Design of a Power Waveform Capture Platform for Plug Load Monitoring

Plug loads in consumer electronic products consume large quantities of energy, often without the knowledge of the user. To facilitate the development of smart plug strips and new building control systems, an open-source power waveform capture platform has been designed and tested. The system was developed to accurately and safely record the voltage and current waveforms for any plug load such as consumer electronic and electrical systems. The device incorporates a commercially available hardware platform that has been reprogrammed to record the voltage and current waveforms and transfer them in real-time to a computer for storage and further processing. The system samples the voltage and current waveforms with a sampling rate of 2048 Hz, and this detailed data can be used to identify the types of waveforms that are associated with various devices, as well as measure any power parameter of interest such as real power, energy, RMS volts, RMS current, power factor, frequency, etc. The system has been tested with several known electrical loads and has been found to perform well. The paper describes the hardware and software, the test setup, and the test results. Since the hardware is inexpensive (about $250) and the software is available for free from the authors, this system can be used by almost anyone to perform detailed studies of the power characteristics of electrical and electronic devices.