AC/DC converter for aeronautics
The invention relates to the electrical power supply of aircraft and notably of large commercial aircraft. According to the invention, the aircraft is equipped with an AC-DC converter that distributes power over a DC network starting from a three-phase alternating voltage of 230 volts applied to its main inputs (E 1 , E 2 , E 3 ). The converter comprises an autotransformer which preferably has nine outputs (A 1 , A 2 , A 3 , B 1 , B 2 , etc.) for a nine-phase rectification. These outputs are applied to a rectifier bridge with 18 diodes. When the aircraft is on the ground, the AC power is delivered at 115 volts from a ground generator; it is applied via a three-phase connector (CAUX) to auxiliary inputs (M 1 , M 2 , M 3 ) connected to intermediate taps of the three-phase windings forming the AC-DC converter.
1. An AC-DC converter, comprising:
an autotransformer having three main inputs configured to be optionally connected to a first three-phase AC supply voltage and more than three outputs and a rectifier bridge with more than three phases connected to the outputs of the autotransformer, the autotransformer comprising a magnetic core with three branches and on each branch a main winding and auxiliary windings, the auxiliary windings of one branch being electrically connected, at one end, to taps of the main windings of this branch or of another branch and, at the other end, to a respective output of the autotransformer, all of the connections exhibiting a circular permutational symmetry allowing a balanced three-phase operation; and
three auxiliary input terminals configured to be optionally connected to a second three-phase AC supply voltage, each one tapped on a respective winding according to a three-phase permutational symmetry, at a location where the amplitude of the voltage is Va/g when the first three-phase AC supply voltage present on the main inputs having an amplitude Va, where g is a number different from 1, and wherein these three auxiliary input terminals are connected to a three-phase connector in order to form an auxiliary three-phase input for the second three-phase AC supply voltage having an amplitude Va/g to be optionally received in replacement for said first three-phase AC supply voltage having the amplitude Va at the main inputs of the AC-DC converter with the same effect as if said first three-phase AC supply voltage were applied to said main inputs.
2. The converter as claimed in claim 1 , wherein the auxiliary input terminals are tapped at a location where the amplitude is Va/2 when the first three-phase AC supply voltage present on the AC-DC main inputs has said amplitude Va.
3. The AC-DC converter as claimed in claim 1 , wherein the main windings are electrically connected in a delta configuration between the three main inputs of the AC-DC converter, the auxiliary windings of one magnetic branch are each connected to a tap of a main winding of another branch, and the auxiliary input terminals are each tapped on a main winding.
4. The converter as claimed in claim 3 , wherein the auxiliary input terminals are center-tap terminals placed in the middle of the main windings.
5. The converter as claimed in claim 1 , wherein the main windings are connected in a delta configuration and have each an end terminal or an intermediate tap connected to one main input through an auxiliary winding.
6. The converter as claimed in claim 2 , wherein the main windings are connected in a delta configuration and have each an end terminal or an intermediate tap connected to one main input through an auxiliary winding.