基于动态电压恢复器的电压暂降治理研究

发布时间：2018-07-08 11:24

本文选题：电压暂降 + 动态电压恢复器　；参考：《燕山大学》2014年硕士论文

【摘要】：随着科学技术的突飞猛进和工业规模的发展壮大，大量精密复杂的敏感性用电设备已被广泛的应用到社会各个领域。电能质量中任何问题都可能导致这些设备非正常工作，以致产生较大的经济损失。因此，有效地改善电能质量是社会进步的必然要求。在众多电能质量问题中，电压暂降对用电设备造成的危害最为普遍。动态电压恢复器(Dynamic Voltage Restorer)能在几个毫秒内瞬间动作，快速消除电压暂降的影响，保证负载可靠的运行。由于有着良好的动态性能和很高的性价比，动态电压恢复器已成为改善电能质量问题的最为有效、经济的电力装置。本文对动态电压恢复器的工作原理和拓扑结构做了详细的分析，并且对电压暂降的检测方法和动态电压恢复器的补偿策略以及控制模式进行了深入的研究。通过采用基于瞬时无功理论及其改进方案来准确、快速地检测不同类型电压暂降的幅值和相位的变化，并且建立仿真模型验证了这种方法能够满足检测要求。针对动态电压恢复器的逆变环节采用恒功率和恒压恒频两种控制模式，并且结合正弦波脉宽调制技术(Sinusoidal Pulse With Modulation)来建立逆变器的仿真模型，使动态电压恢复器输出稳定的正弦波电压，保证其对系统的电压暂降进行可靠补偿。根据动态电压恢复器输出电压、电流及功率的关系，归纳出完全补偿法、同相位补偿法和最小能量补偿法三种常见的补偿策略，并且对最小能量补偿法在不同的补偿条件下进一步展开讨论，最终得到了动态电压恢复器输出有功功率与负载功率因数之间的关系，即降低负载功率因数将可以减少动态电压恢复器的有功输出。基于此结论，对于补偿系统的结构加以改进，即在敏感负载端并联一个带有开关装置的电抗器，当动态电压恢复器对系统进行补偿时投入使用，暂时减少负载功率因数，来保证动态电压恢复器有效地补偿。最后构建仿真模型，，通过对仿真结果进行分析，验证了并联电抗器可以对负载功率因数进行控制，减少了动态电压恢复器能量输出，提高了补偿范围，延长了补偿时间。
[Abstract]:With the rapid development of science and technology and the development of industrial scale, a large number of sophisticated sensitive electrical equipment has been widely used in various fields of society. Any problems in power quality may lead to abnormal operation of these devices, resulting in large economic losses. Therefore, the effective improvement of power quality is the inevitable requirement of social progress. Among many power quality problems, voltage sag is the most common hazard to electric equipment. Dynamic Voltage Restorer can be used in several milliseconds to eliminate the influence of voltage sag and ensure the reliable operation of the load. Because of its good dynamic performance and high performance-price ratio, dynamic voltage restorer has become the most effective and economical power device to improve power quality. In this paper, the working principle and topology of dynamic voltage restorer are analyzed in detail, and the detection method of voltage sag, compensation strategy and control mode of dynamic voltage restorer are studied deeply. Based on the instantaneous reactive power theory and its improved scheme, the amplitude and phase of different voltage sag are detected accurately and quickly, and the simulation model is established to verify that this method can meet the detection requirements. Two control modes, constant power and constant voltage and constant frequency, are adopted in the inverter of dynamic voltage restorer, and the simulation model of inverter is established by using sinusoidal pulse with modulation technology. The dynamic voltage restorer outputs a stable sinusoidal voltage to compensate the voltage sag reliably. According to the relationship among output voltage, current and power of dynamic voltage restorer, three common compensation strategies, complete compensation method, in-phase compensation method and minimum energy compensation method, are summarized. The relationship between the active power output of the dynamic voltage restorer and the load power factor is obtained by further discussing the minimum energy compensation method under different compensation conditions. That is to say, the active power output of the dynamic voltage restorer can be reduced by reducing the load power factor. Based on this conclusion, the structure of the compensation system is improved, that is, a reactor with switch device is connected at the sensitive load end, when the dynamic voltage restorer compensates the system, the load power factor is temporarily reduced. To ensure that the dynamic voltage restorer is effectively compensated. Finally, the simulation model is constructed and the simulation results are analyzed to verify that the parallel reactor can control the load power factor, reduce the energy output of the dynamic voltage restorer, improve the compensation range and prolong the compensation time.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM761.12

【参考文献】