In search of the equivalent neutral path resistance and the effective voltage for compliance with IEEE Std 1459-2010

This paper presents a practical method for a real-time measurement of the ratio ρ = rneq / r (r = line resistance, rneq = equivalent neutral path resistance) of a three-phase four-wire distribution feeder and advocates the possibility of ignoring the zero-sequence voltage component due to its reduced magnitude in practical situations. The ratio ρ has a significant impact on the value of the apparent power as defined in IEEE Std 1459-2010. In practical terms, this quantity is time variable being a function of soil moisture and temperature. This work presents a proposal for measuring the equivalent neutral path resistance considering the smart metering technologies currently available.