A DC/DC converter topology for renewable energy systems

This paper presents a DC/DC converter topology for renewable energy systems. The proposed DC/DC converter can be used to obtain a well‐regulated output voltage from low‐voltage power source, such as wind turbine, photovoltaic array, fuel cell, etc. It has the merits of high efficiency, low device stresses, and low current ripple. The operating principle, theoretical analysis, and design criteria are provided in this paper. A laboratory prototype was successfully implemented. The simulation and experimental results are given to verify the feasibility of the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd.     

基于DSP控制的燃料电池客车用DC／DC变换器研究

简要介绍了研究燃料电池客车用数字化DC/DC变换器的意义,以Boost变换器为例分析了DC/DC变换器主电路工作原理,设计了基于TMS320LF2407A的控制系统硬件电路平台以及控制系统的软件,并给出了燃料电池客车用90 kW Boost变换器试验结果及其技术参数。数字化DC/DC变换器实现了变换器的软开关和可编程的数字化控制,具有良好的输出和响应特性,可以满足燃料电池客车复杂的控制要求及城市工况运行要求,并且已经在城市工况下示范运行。     

氢光联合供电系统的能量管理

将光伏发电和燃料电池发电结合起来,提出了一种基于双输入Buck变换器的氢光联合供电系统,它是由太阳能电池、燃料电池和双输入Buck变换器组成。基于双输入Buck变换器提出了一种氢光联合供电系统的能量管理控制策略,尽可能多地利用了太阳能电池的输出功率。在Saber仿真软件中搭建了一个氢光联合供电系统的仿真模型,对系统进行仿真分析,并在实验室完成了一台原理样机进行实验验证,仿真结果和实验结果均验证了双输入Buck变换器的工作原理和能量管理策略的有效性。     

一种用于燃料电池发电系统的前级DC/DC变换器

针对燃料电池并网发电系统对前级DC/DC变换器的要求.提出并研究了由Boost和推挽正激变换器(Push-Pull Forward Convener,简称PPFC)组合而成的两级式DC/DC变换器.由于推挽正激变换器工作于最大占空比,开关管和输出整流管电压应力小,有利于变换器的优化设计.分析了该变换器的工作原理,给出了电路关键参数的设计.500 W样机试验验证了该设计的可行性.     

氢燃料电池在电力系统后备电源的应用研究

笔者针对变电站直流系统,应用新型氢燃料后备电源替代蓄电池组作为后备电源产品。旨在将氢燃料电源作为直流系统整体后备电源,氢燃料应急移动直流电源,直流技改中氢燃料后备电源的可行性和解决方案进行测试研究,提出新型后备电源设计、采取措施以及提出一整套系统的解决方案。结果显示,将氢燃料电池供电系统代替铅酸蓄电池组作为停电期间的后备电源,只保留少量的铅酸蓄电池作为系统启动过程中的支撑,停电时自动启动、市电恢复时自动进入待机状态,铅酸电池随即进入浮充状态。大量减少铅酸蓄电池的使用,能减少对环境的污染。氢燃料电池供电系统若包含DC/AC逆变设备,即可为通信站的交流负载供电,替代汽柴油机,降低噪音和振动,减少二氧化碳等气体排放。     

一种人工神经网络算法在燃料电池中的应用

提出一种基于人工神经网络的燃料电池混合动力系统。该系统采用两级循环控制,第一级采用神经网络控制,以实现能量跟踪的最大化,在不同的日光、温度和负载条件下提取最大的可利用能量;第二级采用实时/反应能量控制器,通过控制进入燃料电池堆的燃料,同时发送控制信号到能量条件子系统,以满足系统对反应能量的需求。通过时域仿真可知,该系统对混合动力系统稳定有效。     

Design and implementation of a high‐efficiency bidirectional DC‐DC Converter for DC micro‐grid system applications

This paper studies the design and implementation of a non‐isolated dual‐half‐bridge bidirectional DC‐DC converter for DC micro‐grid system applications. High efficiency can be achieved under wide‐range load variations by the zero‐voltage‐switching features and an adaptive phase‐shift control method. A three‐stage charging scheme is designed to meet the fast‐charging demand and prolong the lifetime of LiFePO₄ batteries. A digital‐signal‐processing control IC is used to realize the power flow control, DC‐bus voltage regulation, and battery charging/ discharging of the studied bidirectional DC‐DC converter. Finally, a 10 kW prototype converter with Enhanced Controller Area Network communication function is built and tested for micro‐grid system applications. A light‐load efficiency over 96% and a rated‐load efficiency over 98% can be achieved. Copyright © 2013 John Wiley & Sons, Ltd.     

