Power converter with common mode filter
Various embodiments of the teachings herein include a power converter. The power converter may include: a converter for converting between a first electrical voltage and a second electrical voltage; a common mode filter having a common mode transformer; and a second winding connected to a frequency-selective passive damping circuit arranged on a common core. The common mode transformer has at least two first windings arranged in the same direction on the common core and coupled in series into electrical conductors connected to the converter device.
1. A power converter comprising:
a converter for converting between a first electrical voltage and a second electrical voltage;
a common mode filter having a common mode transformer;
wherein the common mode transformer has at least two first windings arranged in the same direction on a common core and coupled in series into electrical conductors connected to the converter device; and
a second winding connected to a frequency-selective passive damping circuit arranged on the common core;
wherein the frequency-selective passive damping circuit includes one of: (a) a series circuit comprising a resistor and a capacitor and an inductor, (b) a parallel circuit composed of a resistor, a capacitor, and an inductor, and (c) a series circuit comprising a first resistor and a parallel circuit composed of a capacitor and a second resistor.
2. The power converter as claimed in claim 1 , wherein the frequency-selective passive damping circuit comprises a capacitor and/or an inductor.
3. The power converter as claimed in claim 1 , wherein the frequency-selective passive damping circuit comprises a resistor in a current path between terminals of the second winding.
4. The power converter as claimed in claim 1 , wherein the common mode filter device is arranged on a line side of the converter device.
5. The power converter as claimed in claim 1 , wherein the common mode filter device comprises a common mode choke.
6. The power converter as claimed in claim 5 , wherein the common mode filter device comprises capacitors connected from the electrical lines to a reference potential which, together with the common mode choke and the common mode transformer, form an LCL filter or which, together with the common mode choke and the common mode transformer, form an LC filter.
7. The power converter as claimed in claim 1 , wherein the common core comprises a ring-shaped core.
8. The power converter as claimed in claim 1 , wherein the common core has a central bar with an air gap.
9. The power converter as claimed in claim 1 , wherein the frequency-selective passive damping circuit additionally comprises a series-connected capacitor.
10. A power converter comprising:
a converter for converting between a first electrical voltage and a second electrical voltage;
a common mode filter having a common mode transformer;
wherein the common mode transformer has at least two first windings arranged in the same direction on a common core and coupled in series into electrical conductors connected to the converter device; and
a second winding connected to a frequency-selective passive damping circuit arranged on the common core;
wherein the frequency-selective passive damping circuit comprises a first frequency-selective subcircuit having a first cutoff frequency or resonant frequency and a second frequency-selective subcircuit connected in parallel with the first subcircuit and having a second cutoff frequency or resonant frequency that is different from the first cutoff frequency or resonant frequency.