The second generation of smart meters are known as SMETS 2. Full form of SMET is Smart Metering Equipment Technical Specifications. It is with the previous generation known as SMETS 1. SMETS 2 smart meters were introduced in 2018.
For lagging power factor = (IR*cosφ + Ixsinφ)/Vr For leading power factor = (IR*cosφ - Ixsinφ)/Vr Zero voltage regulation occurs on leading power factor only.