TO ENLARGE THE EFFECTIVENESS ACROSS PHOTOVOLTAIC POWER PLANTS WITH CAPACITOR AUGMENT SYSTEM

This paper presents a unique application of continuous mixed -norm (CMPN) algorithm-based adaptive management strategy with the aim of enhancing the low voltage ride through (LVRT) the capability of grid-connected electrical phenomenon (PV) power plants. The PV arrays are connected to the purpose of common coupling through a DC-DC boost converter, a DC-link capacitor, a grid side inverter, and a three-phase step up transformer. The DC-DC converter is used for a maximum power point tracking operation based on the fractional open circuit voltage method. The grid-side inverter is utilized to control the DC-link voltage and terminal voltage at the PCC through a vector control scheme. The CMPN algorithm-based adaptive proportional-integral (PI) controller is used to control the power electronic circuits due to its very fast convergence. The proposed algorithm updates the PI controller gains online without the need to fine tune or optimize. The effectiveness of the proposed control strategy is compared with that obtained using Taguchi approach- based an optimal PI controller taking into account subjecting the system to symmetrical, unsymmetrical faults, and unsuccessful reclosing of circuit breakers due to the existence of the permanent fault

Affine projection algorithm based adaptive control scheme for operation of variable-speed wind generator

This study presents a novel adaptive control scheme for variable-speed wind turbine (VSWT) driven permanent magnet synchronous generator (PMSG) to ensure its operation under different operating conditions. The adaptive control scheme is based on the affine projection algorithm (APA) which provides a faster convergence and less computational complexity than the least-mean-square algorithm. The proposed adaptive controller is used to control both the generator-side converter and the grid-side inverter without giving additional tuning efforts. Each vector control scheme for the converter/inverter has four APA-based adaptive proportional-integral (PI) controllers. Detailed modelling and the control strategies of the system under study are demonstrated. Real wind speed data extracted from Hokkaido island, Japan is used in this study. The dynamic characteristics of a grid-connected VSWT-PMSG are investigated in details to ensure the proposed controller operation under different operating conditions. The effectiveness of the proposed adaptive controller is compared with that obtained using optimised PI controllers by Taguchi method. The validity of the adaptive vector control scheme is verified by the simulation results which are performed using PSCAD/EMTDC environment

AN ALTERNATIVE VIEW OF LOUDSPEAKER NONLINEARITIES USING THE HILBERT-HUANG TRANSFORM

ABSTRACT This paper presents a new approach to nonlinear loudspeaker characterization using the Hilbert-Huang transform (HHT). Based upon the empirical mode decomposition (EMD) and the Hilbert transform, the HHT decomposes nonlinear signals into adaptive bases which reveal nonlinear effects in greater and more reliable detail than current approaches. Conventional signal decomposition techniques such as Fourier and Wavelet techniques analyse nonlinear distortion using linear transform theory. This restricts the nonlinear distortion to harmonic distortion. This work shows that real nonlinear loudspeaker distortion is more complex. HHT offers an alternate view through the cumulative effects of harmonics and intra-wave amplitude-and-frequency modulation. The work calls into question the interpretation of nonlinear distortion through harmonics and points towards a link between physical sources of nonlinearity and amplitude-and-frequency modulation. The work furthermore questions the suitability of traditional signal analysis approaches while giving weight to the use HHT analysis in future work

A New Class of Efficient Adaptive Filters for Online Nonlinear Modeling

Nonlinear models are known to provide excellent performance in real-world applications that often operate in nonideal conditions. However, such applications often require online processing to be performed with limited computational resources. To address this problem, we propose a new class of efficient nonlinear models for online applications. The proposed algorithms are based on linear-in-the-parameters (LIPs) nonlinear filters using functional link expansions. In order to make this class of functional link adaptive filters (FLAFs) efficient, we propose low-complexity expansions and frequency-domain adaptation of the parameters. Among this family of algorithms, we also define the partitioned-block frequency-domain FLAF (FD-FLAF), whose implementation is particularly suitable for online nonlinear modeling problems. We assess and compare FD-FLAFs with different expansions providing the best possible tradeoff between performance and computational complexity. Experimental results prove that the proposed algorithms can be considered as an efficient and effective solution for online applications, such as the acoustic echo cancellation, even in the presence of adverse nonlinear conditions and with limited availability of computational resources

LRLS フィルタにおける時変正則化係数更新のための高速算法

金沢大学理工研究域電子情報通信学系線形適応フィルタの一つとして，正則化係数を定数としたO(N2) のleaky recursive least-squares (LRLS) アルゴリズムが筆者により報告されている．Prof. Ali H. Sayed 等の手法に基づけば時変正則化係数計算アルゴリズムを導入できるが，その計算複雑度はO(N3) となる．本論文では，時変正則化係数の計算精度をほぼ同等に保持したまま，O(N) で計算可能な時変正則化係数計算法を導入したO(N2) のLRLS アルゴリズムを提案する