An Efficient Wind–Photovoltaic Hybrid Generation System Using Doubly Excited Permanent-Magnet Brushless Machine

With ever-increasing concerns on energy issues, the development of renewable energy sources is becoming more and more attractive. This paper first reviews both the wind power and photovoltaic (PV) power generation techniques and their maximum-power-point tracking (MPPT) methods. Then, a new stand-alone wind–PV hybrid generation system is proposed for application to remote and isolated areas. For the wind power generation branch, a new doubly excited permanent-magnet brushless machine is used to capture the maximum wind power by using online flux control. For the PV power generation branch, a single-ended primary inductance converter is adopted to harness the maximum solar power by tuning the duty cycle. The experimental results confirm that the proposed hybrid generation system can provide high efficiency with the use of MPPT.      

Performance evaluation of a MPPT controller with model predictive control for a photovoltaic system

ABSTRACT

Efficiency has been a major factor in the growth of photovoltaic (PV) systems. Different control techniques have been explored to extract maximum power from PV systems under varying environmental conditions. This paper evaluates the performance of a new improved control technique known as model predictive control (MPC) in power extraction from PV systems. Exploiting the ability of MPC to predict future state of controlled variables, MPC has been implemented for tacking of maximum power point (MPP) of a PV system. Application of MPC for maximum power point tracking (MPPT) has been found to result into faster tracking of MPP under continuously varying atmospheric conditions providing an efficient system. It helps in reducing unwanted oscillations with an increase in tracking speed. A detailed step by step process of designing a model predictive controller has been discussed. Here, MPC has been applied in conjunction with conventional perturb and observe (P&O) method for controlling the dc-dc boost converter switching, harvesting maximum power from a PV array. The results of MPC controller has been compared with two widely used conventional methods of MPPT, viz. incremental conductance method and P&O method. The MPC controller scheme has been designed, implemented and tested in MATLAB/Simulink environment and has also been experimentally validated using a laboratory prototype of a PV system.     

基于占空比的无电流传感器最大功率点跟踪系统

为了降低能量收集系统的功率损耗,提出了一种基于占空比的无电流传感器最大功率点跟踪（Maximum Power Point Tracking,MPPT）系统。传统的MPPT方法需要进行直流测量或开路电压测量,本文提出的算法利用滞后切换信息预估发电机的输出功率,可以实现保持最大功率提取,无需进行直流测量。采用MSP430微控制器进行了实现,并调整MPPT算法以适合热电发电机的特性。滞后电压调节器能够将热电发电机输出电压维持在参考电平上,因此可以根据给定的温度条件下提取最大功率。实验分析结果表明,提出的MPPT能量收集系统结构简单、成本较低、功率损耗低,且适用于各类小规模可持续发电。     

风光互补发电系统最大功率跟踪综述

风光互补发电系统的运行需要快速准确地进行最大功率点跟踪,为此综述了风光互补发电系统最大功率点跟踪的几种方法,包括在太阳能电池阵列部分日益成熟、改进和优化策略较多的扰动观察法、电导增量法和恒压控制法;风力发电机部分的叶尖速比控制法、功率信号反馈法、扰动观察法,分别说明了各种跟踪控制方法的优点和不足之处。最后探讨了最大功率点跟踪控制方法的发展思路,对该领域今后的研究方向做了展望。     

Toward multiple maximum power point estimation of photovoltaic systems based on semiconductor theory

Environmental conditions, such as temperature, non‐uniform irradiation, and solar shading, deeply affect the characteristics of photovoltaic (PV) modules in PV‐assisted generation systems. Several local maximum power points (MPPs) are found in the power–voltage curve of PV systems constructed by series/parallel‐connected PV modules under partially shaded conditions. The characteristics of PV systems change unpredictably when multiple MPPs occur, so the actual MPP tracking (MPPT) becomes a difficult task. Conventional MPPT methods for the PV systems under partially shaded conditions cannot quickly find the actual MPP such that the optimal utilization of PV systems cannot be achieved. Based on the p–n junction semiconductor theory, we develop a multipoint direct‐estimation (MPDE) method to directly estimate the multiple MPPs of the PV systems under partially shaded conditions and to cope with the mentioned difficulties. Using the proposed MPDE method, the multiple MPPs of the PV systems under partially shaded conditions can be directly determined from their irradiated current–voltage and power–voltage characteristic curves. The performances of the proposed MPDE method are evaluated by examining the characteristics of multiple MPPs of PV systems with respect to different shading strengths and numbers of the shaded PV modules and also tested using the field data. The experimental results demonstrate that the proposed MPDE method can simply and accurately estimate the multiple MPPs of the PV systems under partially shaded conditions. The optimization of MPP control models and the MPPT for PV systems could be achieved promisingly by applying the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

