Voltage Estimation Method for Power Distribution Networks Using High-Precision Measurements

Abstract

In this study, we propose a voltage estimation method for the radial distribution network with distributed generators (DGs) using high-precision measurements (HPMs). The proposed method uses the section loads center for voltage estimation because individual loads are not measured in the distribution system. The bus voltage was estimated through correction of the section load center by using an HPM at the end of the main feeder. The correction parameter of the section load center was calculated by comparing the initial voltage estimates and the measurements of the HPMs. After that, the voltage of the main feeder was re-estimated. Finally, the bus voltage in the lateral feeder was estimated based on the voltage estimates in the main feeder and the current measurements in the lateral feeder. The accuracy of the proposed algorithm was verified through case studies by using test systems implemented in MATLAB, Simulink, and Python environments. In order to verify the utilization of the proposed method to the practical system, a test with injection of approximately 5% of normally distributed random noise was performed. Through the results of the case studies, when an HPM is installed at the end of the main feeder, it demonstrated that the voltage estimation accuracy can be greatly improved by the proposed method. Compared with the existing methods, the proposed method was less affected by PV and showed robustness to measurement noise.

Distribution System State Estimation Using Hybrid Traditional and Advanced Measurements for Grid Modernization

“…The measurement function definitions and the Jacobian matrix in the SE computations are different when either traditional or smart measurements are included in the measurement vector [73]. In (11), the Jacobian matrix is shown when traditional ( H Traditional ) and smart ( H Smart ) measurements are included in the measurement vector, respectively.…”

“…Moreover, new features, including DGs, two-way communications, electric vehicles, variable loads, etc., will increase the need for accurate DSSE calculations [9,10]. Therefore, installing smart measurement devices, such as Phasor Measurement Units (PMUs) and micro PMUs (µPMUs), currently involve grid modernization projects to improve DSSE results [11,12]. PMUs are extensively used in Transmission Networks (TNs) [13].…”

Weighted Bandwidth Method for Stability Assessment of Complex DC Power Systems on Ships

“…The latter is defined in (12a) as a linear combination of the S control bandwidths, weighted by the conductance ratio m k = G k /G S = P k /P S . Thus, ω S is a sort of center of gravity, whose definition derives from an analogy to the approximated method (i.e., current-line length products) to calculate the aggregated voltage drop of distributed loads in power systems [44,45]. The same procedure on D loads provides the ω D aggregated control bandwidth in (12b).…”