Least square estimator and IEC-60891 procedure for parameters estimation of single-diode model of photovoltaic generator at standard test conditions (STC)

2021 ◽  
Author(s):  
Albert Ayang ◽  
René Wamkeue ◽  
Mohand Ouhrouche ◽  
Mohamad Saad ◽  
Tommy Andy Tameghe ◽  
...  
Keyword(s):  
Standard Test ◽  
Parameters Estimation ◽  
Least Square ◽  
Least Square Estimator ◽  
Test Conditions

A Simple Parameter Estimation Approach to Modeling of Photovoltaic Modules Based on Datasheet Values

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Xiangsai Feng ◽  
Xiangyun Qing ◽  
C. Y. Chung ◽  
Hongqiao Qiao ◽  
Xunchun Wang ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Optimal Parameter ◽  
Standard Test ◽  
Least Square ◽  
Model Parameters ◽  
Electrical Model ◽  
Characteristic Model ◽  
Test Conditions ◽  
Two Parameters ◽  
Simple Parameter

This work presents a simple parameter estimation approach for a photovoltaic (PV) module using a single-diode five-parameter electrical model. The proposed approach only uses the information from manufacturer datasheet without requiring a specific experimental procedure or a curve extractor. The number of parameters to be determined is first reduced from five to two by gaining insight into electrical equations of the model at the standard test conditions (STCs). A nonlinear least square (NLS) objective function is then constructed and minimized by a complete scan for all possible values of the two parameters within some specific ranges based on their physical meaning. Consequently, the single-diode five-parameter electrical model at the STC is determined based on two optimal parameter values. Besides, a PV full characteristic model with consideration of both the irradiance and temperature dependencies is also constructed by using the data at the nominal operating cell temperature (NOCT) test conditions. The proposed approach is easy to implement and free of the convergence problem. The evaluations on several PV modules show that the proposed approach is capable of extracting accurate estimates of the model parameters.

scholarly journals An Improved Generalized Method for Evaluation of Parameters, Modeling, and Simulation of Photovoltaic Modules

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Vandana Jha ◽  
Uday Shankar Triar
Keyword(s):  
Modeling And Simulation ◽  
Standard Test ◽  
Unknown Parameters ◽  
Photovoltaic Modules ◽  
Pv Module ◽  
Test Conditions ◽  
Pv Modules ◽  
Evaluation Of Parameters ◽  
Output Characteristics ◽  
Matlab Programming

This paper proposes an improved generalized method for evaluation of parameters, modeling, and simulation of photovoltaic modules. A new concept “Level of Improvement” has been proposed for evaluating unknown parameters of the nonlinear I-V equation of the single-diode model of PV module at any environmental condition, taking the manufacturer-specified data at Standard Test Conditions as inputs. The main contribution of the new concept is the improvement in the accuracy of values of evaluated parameters up to various levels and is based on mathematical equations of PV modules. The proposed evaluating method is implemented by MATLAB programming and, for demonstration, by using the values of parameters of the I-V equation obtained from programming results, a PV module model is build with MATLAB. The parameters evaluated by the proposed technique are validated with the datasheet values of six different commercially available PV modules (thin film, monocrystalline, and polycrystalline) at Standard Test Conditions and Nominal Operating Cell Temperature Conditions. The module output characteristics generated by the proposed method are validated with experimental data of FS-270 PV module. The effects of variation of ideality factor and resistances on output characteristics are also studied. The superiority of the proposed technique is proved.

scholarly journals On shrinkage and selection: ANOVA model

2018 ◽  
Vol 51 (2) ◽  
pp. 165-191 ◽  
Author(s):  
A. K. Md. Ehsanes Saleh ◽  
M. Arashi ◽  
M. Norouzirad ◽  
B M Goalm Kibria
Keyword(s):  
Lower Bound ◽  
Preliminary Test ◽  
Least Square ◽  
Graphical Display ◽  
Ridge Estimator ◽  
Least Square Estimator ◽  
Projection Scheme ◽  
Anova Model ◽  
Compare And Contrast ◽  
Risk Equivalent

This paper considers the estimation of the parameters of an ANOVA model when sparsity is suspected. Accordingly, we consider the least square estimator (LSE), restricted LSE, preliminary test and Stein-type estimators, together with three penalty estimators, namely, the ridge estimator, subset selection rules (hard threshold estimator) and the LASSO (soft threshold estimator). We compare and contrast the L2-risk of all the estimators with the lower bound of L2-risk of LASSO in a family of diagonal projection scheme which is also the lower bound of the exact L2-risk of LASSO. The result of this comparison is that neither LASSO nor the LSE, preliminary test, and Stein-type estimators outperform each other uniformly. However, when the model is sparse, LASSO outperforms all estimators except “ridge” estimator since both LASSO and ridge are L2-risk equivalent under sparsity. We also find that LASSO and the restricted LSE are L2-risk equivalent and both outperform all estimators (except ridge) depending on the dimension of sparsity. Finally, ridge estimator outperforms all estimators uniformly. Our finding are based on L2-risk of estimators and lower bound of the risk of LASSO together with tables of efficiency and graphical display of efficiency and not based on simulation.

