The active energy management devices Pxt from Michael Koch GmbH
Active Energy Management Devices with internal storage

The PXT-FX increases productivity, saves energy and is an active buffer module for DC links.


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Michael Koch GmbH
Phone: +49 7251 96 26-200
Fax: +49 7251 96 26-210
Technical specifications
Max. Operating voltage UZmax (UL) 848 [VDC]
Max. Operating voltage UZmax (IEC) 1000 [VDC]
Max. Continuous output Pmax (at Uc = 800 VDC) 9 [kW]
Max. Peak power Pmax (at Uc = 800 VDC) 18 [kW] (peak 60s at a cycle time of 240s)
Max. Current storage peak IC 40 [A] (peak for 60s at a cycle time of 240s)
Max. Current storage continuous Ic 20 [A] (continuous)
Energy of integrated capacities 0 [kJ] [kJ] (stand-alone)
Energy of integrated capacities 2 [kJ] [kJ] (stand alone with 1 energy module)
Energy of integrated capacities 4 [kJ] [kJ] (stand alone with 2 energy modules)
Min. starting voltage for the system (DC link or storage) ca. 45 [VDC]
Operating frequency 15 [kHz]
Operating frequency 7,5 [kHz] (down to in operation load-dependent reduction)
Operating frequency 18 [kHz] (Manually adjustable)
Weight 6,0 [kg] (stand alone)
Weight 9,6 [kg] (stand alone with 1 energy module)
Weight 13,3 [kg] (stand alone with 2 energy modules)

With a current load capability of 20 amps duration and 40 amp peak for about one minute compared to storage, which may have a maximum voltage of 450 volts DC, the PxtFX can generate up to 18 kilowatts of power.

The device can be equipped ex works with a storage volume of two or four kilowatt seconds. Built into the device as standard is the automatic detection of the brake transistor switch-on voltage threshold, which enables the device to work with all standard frequency inverters and servo controllers in a plug & play manner. The extensive safety features of the PxtFX protect against reverse polarity of the DC link connections, against the connection of charged storage and against system overload on both the storage and DC link sides. Internal fuses are standard.

New features on the PxtFX include the SD memory card, an external 24-volt supply, status displays via LEDs, boot loading and reset options and 6 digital I/Os. This is supplemented by output functions via a USB module.

The applications are manifold, the devices provide benefits through a single feature or through the combination of two or more features.

The first thing that comes to mind is the recuperation of the machine's braking energy, which increases energy efficiency. The PxtFX can save up to 1.2 kilowatt hours of energy in its smallest expansion stage in one-second cycles per operating hour. In relation to the application itself, savings of up to a good 40 percent can be achieved with the active energy management system based on the PxtFX.

Often, however, other benefits play a greater role than increasing energy efficiency, such as the compensation of so-called brownouts, safe and defined standstill during blackouts, the possible acceleration of production processes with output increases of up to 50 percent, the reduction of network load peaks or even the operation of the electric drive independent of the power grid.