高效燃料电池发电系统前级DC/DC变换器

燃料电池产生的直流电能随负载变化很大,为了在用户端得到稳定可靠的电能,必须加入功率调节环节.采用移相全桥ZVS DC/DC变换器作为一个5kW燃料电池分布式并网发电系统的前级变换器.介绍了主要的设计思路,然后以提高DC/DC变换器的效率为目的,进行了损耗分析.最后,在实验样机上验证了理论分析和设计的正确性.     

Gradient‐based optimization techniques for the design of static controllers for Markov jump linear systems with unobservable modes

The paper formulates the static control problem of Markov jump linear systems, assuming that the controller does not have access to the jump variable. We derive the expression of the gradient for the cost motivated by the evaluation of 10 gradient‐based optimization techniques. The numerical efficiency of these techniques is verified by using the data obtained from practical experiments. The corresponding solution is used to design a scheme to control the velocity of a real‐time DC motor device subject to abrupt power failures. Copyright © 2014 John Wiley & Sons, Ltd.     

A novel low‐loss control strategy for bidirectional DC–DC converter

Bidirectional DC–DC converter with phase‐shift control is commonly used for hybrid electric vehicle and fuel‐cell vehicle applications. This converter is characterized by simple circuit topology and soft‐switching implementation without additional devices. Despite these advantages, the efficiency is poor at light load condition because of high switching and conduction losses caused by high RMS inductor current. To achieve zero‐voltage switching (ZVS) for all power MOSFETs, a constant offset inductor current is maintained to conduct the antiparallel body diodes before MOSFETs turn on. A control strategy of combining duty ratio and phase‐shift modulation is proposed to reach the constant offset current. By reaching the constant offset current, the RMS inductor current can be reduced significantly, and ZVS can be achieved in all load variation ranges, resulting in high efficiency. A 2.5‐kW prototype is implemented to verify the control scheme, and a minimum efficiency of 97.3% is achieved at light load condition. Copyright © 2017 John Wiley & Sons, Ltd.     

A single‐stage LED streetlight driver with PFC and digital PWM dimming capability

This paper proposes a single‐stage light‐emitting diode (LED) driver that offers power‐factor correction and digital pulse–width modulation (PWM) dimming capability for streetlight applications. The presented LED streetlight driver integrates an alternating current–direct current (AC–DC) converter with coupled inductors and a half‐bridge‐type LLC DC–DC resonant converter into a single‐stage circuit topology. The sub‐circuit of the AC–DC converter with coupled inductors is designed to be operated in discontinuous‐conduction mode for achieving input‐current shaping. Zero‐voltage switching of two active power switches and zero‐current switching of two output‐rectifier diodes in the presented LED driver decrease the switching losses; thus, the circuit efficiency is increased. A prototype driver for powering a 144‐W‐rated LED streetlight module with input utility‐line voltages ranging from 100 to 120 V is implemented and tested. The proposed streetlight driver features cost‐effectiveness, high circuit efficiency, high power factor, low levels of input‐current harmonics, and a digital PWM dimming capability ranging from 20% to 100% output rated LED power, which is fulfilled by a micro‐controller. Satisfying experimental results, including dimming tests, verify the feasibility of the proposed LED streetlight driver. Copyright © 2016 John Wiley & Sons, Ltd.     

A half‐bridge resonant DC/DC converter with satisfactory soft‐switching characteristics

In this paper, a half‐bridge resonant DC/DC converter with constant output voltage is proposed, which possesses good soft‐switching characteristics. At rated operating point, the switches can operate almost without switching‐on and off losses. Further, at whole working range, both zero‐voltage‐switching mode of switches and zero‐current‐switching mode of diodes are maintained. Thus, the converter can achieve a high efficiency. Experimental results verify the low switching losses and high efficiency characteristics based on a 200 W prototype. System efficiency is as high as 96% and always above 90% when output power changes from 100% to 20%. Copyright © 2016 John Wiley & Sons, Ltd.     

