Experimental time domain harmonic state estimation using partial measurements

Abstract

The harmonic state estimation analysis has been conventionally developed in the frequency domain. This methodology needs to measure the amplitude and phase angle of the harmonic components of the related waveforms. This paper presents an alternative time domain formulation based on a simplified network model and Kalman filter to assess the global harmonic steady state estimation. Measurements are sampled waveforms registered by a data acquisition system. The proposed methodology has been successfully tested on an experimental electric power test system developed in the laboratory. The reported case study consists of a three phase balanced system with a nonlinear load. An under-determined measurement model case has been tested. The results have been validated by direct comparison of the state estimation response against the actual data taken from laboratory experimental measurements and have also been compared against the simulated values obtained from Simulink®.

Time domain harmonic state estimation in unbalanced power networks based on optimal number of meters and the principle of half‐wave symmetry

“…If only one bus is unobservable among a ZIB and its entire incident buses, the unobservable bus will also be identified as observable by applying the Kirchhoff's current law (KCL) at the ZIB. Currents in the time-domain can be computed using (23)(24)(25)(26).…”

“…Reference [23] proposes a method based on Kalman filter as in [20] but the measurement equation is based on an under-determined condition. In addition, the method uses measurements taken from a scaledown test system set up, which allows observe the behaviour of the Kalman filter assessing the TDHSE when the theoretical model presents errors on modelling and parameter values respect to the real model.…”

“…The methodologies reported in [20] and [22][23][24] do not take into account the use of the optimal number of measuring devices and their optimal placement.…”