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:
Nov. 29, 1994
Filed:
Dec. 08, 1992
William L Erdman, Brentwood, CA (US);
KENETECH Windpower, Inc., Livermore, CA (US);
Abstract
A controlled electrical energy storage apparatus for selectively storing electrical energy from an electrical grid, and selectively releasing the electric energy back into the grid. The apparatus includes a converter coupled to the grid, and a DC energy storage device coupled to the converter. The converter includes a switching circuit having a plurality of high speed electrical switches arranged in pairs. Each switch pair is coupled between one of the phase lines of the AC utility grid and the DC energy storage device. The power flow control unit supplies a power flow control waveform to the switch pairs. The power flow control waveform includes a real waveform for control of real power and an imaginary waveform for control of reactive power independently of the real power. By pulse-width modulating the switches at a high frequency, the converter controls instantaneous currents flowing through each of the phase lines for precise control of the real and reactive power.