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:
Sep. 20, 1994
Filed:
Jun. 12, 1992
Hiroo Konishi, Katsuta, JP;
Hironari Kawazoe, Hitachi, JP;
Junzo Kawakami, Mito, JP;
Tomoharu Nakamura, Hitachioota, JP;
Yukio Tokiwa, Ichihara, JP;
Tatsuhito Nakajima, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An AC system having, for example, a voltage source, an inductance and a load has connected thereto an apparatus for controlling the phase and amplitude of the voltage of the system. The instantaneous current and voltage in the AC electrical system are measured and power measurements derived therefrom. The power measurements may be instantaneous real and imaginary power, instantaneous active and reactive power, or active and reactive power averaged over less than one cycle. The power measurements are then used to derive phase related control values, on the basis of which control signals are generated to a converter. The action of the converter in accordance with the control signals thus controls the amplitude and phase of the voltage. By use of power measurements, it is not necessary to measure the phase of the voltage of the AC system.