A $\mu PMU$ Full Observation Algorithm for Balanced Radial Distribution Grid with PV Integration

Abstract

Due to the growth of distributed energy resources (DER) and new customer devices, there is currently a two-way energy flow in electric distribution grids. As a result, there is increasing tendency in full observation tools for grid protection and management. Micro Phasor Measurement Unit $(\mu \text{PMU})$ measures highly precise time-synchronized current and voltage samples, calculates their respective phasors and online transmits the determined phasors to a phasor data concentrator (PDC). In this paper, two algorithms are proposed. The first algorithm is a full observation algorithm for underground balanced radial distribution grid with minimum numbers of $\mu\text{PMUs}$. This algorithm aids in the development of a monitoring system of the underground balance radial distribution grid for medium voltage (MV) and low voltage (LV) sides. The second algorithm is a backward/forward sweep balanced power flow (BPF) algorithm for underground radial distribution grid with photovoltaic (PV) integration in LV side. The outputs of backward/forward sweep BPF program are compared with ETAP outputs to test algorithm accuracy. To ensure the accuracy of the $\mu \text{PMU}^{\prime}\mathrm{s}$ full observation algorithm, a testing process is used. The output phasors measured by $\mu \text{PMU}$ are implemented from backward/forward sweep BPF outputs at the buses where $\mu \text{PMUs}$ are installed. The $\mu\text{PMU}$ full observation algorithm outputs at the other buses are compared with those obtained from backward/forward sweep BPF. The testing process proves high accuracy of the $\mu \text{PMUs}$ full observation algorithm for various distribution grid operation scenarios.