Electrolytic capacitor module, filter circuit and power converter
An electrolytic capacitor module includes at least two types of electrolytic capacitors ( 4 - 1, 4 - 2 ) having etching pits in electrode foils. The at least two types of electrolytic capacitors ( 4 - 1, 4 - 2 ) are different in length of the etching pits and are connected in parallel. The number of electrolytic capacitors to be mounted is the same or different. The electrolytic capacitors ( 4 - 1, 4 - 2 ) are each an electrolytic capacitor with an etching pit length of 27 [μm] or less or an electrolytic capacitor with an etching pit length over 27 [μm]. Such a configuration enhances performance of the electrolytic capacitors in a high-frequency region, keeps a rate of decrease in capacitance low in the high-frequency region, and enhances a ripple current capability in the high-frequency region.
1. An electrolytic capacitor module comprising at least two types of electrolytic capacitors with different etching pit lengths of tunnel-like etching pits, wherein the electrolytic capacitors are connected in parallel, wherein
the at least two types of electrolytic capacitors each include a capacitor element with a wound electrode foil and an electrolyte consisting of a liquid electrolytic solution,
a first type electrolytic capacitor is an electrolytic capacitor with an etching pit length of 27 [μm] or less, and
a second type electrolytic capacitor is an electrolytic capacitor with an etching pit length over 27 [μm],
an electrode foil of the first type electrolytic capacitor is thinner than an electrode foil of the second type electrolytic capacitor, and
a number of windings of the electrode foil of the first type electrolytic capacitor is larger than a number of windings of the electrode foil of the second type electrolytic capacitor.
2. A filter circuit comprising an electrolytic capacitor module that includes at least two types of electrolytic capacitors with different etching pit lengths of tunnel-like etching pits, wherein the electrolytic capacitors are connected in parallel, wherein
the at least two types of electrolytic capacitors each include a capacitor element with a wound electrode foil and an electrolyte consisting of a liquid electrolytic solution,
a first type electrolytic capacitor is an electrolytic capacitor with an etching pit length of 27 [μm] or less, and
a second type electrolytic capacitor is an electrolytic capacitor with an etching pit length over 27 [μm],
an electrode foil of the first type electrolytic capacitor is thinner than an electrode foil of the second type electrolytic capacitor, and
a number of windings of the electrode foil of the first type electrolytic capacitor is larger than a number of windings of the electrode foil of the second type electrolytic capacitor.
3. A power converter comprising a filter circuit provided with an electrolytic capacitor module that includes at least two types of electrolytic capacitors with different etching pit lengths of tunnel-like etching pits, wherein the electrolytic capacitors are connected in parallel, wherein
the at least two types of electrolytic capacitors each include a capacitor element with a wound electrode foil and an electrolyte consisting of a liquid electrolytic solution,
a first type electrolytic capacitor is an electrolytic capacitor with an etching pit length of 27 [μm] or less, and
a second type electrolytic capacitor is an electrolytic capacitor with an etching pit length over 27 [μm],
an electrode foil of the first type electrolytic capacitor is thinner than an electrode foil of the second type electrolytic capacitor, and
a number of windings of the electrode foil of the first type electrolytic capacitor is larger than a number of windings of the electrode foil of the second type electrolytic capacitor.