The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2012
Filed:
May. 12, 2010
Juha Jaakko Pyrhönen, Lappeenranta, FI;
Pertti Tapani Silventoinen, Lappeenranta, FI;
Mikko Pekka Juhani Kuisma, Lappeenranta, FI;
Valentin Dzhankhotov, Lappeenranta, FI;
Juha Jaakko Pyrhönen, Lappeenranta, FI;
Pertti Tapani Silventoinen, Lappeenranta, FI;
Mikko Pekka Juhani Kuisma, Lappeenranta, FI;
Valentin Dzhankhotov, Lappeenranta, FI;
The Switch Drive Systems Oy, Lappeenranta, FI;
Abstract
A filter appliance comprises first electrical terminals (-) for connecting to a multiphase electrical converter device, second electrical terminals (-) for connecting to a load, main current coils formed of foil conductors and connected between the first and the second electrical terminals, and shielding coils whose first ends are electrically connected to a third electrical terminal () of the filter appliance. Each of the shielding coils is formed of foil conductor that is alongside and a distance apart from the foil conductor of the corresponding main current coil so as to form a capacitive shield between successive turns of the main current coil. When the third electrical terminal is connected to constant electrical potential, the shielding coils reduce the common mode voltage applied to the load and, for example, a risk of bearing damages in an electrical motor driven by a multiphase electrical converter device is reduced.