Performance of electric power meters and analyzers in adjustable-speed drive applications

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:345229

Czarkowski, D; Domijan, A Jr ^[1]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Electrical and Computer Engineering

Electric adjustable-speed drives (ASDs) are increasingly used in heating, ventilating, and air-conditioning (HVAC) equipment due to the energy savings and comfort of operation they offer. Power electronic circuits that are employed in ASDs shape their input and output voltage and current waveforms, making them highly distorted from typical power-grid sinusoids. Accurate measurements of voltage, current, and power under nonsinusoidal conditions are essential for determining the efficiency of an HVAC unit and performing separation of losses between an ASD and an electric motor. That information is invaluable for HVAC equipment designers, manufacturers, and users. Three modern power meters and analyzers were tested to determine their accuracy with various nonsinusoidal waveforms applied. The meters were subjected to waveforms that are produced by the three most common ASD technologies used in air conditioners and heat pumps, namely, PWM induction, DC-brushless, and switched-reluctance drives. The tests were performed under field conditions and in a computer-controlled laboratory environment. The results obtained show that some meters can accurately measure electric power at the input to ASDs. However, the output power of ASDs for DC-brushless and switched-reluctance technology was not measured with acceptable accuracy by any of the tested meters. Possible reasons for meter inaccuracies and suggestions for performance improvement are given.

• OSTI ID: 345229
• Report Number(s): CONF-9702141--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ELECTRIC MOTORS
ELECTRONIC CIRCUITS
LOSSES
PERFORMANCE
POWER METERS
SPACE HVAC SYSTEMS
SPEED REGULATORS
WAVE FORMS