The Meaning, Analysis, and Consequences of Negative Frequency in Electric Power Systems

This paper addresses a subject from AC circuits in electric power engineering. Frequency in these circuits is nominally taken as a positive quantity, and the paper discusses the possibility of negative frequency. Both single phase and three phase circuits are considered. The calculation of active and reactive power, and harmonics and phase order are analyzed. The paper is intended somewhat of a puzzle, with open ended questions as to the existence and value of negative frequency signals. Electrical engineering undergraduate students may see this topic in their course work, and therefore educational issues are reviewed.