Date: Nov 03rd, 2021, 04:30 PM to 06:00 PM (MDT)

Presented by: John Voisine of Landis+Gyr Lafayette, IN, USA

Register Online Now

Abstract: There is a fundamental basis for the measurement of electrical energy delivered to a load. This energy is referred to as active energy, with SI unit of watt-hour (Wh). Similarly, the rate of change of active energy is called active power, with SI unit of watt (W). Algorithms used for calculating active energy and active power in revenue grade electricity meters yield consistent results. In contrast, understanding and defining the fundamental basis for apparent energy, with SI unit of volt-ampere hour (VAh) and apparent power, with SI unit of volt-ampere (VA) remains elusive. Consequently, various algorithms are used in electricity meters and these yield results that are often inconsistent and differ significantly due to such factors as harmonic content, polyphase connection system (wye, delta, etc.), and polyphase load imbalance. Active energy conforms to the law of conservation of energy whereas apparent energy does not. Rather than continue trying to understand and define the “right” or “true” meaning of apparent energy, a new concept of “Source VA” is proposed. Source VA gives consistent results on the physical sizing needs of the infrastructure used to deliver active energy. In understanding Source VA, it is helpful to think in terms of a progression of incentives used in managing the efficiency of energy delivery. The terms Source VA and Source Apparent Power are used interchangeably.