全固态高压直流断路器的设计

发布时间：2018-01-19 18:49

本文关键词： 直流断路器 SiC MOSFET 高压全固态　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：高压直流断路器(HVDC breaker,high voltage direct current breaker)是在高压直流电路发生过载或者短路时及时将直流电路断开,电路故障消除后将电路重新复位的电力保护电路。高压直流断路器主要用在高压直流输电系统和配电系统中,保证直流电路系统的安全可靠运行。近年来,一方面,随着可再生能源的开发,为了减小输送过程中电能的损耗,在远距离输电过程中越来越多的采用直流输电技术;另一方面,随着科学技术的飞速发展,个人和企业对电能质量的要求不断提高,在电能的分配过程中采用直流配电是提高电能质量的一个重要方式和发展方向。高压直流断路器作为保障直流输电系统和配电系统安全稳定运行的关键性部件,人们越来越重视直流断路器的研发,成为当前电力电子领域的一大研究热点。随着半导体工艺的不断进步,SiC功率器件越来越成熟。相对于传统Si功率器件,SiC功率MOSFET具有耐高压、高温、高开关速度以及低导通阻抗等一系列优点,使得SiC功率MOSFET作为电力电子开关元件应用越来越广泛;同时和新型Si材料IGBT相比较,SiC功率MOSFET开关速度更快,温度的变化对器件性能的影响更小。通过分析可知,SiC功率MOSFET满足全固态高压直流断路器对全控型电力电子开关元件的要求。本文的主要工作是基于SiC功率MOSFET开关元件,设计并制作了全固态高压直流断路器。论文首先介绍了直流断路器的应用背景和现状;然后着重分析了直流断路器的工作原理以及SiC功率MOSFET的优势和电路特性;然后根据直流断路器电路功能,将电路主要分为四个功能模块电路,并使用一个负载电路用于模拟短路故障。四个功能电路模块根据负载电路电流的变化,产生相应的控制信号控制直流断路器的关断或者复位;其中电流检测电路检测负载电路电流的变化,电平锁定电路锁定产生的控制信号,栅极驱动电路实现栅源电压的升压和虚地,复位检测电路避免电路的误开启;然后在四个功能电路模块的基础上设计出具有SiC功率MOSFET驱动电路的全固态高压直流断路器电路;最后根据设计的电路图,制作出直流断路器样机。本文设计的高压直流断路器电路采用OrCAD仿真软件进行设计,并进行了仿真验证,仿真结果表明该直流断路器电路实现了功率为12KW的负载电路的关断和复位,栅极驱动电路待机功耗为0,同时直流断路器实现了控制信号的锁定、栅源电压的升压和虚地,避免了直流断路器的误开启操作;最后对直流断路器样机进行了相应的测试,测试结果表明直流断路器实现了对负载电路的电力保护,功能和仿真结果相一致,样机的反应时间约为30μs。本文设计的直流断路器应用范围有限,主要用于纯阻性负载电路;可以通过软开关技术消除容性负载中产生的过电流或者感性负载中的过电压,将其应用范围扩大到所有的负载电路。
[Abstract]:HVDC breaker. High voltage direct current breaker is to break the DC circuit in time when the high voltage DC circuit is overload or short circuit. In recent years, HVDC circuit breaker is mainly used in HVDC transmission system and distribution system to ensure the safe and reliable operation of DC circuit system. On the one hand, with the development of renewable energy, in order to reduce the loss of electrical energy in the transmission process, DC transmission technology is used more and more in the long distance transmission process. On the other hand, with the rapid development of science and technology, individuals and enterprises to improve the quality of power. DC distribution is an important way to improve power quality in the process of power distribution. HVDC circuit breaker is the key component to ensure the safe and stable operation of HVDC transmission system and distribution system. More and more attention has been paid to the research and development of DC circuit breakers, which has become a major research hotspot in the field of power electronics. Compared with the traditional Si power device, sic power MOSFET has a series of advantages, such as high pressure, high temperature, high switching speed and low on-on impedance. SiC power MOSFET is more and more widely used as power electronic switch element. At the same time, compared with the new Si material IGBT, sic power MOSFET switch speed is faster, and the influence of temperature on the device performance is less. SiC power MOSFET meets the requirements of all-solid-state HVDC circuit breakers for full-control power electronic switch components. The main work of this paper is based on SiC power MOSFET switch elements. All solid-state HVDC circuit breakers are designed and fabricated. Firstly, the application background and current situation of DC circuit breakers are introduced. Then, the working principle of DC circuit breaker and the advantages and circuit characteristics of SiC power MOSFET are analyzed. Then according to the circuit function of DC circuit breaker, the circuit is divided into four functional modules, and a load circuit is used to simulate the short-circuit fault. Generating a corresponding control signal to control the turn-off or reset of the DC circuit breaker; The current detection circuit detects the change of the load circuit current, the control signal generated by the level locking circuit, the gate drive circuit realizes the voltage boost and virtual ground of the gate source voltage, and the reset detection circuit avoids the false opening of the circuit. Then the all-solid-state HVDC circuit breaker with SiC power MOSFET driving circuit is designed on the basis of four functional circuit modules. Finally, according to the circuit diagram of the design, the prototype of DC circuit breaker is made. The circuit of HVDC circuit breaker designed in this paper is designed by OrCAD simulation software, and verified by simulation. The simulation results show that the circuit can turn off and reset the load circuit with power of 12KW, the power consumption of the gate drive circuit is 0, and the control signal of the circuit breaker is locked. The boost of gate source voltage and virtual ground avoid the misoperation of DC circuit breaker; Finally, the prototype of DC circuit breaker is tested. The test results show that DC circuit breaker realizes the power protection of load circuit, and the function is consistent with the simulation result. The reaction time of the prototype is about 30 渭 s. The DC circuit breaker designed in this paper has a limited application range and is mainly used in pure resistive load circuit. The overcurrent generated in capacitive load or the overvoltage in inductive load can be eliminated by soft-switching technology, and its application scope can be extended to all load circuits.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM561

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