Brief description: Project Clinical Center Kassel

The emergency power plant has a total power of 2050 kVA and consists of three units with an individual performance of 680 kVA.

For the actual power supply two of the three units would be adequate. But through the use of three standby power units, a higher availability can be achieved. So for maintenance work, a mobile rental unit is no longer necessary. In addition to that, the emergency power plant is designed for a p
arallel grid trial run, which enables the customer to shut down peak demands or to integrate the unit to the interconnection of “Minutes-reserve”.

The emergency power system is designed in a way that, in case of a power failure, all of the three power units inherit the feed-in of the SV-Rail within 12 seconds after the detection. Such a fast supply of SV-rail applied function is called ramp-synchronization. In a conventionally designed power plant with three generators, it would be last at least 40 seconds until the supply of the SV-rail would be initiated.

The trial run with the network reference scheme provides that all power plants start at first. Only if all three generators are synchronized to the generator busbar, it will also be synchronized to the SV-rail so that the entire emergency power plant operates parallel to the grid. Now, the performance of the plant is being raised until the power relation of the SV-rail is approximately 0 kW. In this case, the network dome switch, which connects the SV-rail with the AV-rail, opens and the emergency power plant has inherited the sole care of the SV-rail. Upon termination of the test operation, the system is synchronized parallel to the network again to give the feed-in back to the grid.

The network parallel testing runs similar to the trial run with the network reference scheme, except that the emergency power plant operates parallel to the grid during the whole process and delivers as much power into the grid as desired by the customer. In addition, the emergency power plant has the possibility to start the
trial run with the network reference scheme or the parallel network testing from afar with help of a connected fieldbus interface (Profibus DP). For the network parallel testing the default value of performance can also be communicate.