scholarly journals Vibration Parameters Estimation by Blade Tip-Timing in Mistuned Bladed Disks in Presence of Close Resonances

2020 ◽  
Vol 10 (17) ◽  
pp. 5930
Author(s):  
Saeed Bornassi ◽  
Christian Maria Firrone ◽  
Teresa Maria Berruti
Keyword(s):  
Frequency Response ◽  
Optimization Technique ◽  
Numerical Test ◽  
Parameters Estimation ◽  
Least Square ◽  
Response Curves ◽  
Bladed Disks ◽  
Bladed Disk ◽  
Resonance Frequencies ◽  
Blade Tip

The present paper is focused on the post processing of the data coming from the Blade Tip-Timing (BTT) sensors in the case where two very close peaks are present in the frequency response of the vibrating system. This type of dynamic response with two very close peaks can occur quite often in bladed disks. It is related to the fact that the bladed disk is not perfectly cyclic symmetric and the so called “mistuning” is present. A method based on the fitting of the BTT sensors data by means of a 2 degrees of freedom (2DOF) dynamic model is proposed. Nonlinear least square optimization technique is employed for identification of the vibration characteristics. A numerical test case based on a lump parameter model of a bladed disk assembly is used to simulate different response curves and the corresponding sensors signals. The Frequency Response Function (FRF) constructed at the resonance region is compared with the traditional Sine fitting results, the resonance frequencies and damping values estimated by the fitting procedure are also reported. Accurate predictions are achieved and the results demonstrate the considerable capacity of the 2DOF method to be used as a standalone or as a complement to the standard Sine fitting method.

scholarly journals Exploring relationships among recall effectiveness indicators in the US meat and poultry industry

2019 ◽  
Vol 22 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Jianbin Yu ◽  
Neal H. Hooker
Keyword(s):  
Simultaneous Equation ◽  
Equation Model ◽  
Vital Role ◽  
Economic Consequences ◽  
Least Square ◽  
Least Square Estimator ◽  
Recovery Rates ◽  
The Us ◽  
Food Recalls ◽  
Completion Times

Food recalls need to balance speed and completeness, consumer and firm interests and thus meet managerial and social goals. Effective recalls play a vital role in protecting public health and reducing economic consequences. This paper develops a simultaneous equation model to explore the relationships among three effectiveness indicators; discovery time, completion time and recovery rate. A three-stage least square estimator is applied to control for endogeneity among these indicators. The results suggest that higher recovery rates are associated with shorter discovery times. Longer discovery times led to longer completion times. Longer completion times elicited higher recovery rates. Recalls with high risk to human health had shorter discovery times but longer completion times and lower recovery rates. Recalls issued by large plants had shorter discovery times. Large recalls and national distribution channels negatively impacted discovery times. Compared to other stakeholders, government agencies took longer to discover the problem leading to a recall.

Adaptive Mismatch Compensation for Rate Integrating Vibratory Gyroscopes With Improved Convergence Rate

2014 ◽  
Author(s):  
Fu Zhang ◽  
Ehsan Keikha ◽  
Behrooz Shahsavari ◽  
Roberto Horowitz
Keyword(s):  
Convergence Rate ◽  
Degrees Of Freedom ◽  
Rotation Angle ◽  
Least Square ◽  
Parameter Estimates ◽  
Unknown Parameters ◽  
Least Square Estimator ◽  
Vibratory Gyroscopes ◽  
Adaptive Compensator ◽  
Simulation Results

This paper presents an online adaptive algorithm to compensate damping and stiffness frequency mismatches in rate integrating Coriolis Vibratory Gyroscopes (CVGs). The proposed adaptive compensator consists of a least square estimator that estimates the damping and frequency mismatches, and an online compensator that corrects the mismatches. In order to improve the adaptive compensator’s convergence rate, we introduce a calibration phase where we identify relations between the unknown parameters (i.e. mismatches, rotation rate and rotation angle). Calibration results show that the unknown parameters lie on a hyperplane. When the gyro is in operation, we project parameters estimated from the least square estimator onto the hyperplane. The projection will reduce the degrees of freedom in parameter estimates, thus guaranteeing persistence of excitation and improving convergence rate. Simulation results show that utilization of the projection method will drastically improve convergence rate of the least square estimator and improve gyro performance.

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