Harmonic State Estimation on a Radial Distribution System with Distributed Generation

In the present work, a state estimation technique is applied to calculate the amplitudes and phase angles of the harmonic currents injected at the buses of a power distribution system. To this effect, the model of a 50-Hz 13.2-kV 4-bus radial system is used. The grid (source) and a generator are connected at opposite ends of the system, following a configuration known as distributed generation, which is becoming quite usual nowadays. In this particular implementation, the nodal harmonic voltages are presented as the state variables instead of the harmonic currents. This follows the same structure as a traditional fundamental frequency state estimation. As a further step, the injected harmonic currents are calculated from the corresponding injected powers and nodal voltages.