scholarly journals Thévenin Equivalent Parameter Adaptive Robust Estimation Considering the Erroneous Measurements of PMU

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4865
Author(s):  
Anan Zhang ◽  
Wenting Tan ◽  
Ming Cheng ◽  
Wei Yang
Keyword(s):  
Parameter Estimation ◽  
Power Systems ◽  
Measurement Errors ◽  
Measurement Data ◽  
Estimation Algorithm ◽  
Recursive Least Squares ◽  
Measurement Unit ◽  
External Interference ◽  
Equivalent Parameter ◽  
Thevenin Equivalent

Parameter estimation based on the measurement data of the phasor measurement unit (PMU) is an important approach for identifying the Thévenin equivalent parameters (TEPs) of power systems. However, in the process of acquiring or transmitting data in PMU, measurement errors due to external interference or internal system faults will affect the accuracy of parameter estimation. In this paper, a TEP estimation algorithm based on local PMU measurement is proposed. The algorithm considers the errors of the PMU and introduces Huber function and projection statistics (PS) to eliminate the effects of outliers and leverage measurements, respectively. Additionally, a variable forgetting factor (VFF) is used to quickly eliminate the historical data with measurement deviation and track the changes of the system. The regularization technique is used to solve the divergence problem in the inverse process of the ill-conditioned matrix, thereby improving the stability and generalization performance of the algorithm. Finally, by minimizing the cost function of this algorithm, a recursive formula for the equivalent parameter estimation is derived. The effectiveness of the algorithm is verified on the IEEE 118-bus and IEEE 30-bus systems, and compared with recursive least squares (RLS) and Huber’s M-Estimation; the mean relative errors decreased by 94.75% and 84.77%, respectively.

scholarly journals The Design of a Low Cost Phasor Measurement Unit

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2648 ◽  
Author(s):  
Antonio Delle Femine ◽  
Daniele Gallo ◽  
Carmine Landi ◽  
Mario Luiso
Keyword(s):  
Power Systems ◽  
High Performance ◽  
Low Cost ◽  
Data Communication ◽  
Estimation Algorithm ◽  
Building Blocks ◽  
Processing Technique ◽  
Measurement Unit ◽  
Signal Processing Technique ◽  
Phasor Measurement

The widespread diffusion of Phasor Measurement Units (PMUs) is a becoming a need for the development of the “smartness” of power systems. However, PMU with accuracy compliant to the standard Institute of Electrical and Electronics Engineers (IEEE) C37.118.1-2011 and its amendment IEEE Std C37.118.1a-2014 have typically costs that constitute a brake for their diffusion. Therefore, in this paper, the design of a low-cost implementation of a PMU is presented. The low cost approach is followed in the design of all the building blocks of the PMU. A key feature of the presented approach is that the data acquisition, data processing and data communication are integrated in a single low cost microcontroller. The synchronization is obtained using a simple external Global Positioning System receiver, which does not provide a disciplined clock. The synchronization of sampling frequency, and thus of the measurement, to the Universal Time Coordinated, is obtained by means of a suitable signal processing technique. For this implementation, the Interpolated Discrete Fourier Transform has been used as the synchrophasor estimation algorithm. A thorough metrological characterization of the realized prototype in different test conditions proposed by the standards, using a high performance PMU calibrator, is also shown.

Decoupled Scalar Approach for Aircraft Angular Motion Estimation Using a Gyro-Free Inertial Measurement Unit

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Ali Dehghan Manshadi ◽  
Fariborz Saghafi
Keyword(s):  
Motion Estimation ◽  
Inertial Measurement Unit ◽  
Measurement Data ◽  
Estimation Algorithm ◽  
Monte Carlo Analysis ◽  
Angular Motion ◽  
Measurement Unit ◽  
Scalar Form ◽  
Inertial Measurement ◽  
Aircraft Dynamics

Abstract In-flight aircraft angular motion estimation based on an all-accelerometers inertial measurement unit (IMU) is investigated in this study. The relative acceleration equation as the representative of a rigid-body kinematics is manipulated to present the state and measurement equations of the aircraft dynamics. A decoupled scalar form (DSF) of the system equations, as a free-singularity problem, is derived. Mathematical modeling and simulation of an aircraft dynamics, equipped with an all-accelerometers IMU, are employed to prepare measurement data. Taking into account the modeling of accelerometer error, the measurement data have been simulated as a real condition. Three extended Kalman filters (EKFs) are used in parallel to estimate aircraft angular motion. Performance of the estimation algorithm is assessed by Monte Carlo analysis. As a result, the presented decoupled scalar approach using a gyro-free IMU (GF-IMU) provides an uncorrelated estimate of the in-flight aircraft motion components.

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