The identification of the true energy savings realized from high efficiency electronic loads

High efficiency electronic loads have been proposed to reduce power system energy use and peak demand. In order to promote the use of these special loads, many electric utility companies offer rebates to their consumers. These rebates are intended to encourage the use of high efficiency loads as new installations or retrofits. In many cases, these devices employ power electronics to control energy flow. For example, adjustable speed drives (ASDs) are used in heat pumps and air conditioners; and electronic ballasts are used to energize compact fluorescent lamps. What seems to be overlooked, however are the losses in the distribution system, especially the distribution transformer due to current wave harmonics that result from serving power to switched electronic loads. This paper proposes a method that quantifies losses in the distribution network due to nonsinusoidal waveforms. This algorithm accounts for the magnetic characteristics of the distribution transformer by iteratively solving for the voltages and currents throughout the circuit. The methodology is illustrated by calculating the additional distribution system losses due to electronic loads such as electronic ballast fluorescent lighting and ASD heat pumps.<
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