High-voltage direct-current supply with over-current protection

摘要

A high-voltage direct-current supply system which includes over-current protection and in which the load current supplied by a high-voltage source is measured in a current-measuring device. The high-voltage source includes a plurality of series-connected medium-high voltage sources each of which can be individually turned on and off and each of which includes at least one switching element. The switching elements are switched to interrupt the load current through the respective medium-high voltage source in the event that the load current exceeds a predetermined limit, as detected by a load current limit detector. By providing plural medium-high voltage sources with associated switching devices to derive a composite output voltage from the sum of the outputs of the individual medium-high voltage sources, an economic, flexible and functionally reliable supply unit is produced which has a high efficiency and long service life.