【作者】 张勇强；

【导师】 金新民；

【作者基本信息】 北京交通大学 ， 电力电子和电力传动， 2007， 硕士

【摘要】 直流变换器是电力电子变换器的重要组成部分,软开关技术是电力电子装置向高频化、高功率密度化发展的关键技术,是现代电力电子技术研究的热点之一。微处理器的出现促进了电力电子变换器的控制技术从传统的模拟控制转向数字控制,数字控制技术可使控制电路大为简化,并能提高系统的抗干扰能力、控制灵活性、通用性以及智能化程度。本文通过对数字化移相全桥ZVZCS直流变换器的分析与设计,对软开关和数字控制技术进行了研究和实验。移相全桥直流变换器的软开关技术分为零电压开关(ZVS)和零电压零电流开关(ZVZCS)两大类。本文对这两类软开关进行了比较分析,并对ZVZCS软开关的工作原理进行了详细分析,总结了几种典型的实现方案,并选择其中的利用输出祸合电感实现的ZVZCS软开关电路进行了实验研究。本文大体由三部分组成:第一部分针对采用副边辅助回路的ZVZCS软开关电路,进行了原理分析,给出了电路方程。第二部分详细介绍了主电路元器件的参数设计和选型,以及以TMS320F2812为核心的控制系统软硬件设计。第三部分给出了实验波形分析和运行状况的介绍。最后的实验结果表明:主电路参数设计正确、合理,满足变换器设计要求:电路成功实现了ZVZCS,且具有辅助电路结构简单、无耗能元件和有源开关,副边整流管电压应力小,整体效率高等优点;控制系统硬件结构简单、控制精度高;控制软件工作正常,正确实现了所有功能,从而验证了所选方案的正确性。更多还原

【Abstract】 DC/DC converter is a main part of power electronic converter. Soft Swithing technique is a hotspot of power electronic field. It is the key technique in high frequency and high density converter. With the advent of microprocessor, there has been an increased interest in digital control of switch mode power supply, instead of analog control. The digital control scheme has many advantages in simplifying the control circuit, improving the anti-interference ability, control precision and flexibility, general and intelligent level.In order to research on soft-switching and digital control technology, this paper proposes a digital controlled phase-shift ZVZCS full bridge converter and analyses its principle of operation.There are two soft-switch schemes of phase-shift full-bridge DC/DC converter: zero-voltage switching (ZVS) and zero-voltage zero-current switching (ZVZCS). This paper compares and analyses the two schemes. On the analyses of several typical ZVZCS circuit topologies, a ZVZCS full bridge PWM converter with a simple auxiliary circuit is introduced.This paper composes of three sections:The first one analysis the operation mode of ZVZCS full bridge PWM converter with a simple auxiliary circuit and deduces the circuit equation.The second part introduces the component parameter design of main circuit and then presents the control system both hardware and software.The third part shows the operation performance and analyses the waveform.The Experiment results show:Main circuits parameter is right, reasonable and achieve all design require: Zero-voltage zero-current switching is achieved correctly, and the converter has many advantages such as simple auxiliary circuit, low voltage stress of rectifier diode and high efficiency; The control system’s hardware structure is simple, highly integrated and easy to implement; The control system’s software works properly and fulfill all functions, the correctness of the whole design is validated.更多还原