An electric supply
system comprising two or more phases (R2, S2, T2), one
rectifier (101, 103, 105) for each phase, the second primary terminals of said rectifiers (101, 103, 105) being interconnected, also comprises an Artificial Neutral Point (ANP) creating means (A2) for creating an artificial neutral point (NA2) in the electric supply
system, connected in parallel with said rectifiers. The ANP means (A2) short-circuits the zero sequence
voltage component of the
system but does not affect the positive and negative sequence components. The ANP means (A2) includes
magnetic components of such a kind that the vector sum of the phase voltages is zero. According to a first embodiment, the ANP means (A2) comprises one
transformer (113, 115, 117) for each phase, the primary winding of each
transformer connected to the respective phase (R2, S2, T2) in a star configuration, the secondary windings serially connected and the
interconnection point of the primary windings forming an artificial neutral point.