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Iterative Parameter Estimation for Photovoltaic Cell Models by Using the Hierarchical Principle
Xiangxiang Meng,Yan Ji,Junwei Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8
This paper considers the parameter estimation problems of photovoltaic cell models. In order to overcome the complexity of the model structure, through applying the hierarchical identification principle and decomposing the photovoltaic cell model into two sub-models with a smaller number of parameters. The nonlinear identification model becomes a combination of a linear sub-model and a nonlinear sub-model. A two-stage gradient-based iterative and a two-stage Newton iterative algorithms are proposed to estimate the parameters of photovoltaic cell models by using the negative gradient search and the Newton method. The performance of the proposed algorithms is assessed by using the simulation from the experimental data, and the evaluation results test the effectiveness of the proposed algorithms. In particular, the model built by using the obtained parameter estimates can fit the I-V curve, the P-V curve and the maximum power point well.
Chen Youyuan,Yu Haisheng,Meng Xiangxiang,Ding Hao,Gao Xunkai 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3
In this paper, a novel cooperative controller combining Linear Quadratic optimal control based on feedback linearization (LQ-FL) and state error port-Hamiltonian (EPH) with integral term is proposed for permanent magnet synchronous motor. Firstly, the LQ-FL is presented to ensure rapid dynamic performance, and the EPH method makes up for the shortcomings of the system in steady-state performance. The integral term is utilized to eliminate the position tracking steady-state error. Secondly, the Gaussian function is utilized to coordinate the two controllers and make them play their respective superiorities. Then, a nonlinear disturbance observer is used to resolve the total disturbance caused by parameter changes, modeling errors and external disturbance. Finally, the efectiveness and robustness of the proposed controller are verifed by simulation and experiments.
Feng Xu,Tingting Tao,Qiangwen Chen,Xiangxiang Meng,Jiaping Yan,Jie Chang 한국유전학회 2016 Genes & Genomics Vol.38 No.12
3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) catalyzes the condensation of acetyl-CoA and acetoacetyl- CoA to form 3-hydroxy-3-methylglutaryl-CoA as the first committed enzyme in the mevalonate (MVA) pathway. HMGS plays an important role in the biosynthesis of the sesquiterpene, which is the main constituent of essential oil in Matricaria chamomilla. In this paper, a HMGS gene designated as McHMGS (GenBank Accession No. KU529970) was successfully cloned from M. chamomilla. The full-length cDNA of McHMGS was 1495-bp and contained a 1374-bp open reading frame. It encoded a 458-amino-acid protein with a calculated molecular weight of about 50.7 kDa and isoelectric point of 5.69. Sequence comparison revealed that McHMGS showed extensive homology with HMGSs from other plant species. Phylogenetic tree analysis indicated that McHMGS is clustered with the HMGS of Asteraceae in the dicotyledoneae clade. Further functional complementation of McHMGS in hmgsdeficient mutant yeast strain YSC6274 demonstrated that cloned McHMGS cDNA encodes a functional HMGS and mediates the MVA biosynthesis in yeasts. The tissue expression pattern analysis revealed that McHMGS expression level is highest in the flowers and lowest in the stems. Quantitative real-time PCR analysis showed that the expression of McHMGS was induced by MeJA, and the expression level is highest 24 h after induction. The characterization and expression of McHMGS can help in further studying the role of McHMGS gene in the biosynthesis of sesquiterpene in M. chamomilla.