Laboratory with highest impulse current and 50 Hz-short-current parameters specially designed for the qualification-testing of SPDs

The “class I and II operating duty tests” according to IEC/EN 61643-11 is an essential test for the qualification of surge protective devices (SPDs) connected to low-voltage power systems (LVPS). To perform this test a setup is required which offers the possibility to stress the SPD with defined surge-current impulses while it is connected to a power supply simulating the characteristic of the real LVPS in which the SPD should operate. In this regard, a new test facility is designed and constructed. One of its feature is a 50 Hz power system (PS) which provides unique fine adjustment possibilities for the test voltage, the short-circuit current and the power factor in a wide range of values. Its technical design and performance are described and discussed in detail. Furthermore, the technical implementation of the required coupling of this PS with a surge-current generator is presented. This addresses technical measures to protect the PS against electrical stress due to partial surge currents which can occur under certain circumstances during the above mentioned test procedure. Finally, test results obtained from lightning current arresters are presented to demonstrate the performance of the test facility.