基于推挽电路的光伏电池最大功率点追踪系统

太阳能光伏阵列的输出特性受外界环境因素的影响,为了使光伏阵列工作在最大功率点,因此经常在系统中加入最大功率追踪器。文中论述了一种利用推挽电路对光伏电池进行最大功率点追踪(MPPT)的控制器,以TMS320LF2407DSP为控制核心。通过Matlab仿真,结果表明控制器能够准确追踪最大功率点。     

基于太阳能供电的温室环境智能监控系统

系统设计包含太阳能供电和环境智能监控两模块,利用太阳能光伏组件阵列进行光电转换为系统提供电能,并且采用了MPPT和自跟踪的方法,实现对太阳能的高效率利用。借助传感器和微处理器实现环境智能监控,所控制的因子有温度、湿度、COz浓度以及光照,使农作物生长在最为合适的环境中,提高农作物产量与质量。     

A PSO‐based maximum power point tracking for photovoltaic systems under environmental and partially shaded conditions

To increase the efficiency of photovoltaic (PV) systems, maximum power point (MPP) tracking of the solar arrays is needed. Solar arrays output power depends on the solar irradiance and temperature. Also the mismatch phenomenon caused by partial shade will affect the output power of solar systems and lead to the incorrect operation of conventional MPP tracker. Under partially shaded conditions, the solar array power–current characteristic has multiple maximum. This paper presents a maximum power point tracking (MPPT) with particle swarm optimization method for PV systems under partially shaded condition. The performance of the proposed method is compared with perturb and observe (P&O), improved P&O, voltage‐based maximum power point tracking and current‐based maximum power point tracking algorithms, especially, under partially shaded condition. Simulation results confirm that proposed MPPT algorithm with high accuracy can track the peak power point under different insolation, temperature and partially shaded conditions, and it has the best performance in comparison with four mentioned MPPT algorithms. Also under rapidly changing atmospheric conditions, the P&O algorithm is diverged. Copyright © 2013 John Wiley & Sons, Ltd.     

基于CC2430的无线传感器供电电源设计

针对连续阴雨天太阳能电池效率下降时,基于CC2430的无线传感器供电电源不能及时传输故障信息的问题,提出了一种利用半导体温差发电技术结合单晶硅太阳能电池为无线传感器持续提供电能的新方法,实现了在无现场供电的情况下,变电站运行设备中大电流回路连接点发热温度的实时采集。对比分析了在不同光线强度下,单晶硅太阳能电池对超级电容充电性能的影响,并设计了测温节点的软件程序。     

Large-signal stability analysis of spacecraft power processingsystems

The authors present a comprehensive large-signal stability analysis of a solar-array power system. The stability of the equilibrium points of a system with a typical nonlinear load characteristic is analyzed. Employing state-plane analysis techniques, the dynamic behavior of the system from an arbitrary initial condition is characterized, and the region of the desired stable operation is identified. The stability and transient response of the system operation near the solar array's maximum power point are evaluated. The dynamic response of the spacecraft power system operating in the shunt mode and battery-discharge mode is analyzed     

New Maximum Power Point Tracker Using Sliding-Mode Observer for Estimation of Solar Array Current in the Grid-Connected Photovoltaic System

A new maximum power point tracker (MPPT) for a grid-connected photovoltaic system without solar array current sensor is proposed. The solar array current information is obtained from the sliding-mode observer and fed into the MPPT to generate the reference voltage. The parameter values such as capacitances can be changed up to 50% from their nominal values, and the linear observer cannot estimate the correct state values under the parameter variations and noisy environments. The structure of a sliding-mode observer is simple, but it shows the robust tracking property against modeling uncertainties and parameter variations. In this paper, the sliding-mode observer for the solar array current has been proposed to compensate for the parameter variations. The mathematical modeling and the experimental results verify the validity of the proposed method.     

