Comsys – Perfecting Power

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The benefits of using ADF Power Tuning on a ship or rig are many, including:

  • Less hassle during retrofits
  • Doubled mean time between failures
  • Reduced running cost
  • Lower capital expenditures


THD compliance and common issues

It’s no secret that ships operate on weak grids with large dynamic loads. Common power quality problems for ships, harbor cranes, and marine vessels are reactive power, imbalances, flicker, and harmonics—which can cause power failures and damage sensitive equipment.

A unique challenge for the marine industry is meeting the class requirements that define strict rules regarding harmonics. This is complicated by the increased use of variable-frequency drives (VFD), which are commonly used to conserve energy, but, as a side effect, enhance harmonics. In the past, the common low harmonic solution has been to compensate large loads individually through the use of AFE drives or multipulse drives with a phase-shifting transformer, but these solutions are unnecessarily heavy and complicated.

Six advantages for you

1. Seamlessly meeting standards

The ADF product range has been certified according to most marine standards, such as DNV GL, ABS, and BV.


Additionally, these regulatory bodies mandate THD (total harmonic distortion) limitations for operating vessels. Non-compliance comes with heavy fines or even a demand to cease operations. The highly dynamic capabilities of ADF technology make this solution ideal for achieving THD limits.

2. Take advantage of standard six-pulse drives

ADF Power Tuning can be applied to the main bus bar. Because of this, all loads in the systems can use standard six-pulse drives. There is no longer a need for different types of front end units.

Six pulse drive

Standard six-pulse drives are less expensive and easier to source and service—not to mention reliable. Combined with the modular structure of ADF Power Tuning, we enable dependable redundancy.*

*By using multiple modules and the multi-master functionality, ADF Power Tuning enables you to maintain significant compensation, even if one power module fails.

3. Simplify your THD mitigation

By applying a stack of filter modules on the main bus bar, we eliminate the need for THD compensation on individual drives. And the modular central filtering units keep the harmonics on the bus bar within class requirements.

4. Double the mean time between failure of large drive functions

With ADF Power Tuning, you can expect your MTBF (mean time between failures) to double. Unlike AFE (active front-end drives), ADF Power Tuning is connected in parallel (in shunt) with the drive on the bus bar, making drive function completely unaffected even in the face of a filter failure.

With ADF Power Tuning, you can expect your MTBF (mean time between failures) to double.

5. Save fuel

A typical MPSV (multi-purpose supply vessel) consumes about 4,500 – 7,000 tons of fuel per year. The efficiency of typical diesel electric propulsion indicates that about 5% in losses occur through the active front-end (AFE) drives or multi-pulse drives.

If ADF Power Tuning is implemented, the losses of energy compared to AFE are 30%-40% lower. And with reduced energy demands comes decreased fuel consumption.

If ADF Power Tuning is implemented, the losses of energy compared to AFE are 30%-40% lower.

6. Minimize hassle when retrofitting drive equipment

A common problem when installing drives on an existing vessel is the increase in harmonics on the ship’s grid. This can be especially disruptive because the grid is often not sized for such changes in electrical loads. Additionally, there is often a space constraint, making it challenging to fit conventional low harmonic drives, particularly large AFE drives.

While the common solution to this issue has been to use AFE drives or multi-pulse transformers for large loads, with ADF Power Tuning, the filter is decoupled from the drives. This makes it possible to be placed anywhere and greatly simplifies installation, providing flexibility in decision-making and space-utilization.

Applications by Industry

This section exemplifies applications in various industries where the ADF Active Filter can be used to improve operational and environmental performance. Click on your industry to learn more.


Water Treatment

Pumps and feeding screws are used in the water treatment industry to dynamically control liquid levels, flows and consistencies. ADF Active Filter is the tool to save energy and take the sting out of harmonics and other disturbance behaviours.

