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:
Mar. 28, 2006
Filed:
Feb. 26, 2004
Nobuyuki Kobayashi, Tokyo, JP;
Hirokazu Tokuda, Tokyo, JP;
Nobuyuki Kobayashi, Tokyo, JP;
Hirokazu Tokuda, Tokyo, JP;
Abstract
An uninterruptible power supply system prevents an output voltage from dropping due to an operation delay of a relay for isolating an alternating-current power source side and avoids an unexpected current flowing between the alternating-current power source side and the uninterruptible power supply system side. When short circuit occurs, a parallel converter connected in parallel to input terminals connected to an alternating-current power source is made to operate so that the output voltage thereof becomes '0' or the input voltage Vin and a series inverter connected in series between an input relay and one of output terminals is made to carry out a compensating operation with a smoothing capacitor taken as a power source so that a value of an applied voltage to the output terminals becomes an output voltage command value Vout*. This makes the output voltage of the parallel converter become '0' or Vin to produce no electric potential difference between the alternating-current power source side and the output side of the parallel converter. Therefore, no current flows between the alternating-current power source side and the parallel converter, and a value of an applied voltage to the output terminals is to be continuously maintained at the output voltage command value Vout* by the series inverter.