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11.
Improving the transient response of power generation systems using automation control in a precise manner is the key issue. We design a fuzzy proportional integral derivative (PID) controller using Matlab and programmable logic controllers (PLCs) for a set point voltage control problem in the automatic voltage regulator (AVR) system. The controller objective is to maintain the terminal voltage all the time under any loads and operational conditions by attaining to the desired range via the regulation of the generator exciter voltage. The main voltage control system uses PLCs to implement the AVR action. The proposed fuzzy controller combines the genetic algorithm (GA), radial-basis function network (RBF-NN) identification and fuzzy logic control to determine the optimal PID controller parameters in AVR system. The RBF tuning for various operating conditions is further employed to develop the rule base of the Sugeno fuzzy system. The fuzzy PID controller (GNFPID) is further designed to transfer in PLCs (STEP 75.5) for implementing the AVR system with improved system response. An inherent interaction between two generator terminal voltage control and excitation current is revealed. The GNFPID controller configures the control signal based on interaction and there by reduces the voltage error and the oscillation in the terminal voltage control process. We achieve an excellent voltage control performance by testing the proposed fuzzy PID controller on a practical AVR system in synchronous generator for improve the transient response. 相似文献
12.
The uncertainty associated with modeling and performance prediction of solar photovoltaic systems could be easily and efficiently solved by artificial intelligence techniques. During the past decade of 2009 to 2019, artificial neural network (ANN), fuzzy logic (FL), genetic algorithm (GA) and their hybrid models are found potential artificial intelligence tools for performance prediction and modeling of solar photovoltaic systems. In addition, during this decade there is no extensive review on applicability of ANN, FL, GA and their hybrid models for performance prediction and modeling of solar photovoltaic systems. Therefore, this article focuses on extensive review on design, modeling, maximum power point tracking, fault detection and output power/efficiency prediction of solar photovoltaic systems using artificial intelligence techniques of the ANN, FL, GA and their hybrid models. In addition, the selected articles on the solar radiation prediction using ANN, FL, GA and their hybrid models are also summarized. Total of 122 articles are reviewed and summarized in the present review for the period of 2009 to 2019 with 90 articles in the field of {ANN, FL, GA and their hybrid models} + solar photovoltaic systems and 32 articles in the field of {ANN, FL, GA and their hybrid models} + solar radiation. The review shows the suitability and reliability of ANN, FL, GA and hybrid models for accurate prediction of the solar radiation and the performance characteristics of solar photovoltaic systems. In addition, this review presents the guidance for the researchers and engineers in the field of solar photovoltaic systems to select the suitable prediction tool for enhancement of the performance characteristics of the solar photovoltaic systems and the utilization of the available solar radiation. 相似文献
13.
针对目前岩爆倾向性中预测模型权重确定存在不足导致模型精度不高的现状,为更准确地预测岩爆倾向性,提出综合运用粗糙集理论中的代数观和信息观,确定属性最优权重,并修正岩爆倾向性与评价指标之间的关系,建立岩爆等级理想点矩阵。根据岩爆发生条件,选取岩石脆性指数、切应力指标和弹性应变能指数3项指标作为岩爆判别指标,以国内外20组典型岩爆数据为样本,建立改进的粗糙集—理想点法(RS-TOPSIS)岩爆倾向性预测模型,并应用该模型对玲珑金矿等工程实际进行了岩爆倾向性预测。结果表明:改进后样本预测精度相比于改进前有了显著提高,所建立的模型对实际工程的岩爆倾向性预测效果良好,预测结果更准确。 相似文献
14.
In this paper, a new scheme of logic function realization in dynamic positive feedback source-coupled logic (D-PFSCL) style is proposed. The existing scheme implements only NOR/OR based realization of a logic function. Thus, a complex function in D-PFSCL has high gate count which degrades the overall circuit performance measured in terms of power and delay. This paper therefore aims to resolve the issue by proposing a scheme which modifies the structure of a D-PFSCL gate. The modified gate exhibits AND/OR functionality and is used to realize various functions. Simulations have been carried out by implementing various functions and comparing their performance with the existing schemes at 1 GHz. The results of performance comparison with existing schemes indicates significant reuduction in gate count resulting in overall performance improvement. 相似文献
15.
