Using smart meters for load monitoring and active power-factor correction

This paper proposes a cost-effective approach to active power-factor correction that uses a smart meter installed at a service entry and a dedicated active power filter. The power circuit could be connected at a conventional 240V AC outlet in a home, or it could be installed at a transformer secondary and coordinate with several downstream meters. The smart meter is a non-intrusive load monitor (NILM) that measures the active, reactive, and harmonic content of the line current. This information is fed to the dedicated active power filter. The NILM determines the amount of reactive and harmonic current fed to the downstream loads, which may include the current supplied by the active power filter itself. Despite this, the reactive current can be reduced to nearly zero. The active power filter can also be provided with external commands from the grid operator. This scheme is particularly useful in virtual power plant (VPP) applications involving demand dispatch in support of distributed intermittent renewables. The paper describes the control scheme needed by the power circuit and presents experimental results.