Offshore Oil and Gas Industry

Offshore oil and gas platforms sometimes suffer from weak or instable electrical networks. This is a consequence of own local power generation. By letting ADF Active Filter monitor and manage the network, production uptime is ensured through disturbance free and reliable power supply.


The economics of continuous processes like refinery are based on high availability, high volumes and cost awareness. Reduced energy costs and mitigated production disturbances are some of the benefits of ADF Active Filter. Compressors and pumps are two typical applications within refinery.

Steel and Aluminium Industry

Manufacturing of steel and aluminium is highly energy intensive why every percent reduced energy consumption quickly can send large savings directly to the bottom line. Moreover, processes like induction melting might cause electrical interference with other equipment.

Harbour Cranes

Loading and unloading ships involves large cranes with considerable energy costs. Especially hydraulic cranes display a dynamic demand for reactive power that active filtering technology like ADF Active Filter is outstanding to satisfy.

Automotive Industry

Being one of today's most competitive industries, automotive manufacturers constantly seek ways to streamline production and reduce costs. This often includes automation and installation of advanced machinery. Equipment like electric welding systems, robots and presses share rapid and complex electrical behaviour. Traditional passive technologies to suppress reactive power are unable to follow their dynamic behaviour leading to higher energy consumption. ADF Active Filter ensures complete power factor control and lower energy costs.


The foundry business is very energy intensive. The consumption behaviour is dynamic, i.e. it varies over time, which stresses the importance of active filtering technology to optimize the energy conditions.

Metal Processing

Milling, welding, and grinding are examples of metalworking processes where electricity is used dynamically and randomly. ADF Active Filter surge for the right amount of reactive power at every instant. It is even capable of managing the high and rapid currents stemming from electrical welding systems.

Manufacturing Industry

Manufacturing in today's competitive business environment means adding more value to products and machineries. This leads to more sophisticated constructions and complex assembly. The cost of failure increases and accentuates the importance of disturbance free production. ADF Active Filter is your assurance for optimal energy conditions and minimized consumption.

Pulp and Paper Industry

The start and stop of large machinery, like wood chippers and the paper machine itself, can cause voltage variations and transients to spread throughout the network. The paper finishing process with its large cranes and slitter cuts is another area of interest. Not to forget is the handling of the process water and water treatment facility where variable-speed drives and pumps consume reactive power and generate harmonics.

Plastic Fabrication

Injection moulding and 3D-layering are examples of plastic fabrication processes where automation and variable-speed drives are essential to maintain constant quality and avoid disturbances. ADF Active Filter resolves that and ensures safe and optimal energy conditions for sensitive manufacturing processes.


The packaging industry features large machines whose energy consumption becomes more complex as automation increases. Also, the fabrication of the packaging material itself often involves lamination and extrusion, two well-known applications where ADF Active Filter has proven its performance.

Process Industry

An increasing amount of equipment with non-linear electrical behaviour is connected to the network as process plants are becoming automated. These machineries, including variable-speed drives and computerized machines, pollute the network with disturbances and losses that add up to considerably higher energy costs. Large energy consuming machines constitute other applications with large savings potential.

Food Processing

Food processing can be comprised of liquid processing, grinding, milling, pressing and many more processes. They all share similar dynamic reactive behaviour that is ideal to manage with ADF Active Filter.

Utility Companies

The European electricity system is under strain due to overall growth. This can be solved by either investing in more capacity or reducing consumption by users. Saving rather than investing in new capacity is an extremely cost effective way for society and beneficial for the environment. Comsys provides the unique ADF Active Harmonic Filter solution, which reduces consumption as well as peak demand and at the same time improves end user productivity.

Furthermore, an increasing number of connected equipment with non-linear electrical behaviour is connected to the network. These cause losses and reduce network productivity. By removing the loss creating behaviours, ADF Active Filter gives room for supplying more customers and improve network capacity for utilities.

Please contact Comsys AB or our partners for a consultation »