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:
Oct. 29, 1991
Filed:
Apr. 25, 1990
Richard L Longini, Pittsburgh, PA (US);
Other;
Abstract
A method and apparatus for digitally measuring electrical energy consumption from a transmission line carrying alternating current. Instead of actually measuring current from a transmission line conductor, the time derivative of the magnetic field induced by current flowing in the conductor is measured thereby obtaining a reading which is proportional to the time derivative of the current flow. Using an appropriate microcomputer, the time derivative of the magnetic field (the magnetic field rate of change) is represented with an algorithmic series for expressing cyclic phenomena, such as the Fourier series of low order. An approximation of the power consumption is then computed by converting the time derivative of the current as expressed in the algorithmic series and a voltage measurement from the conductor mathematically to a power reading, and the power reading is summed to obtain a number value proportional to the energy consumption. Even harmonics and high frequency harmonics may be eliminated in the algorithmic expression of the current derivative to further simplify computer computations and required hardware, and the magnetic rate of change pickup and the voltage pickup are preferably filtered to remove unwanted noise.