Development of a microcontroller-based, photovoltaic maximum powerpoint tracking control system

Maximum power point tracking (MPPT) is used in photovoltaic (PV) systems to maximize the photovoltaic array output power, irrespective of the temperature and irradiation conditions and of the load electrical characteristics. A new MPPT system has been developed, consisting of a buck-type DC/DC converter, which is controlled by a microcontroller-based unit. The main difference between the method used in the proposed MPPT system and other techniques used in the past is that the PV array output power is used to directly control the DC/DC converter, thus reducing the complexity of the system. The resulting system has high-efficiency, lower-cost and can be easily modified to handle more energy sources (e.g., wind-generators). The experimental results show that the use of the proposed MPPT control increases the PV output power by as much as 15% compared to the case where the DC/DC converter duty cycle is set such that the PV array produces the maximum power at 1 kW/m² and 25°C     

Comparative analysis of maximum power point tracking controller for wind energy system

This paper proposes an adaptive maximum power point tracking (MPPT) control method to achieve the maximum power from the wind turbine (WT) power generation system. The MPPT control method has a vital role to find the maximum power point, and also compute the simulation results in both analysis such as offline using MATLAB/SIMULINK? and online using OPAL-RT simulator. The proposed adaptive perturb and observe (P&;O) algorithm provides better results using the OPAL-RT simulator compared to the P&;O method using MATLAB/SIMULINK?. The power generation through doubly fed induction generator (DFIG) WT system is becoming important day by day throughout the world. The simulation result by OPAL-RT simulator showed that the efficiency of WT-DFIG has been enhanced.     

多路输入大功率LED智能驱动电路系统设计

采用单片机智能控制以实现由风、光、市电多路输入的大功率LED驱动电路设计。其中,风光发电互补系统实现了不同工作情况下的最大功率点跟踪控制策略,并以模拟的风光能源展示发电特性,完善了风光互补措施。蓄电池充电控制方案分段优化充电过程,以智能化操控实现能源的最大利用。从而实现了驱动电路整体最优性能的设计。     

应用于能量收集的DC-DC电路研究综述

随着物联网技术(IoT)的发展,越来越多的IoT传感器被应用于环境检测、物流管理、生产制造和医疗保健等领域。IoT传感器的使用年限取决于内部电池的使用时间,而内部电池是不可拆卸的,因此一旦电池损坏或者电量耗尽,则需要更换新IoT传感器,这大大提高了成本。能量收集技术的发展为解决该难题提供了新方向,该技术将环境中的微弱能量收集起来,通过相关技术转换成电能,为IoT传感器供电,摆脱了其对电池的依赖。文章综述了能量收集系统的关键技术,比较了不同电路结构的优缺点,并且总结了最大功率追踪技术(MPPT),表明MPPT技术从一维MPPT技术发展到三维MPPT技术,现在已有更多的辅助技术来提高MPPT电路的跟踪精度。为了实现更广泛的应用,多输入多输出的转换器已然成为研究重点,文章综述了多能量源输入多输出电压的转换器结构,静态功耗和动态范围等性能指标成为关注的重点。     

独立太阳能扬水系统专用变频器的开发

开发完成独立太阳能能扬水系统专用变频器，具备全自动运行、最大功率点跟踪控制、运行数据存储等功能。针对无蓄电池的太阳能扬水系统特性，采用自主研究的混成最大功率点跟踪控制法和优化最小调节步长。在光照强度快速变化的状况下，新的最大功率点跟踪疗法比传统方法具有型高的响应速度、更好的稳定性。长期运行试验表明，专用变频器各项技术指你优良，性能稳定，可靠性高，能够确保系统在最大功率点的稳定运行。     

IOT Based Augmented Perturb-and-Observe Soft Switching Boost Converters for Photovoltaic Power Systems in Smart Cities

This paper focuses on IOT based soft switching boost converter based solar energy applications for smart cities and making cities smarter and greener around the globe. It presents one of the applications of the Internet of Things to design and implementation of a highly efficient boost converter used for powering the Arduino and the Bluetooth device for controlling the switching of the led and buzzer by using smart city applications. The soft switching boost converter is essential to maximize the low-level voltage obtained from the solar board to the enhanced voltage conversion ratio for the efficient electric power generation. In this paper, the three separate methodologies of DC–DC boost converters with additional resonant/snubber circuit and resistive load associated with solar panel modules proposed with maximum power point tracking (MPPT) control. The MPPT is obtained by modified augmented perturb and observe algorithm. IoT helps Smart City(SC) systems to support various network functions throughout the generation, transmission, distribution and consumption of energy by incorporating IoT devices (such as sensors, actuators and smart meters), as well as by providing the connectivity, automation and tracking for such devices. It is utilized to extract the most extreme power from solar panel by controlling the duty ratio of the suggested soft switching based boost converter. In this paper a smart IOT system is used to control and monitoring the effect of reference power variations, parameter values to the voltage control to the converter. The solar panel, boost converter and the MPPT is modeled using MATLAB/SIMULINK environment and reach the power transfer efficiency up to 97%.     

