Patent ID: 8085122

Claim:
A high voltage step-up dry power transformer comprising: at least one module which defines a lower voltage primary side and a higher voltage secondary side and which comprises at least one primary winding and at least one secondary winding, wound concentrically around a ferromagnetic core body, and at least one shielding and/or insulating surface structure being arranged between the primary and secondary windings, transformer ( 1 ), wherein the primary winding(s) at a lower voltage is situated outwardly, in that the outer primary winding ( 2 ) or winding parts ( 2 ′) is (are) made of at least one insulated high voltage cable ( 7 ) and in that the at least one intermediate conductive surface structure ( 5 ) and/or the core body ( 4 ) are set at a referential DC potential which is a fraction of the output voltage on the secondary side of the or each module ( 1 ′).