Multi-phase distribution state estimation with only direct measurements

There are mainly two kinds of state estimation measurements' model in recent research. One model considers that direct measurements and indirect measurements are uncorrelated, the other model considers that indirect measurements have strong correlation with the direct measurements where they are derived, and the correlation can be described as covariance elements in weight matrix. In fact, without using the indirect measurements, state estimation can already be solved with only direct measurements. This paper proposes a state estimation method which only adopts direct measurements. Its efficiency and accuracy are certified by numerical tests.