Robust state estimator design for a solar battery charging system

This article describes a robust state estimator design for a solar battery charger where there is significant noise in the output measurements of the solar array voltage that causes degradation in the performance of the maximum power point tracking. The application of the extended Kalman filter, to the photovoltaic system, can lead to enhanced state estimation results so that a recursive solution can be obtained to achieve the most accurate estimate from the noisy signals. Additionally, as a consequence of applying the Kalman filter (KF), the immeasurable state of the inductor current can be estimated without a current sensor. The proposed controller uses the estimated solar array voltage for maximum power point tracker, and the estimated inductor current for determining the battery current controller. The methods for system modeling and design of the extended KF are presented, and the experimental results verify the validity of the proposed system.     

Solar-cell panel simulator

The energy generated by solar cells can be transformed into a.c. power by means of inverters. In most cases these inverters cannot be tested under real conditions, since large solar-cell arrays are not yet available at reasonable prices. Therefore, a circuit that simulates a solar-cell array has been developed.     

Solar Battery Chargers for NiMH Batteries

This paper proposes new solar battery chargers for NiMH batteries. First, it is shown that existing charge-control methods can fail when charging by solar arrays in changing environmental conditions. This article discusses the reasons for the failure and introduces new voltage and temperature-based charge- control techniques. To increase charge speed, a maximum power point tracker is also implemented within the micro-controller of the proposed charger.     

910 nm高峰值功率垂直腔面发射激光光源

报道了910 nm高峰值功率垂直腔面发射半导体激光器列阵(Vertical Cavity Surface Emitting Laser,VCSEL)的设计方法及测试结果.所制备的910 nm VCSEL列阵在准连续工作时激光功率达到2 W;在重复频率10 kHz,脉冲宽度30 ns,工作电流60 A的电脉冲驱动条件下,VCSEL列阵峰值输出功率达到25.5 W.随着工作电流的增加,VCSEL列阵输出的激光光谱呈现明显办展宽现象,证实VCSEL列阵即使在窄脉冲工作时大的电流驱动仍然会产生严重的内部热效应;VCSEL列阵输出激光的光脉冲波形在驱动电流增大至60 A时脉宽仅展宽了6 ns左右,证实VCSEL阵列具有非常优越的脉冲响应特性.对VCSEL列阵进行光束准直处理后,在1 m距离处得到了近圆形的均匀光斑.我们相信这种高功率的910 nm面阵光源在未来汽车光探测测距(LiDAR)等智能驾驶领域具有很大的应用潜力.     

一种光伏模拟电源的设计

为给被测试的光伏逆变器提供一个测试其最大功率点性能的环境,设计了一种光伏模拟电源。其主要由整流滤波电路和DC/DC电源组成。整流滤波电路将交流电变成直流,开关电源部分完成降压功能,通过将输出电压采样送入误差比较器中与控制器RAM中的电压进行比较,来控制输出电流和电压,使其工作在对应的I-V曲线上。文中设计的光伏模拟电源可人为地输入温度和日照来模拟太阳能光伏曲线。     

Single-Chip Eye Tracker Using Smart CMOS Image Sensor Pixels

The eye tracker is a system that detects the point where the user gazes on. The conventional eye tracker using a Charge-Coupled Device (CCD) camera needs many peripherals and software computation causing high cost, computation time and power consumption. This paper proposes a single-chip eye tracker using smart CMOS Image Sensor (CIS) pixels. The proposed eye tracker does not require additional peripherals and operates at higher speed than the conventional approach. The prototype chip was designed and fabricated for a 32 × 32 smart CIS pixels array with a 0.35-μ m CMOS process. The test results show ± 1 pixel error at the rate of 125 frame-per-second. The power consumption is 260 mW with 3.3 V supply voltage and the silicon area is 3.8 mm²     

倾角传感器在太阳能跟踪系统中的应用研究

太阳能以其普遍性、永久性、无污染、分布广、利用方便等优点成为各国竞相研究和开发的热点。对太阳能跟踪控制系统中的倾角传感器应用进行了研究,以检测太阳能电池板的倾角,使得太阳能电池板在俯仰方向上与太阳的高度保持一致。设计了倾角传感器检测电路,通过对倾角传感器输出数据的采集和滤波处理,滤除了太阳能电池板在转动过程中因抖动而产生的随机误差信号,实现了在俯仰方向上的精确测量。     

基于DSP的光伏最大功率跟踪技术的研究

光伏电池的最大功率点受光照强度、环境温度和负载大小等外界因素的影响而不断变化,因此很有必要对光伏电池的最大功率点进行时时跟踪以提高光伏电池的利用率.以分析光伏电池输出特性为基础,在实验室环境下用直流电源和可变电阻来模拟光伏电池,并选择Boost电路实现DC/DC变换来搭建实验电路;同时该实验采用DSP(TMS320F2812)作为控制器来进行最大功率跟踪算法的控制.实验结果表明,该方法可以有效地完成光伏的最大功率跟踪.     