光伏电池MPPT扰动观察法的研究现状

为了提高太阳电池的利用率并降低系统成本,需要采用最大功率跟踪(MPPT)控制策略使光伏阵列获得最大功率输出。在众多的MPPT控制方法中,扰动观察法由于原理简单、易于实现而成为MPPT控制中应用和研究最为广泛的方法之一。但传统的扰动观察法在稳态下由于其固定的扰动步长会在最大功率点(MPP)附近形成振荡,并且当外界环境发生快速变化时会出现误判断的现象。为了克服以上不足,研究者们提出了很多改进方案。文章对这些改进方案进行了综述,这些改进方案主要包括以下三类:变步长的改进方法、改进的新方法以及与其他方法结合的扰动观察法。     

光伏电池输出特性与最大功率点跟踪的仿真分析

根据太阳能光伏电池的等效电路特点,建立了相应的光伏电池组件的仿真模型。该模型可以实现在不同光照强度和温度下光伏组件的输出特性,在此模型基础上研究了光伏组件最大功率追踪方法(MPPT)。在众多最大功率追踪方法中,扰动法有着比较优秀的控制效果。针对最常用的最大功率点跟踪方法-扰动观察法,提出一种改进型的扰动法算法,通过仿真结果和实验证明该方法在一定程度上可解决光伏电池输出非线性的问题,有效避免跟踪偏差,提高光伏电池的输出效率,且动态响应速度快,使光伏系统具有良好的动态和稳态性能。     

Combined low-cost, high-efficient inverter, peak power tracker andregulator for PV applications

A novel compound power converter that serves as a DC-to-AC inverter, maximum power point tracker (MPPT), and battery charger for stand-alone photovoltaic (PV) power systems is introduced. A theoretical analysis of the proposed converter is performed, and the results are compared with experimental results obtained from a 1.5 kW prototype. The overall cost of PV systems can thus be reduced by using load management control and efficiency-optimization techniques. Power flow through the converter is controlled by means of a combination of duty cycle and output frequency control. With load management, large domestic loads, such as single phase induction motors for water pumping, hold-over refrigerators, and freezers, can be driven by day at a much higher energy efficiency. This is due to the high efficiency of the inverter with high insolation, and because the inverter uses the energy directly from the solar array. The battery loss component is thus reduced     

Investigation of Maximum Power Point Tracking for Thermoelectric Generators

In this paper, a thermoelectric generator (TEG) model is developed as a tool for investigating optimized maximum power point tracking (MPPT) algorithms for TEG systems within automotive exhaust heat energy recovery applications. The model comprises three main subsystems that make up the TEG system: the heat exchanger, thermoelectric material, and power conditioning unit (PCU). In this study, two MPPT algorithms known as the perturb and observe (P&O) algorithm and extremum seeking control (ESC) are investigated. A synchronous buck–boost converter is implemented as the preferred DC–DC converter topology, and together with the MPPT algorithm completes the PCU architecture. The process of developing the subsystems is discussed, and the advantage of using the MPPT controller is demonstrated. The simulation results demonstrate that the ESC algorithm implemented in combination with a synchronous buck–boost converter achieves favorable power outputs for TEG systems. The appropriateness is by virtue of greater responsiveness to changes in the system’s thermal conditions and hence the electrical potential difference generated in comparison with the P&O algorithm. The MATLAB/Simulink environment is used for simulation of the TEG system and comparison of the investigated control strategies.     

