Are you experiencing production stoppages, failing PLCs or jammed variable speed drives even though the main voltage is not completely lost? Chances are that voltage dips ( voltage sags) are the cause. In modern, state-of-the-art installations, these short voltage drops are disastrous for continuity.
A SAG Compensator (or Active Voltage Conditioner) corrects these dips in real time. Unlike a conventional UPS, this system often does not use batteries, but advanced power electronics to maintain voltage. The result: your critical processes keep running even when the grid fluctuates.
Short on time? Here are the key points you need to know:
The problem: Short voltage drops (dips) cause sensitive electronics to shut down or reset, leading to costly downtime.
The cause: often external (short circuit elsewhere in the grid, thunderstorms) or internal (switching on heavy motors).
The solution: A SAG Compensator injects extra voltage at lightning speed to restore the sine wave form.
The difference: Whereas a UPS uses batteries for complete failure, a SAG Compensator is optimised for dips: more efficient, compact and low-maintenance.
This technology is indispensable in environments where fault tolerance is zero and restart times lead to major financial losses.
A SAG Compensator, also known as an Active Voltage Conditioner (AVC), is a piece of power electronics placed in series between the power grid and your critical load.
You can compare it to the active suspension of a car. When you drive over a pothole (the stress dip), the suspension immediately pushes the wheel down so that the body (your installation) remains stable and straight.
The system continuously measures the input voltage. As soon as it drops below a set threshold (e.g. 90% of nominal voltage), the compensator "injects" the missing voltage within milliseconds. This happens so quickly (often <3 milliseconds) that connected equipment such as relays, PLCs and robotics do not notice any disturbance.
The quality of our electricity supply is under pressure due to the energy transition. Although complete power outages (blackouts) are rare in the Netherlands and Belgium, voltage dips occur daily. For modern electronics, a dip is often just as fatal as a blackout.
The consequences are often greater than first thought:
Nuance: Many companies think their energy supplier is responsible for a perfect sine wave. The reality is that the grid operator works according to the EN 50160 standard. This standard allows considerable margins in voltage variations. A dip is often "compliant with the standard", but disastrous for your process.
Voltage dips are often force majeure. They occur due to physical laws in the power grid. We distinguish two main categories:
1. External causes (from the grid) This is the most common cause.
2. Internal causes (within your installation)
When companies experience outages, they often traditionally turn to an Uninterruptible Power Supply (UPS). While a UPS is useful, for voltage dips only, it is often an expensive and inefficient choice. A SAG Compensator is specifically designed for this problem.
Below are the main differences for a technical consideration:
1. Maintenance and Batteries
2. Efficiency (Yield)
3. Footprint
When to choose what?
In practice, our engineers often see investment in solutions that do not eliminate the problem.
Want to structurally get rid of voltage dips? Follow these steps for a solid approach.
Selecting the right voltage compensation is complex engineering work. Engage a specialist if:
At HyTEPS, we first analyse the installation with measurements and simulations. We do not sell a "box", but guarantee to solve the problem.
Delve further into the subject matter via these related pages:
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 the next production stop. Our engineers can precisely identify whether voltage dips are your bottleneck with a targeted measurement.
HyTEPS
Beemdstraat 3
5653 MA Eindhoven
