Modern electrical installations are more efficient than ever, but this progress has a downside. The increase in power electronics is causing growing 'contamination' of voltage and current. Harmonic contamination is a complex Power Quality phenomenon that can lead to unexplained faults, overheating and even fire in your installation.
It is crucial for plant managers and technical managers to recognise these risks in time. Where linear loads used to be the norm, modern non-linear loads such as LED lighting and variable speed drives create a distorted sine wave form. HyTEPS helps you recognise the signals and offers a structural solution to ensure your operational reliability.
The cause: Non-linear loads (such as LED, variable speed drives, EV chargers) distort the sinusoidal form of the current.
The risk: This distortion leads to additional heat generation, component wear, zero current and unexplained failure of sensitive equipment.
The standard: EN 50160 sets a limit of 8% for total voltage distortion (THDu), but in critical environments we recommend a maximum of 4%.
The solution: measuring is knowing. An Active Harmonic Filter (AHF) can dynamically compensate for pollution and restore Power Quality.
Harmonic contamination is an issue in any modern environment with many power electronics. This article was written specifically for:
Installation managers in industry dealing with variable speed drives and production downtime.
Technical Managers in hospitals and data centres where continuity is vital.
Engineers on marine projects where island operation and generators are particularly susceptible to contamination.
Facility Managers in large office buildings with lots of LED lighting, heat pumps and charging stations.
In an ideal situation, the voltage in your installation is a perfect sine wave form with a frequency of 50 Hz. We speak of harmonic pollution when this sine wave form becomes distorted. This distortion occurs because certain devices absorb the current not evenly, but in pulses.
Technical definition: Harmonics are voltages or currents with a frequency that is a multiple of the fundamental frequency (50 Hz). For example, the 3rd harmonic is 150 Hz, the 5th is 250 Hz.
A comparison: Imagine an orchestra playing a perfect symphony (the 50 Hz sine wave). Harmonic pollution can be compared to instruments playing right through the piece at wrong pitches. If this happens too loudly, the original melody can no longer be heard. In your installation, this means that equipment no longer recognises the 'melody' (the voltage) and stops working.
It sounds contradictory: the very equipment we install for energy saving and modernisation is the biggest source of harmonic pollution. We call these devices with non-linear loads.
Common sources are:
These devices use power electronics (such as diodes and thyristors) to control current. This process produces harmonic currents that flow back into the grid where they affect the voltage quality for other devices.
Solving harmonic contamination requires a step-by-step approach. Simply installing a filter without analysis is not recommended.
1. Measurement and Analysis Everything starts with a Power Quality measurement (baseline measurement). Our engineers map the harmonic spectrum (THDu, THDi and specific orders). We analyse whether the values are within the standards (e.g. EN 50160 or IEC 61000-2-4).
2. Active Harmonic Filter (AHF) The most effective solution is often an Active Harmonic Filter. This device acts as an 'anti-noise' system for your power. The filter continuously measures pollution and injects a counter current at lightning speed.
3. Passive Filter (specific situations) For very constant loads, a passive filter can sometimes suffice. This is a static solution tuned to one specific frequency. This is less flexible than an active filter.
When addressing Power Quality, we regularly see the same misunderstandings in practice:
Focus on THDu instead of THDi: People often only look at voltage distortion (THDu). However, the current distortion (THDi) is the source of the problem. A low THDu does not automatically mean there are no harmful harmonic currents running.
"It meets the standard, so it's good": The standard norm(EN 50160) allows up to 8% contamination. For sensitive equipment in hospitals or data centres, this is often already too high. HyTEPS uses a stricter guideline of 5% there.
Going blind on capacitor banks: Placing a standard capacitor bank in a contaminated grid is dangerous. Without filter chokes, resonance can occur, leading to damage.
Symptom management: replacing a faulty circuit board or fuse does not solve the cause (the contamination). The problem will recur.
Recognise the signals in your installation. If you recognise one or more of the points below, further investigation is required:
Next step: Do you recognise these signals? Then schedule a measurement. No diagnosis is possible without data.
Symptoms are often subtle until things go wrong. Look out for unexplained machine failures, flickering lights, cables getting hot or transformers buzzing. Also, if electronics (PLCs, drivers) fail earlier than the service life indicates, chances are that the power quality is insufficient. A Power Quality measurement provides the answer.
This is possible, provided you have a high-quality Power Quality Analyzer (according to IEC 61000-4-30 Class A) and the knowledge to interpret the data. Collecting data is easy; analysing the correlation between events, harmonics and your specific business processes requires specialist engineering knowledge. We are happy to support you in the analysis.
Not by definition. NEN-EN 50160 describes the minimum requirements for voltage at the grid operator's transfer point. However, modern equipment can be more sensitive and malfunction even if the voltage is within this standard. We therefore look beyond the standard: we look at the compatibility between your power supply and your connected load.
Peace of mind, certainty and insight. You get a clear diagnosis of the 'health' of your electrical installation. We pinpoint the cause of faults, enabling you to avoid unplanned downtime and reduce fire risks or unnecessary energy losses. You receive a concrete advisory report with practical points for improvement.
No, that is a misconception. A filter is a powerful tool, but not a panacea. Sometimes the solution lies in changing transformer settings, redistributing loads or adjusting cabling. HyTEPS always recommends a thorough analysis and simulation before we recommend hardware, to avoid unnecessary investments.
Yes, significantly. Solar panel inverters and LED lighting drivers are non-linear loads that cause harmonics and sometimes supraharmonics. This can lead to interference with other equipment or overloading of the neutral conductor. When renovating or preserving, a Power Quality check is essential to ensure operational reliability.
We call this phenomenon 'nuisance tripping'. Often the cause is not the total amount of current, but the distortion of the current (harmonics) or short peak currents that your measuring equipment misses. This contamination can extra heat up thermal protections or confuse electronic protections, causing them to switch off wrongly. A specialised measurement can find out exactly why a protection reacts.
For a reliable picture, we usually measure at least one to two weeks. This is necessary to capture a full duty cycle, including weekends and peak loads. For specific acute failures, we can also take short-term measurements or deploy 'continuous waveform recording' to capture transients.
Your installer is an expert in installation and maintenance (the 'general practitioner'). HyTEPS is the specialist (the 'Power Quality Doctor'). We have advanced measuring equipment, simulation software and in-depth knowledge of theoretical electrical engineering and regulations. We often work together with installers to solve complex puzzles that fall outside standard knowledge.
After the measurement, you receive a report with conclusions in understandable language as well as technical details. If necessary, we simulate the possible solutions in our software. So you know exactly what the effect of a measure will be in advance. We then supervise the implementation and verify the result with a follow-up measurement.
Don't wait for a failure to shut down your process. Our engineers can simulate your plant, measure and implement the right solution (such as an Active Harmonic Filter). We take responsibility from diagnosis to commissioning.
HyTEPS
Beemdstraat 3
5653 MA Eindhoven