Short-current pulse-based maximum-power-point tracking method formultiple photovoltaic-and-converter module system

This paper proposes a novel maximum-power-point tracking (MPPT) method with a simple algorithm for photovoltaic (PV) power generation systems. The method is based on use of a short-current pulse of the PV to determine an optimum operating current where the maximum output power can be obtained and completely differs from conventional hill-climbing-based methods. In the proposed system, the optimum operating current is instantaneously determined simply by taking a product of the short-current pulse amplitude and a parameter k because the optimum operating current is exactly proportional to the short current under various conditions of illuminance and temperature. Also, the system offers an identification capability of k by means of fast power-versus-current curve scanning, which makes the short-current pulse-based MPPT method adaptive to disturbances such as shades partially covering the PV panels and surface contamination. The above adaptive MPPT algorithm has been introduced into a current-controlled boost chopper and a multiple power converter system composed of PV-and-chopper modules. Various operating characteristics have experimentally been examined on this multiple PV-and-chopper module system from a practical viewpoint and excellent MPPT performance has been confirmed through the tests     

Photovoltaic scavenging systems: Modeling and optimization

The interest in embedded portable systems and wireless sensor networks (WSNs) that scavenge energy from the environment has been increasing over the last years. Thanks to the progress in the design of low-power circuits, such devices consume less and less power and are promising candidates to perform continued operation by the use of renewable energy sources. The adoption of maximum power point tracking (MPPT) techniques in photovoltaic scavengers increases the energy harvesting efficiency and leads to several benefits such as the possibility to shrink the size of photovoltaic modules and energy reservoirs. Unfortunately, the optimization of this process under non-stationary light conditions is still a key design challenge and the development of a photovoltaic harvester has to be preceded by extensive simulations. We propose a detailed model of the solar cell that predicts the instantaneous power collected by the panel and improves the simulation of harvester systems. Furthermore, the paper focuses on a methodology for optimizing the design of MPPT solar harvesters for self-powered embedded systems and presents improvements in the circuit architecture with respect to our previous implementation. Experimental results show that the proposed design guidelines allow to increment global efficiency and to reduce the power consumption of the scavenger.     

Power-Electronics-Based Solutions for Plug-in Hybrid Electric Vehicle Energy Storage and Management Systems

Batteries, ultracapacitors (UCs), and fuel cells are widely being proposed for electric vehicles (EVs) and plug-in hybrid EVs (PHEVs) as an electric power source or an energy storage unit. In general, the design of an intelligent control strategy for coordinated power distribution is a critical issue for UC-supported PHEV power systems. Implementation of several control methods has been presented in the past, with the goal of improving battery life and overall vehicle efficiency. It is clear that the control objectives vary with respect to vehicle velocity, power demand, and state of charge of both the batteries and UCs. Hence, an optimal control strategy design is the most critical aspect of an all-electric/plug-in hybrid electric vehicle operational characteristic. Although much effort has been made to improve the life of PHEV energy storage systems (ESSs), including research on energy storage device chemistries, this paper, on the contrary, highlights the fact that the fundamental problem lies within the design of power-electronics-based energy-management converters and the development of smarter control algorithms. This paper initially discusses battery and UC characteristics and then goes on to provide a detailed comparison of various proposed control strategies and proposes the use of precise power electronic converter topologies. Finally, this paper summarizes the benefits of the various techniques and suggests the most viable solutions for on-board power management, more specific to PHEVs with multiple/hybrid ESSs.      

Improving Solar Power Generation and Defects Detection Using a Smart IoT System for Sophisticated Distribution Control (SDC) and Independent Component Analysis (ICA) Techniques

These days, peoples are more concerned respects petroleum product energy and conservational issues caused on the power generation networks and renewable power resources at any other time. Amongst the renewable power resources, solar and windmill power generations are essential competitors. Photovoltaic modules additionally have moderately least transformation effectiveness. General system price was decreased utilizing significant productivity control which are made to determine for most significant achievable energy from solar PV array module utilizing MPPT procedures. Existing solar power generation likewise have the burden of being for the day outputs is less immediate introduction from natural sun radiation. By utilizing the Internet of Things (IoT) strategies for monitoring and controlling the solar power generation was significantly enhance the performance, and maintenance of the solar power plant. In this work explicitly argue advances IoT technique to increase output result of solar power generation at the system level. Covering turning the photovoltaic system in the position of maximum sunlight, obtaining significant available power obtained from the solar PV array and significant battery health management by using sophisticated distribution control (SDC) and independent component analysis techniques (ICA).The simulation work done under with the MATLAB software using proposed SDC and ICA logics the simulation results demonstrate the efficiency of the proposed method and its ability to track the maximum power of the PV panel. Over 97% efficiency achieved by using SDC and ICA methods.     

小型风光互补控制策略研究

文中通过对比风光互补系统各种常用最大功率点跟踪（MPPT）控制策略,提出了改进的MPPT控制策略。光伏电池阵列输出功率通过电压反馈扰动MPPT控制策略进行控制,风力发电机输出的功率采用变步长扰动MPPT控制策略;在蓄电池支路上串联一个MOSFET管,起到截止充电功能,并提出了改进的三段式充电方法。