Harmonic analysis of the power distribution Neutral-to-Earth Voltage (NEV) test case using four-wire three-phase harmonic current injection method

This work presents several harmonic analyses using the four-wire three-phase harmonic current injection method (FHCIM) to simulate the power distribution neutral-to-earth voltage (NEV) Test Case. FHCIM is a fast and reliable Newton-Raphson multi-frequency power flow methodology to simulate unbalanced three-phase electric power systems with explicit representation of the network characteristics and components, including the harmonic couplings of non-linear loads as well as neutral conductors and groundings. The NEV test case is a radial distribution network in which the neutral voltages and currents present an important role due the system unbalances, grounding impedances and neutral conductors. Harmonic distortion on real networks, are due to the proliferation of non-linear loads, and can affect both neutral-to-earth voltage levels and neutral currents. Therefore, a digital tool for harmonic analysis is becoming very important for planning studies of electrical power systems. Simulations of the original NEV test case with unbalanced 3^rd harmonic loads, as well as a modified case with non-linear loads, represented by SVCs, were carried out with the purpose of investigating the presence of a wide harmonic propagation spectrum.