Patent ID: 7453331

Claim:
A three-phase harmonic line filter, comprising: a first filter branch between a first filter input and a first filter output, the first filter branch comprising a first series connection of three inductances including an input inductance or an output inductance, connected between the first filter input and the first filter output and wound onto three different legs of a three-leg filter core; a second filter branch between a second filter input and a second filter output, the second filter branch comprising a second series connection of three inductances including an input inductance or an output inductance, connected between the second filter input and the second filter output and wound onto three different legs of the three-leg filter core; and a third filter branch between a third filter input and a third filter output, the third filter branch comprising a third series connection of three inductances including an input inductance or an output inductance, connected between the third filter input and the third filter output and wound onto three different legs of the three-leg filter core, wherein the input inductances or the output inductances of the three filter branches are wound onto different legs of the three-leg filter core; wherein the first filter branch includes a first shunt inductance; wherein the second filter branch includes a second shunt inductance; wherein the third filter branch includes a third shunt inductance; wherein a node where two inductances out of the at least three inductances of the first series connection are connected is coupled to a first terminal of a capacitive energy storage via the first shunt inductance; wherein a node where two inductances out of the at least three inductances of the second series connection are connected is coupled to a second terminal of the capacitive energy storage via the second shunt inductance; wherein a node where two inductances out of the at least three inductances of the third series connection are connected is coupled to a third terminal of the capacitive energy storage via the third shunt inductance; and wherein the three shunt inductances are arranged on the three legs of the three-leg filter core.