【作者】 王成武；

【导师】 杜少武；

【作者基本信息】 合肥工业大学 ， 电力电子与电力传动， 2003， 硕士

【摘要】 双向DC/DC变换器是根据需要调节能量双向传输的直流到直流的变换器。随着科技和生产的发展，对双向DC/DC变换器的需求越来越多，主要有直流不停电电源系统、航天电源系统、直流电机驱动系统、混合能源电动汽车、装甲车电源系统等应用场合，而大功率双向DC/DC变换器技术是电力电子领域的一个难点问题 在某大型车载电源系统中所需的双向DC/DC变换器，其主要实现的功能是实现能量的双向流动：①将270V直流电转换成48V直流电给蓄电池充电，其主要技术指标有：额定功率5kw；电源电压：270V±10％(DC)；额定输出电压：48V(DC)；额定电流：102A；过载能力：150A，2分钟；效率大于等于85％，具有过压、欠压、过流等保护功能。②将蓄电池的28V直流电转换成270V直流，额定功率7.5kw额定电流：28A；过载能力40A，2分钟；效率大于等于85％，具有过压、欠压、过流等保护功能。 鉴于上述特殊要求，为实现能量的双向流动问题，提出了一种新型的双向DC/DC变换器拓扑结构；桥式双向直流变换器适合大、中功率场合，并且较易通过移相控制实现软开关，本文在系统分析了双向PWM DC/DC全桥变换器的两类软开关方式(即零电压(ZVS)和零电压-零电流(ZVZCS))后，针对本课题确定了其控制策略即PS-FB-ZVZCS-PWM方式。 新型拓扑结构的特点：新型拓扑结构为有隔离变压器和无源辅助网络的移相全桥ZVZCS-PWM变换器，从两边看都是全桥移相式ZVZCS-PWM功率变换器；拓扑结构简单。 本论文对基于PS-FB-ZVZCS-PWM软开关的双向DC/DC变换技术进行了拓扑结构和控制方法的理论分析、Pspice仿真和实验，并得出了相应的仿真和实验波形。采用PIC单片机控制，通过无源谐振电路、饱和电感、UC3875移相控制，新型变换器中所有有源开关管均能在双向工作模式中实现软开关，变换器有较宽的软开关负载适应范围，减小了开关损耗；同时运用同步整流器工作方式，降低了变换器的通态损耗。从而将大大缩小变换器的体积和重量，提高变换器的功率密度。更多还原

【Abstract】 Bi-directional DC-DC converters allow the transfer of power between two DC sources in either direction. They are increasingly used in applications such as DC uninterruptible power supply, aerospace power system, DC motor drive systems and hybrid-energy electric vehicles, armored car power system, etc. High power bi-directional DC-DC converters are a difficult problem in power electronics field.The main function of bi-directional DC-DC converter applied in some big car carried power system is the transfer of power between two DC sources in either direction:(1) transfer dc 270v into dc 48v to charge storage battery, its main technology parameters: power rating:5kw; electrical source voltage: 270V± 10%(DC); output voltage rating :dc 48v;rated current: 102A;capacity of over loading:150A,2 minutes; efficiency > 85% ;and safeguarding functions of over voltage, lack of voltage, over current, etc.(2) transfer dc 48v into dc 270v to charge storage battery, its main technology parameters: power rating:5kw; electrical source voltage: 48V±10%(DC); output voltage rating :dc 270v;rated current:28A;capacity of overloading:40A,2 minutes; efficiency >85%;and safeguarding functions of over voltage, lack of voltage, over current, etc.According to above special needs, a new topology of bi-directional DC-DC converter is put forward in the dissertation in order to allow the transfer of power between two DC sources in either direction. Bridge bi-directional DC-DC converter that is easier realized soft switching is applied in high & medium powers. Two sorts of soft-switching modes (ZVS &ZVZCS) of bi-directional PWM DC-DC converter is analyzed by the numbers. Control strategy of PS-FB-ZVZCS-PWM is applied in the dissertation.Characteristics of the new topology: The topology is a phase-shifted full-bridge ZVZCS PWM (PS-FB-ZVZCS-PWM) bi-directional DC-DC converter with isolated transformer and passive network. There is a PS-FB-ZVZCS-PWM converter receptively from two sides. Therefore, thenew topology is simple.Theory analysis, Pspice simulation, experiment of the new topology and its control strategy based on PS-FB-ZVZCS-PWM bi-directional DC-DC converter are introduced. Results of Pspice simulation & experiment are also presented. All of active switches in the new converter with PIC singlechip, UC3875, passive resonance network, saturation inductance can achieve soft switching in both forward and backward operation modes, so switching losses of the converter is reduced. The new converter maintains soft switching in wide load rang. Moreover, Synchronous rectifier operation makes conduction losses of the converter reduced. As a result, weight and volume of the converter will be reduced largely, and the converter will have high power density.更多还原