It is a scenario that we at HyTEPS see more and more often: installations that inexplicably fail, control systems that "ghost" and LED lights that flicker, while the Power Quality analyser gives a neat, green status. Harmonic pollution (THD) is low and voltage is stable. Yet your process is at a standstill. Chances are you are dealing with supraharmonics: pollution in the frequency range from 2 to 150 kHz.
This phenomenon is referred to by many as the "blind spot" of contemporary electrical engineering. Why? Because the standard standard(EN 50160) and most measuring equipment only look up to 2.5 kHz (the 50th harmonic). Anything above that is ignored.
However, in a modern environment full of inverters, LED drivers and EV chargers, this area is anything but quiet. Supraharmonics pose a growing risk to the operational reliability of advanced installations. Where standard solutions stop, HyTEPS' expertise begins. We make the invisible visible, analyse the interaction between your equipment and the installation, and provide a definitive solution.
What is it: High-frequency voltage and current distortion (2 kHz - 150 kHz).
The cause: switching frequencies of power electronics (PV, EV, VSD, LED).
The risk: PLC failures, defective capacitors, communication failures (smart grid).
The solution: high sampling rate (>2.5 kHz) measurement and impedance correction.
Supraharmonics are inextricably linked to the energy transition and digitalisation. Old, linear installations (with motors direct-online and light bulbs) do not suffer from this. The problem arises precisely where there has been investment in efficiency.
This information is essential for:
Technical Managers and Installation Managers (IV): You are responsible for continuity. If new equipment (such as heat pumps or charging stations) causes failure of existing processes, you need to be able to pinpoint the cause to management or suppliers.
Electrical Engineers: You design or manage complex installations. Knowledge of impedance behaviour at higher frequencies is necessary to avoid resonance problems at the design stage.
Facility Managers: You get complaints about buzzing noises, faulty lighting or faltering building management systems after a renovation.
Maintenance Parties: You look for a cause when components such as capacitors or power supplies fail much faster than the specifications promise.
The paradox of supraharmonics is that the technology that helps us become more sustainable (inverters, Active Front End drives) is also the source of this pollution. Without the right knowledge and measures, an investment in sustainability can lead to a decrease in reliability.
To understand supraharmonics, we need to look at the full frequency spectrum of Power Quality and EMC (Electromagnetic Compatibility). Historically, there has been a gap in regulation and attention:
Supraharmonics are in the twilight zone between these: from 2 kHz to 150 kHz.
For a long time, it was assumed that there was little emission in this frequency range. With the advent of modern power electronics, this has changed radically. Devices convert alternating current (AC) to direct current (DC) - and vice versa - using switching techniques (Switching). The switching frequencies of these components lie exactly in this 'forgotten' area.
A key distinction from classical harmonics is their behaviour. Whereas low harmonics are often static, supraharmonics are highly dynamic. They often arise not from a single dominant source, but from a complex interaction (resonance) between the filters of different devices and the impedance of the installation. It is a system phenomenon, not a pure device phenomenon.
The danger of supraharmonics is often underestimated because voltage levels in this frequency range are relatively low. However, due to the natural laws of electricity, even low voltages at high frequencies can cause devastating currents.
Because your standard power meter does not sound an alarm, you should pay attention to secondary symptoms.
Supraharmonics are a by-product of modern electrical energy conversion. Almost all modern equipment uses Switch Mode Power Supplies (SMPS) or inverters.
Primary enablers:
The resonance effect (Amplification): Often the emission from one piece of equipment is within limits. The problem arises from interaction. Each device has an EMC filter with capacitors. The grid inductance and capacitance of all those filters together form a resonant circuit. If the resonant frequency of that circuit coincides with the switching frequency of an inverter, the current is amplified many times. This explains why a problem sometimes occurs only after an 'innocent' device has been added.
Solving supraharmonic problems requires a different approach than classic Power Quality issues. Blindly placing capacitors or installing standard filters is counterproductive.
Step 1: High-frequency measurement (Continuous Waveform Recording)
Because standard meters are blind above 2.5 kHz, HyTEPS engineers deploy advanced measurement equipment that samples down to the MHz range. We perform spectrum analysis to see exactly which frequencies (e.g. 23 kHz or 48 kHz) are dominant. With Continuous Waveform Recording, we also capture transient peaks that occur during specific switching behaviour.
Step 2: Impedance analysis
Measuring is knowing, but understanding is solving. We not only look at pollution, but also model the impedance of your installation. Where are the resonance points? Which device 'fights' with which other device?
Step 3: Targeted measures
Depending on the analysis, we advise:
In practice, we often see attempted solutions that exacerbate the problem.
Do you suspect supraharmonic disturbances? Run through these points:
Not every failure requires in-depth supraharmonic analysis. However, in the following situations, waiting is not an option:
HyTEPS has the expertise and tools to identify this invisible problem and take responsibility for the solution.
Don't keep searching in the dark. A standard measurement won't give you answers, a specialist analysis from HyTEPS will. Speak to one of our engineers to discuss your situation and draw up a plan of action. We will make sure your installation is once again doing what it was designed to do: run reliably.
HyTEPS
Beemdstraat 3
5653 MA Eindhoven
