Low-Cost Embedded Measurement System for Power Quality Frequency Monitoring

Power quality (PQ) analysis involves the measurement of quantities that characterize the power grid. However, since traditional monitoring equipment is expensive, the measurements are typically performed at few selected locations, not on a regular basis and typically to address customer or grid problems. Recent advances in power electronics combined with the increasing penetration of renewable energies have increased the need for cheaper and portable power quality devices. One of the key parameters in power quality assessment is the power grid frequency since many of the other PQ parameters depend on the power grid frequency. The method suggested in IEC 61000-4-30 to measure the power grid frequency is to count the number of zero crossings in the voltage waveform that occur during a known time interval. In this paper, a new electrical power grid frequency estimation algorithm based in selected calculation of frequency components using the Goertzel algorithm and implemented in a low-cost STM-32 development board is presented. The proposed solution is suited for wide deployment in a smart grid for comprehensive power grid monitoring