【作者】 王鹏；

【导师】 曹云东； 刘树鑫；

【作者基本信息】 沈阳工业大学 ， 电气工程， 2018， 硕士

【摘要】 真空断路器在电力系统中主要起到保护和控制的作用,是智能电网中核心输配电设备之一。随着各种核心技术的不断突破和新型灭弧室、操动机构的发展,真空断路器的各项技术参数不断提高。在中压电力网络中,真空断路器已经处于统治地位。针对真空断路器小型化,课题组前期在结合真空灭弧室、操动机构、触头材料、真空电弧特性及开断性能等最新研究的基础上提出了一种三相旋转盘式真空断路器,但是也还存在主回路绝缘、三相同步开断、操动机构设计等问题需加以改进。本文在前期三相旋转盘式真空断路器结构研究基础上,针对主回路绝缘和开断能力进行改进研究,提出了一种新型三相旋转盘式真空灭弧室主回路线路布局及结构。新型模型主回路由同向分布改为异向分布,缩短了主回路线路长度,降低了主回路绝缘负担。新模型在原中心导电极位置嵌入操动机构,在满足同步开断的同时实现了断路器的小型化设计。改变导体软连接的方式降低了真空断路器合闸时刻进出线端导电杆对端盖的冲击力,从而提高了断路器使用寿命。通过对真空灭弧室电场进行三维数值仿真,计算得到各部位电场分布,通过对比计算真空灭弧室内部易发生击穿位置场强最大值及场强分布均匀性,验证了新型真空灭弧室主回路设计的可行性。为了进一步提高真空断路器的开断性能,本文提出了一种新型结构的两极式纵磁触头。利用三维有限元法对触头电弧中心平面的纵向磁场进行数值仿真计算,计算可得电流峰值和电流过零时刻的纵向磁场分布,以及纵向磁场的滞后时间。与旧式两极式纵磁触头磁场分布进行对比计算可得,新型结构触头纵向磁场强度在电流峰值时刻更强,电流过零时刻减弱,滞后时间相对有所延长,新型触头满足了改进需求。对新型真空断路器模型单相回路在额定工作电流及额定短路电流情况时的温度场分别进行了数值仿真计算,通过仿真结果可知,额定短路电流情况下只有添加散热片才能使断路器温升满足相关规定。最后,结合新型三相旋转盘式真空灭弧室特殊的运动方式,本文初步设计了新型双E型电磁铁操动机构和圆筒型永磁直线电机操动机构。还设计了与三相旋转盘式真空灭弧室运动方式相匹配的连接装置,完成了三相旋转盘式真空灭弧室与操作机构的装配。本文还对新型双E型电磁铁操动机构和圆筒型永磁直线电机操动机构分别进行了结构设计和电磁设计,验证了圆筒型永磁直线电机操动机构相比新型双E型电磁铁操动机构而言具有更小的结构尺寸。圆筒型永磁直线电机操动机构更加有利于实现新型三相旋转盘式真空断路器小型化,为进一步完善产品设计提供了理论参考。更多还原

【Abstract】 Vacuum circuit breaker plays an important role of protection and control in the power system,it is one of the core power transmission and distribution equipment in the smart grid.With the continuous breakthrough of various core technologies and the development of new arc extinguishing chamber and operating mechanism,the technical parameters of the vacuum circuit breaker have been continuously improved.In the medium voltage power network,vacuum circuit breakers have been in a dominant position.In view of the miniaturization of vacuum circuit breaker,based on the previous research on vacuum interrupter,operating mechanism,contact material,characteristics of vacuum arc and breaking performance,a three-phase rotation disc vacuum circuit breaker has been proposed.However,there are still some problems such as main circuit insulation,three-phase synchronous opening and the operating mechanism design need to be further improved.Based on the study of the three-phase disc rotation vacuum interrupter in the early stage,this paper researched on the main circuit insulation and breaking capacity of the vacuum circuit breaker for a further performance improvement,and proposed a new structure and main circuit line layout model.In this new model,the main circuit distribution was changed from the same direction to the opposite,which shortened the length of the main circuit line as well as reduced the insulation load of the main circuit.Some adjustments were also made to the position of operating mechanism,and in the case of synchronous breaking,the miniaturization design was achieved.Besides,the flexible connection mode of the conductor was changed to reduce the impact force produced between the conductive rods and the end cap and then extended the mechanical life of the circuit breaker.Based on the numerical simulation of the three-dimensional electromagnetic field,the distribution of the electric field within the vacuum interrupter has been studied.The maximum of the field strength within the vacuum interrupter and the electric field intensity distribution at the breakdown position were analyzed and calculated to optimize the design of new model.In order to further improve the breaking performance of vacuum circuit breaker,a new type of two pole longitudinal magnetic contact is proposed in this paper.The 3-D finite element method is used to simulate the longitudinal magnetic field in the center of the contact arc,and the longitudinal magnetic field distribution of the available current peak current and current zero crossing time,as well as the lag time of the longitudinal magnetic field.Compared with the magnetic field distribution of the old bipolar longitudinal magnetic contact,the longitudinal magnetic field strength of the new type structure contact is stronger at the peak current,the current zero time is weakened,the lag time is relatively prolonged,and the new contact meets the improvement demand.The temperature field of the new vacuum circuit breaker model single-phase circuit conductor under rated working current and rated short-circuit current is calculated.The calculation results show that under the condition of rated short-circuit current,the temperature rise of circuit breaker can be satisfied only by adding heat sink.Finally,a new double E electromagnet operating mechanism and cylinder type permanent magnet linear motor operating mechanism are designed in this paper,combined with the special movement mode of the new three-phase rotation disc vacuum interrupter.The connection device which matches the motion of the three-phase rotation disc vacuum interrupter is also designed,and the assembly of the three-phase rotation disc vacuum interrupter and the operating mechanism is completed.The structure design and electromagnetic design of both the new double E electromagnet operating mechanism and cylinder permanent magnet linear motor operating mechanism are also carried out.It is proved that the cylinder permanent magnet linear motor operating mechanism has smaller structure size compared with the new double E electromagnet operating mechanism.The cylinder permanent magnet linear motor operating mechanism is more conducive to realize the miniaturization of the new three-phase rotation disc vacuum circuit breaker,which provides a theoretical reference for further improvement of the product design.更多还原