开关变压器并用式软起动系统研究

发布时间：2018-05-05 00:38

本文选题：开关变压器并用 + 电机　；参考：《西华大学》2015年硕士论文

【摘要】：电机在直接起动过程中,起动电流是额定电流的数倍,可达7倍之多,起动转矩也会增加一倍多,而在现代工业中,大电机的应用越来越广泛,尤其是高压大功率电机的应用,其电压可高达10kV,因此在直接起动时会产生的大电流和强转矩会危及到设备的安全,因此在电机起动时要考虑采取软起动方法。比较流行的软起动方式有变频软起及晶闸管阀组,新兴的开关变压器式电机软起动能够有效抑制起动电流与起动转矩,提高起动性能,同时也避免了开关器件串联时的不稳定性。本文立足电机的软起动问题,对开关变压器并用技术进行了深入的研究。首先,阐述了开关变压器技术的工作原理,并对工作过程中的各种特性进行了详尽的分析,其中励磁涌流的机理及其对电机起动所产生的影响是分析的重点,同时给出了变压器的容量计算原则。其次,研究了开关变压器式的高压电机软起动的原理,提出了开关变压器并用技术,建立基于开关变压器软起动系统的数学模型,通过仿真分析验证了开关变压器并用技术的可行性。针对上述相控交流调压存在的问题,设计了开关变压器并用模块,这种并用式高压电机软起动装置是一种由多个变压器与晶闸管组合的开关变压器模块构成的大功率交流调压装置,主要应用于大功率高压电动机的软起动领域,运用开关变压器模块并用技术,可以对任意大容量的电动机实施软起动,这一技术使该装置成为一种性能优异、可靠性非常高的软起动设备。在本研究中,系统地探索了基于开关变压器并用技术大功率电机软起动问题,并结合研究成果设计了一款工业样机。设计并实施了相关的实验,实验结果表明,开关变压器并用技术可有效地提高开关变压器的起动容量,在大功率电动机的起动过程中,原本威胁系统安全运行的各种冲击得到了有效的抑制。提升了系统的稳定性和可靠性。最后利用MATLAB软件开发出一款仿真软件,该软件在基于开关变压器的电机软起动技术的仿真计算中表现良好,该软件实现了电动机在软起动时的一些电气参数的估算,如:起动时间、起动电流、电压波动率及发热量等。
[Abstract]:In the direct starting process, the starting current is several times of the rated current, which can be as many as 7 times, and the starting torque will increase by more than twice. However, in modern industry, the application of large motor is more and more extensive, especially the application of high-voltage and high-power motor. The voltage can be as high as 10kV, so the high current and strong torque produced when starting directly will endanger the safety of the equipment. Therefore, the soft starting method should be considered when the motor starts. The popular soft starting methods are frequency conversion soft start and thyristor valve group. The new switch transformer motor soft start can effectively restrain the starting current and start torque and improve the starting performance. At the same time, the instability of switching devices in series is avoided. Based on the soft starting problem of the motor, this paper makes a deep research on the technology of switching transformer. First of all, the working principle of switching transformer technology is expounded, and various characteristics in the working process are analyzed in detail, among which the mechanism of inrush current and its influence on motor starting are the key points of the analysis. At the same time, the calculation principle of transformer capacity is given. Secondly, the principle of soft start of high voltage motor based on switch transformer is studied, and the mathematical model of soft start system based on switch transformer is established by using the technology of switch transformer. The feasibility of using switch transformer is verified by simulation analysis. Aiming at the problems of the phase-controlled AC voltage regulation, the switch transformer and the module are designed. This kind of soft starting device of high voltage motor is a kind of high power AC voltage regulator composed of several transformers and thyristors, which is mainly used in the field of soft starting of high power high voltage motors. By using switch transformer module and technology, the soft start of any motor with large capacity can be carried out, which makes the device a kind of soft starting equipment with excellent performance and high reliability. In this study, the soft-start problem of high-power motor based on switch transformer and technology is systematically explored, and an industrial prototype is designed based on the research results. Related experiments are designed and implemented. The experimental results show that the starting capacity of the switch transformer can be improved effectively by using the technology, which can be used in the starting process of the high-power motor. All kinds of shocks that threaten the security of the system are effectively suppressed. The stability and reliability of the system are improved. Finally, a simulation software is developed by using MATLAB software. The software performs well in the simulation calculation of motor soft start technology based on switch transformer. The software realizes the estimation of some electrical parameters of motor in soft start. For example: starting time, starting current, voltage fluctuation and calorific value.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM41

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