Puhan Subhranshu Sekhar, Sharma Renu
Department of Electrical Engineering, ITER, SOA Deemed to be University, Bhubaneswar, India.
Sci Rep. 2025 Jul 26;15(1):27301. doi: 10.1038/s41598-025-11924-9.
This manuscript presents the analysis and design of a fixed normalized least mean fourth (XE-NLMF) based algorithm for a single-stage, three-phase grid-integrated solar photovoltaic (SPV) system. The SPV system comprises a solar PV array, a voltage source converter (VSC), a three-phase utility, and a combination of linear and nonlinear loads. The conventional least mean fourth (LMF) algorithm is known for its lower steady-state error and enhanced stability in noisy environments. However, the proposed XE-NLMF algorithm demonstrates superior steady-state performance compared to the conventional LMF technique. In this study, an SPV array coupled with the perturb and observe (P&O) method for maximum power point tracking (MPPT) is integrated with a VSC-based converter controlled using the XE-NLMF algorithm, interfacing with a three-phase utility. The performance of the proposed VSC-based controller is evaluated in a MATLAB simulation environment under various operating conditions, including changes in solar insolation levels, load unbalancing, grid weakness, and different load combinations (linear and nonlinear). Finally, the novelty lies in the stability of the proposed controller, which is assessed by using (i) Time Domain State Space System Generation, (ii) novel pole-zero analysis technique, (iii) Stability using Impulse response from Inverse Transform, (iv) in the Z-domain by using Lypaunouv Stability analysis and by normal Zdomain analysis to realise the real time analysis by stability analysis. Moreover, the proposed controller ensures compliance with IEEE-519 standards by maintaining power quality and limiting harmonic distortions.
本文提出了一种基于固定归一化最小均方四阶（XE-NLMF）算法的单级三相并网太阳能光伏（SPV）系统的分析与设计。该SPV系统包括太阳能光伏阵列、电压源变换器（VSC）、三相公用事业电网以及线性和非线性负载的组合。传统的最小均方四阶（LMF）算法以其较低的稳态误差和在噪声环境中增强的稳定性而闻名。然而，所提出的XE-NLMF算法与传统的LMF技术相比，具有更优异的稳态性能。在本研究中，一个采用扰动观察（P&O）方法进行最大功率点跟踪（MPPT）的SPV阵列与一个基于VSC的变换器集成在一起，该变换器采用XE-NLMF算法进行控制，并与三相公用事业电网相连。在MATLAB仿真环境中，对所提出的基于VSC的控制器在各种运行条件下的性能进行了评估，包括太阳光照水平的变化、负载不平衡、电网薄弱以及不同的负载组合（线性和非线性）。最后，该研究的新颖之处在于所提出控制器的稳定性，通过以下方式进行评估：（i）时域状态空间系统生成，（ii）新颖的零极点分析技术，（iii）利用逆变换的脉冲响应进行稳定性分析，（iv）在Z域中通过李雅普诺夫稳定性分析和常规Z域分析来实现稳定性的实时分析。此外，所提出的控制器通过维持电能质量和限制谐波失真确保符合IEEE-519标准。
