电厂变频器用低电压穿越电源研究

发布时间：2018-03-15 03:02

本文选题：变频器　切入点：低电压穿越　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：变频器作为一种性能优良的调速装置已广泛应用于发电厂,然而当电厂发生厂内电压跌落时易触发变频器欠压保护,引起相关系统的一系列动作,严重时可导致发电机组跳机。因此,变频器的低电压穿越问题受到了广泛关注。变频器本身无低电压穿越功能,本体难以改造,所以配置一定的辅助设备以实现变频器的低电压穿越功能具有重要的现实意义。论文通过参阅相关国内外文献,确立了系统设计的目标,提出采用加装电力电子装置实现变频器低电压穿越功能的方案。论文详细阐述了火电厂辅机变频器低电压穿越电源的原理,以单重BOOST DC/DC电路为基础,建立了PSLFI(Power Supply with LVRT Capability for Frequency Inverters)的数学模型,探讨了其工作模式及处于运行模式时的起动、退出判据。在此基础上,讨论了PSLFI的软硬件设计的关键问题。在硬件设计方面,以BOOST基本DC/DC电路为基础,设计了包括三相不控整流及三重交错并联的BOOST的拓扑结构,并根据设计要求,确定了PSLFI元器件参数及控制辅助电路。在软件设计方面,在双闭环控制方法的基础上,提出了外环采用优化的模糊自适应PI控制算法与bang-bang滞环控制结合的复合算法。利用自行开发的控制器及RTDS实时仿真系统,完成了硬件在环的闭环仿真实验,仿真结果验证了参数设计的合理性,并为现场实验中的PI参数的调试起到了指导作用。最后,在某电厂内与给煤机、变频器进行了现场联机实验。实验结果表明：论文设计的PSLFI在给煤机系统电压跌落不同深度时,均可实现额定状态下直流稳定输出,且变频器控制电源也能保证给煤机变频器控制回路可靠运行,保证了在系统电压跌落时,变频器及敏感负荷无扰动运行。
[Abstract]:As the inverter speed regulating device with excellent performance has been widely used in power plants, however, when the plant is easy to trigger voltage drop occurred in inverter undervoltage protection, causing a series of actions related to the system, which can lead to the generator tripping. Therefore, low voltage across the inverter has been widely concerned. The inverter itself low voltage ride through the function of ontology, difficult transformation, has important practical significance so configure some auxiliary equipment to achieve frequency converter LVRT.
This paper by referring to relevant literature at home and abroad to establish the target of system design, the installation of power electronic device to realize the function of low voltage ride through the inverter. The paper elaborates on the principle of low voltage ride through the power of the auxiliary inverter power plant, with single BOOST DC/DC circuit as the foundation, established the PSLFI (Power Supply with LVRT Capability for Frequency Inverters) mathematical model, discusses its working mode and at the start, the operation mode of the exit criteria. On this basis, discussed the key problems of design of hardware and software of PSLFI. In the aspect of hardware design, the BOOST basic DC/DC circuit as the foundation, the design of topology including three-phase uncontrolled rectifier and BOOST three interleaved, and according to the design requirements, to determine the PSLFI parameters and control components auxiliary circuit. In software design, the double closed-loop control method based on Based on the proposed loop using composite algorithm of adaptive fuzzy PI control algorithm and bang-bang with hysteresis control optimization. Using the self-developed controller and the RTDS real-time simulation system, the hardware in the loop simulation test loop, the simulation results verify the rationality of parameter design, and debugging for the PI parameter in the experiment site plays a guiding role.
Finally, in a power plant and coal feeder, the inverter conducted on-site on-line experiment. The experimental results show that the design of the PSLFI in the coal feeder system voltage sag at different depths, can stabilize the output DC under rated condition, and frequency converter control power supply can also ensure that the coal feeder control circuit of frequency converter to ensure reliable operation. The drop in the system voltage, frequency converter and load sensitive operation without disturbance.

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM921.51

【参考文献】