Estimation of nonsinusoidal bus voltage waveforms in power systems

This paper presents a method of estimation of nonsinusoidal bus voltage waveforms for power systems, and then harmonic levels at buses are obtained accordingly, which should be frequently monitored in today´s power systems due to the emerging nonlinear loads and power conditioning devices. A discrete time model for the network concerned is utilized for this reason and the corresponding measurement equations are derived. The sampling frequency is chosen according to the highest harmonics of interest. A special transformation for the measurement equations is conducted in order to enhance the sparsity of the corresponding discrete time matrix equations and the computational efficiency as well. Zero injection constraints are also included to take advantage of the increased redundancy. The results of simulations under various noise cases are presented. Performance of the developed algorithm is evaluated both in terms of CPU time and accuracy based on the simulations