【作者】 王子建；

【导师】 何俊佳；

【作者基本信息】 华中科技大学 ， 高电压与绝缘技术， 2009， 博士

【摘要】 在分析已有故障限流器的基础上,针对基于快速真空开关的电弧电流转移型故障限流器开展了仿真与实验研究,研制了10kV故障限流器样机,并成功进行了现场试验。快速真空开关是故障限流器中的关键部件。在对电磁斥力机构进行合理简化的基础上,利用有限元方法,建立了电磁斥力机构场路耦合瞬态动力学特性分析的二维有限元模型。为了验证仿真模型的正确性,建立了简化的实验验证模型,并在不同储能电压下,对验证模型的放电电流以及满行程时间进行了实际测量,测量结果验证了仿真模型的正确性。在此基础上,就金属盘、分闸线圈的结构参数,线圈匝数以及储能电容的容量对电磁斥力的影响进行了仿真分析,得出了一般性的设计指导原则。另外,为了进一步提高快速真空开关的分闸速度,提出了在线圈周围加装导磁材料以及利用脉冲成形网络作为其放电回路的设想,并利用仿真模型对其效果进行了仿真分析。最后利用12kV-2500A/40kA真空开关管、双向电磁斥力机构以及可倒翻碟簧双稳机构研制了10kV快速真空开关样机,实测其固有分闸时间为0.5ms,满行程时间为1.6ms。为了验证快速真空开关的电弧电流在强迫过零之后能否熄弧,利用LC振荡回路模拟短路电流,对电弧电流转移型故障限流器的限流效果进行实验研究。在实验过程中,改变TVS支路电流的频率和幅值,以观察限流器的限流效果。实验结果表明,对于10～30kA(峰值)范围内的短路电流,TVS支路电流频率在2600～8200Hz范围内变化时,只要投入足够大的反向电流,使电流出现过零点,则快速真空开关就可以过零熄弧。在以上工作的基础上,完成了限流器的设计,确定了限流器的内部参数及保护、控制逻辑,另外,针对快速真空开关样机在实验过程中反映出来的问题,进行了仿真分析,提出了改进的措施,进一步完善了快速真空开关样机。对于TVS触发可靠性不高及使用寿命的问题,借鉴了已有的研究成果,对TVS的触发可靠性及使用寿命进行了实验研究。最后,研制了10kV故障限流器样机,并进行了现场短路限流试验。试验结果表明,限流器可以有效限制短路电流的峰值和有效值,对于母线电压跌落也有较好的抑制效果。更多还原

【Abstract】 Based on the analysis of existing fault current limiter, simulation and experimental study of arc current-transferring type fault current limiter were carried out. A 10kV fault current limiter prototype was developed, which was successfully experimented in field experiments.A two dimensional(2D)finite element model is applied to analyze the dynamic characteristics of the electromagnetic repulsion mechanism. In order to verify the validity of the simulation results, a simplified electromagnetic repulsion mechanism is established. The discharge current and the contact time between metal tie rod and cushioning device are measured. A good agreement between the measurements and the simulation results is obtained. Detailed investigations are performed by simulation regarding the impacts of various structure parameters and capacity of energy storage capacitor on the dynamic characteristics of the electromagnetic repulsion mechanism. Two methods are put forward for increasing the opening velocity of the switch. Based on the simulation results, a 12kV-2500A/40kA high speed switch prototype with an electromagnetic repulsion mechanism and a disk spring mechanism is developed. It can open within 0.5 ms from the trip signal, and the travel time is 1.6ms.In order to verify if high speed vacuum switch arc current could extinct after the forced zero-crossing, the experimental study on limiting effects of the fault current limiter was carried out, by using a LC oscillation circuit to simulate the short-circuit current. During the process of experiments, the frequency and amplitude of the TVS branch current were changed to figure out if the limiting effect changed. Experimental results showed that, for short-circuit current within scope of 10～30kA (peak value), while the frequency of TVS branch current changed within 2600～8200Hz, the high speed vacuum switch could be zero-extinction, by injecting a reverse current large enough to force the current down to zero.Based on the work in the above, the design of fault current limiter was completed, including the decision of the internal parameters, and logic of protection and control. Addressing the emerged problems of the switch prototype during the experiments, simulation analysis was conducted, from which improvement measures were proposed, and the switch prototype was also improved. Because of the low trigger reliability and short lifetime of TVS, further experimental studies were carried out drawing on existing research results. Finally, a 10kV fault current limiter prototype was developed, and the on-site short-circuit current limiting test was conducted. Experimental results showed that the fault current limiter was effective in curbing the short-circuit current peak and RMS, and it also performed well on inhibiting the bus voltage drop.更多还原