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1.
This paper presents a combined control and modulation technique to enhance the power quality (PQ) and power reliability (PR) of a hybrid energy system (HES) through a single-phase 11-level cascaded H-bridge inverter (11-CHBI). The controller and inverter specifically regulate the HES and meet the load demand. To track optimum power, a Modified Perturb and Observe (MP&O) technique is used for HES. Ultra-capacitor (UCAP) based energy storage device and a novel current control strategy are proposed to provide additional active power support during both voltage sag and swell conditions. For an improved PQ and PR, a two-way current control strategy such as the main controller (MC) and auxiliary controller (AC) is suggested for the 11-CHBI operation. MC is used to regulate the active current component through the fuzzy controller (FC), and AC is used to regulate the dc-link voltage of CHBI through a neural network-based PI controller (ANN-PI). By tracking the reference signals from MC and AC, a novel hybrid pulse width modulation (HPWM) technique is proposed for the 11-CHBI operation. To justify and analyze the MATLAB/Simulink software-based designed model, the robust controller performance is tested through numerous steady-state and dynamic state case studies.  相似文献   
2.
The current and future status of the internet is represented by the upcoming Internet of Things (IoT). The internet can connect the huge amount of data, which contains lot of processing operations and efforts to transfer the pieces of information. The emerging IoT technology in which the smart ecosystem is enabled by the physical object fixed with software electronics, sensors and network connectivity. Nowadays, there are two trending technologies that take the platform i.e., Software Defined Network (SDN) and IoT (SD-IoT). The main aim of the IoT network is to connect and organize different objects with the internet, which is managed with the control panel and data panel in the SD network. The main issue and the challenging factors in this network are the increase in the delay and latency problem between the controllers. It is more significant for wide area networks, because of the large packet propagation latency and the controller placement problem is more important in every network. In the proposed work, IoT is implementing with adaptive fuzzy controller placement using the enhanced sunflower optimization (ESFO) algorithm and Pareto Optimal Controller placement tool (POCO) for the placement problem of the controller. In order to prove the efficiency of the proposed system, it is compared with other existing methods like PASIN, hybrid SD and PSO in terms of load balance, reduced number of controllers and average latency and delay. With 2 controllers, the proposed method obtains 400 miles as average latency, which is 22.2% smaller than PSO, 76.9% lesser than hybrid SD and 91.89% lesser than PASIN.  相似文献   
3.
An excessive use of non-linear devices in industry results in current harmonics that degrades the power quality with an unfavorable effect on power system performance. In this research, a novel control technique-based Hybrid-Active Power-Filter (HAPF) is implemented for reactive power compensation and harmonic current component for balanced load by improving the Power-Factor (PF) and Total–Hormonic Distortion (THD) and the performance of a system. This work proposed a soft-computing technique based on Particle Swarm-Optimization (PSO) and Adaptive Fuzzy technique to avoid the phase delays caused by conventional control methods. Moreover, the control algorithms are implemented for an instantaneous reactive and active current (Id-Iq) and power theory (Pq0) in SIMULINK. To prevent the degradation effect of disturbances on the system's performance, PS0-PI is applied in the inner loop which generate a required dc link-voltage. Additionally, a comparative analysis of both techniques has been presented to evaluate and validate the performance under balanced load conditions. The presented result concludes that the Adaptive Fuzzy PI controller performs better due to the non-linearity and robustness of the system. Therefore, the gains taken from a tuning of the PSO based PI controller optimized with Fuzzy Logic Controller (FLC) are optimal that will detect reactive power and harmonics much faster and accurately. The proposed hybrid technique minimizes distortion by selecting appropriate switching pulses for VSI (Voltage Source Inverter), and thus the simulation has been taken in SIMULINK/MATLAB. The proposed technique gives better tracking performance and robustness for reactive power compensation and harmonics mitigation. As a result of the comparison, it can be concluded that the PSO-based Adaptive Fuzzy PI system produces accurate results with the lower THD and a power factor closer to unity than other techniques.  相似文献   
4.
Injector is the critical element in the Liquid Rocket Engine (LRE), to ensure proper mixing of propellants (fuel and oxidizer) in the thrust chamber for achieving the optimum thrust. LRE injector is calibrated in order to deliver required flow rates of propellants by sizing the orifices through simple injector water calibration (IWC) techniques. In LRE-IWC process, a huge 6” turbine flow meter (TFM) is employed for the flow-rate measurement. In order to achieve and maintain the required accuracy and precision in the LRE-IWC process, periodical calibration of TFM is mandatory. It involves tremendous time, cost and human effort. Soft sensors can provide an economical and effective alternative solution for TFM flow-rate measurement. The objective of the proposed work is to develop and implement a recurrent neural network based soft sensor (RNN-SS) for TFM flow-rate measurement. In the LRE-IWC process, experimental flow trials were carried out for different flow patterns, and the necessary measurement data were generated for the soft sensor design. The designed RNN-SS was trained by tuning various hyper parameters to replace the TFM, using three related measurement parameters acquired during the experimental trials. The precise TFM flow-rate estimation was achieved by the designed RNN-SS, with a worst-case mean absolute percentage error (MAPE) of 1.91% for the experimental flow patterns considered, with good repeat-ability. The proposed RNN-SS model for TFM flow-rate estimation gives a MAPE of 0.58%, for the required flow-pattern which is well suited for practical use.  相似文献   
5.