Static Var Compensator and Active Power Filter With Power Injection Capability, Using 27-Level Inverters and Photovoltaic Cells

An active power filter and static var compensator with active power generation capability has been implemented using a 27-level inverter. Each phase of this inverter is composed of three ldquoHrdquo bridges, all of them connected to the same dc link and their outputs connected through output transformers scaled in the power of three. The filter can compensate load currents with a high harmonic content and a low power factor, resulting in sinusoidal currents from the source. To take advantage of this compensator, the dc link, instead of a capacitor, uses a battery pack, which is charged from a photovoltaic array connected to the batteries through a maximum power point tracker. This combined topology make it possible to produce active power and even to feed the loads during prolonged voltage outages. Simulation results for this application are shown, and some experiments with a 3-kVA device are displayed.     

新型节能回馈电容在电梯变频器中的应用

本文提出了一种新型的电梯用超级电容器节能回馈装置,该装置可以将电梯重载下行或是轻载上行时产生的势能转化为超级电容电能储存起来,并在电机处于电动工况时作为辅助电源与市电并行供电,从而即减少电梯运行所需的电能损耗又减低了电机工作温度。     

LED特定光谱照明在植物生长中的应用

本文公开了一种用于植物生长的特定光谱模拟照明装置及模拟方法,突破了单光源设计思路,设计基于LED组合的六边形可扩展光源阵列,通过单片机控制和采用电感式开关稳流电源实现受控供电．采用单色标定方法确定光源构型参数,利用最小二乘非线性曲线拟合实现了对特定光谱的模拟。装置具有”模拟特定光谱、轻小可靠高效、便于扩展、通用性强”的优点。仿真试验结果表明,本方法可以有针对性地灵活模拟特定生物的可见光吸收光谱,解决了生物培养中如何高效灵活给光的技术难题,为生物科学研究、特殊环境生物培养和保鲜等提供了新的技术手段。     

Automated dual‐axis planar solar tracker with controllable vertical displacement for concentrating solar microcell arrays

Concentrator photovoltaics are able to maintain power output for extended hours while reducing the quantity of expensive high performance compound semiconductor solar materials. One of the limitations in concentrator photovoltaics is the bulky and heavy form factors of solar tracking systems which usually require dedicated installation locations and resistance to wind loading. This paper describes a planar solar tracker that requires only micro or millimeter scale lateral and vertical displacements of a microlens array to maintain both the optimum lateral locations and focal lengths at various incident angles of light, using dual‐axis actuations. Experimental results for lateral solar tracker were obtained under a solar simulator considering the effects of the rotation and revolution of the Earth, and under the Sun on a rooftop with the actual system, to demonstrate the concept and practical performance. Copyright © 2016 John Wiley & Sons, Ltd.     

Performance monitoring in UMR's solar car

We describe the instrumentation in UMR's solar car. Accurate knowledge of the operating parameters inside the solar car is shown to be crucial to maintaining high efficiency and reliability. The power trackers keep the solar array operating at its highest efficiency by conditioning the input and maintaining the maximum power point of the solar cells     

Integrated Solar Energy Harvesting and Storage

To explore integrated solar energy harvesting as a power source for low power systems, an array of energy scavenging photodiodes based on a passive-pixel architecture for CMOS imagers has been fabricated together with storage capacitors implemented using on-chip interconnect in a 0.35-mum bulk process. Integrated vertical plate capacitors enable dense energy storage without limiting optical efficiency. Tests were conducted with both a white light source and a green laser. Measurements indicate that 225 muW/mm² output power may be generated by white light with an intensity of 20 kLUX.