64 active filters ensure maximum voltage quality at Munich airport
Many of the GRIDCON® ACF active filters were fitted in air-conditioned outdoor cases designed for this purpose. Martin Zitzelsberger (Flughafen München GmbH) and Tobias Knispel (MR) are very satisfied with the solution.
Munich Airport is the first 5-star airport in Europe. Achieving this level of excellence requires ongoing investment, such as that currently being made in the satellite terminal, which is nearing completion. Environmental protection is an important aspect here. So the companies Terminal 2 Gesellschaft and Flughafen München GmbH (FMG) are investing in the installation of pre-conditioned air (PCA) systems. Active filters from Maschinenfabrik Reinhausen (MR) play an important role here.
By the summer of 2016, 64 passenger boarding bridges will have PCA systems to provide the planes in their parking positions with temperature-controlled fresh air. Directly beside the parking position next to the building, outside air is treated in an air treatment system, i.e. filtered, compressed and cooled or heated. This air is then transported straight into the aircraft cabin via an insulated hose. The systems will take the place of the auxiliary power unit used to date – and will avoid noise, unnecessary kerosene consumption and therefore unnecessary CO2 and NOx emissions. More than 23,500 tons of carbon dioxide (CO2) will be saved annually.
One main component of the PCA system is the AHU (Air Handling Unit), which ensures that the air is conditioned and distributed. The speed of the three internal drives of the AHU with various outputs is controlled by 6-pulse frequency converters (B6). Unlike situations where pure AC consumers are connected to the grid, frequency converters with inverter circuits at the input end cause distortions in the sinusoidal grid AC voltage.
Harmonic currents with different amplitudes and frequencies form. Depending on the grid reactance, superimposing the fundamental component with these higher frequency currents may have a major effect, of relevance to safety, on other electronic components in the grid. The clients decided to implement the filtering needed centrally at each AHU.
MR has a solution to this problem: GRIDCON® ACF. The modular active filters were adapted to the relevant output classes of the AHU and maintain the voltage quality and an interference-free power supply in the airport's own grid. A total of 64 active filters were installed – most of which had to be housed outdoors with air-conditioned outdoor cases designed especially for this purpose. Active filters take the strain off the grid, extend the service life of equipment, and improve the safety of industrial facilities.
The 64 installed GRIDCON® ACF active filters from Maschinenfabrik Reinhausen ensure an interference-free supply of power in the grid at Munich airport. The touch panel makes simple commissioning and operation possible. Tobias Knispel (left, MR) explains to Siegfried Mannes (Terminal 2 GmbH) how the touch panel works.
The function of the active filters is clearly displayed on the touch panel. Sophisticated control procedures produce a current (blue) in opposition to the distorted load current (green), which is added to the grid current (red) to produce a purely sinusoidal, undistorted current. The interfering current harmonics are eliminated and the voltage quality is improved considerably.
In a complex, multi-stage bidding process, the MR project solution suggestion prevailed over others from well-known competitors. The experts from MR's Power Quality (PQ) division impressed the client with their filter design, which was calculated specifically for the application and was very precise and therefore cost-effective. The impressive service concept and MR's ability to supply and commission a pilot system in the period required by the client also helped clinch the order.
Regular operation of the first PCA system with active MR filters commenced just a few days after the order was placed. After analyzing the results of the one-week test run, the expert from the Technical Inspection Association (TÜV) commissioned by the airport confirmed that compliance with the rigorous limit values had been consistent.
The PQ Power Quality division at MR has been delivering filter and compensation systems for clean low- and medium-voltage grids the world over for over 15 years. The division's work focuses on reducing harmonics and compensating for reactive power in public and industrial distribution grids.