in the proper detection tool, such as PQAs, and simulation software that engineers and businesses can further improve system performance, reduce losses in energy consumption, and observe compliance with standards for power quality. Ultimately, the solution of harmonics does help in improving the reliability of the system along with that of a sustainable as well as efficient electrical infrastructure.
We design and manufacture high-quality switchboards. Contact us today to discuss your requirements and get started!