某出口型号交流电力机车牵引控制系统要求变流器控制逻辑具备接触器控制、牵引系统数据交互、变流器故障保护、变流器启动自检等功能。针对以上功能,基于MATLAB中的Simulink/Stateflow可视化编程工具进行牵引控制模型的搭建,遵循模块化编程理念,采用较少的程序代码编写实现复杂的逻辑控制模型,生成逻辑清晰的控制功能流程图,进行半实物仿真测试,增强控制模型的可靠性。通过该变流器产品型式试验检验,验证变流器控制逻辑的功能可以满足控制系统的需求。 相似文献
16.
The process of elaboration of the symbolic universe leads to exciting insights regarding the search for human emotional security. The symbols end up as explanatory axes of universal reality and on them are constructed myths that form a superstructure for belief systems. Human society is a multi-level system with a material structure (society), an ideological superstructure (belief systems, values, etc.) and a super superstructure with two parts: mythical (origin and justification) and utopic (final goal). All mythical belief systems have a numinous-religious nature. 相似文献
17.
《Planning》2015,(2)
目的:正确的临床决策必须遵循逻辑规律。本文旨在剖析用逻辑学方法提高临床思维训练的可行性。方法:进行临床医学和逻辑学的跨学科整合研究,重点探讨三类常用逻辑方法:演绎法、归纳法和溯因推理法在临床实践中的应用。 结果:发现演绎、溯因和归纳推理分别对应于:①评估临床资料;②提出诊断假设和③完善初步诊断这三种临床思维活动。发现并概括临床思维和医疗实践中包含的逻辑规律,有助于提高思维的准确性、有效性和清晰性。结论:掌握临床思维的逻辑规律,并在中针对性地加以应用,有助于培养医生的思维和决策能力。 相似文献
18.
在铁路运煤装车过程中为了快速、准确地识别车号,提出一种基于机器视觉的运煤车车号识别技术。将连通区域提取与投影分割法结合,实现车号的粗定位、细分割,并对图像中的断裂字符进行二次分割,构建了基于BP神经网络的分类模型进行车号识别,提升了煤炭装车的效率和精度。 相似文献
19.
The intermittent wind power in isolated hybrid distributed generation (IHDG) may cause serious problems associated with frequency (f) and power (P) fluctuation. Energy storage devices such as battery, super capacitor, and superconducting magnetic energy storage (SMES) may be used to reduce these fluctuations associated with f and P. This paper presents a study of IHDG power system for improving both f and P deviation profiles with the help of SMES. The studied IHDG power system is consisted of wind turbine generator and diesel engine generator. Both f and P control problems of the studied power system model are addressed in presence or absence of SMES. Fuzzy logic based proportional–integral–derivative (PID) controller with SMES is used for the purpose of minimization of f and P deviations. The different tunable parameters of the PID controller and those of the SMES are tuned by a novel quasi-oppositional harmony search algorithm. Performance study of the IHDG power system model is carried out under different perturbation conditions. The results demonstrate minimum f and P deviations may be achieved by using the proposed fuzzy logic based PID controller along with SMES. 相似文献
20.
Power transformers are protected by different relays that operate independently. Malfunction of each relay has a major role in reducing the reliability of the protection system. In order to mitigate the main drawbacks of the power transformer relays, an overall protection scheme is presented in this paper. This scheme proposes a novel multi criterion algorithm using decision-making based on fuzzy logic. In this paper the outputs of restricted earth fault relay and a directional check unit, are combined with the output of the differential protection relay. Therefore, problems that are pertaining to independent operation of each relay have been mitigated and the relays cover protection blind spots of each other. The improved power transformer protection (IPTP) scheme enhances the sensitivity and reliability of the power transformer protection. Extensive simulations are used to measure the effectiveness and merit of the proposed IPTP relay. The above efforts result in a multi criteria approach for protection of power transformers. 相似文献