固体氧化物燃料电池发电系统模型建立及逆变器仿真研究

以固体氧化物燃料电池发电系统为研究对象,以释放变换器上电感能量,减少电容充电时间为目的,提出了在DC/DC变换器中增加一个反激式绕组。该反激式绕组的输出端、接地端分别与DC/DC变换器的输出端、输出接地端相连,构成输出回路,以释放输入电感启动时多余能量,保证输出直流母线电压的稳定性。逆变器输出电压控制采用模糊PID控制策略,可在固体氧化物燃料电池输出电压不稳定时,通过监测该系统的输出电压和给定电压差值,在线调整KP、Kd、Ki控制输出量。该控制策略与传统PID控制策略进行了比较,比较结果证明其性能优于传统PID控制策略。采用Matlab软件搭建系统模型,固体氧化物燃料电池发电系统的仿真研究验证了以上的理论分析。     

一种可拓展双输入高增益DC/DC变换器

针对光伏发电系统中光伏电池板集成汇流的需求,提出了一种可拓展双输入高增益DC/DC变换器。该变换器采用了一种新型拓扑结构,可在实现输入输出电压高增益变换的同时降低了开关器件的电压应力。此外,所提变换器还具有可拓展性,可以根据不同的光伏电池板数量和输出电压要求对端口进行扩展,从而降低系统的复杂性和成本。首先详细介绍了所提变换器的拓扑结构,并推导出变换器在不同工作模态下的运行原理。然后,对该变换器的增益特性、开关器件的电压和电流应力、关键器件的参数选择和损耗计算等方面进行了深入的理论分析。最后,搭建了一台输出功率为1 kW的实验样机,并进行了实验测试。实验结果验证了所提变换器理论分析的正确性和可行性。     

Analysis and implementation of a high‐efficiency zero‐voltage‐zero‐current‐switching DC–DC converter

A high‐efficiency zero‐voltage‐zero‐current‐switching DC–DC converter with ripple‐free input current is presented. In the presented converter, the ripple‐free boost cell provides ripple‐free input current and zero‐voltage switching of power switches. The resonant flyback cell provides zero‐voltage switching of power switches and zero‐current switching of the output diode. Also, it has a simple output stage. The proposed converter achieves high efficiency because of the reduction of the switching losses of the power switches and the output diode. Detailed analysis and design of the proposed converter are carried out. A prototype of the proposed converter is developed and its experimental results are presented for validation. Copyright © 2011 John Wiley & Sons, Ltd.     

燃料电池汽车用DC/DC变换器的控制策略及仿真

结合燃料电池汽车的特殊应用场合，提出了一种结构简单、转换效率高的DC／DC变换器，针对这种特殊的DC／DC变换器及应用控制要求，得出一种旨在完成功率流分配的基本控制方法。     

基于GaN器件大功率双向DC/DC变换器的设计与仿真

介绍了一种新的高功率双向隔离式DC/DC变换器作为高功率转换系统的主要电路.DC/DC变换器使用基于氮化镓(GaN)的功率开关器件.对10 kW GaN大功率DC/DC变换器的拓扑结构进行了优化、参数化和分析,并通过仿真和实验验证了其有效性.它由使用新型的GaN晶体管组成的两个单相全桥电路、两个输入/输出电感和一个高频...     

燃料电池电动汽车用功率斩波器快速控制原型设计

介绍了燃料电池电动汽车动力系统中DC／DC斩波器的工作原理,并对其控制算法进行分析。通过Simulink／Stateflow工具箱建立相应快速控制原型,生成适合DSP的自动嵌入式代码,完成燃料电池电动汽车用DC／DC斩波器控制算法设计。仿真结果表明,基于Simulink／Stateflow的快速设计原型并生成代码的开发方法加快了工程进度,提高了代码的稳定性。     

Digital Control of a Power Conditioner for Fuel Cell/Super-capacitor Hybrid System

This article proposes a digital control scheme to operate a proton exchange membrane fuel cell module of 1.2 kW and a super-capacitor through a DC/DC hybrid converter. A fuel cell has been proposed as a primary source of energy, and a super-capacitor has been proposed as an auxiliary source of energy. Experimental validation of the system implemented in the laboratory is provided. Several tests have been performed to verify that the system achieves excellent output voltage (V₀) regulation and super-capacitor voltage (V_SC) control under disturbances from fuel cell power (P_FC) and output power (P₀) as well as other perturbations described in analysis results.     

数字式多相电流吸收负载研究

设计了基于数字控制的多相电流吸收负载。从系统可靠性与灵活性方面考虑,系统采取了以宽安全工作区的线性MOSFET作为能耗元件,以数字控制回路代替传统的模拟回路的方案。调制模式采用多相交错PWM的方案进行主动式电流纹波抑制,克服了数字电力电子系统中有限开关频率与有限采样率的问题;在此基础上设计了功率电路与采样电路;并根据系统模型设计了可用于恒流与脉冲电流负载模式的数字控制器。样机采用dsPIC33FJ64GS606为主控芯片实现高精度四路交错PWM与实时控制;实验测试表明,该电流吸收负载具有较好的稳态、动态特性,可用于未来数字化的电源测试设备。