Method of T-Connection Line Parameter Estimation in Distribution Network Based on PMU And AMI

In recent years, micro-phasor measurement unit $(\mu \mathrm {P}\mathrm {M}\mathrm {U})$ and advanced metering infrastructure (AMI) have been gradually applied to distribution network, providing a large amount of distribution network measurement data, which makes it possible for parameter estimation of distribution network containing T-connection lines. This paper proposes a parameter estimation method for T-connection line in distribution network based on $\mu \mathrm {P}\mathrm {M}\mathrm {U}$ and AMI. Firstly, the T-connection line model considering the actual installation location of the $\mu \mathrm {P}\mathrm {M}\mathrm {U}$ and AMI in distribution network is constructed, and the virtual measurement is determined with real-time measurement data of the $\mu \mathrm {P}\mathrm {M}\mathrm {U}$ and AMI. Secondly, the measurement function equation and Jacobi matrix based on augmented state estimation method are listed. Thirdly, a weighted least square model with voltage phasor and T-connected line parameters as its augmented state variables is established based on multi-interval $\mu \mathrm {P}\mathrm {M}\mathrm {U}$ and AMI measurement data. Finally, the effectiveness of the proposed algorithm is validated by the four T-connection line zones of the NEV test feeder, and the accuracy of estimation parameters of different lines is analyzed. The method overcomes the difficulty of estimating the parameters of T-connection lines under the condition of insufficient measurement data in traditional distribution network, laying the foundation for the real-time optimization operation of the distribution network.