基于新型碳化硅MOSFET的低压直流断路器研究

发布时间：2018-05-24 21:19

本文选题：直流断路器 + SiC-MOSFET　；参考：《华北电力大学》2017年硕士论文

【摘要】：低压直流断路器(LVDC breaker,low voltage direct current breaker)的作用是在低压直流电路发生故障、过载或不正常运行时断开电路。低压直流断路器主要应用于低压直流配电网中,近年来,随着科技的不断发展,直流配电可以带来更高的电能质量,使得直流的应用范围更加广泛,而直流断路器是支撑直流配电网安全稳定运行的关键部分,因此直流断路器一直是近几年的研究热点。近些年直流断路器的性能已逼近Si材料的极限,若要研制出性能更优越的断路器则需要采用新的半导体材料,随着近几年碳化硅材料研究的不断成熟,其具有低导通损耗、耐高温、高频和开断速度快等优点,将其与硅MOSFET和IGBT比较后发现,碳化硅MOSFET特别适合作为开关元件用于直流断路器中。本文的主要工作是研究击穿电压为1.2k V的碳化硅MOSFET用于500V直流断路器的可行性,并在此基础上尝试样机试制。论文首先介绍了直流断路器的研究背景和研究现状,以及碳化硅MOSFET优异的性能;其次介绍了当前三大主流直流断路器的工作原理及其优缺点;然后从材料属性、直流电压等级、绝缘和用电安全等多角度来确定本文设计的断路器的工作电压500V;接着详细介绍了SiC-MOSFET开通和关断过程中的电路特性,以及用Saber软件实现SiC-MOSFET建模的具体过程;接着搭建了简易低压直流电路模型,并估算模型中各元件的参数;然后利用该模型分析了碳化硅MOSFET在开断电路正常工作和故障时的过电压大小,并在此基础上设计了二种过电压保护电路保证SiC-MOSFET的安全可靠工作,并对二种过电压保护电路优缺点进行比较;最后完成断路器中主电路、过电压保护电路、电流检测电路、控制电路和驱动电路五个部分的设计,然后依据电路图完成样机的试制。本文设计的断路器开断容量较小,体积较大,通过后续的不断改进和完善有望实现该断路器在实际生活中的应用。
[Abstract]:The function of LVDC breaker voltage direct current breaker) is to disconnect the circuit when the low voltage DC circuit has a fault, overload or abnormal operation. Low-voltage DC circuit breakers are mainly used in low-voltage DC distribution networks. In recent years, with the continuous development of science and technology, DC distribution can bring higher power quality, making DC applications more extensive. DC circuit breaker is the key part to support the safe and stable operation of DC distribution network, so DC circuit breaker has been the research hotspot in recent years. In recent years, the performance of DC circuit breaker has approached the limit of Si material. If we want to develop the circuit breaker with better performance, we need to adopt new semiconductor material. With the development of silicon carbide material in recent years, it has low conduction loss. Compared with silicon MOSFET and IGBT, silicon carbide MOSFET is particularly suitable for DC circuit breakers. The main work of this paper is to study the feasibility of using silicon carbide MOSFET with a breakdown voltage of 1.2 kV for 500V DC circuit breakers. This paper first introduces the research background and research status of DC circuit breaker, and the excellent performance of silicon carbide MOSFET; secondly, introduces the working principle, advantages and disadvantages of the three main current DC circuit breakers; and then from the material properties, DC voltage grade, The working voltage of the circuit breaker designed in this paper is determined from many angles, such as insulation and power safety, then the circuit characteristics in the process of SiC-MOSFET turn-on and turn-off are introduced in detail, and the concrete process of modeling SiC-MOSFET with Saber software is introduced in detail. Then a simple low-voltage DC circuit model is built, and the parameters of each component in the model are estimated, and then the overvoltage of silicon carbide MOSFET during the normal operation and failure of the circuit is analyzed. On this basis, two kinds of overvoltage protection circuits are designed to ensure the safety and reliability of SiC-MOSFET, and the advantages and disadvantages of the two overvoltage protection circuits are compared. Finally, the main circuit of circuit breaker, over-voltage protection circuit and current detection circuit are completed. Control circuit and drive circuit design of five parts, and then according to circuit diagram to complete the prototype trial production. The circuit breaker designed in this paper has a small breaking capacity and a large volume. It is expected that the circuit breaker will be used in real life through continuous improvement and improvement.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM561

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