李丽  刘超  赵苓 《液压与气动》2022,(5):159-166
针对带有迟滞非线性的气动运动模拟平台的轨迹跟踪提出了带有切换扩张状态观测器的自抗扰控制方法。气动运动模拟平台的迟滞非线性特性主要指气动人工肌肉在正向充气反向放气时长度和拉力曲线的差异。针对此特性设计了切换扩张状态观测器来估计和补偿模型非线性,分别对于气动人工肌肉正反向充放气的不同模型采用不同的观测器增益,以提高状态估计效果,减小跟踪误差。进一步,设计了状态误差反馈控制器,得到了基于切换扩张状态观测器的二阶非线性动态系统全局有界稳定的充分条件。最后实验结果证实了所设计的切换扩张状态观测器的实际效果。  相似文献   
6.
This article presents a state-space model with time-delay to map the relationship between known input-output data for discrete systems. For the given input-output data, a model identification algorithm combining parameter estimation and state estimation is proposed in line with the causality constraints. Consequently, this article proposes a least squares parameter estimation algorithm, and analyzes its convergence for the studied systems to prove that the parameter estimation errors converge to zero under the persistent excitation conditions. In control system design, the U-model based control is introduced to provide a unilateral platform to improve the design efficiency and generality. A simulation portfolio from modeling to control is provided with computational experiments to validate the derived results.  相似文献   
7.
针对共交直流母线的三电平逆变器直接并联系统的零序环流问题,建立了零序环流的等效模型,根据零序环流产生机理与特性进行了分类,并给出相应的抑制措施。针对零序环流的低频分量,提出了基于一阶全通滤波器的比例复数积分(Proportional Complex Integral, PCI)控制器对零序电压分量调节的方法,并根据控制系统稳定性要求对控制器参数进行了设计。最后,利用仿真与实验平台验证了文中所提控制方法对零序环流抑制的有效性。  相似文献   
8.
电流潮流控制器(Current Flow Controller, CFC)可以增加直流电网潮流控制自由度,实现直流电网潮流优化分布,但也使得原始潮流算法对于加装控制器后的直流电网不再完全适用。基于等效功率注入模型和联立求解法,文中提出了一种特定潮流控制目标下,计及CFC的直流电网潮流算法。将CFC对被控支路潮流的调配作用转移到控制器安装支路节点处;将装设CFC引入的附加约束方程组与直流潮流计算约束方程组联立求解,保留了牛顿-拉夫逊法的二次收敛特性,提高了运算效率,保证了运算精度。基于PSCAD/EMTDC仿真平台建立的多端直流环网潮流计算,与所提出的基于等效功率注入模型潮流计算结果进行对比验证,验证了所提方法的有效性和准确性。  相似文献   
9.
针对双馈风电场存在谐波污染问题,文中提出将具有谐振控制器功能的链式STATCOM应用于双馈风电场。分析了具有谐振控制器功能的链式STATCOM数学模型,然后对谐振控制器的控制特性进行改进,提出了一种具有低次谐波抑制作用的PIR-VPI混合控制方法。研究了该混合控制方法的工作原理,并建立数学模型,对参数进行设计,在MATLAB中进行验证。理论分析和仿真结果验证了此方案应用于双馈风电场中谐波抑制的有效性。  相似文献   
10.
为提升机械臂设备的准确分拣能力,设计基于RBF-BP算法的机械臂多自由度分拣控制系统。利用RBF-BP前馈神经网络,规划机械臂设备的运动轨迹路线,实现基于RBF-BP算法的机械臂运动轨迹建模。确定工业相机在总功能框架中所处连接位置,根据机械臂选型情况,确定可编程逻辑控制器、变频控制器对于所选机械臂元件的调节能力,完成对系统功能模块的开发。借助传输信道,将Sorting分拣指令、ToolControl控制指令反馈回核心控制主机,建立完整的指令执行回路,再联合相关硬件设备结构,实现基于RBF-BP算法的机械臂多自由度分拣控制系统设计。实验结果表明,在抓取能力相同的情况下,应用RBF-BP算法控制系统机械臂成功分拣的工件数量为19件,机械臂抓取成功率为95%,说明所设计系统满足提升机械臂准确分拣能力的设计初衷。  相似文献   
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