University of Texas System

The Institute of Electrical and Electronics Engineers, Incorporated

Wei-Jen Lee

Babak Fahimi

Wei Wang

Tammy L Gammon

Zhenyuan Zhang

Morgan M Kiani

An arc flash hazard assessment method includes storing electrical equipment data in memory, defining an arc flash model function based on the data, and estimating the model function based on a weighted average of interpolated and extrapolated values. The electrical equipment data may include an operating voltage, a fault current, and a clearing time. The model function is defined for at least three reference voltages V, Vand V, with the interpolated value at operating voltage V, between voltages Vand V, and the extrapolated value from reference voltages Vand V. At the arc flash protection boundary, the estimated model function has a predefined incident energy value of 1.2 cal/cm(or about 5.02 J/cm), or less.

Systems and methods for arc flash hazard assessment

Methods and apparatuses for substantially eliminating torque pulsation in a doubly fed induction machine are disclosed. An example method comprises: measuring a stator current of the doubly fed induction machine, measuring a rotor current of the doubly fed induction machine, calculating a total magnetic flux density in an airgap of the doubly fed induction machine, calculating a tangential force density, calculating an electromagnetic torque, repeating the calculation of the electromagnetic torque over one electrical cycle to estimate a torque pulsation, determining a new rotor current that substantially eliminates the torque pulsation by referencing a set of optimal rotor currents in a look-up table, and changing the rotor current in response to the determination. Other embodiments are described and claimed.

Methods and apparatuses for elimination of torque pulsation in doubly fed induction generators using the field reconstruction method

Growing community of inventors

Colleyville, TX, United States of America

Wei-Jen Lee