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:
Feb. 19, 2008
Filed:
Jun. 29, 2005
Jeffrey K. Petter, Williston, VT (US);
Belvin Freeman, Moretown, VT (US);
Jeffrey K. Petter, Williston, VT (US);
Belvin Freeman, Moretown, VT (US);
Northern Power Systems, Inc., Waitsfield, VT (US);
Abstract
A system and method are disclosed for controlling DC to AC power converters (inverters) that are operated as voltage sources and are paralleled on the AC side. This method allows for controlling frequency while sharing real power. The disclosed method requires no communication between inverters for proper load sharing, thus enhancing reliability of a system of parallel inverters. The only signals required for control are the AC voltage and frequency and their reaction to the inverter output current. The present invention allows a multiplicity of inverters or active rectifiers to share power in relation to their share of the available power capacity of the system. This makes it possible to parallel DG sources with various response times while they are connected to either a utility grid or in a stand-alone power network with no communications required between inverters. The addition of communications to the system allows the dispatch of energy for economic reasons and to fine tune load balance. Communications can be used for systems status and maintenance but is not required for reliable short-term operation.