Abstract: The invention relates to a power semiconductor module having at least one power semiconductor switch, a cooling system, control electronics and a relieving network. According to this invention, these components are cast with an insulating medium to form a solid block, with the connections of the power semiconductor switch, the control equipment and the cooling system projecting out of the block. This yields a compact power semiconductor module which can be installed in an outdoor framework structure and is encapsulated to insulate it against environmental influences.

Abstract: An energy transmission system includes a high-voltage direct-current transmission main in the form of a ring for supplying consumers located within the ring. The high-voltage d.c. main is fed from a three-phase network through rectifiers, and power output groups located at a plurality of points within the ring are connected to the latter. Each power group consists of a plurality of partial inverters connected in series between the poles of the d.c. main and an alternating current consumer network to be supplied is connected to the output of the inverters. Each output group of inverters includes a regulating device to monitor and regulate current and voltage to pre-set values dependent upon the power requirement of the inverter group such that one inverter of a group regulates the common direct-current applied to the output group and the other inverters of the group regulate their direct voltage so that the resulting sum voltage is equal to the amplitude of the direct voltage of the common main.