为确保风电区域网内动态无功合理分布和电压达标,大量静止无功发生器(static var generator,SVG)被接入风场和风场汇流站,但由于SVG机间交互作用导致的设备负交互问题也开始显现。针对此类问题,首先分析H桥级联型SVG双机拓扑结构,针对...为确保风电区域网内动态无功合理分布和电压达标,大量静止无功发生器(static var generator,SVG)被接入风场和风场汇流站,但由于SVG机间交互作用导致的设备负交互问题也开始显现。针对此类问题,首先分析H桥级联型SVG双机拓扑结构,针对双机载波异步条件下产生的机间高次谐波电压差进行数学推导,研究高次谐波环流对SVG内H桥子模块电容直流电压动态稳定性的影响。通过对各H桥子模块电容吸收有功功率差异的推导分析,发现非特征谐波与H桥子模块直流电压失衡之间的内在联系,指出当谐波环流导致非特征次谐波越限时,将会引发各H桥模块直流电压不平衡,并且提出一种直流电压均衡控制策略来解决SVG直流电压失衡的问题,实现各H桥子模块直流电压稳定,最后通过仿真验证了理论分析和所提控制策略的正确性。展开更多
The time domain harmonic balance method is an attractive reduced order method of analyzing unsteady flow for turbomachines. However, the method can admit non-physical solutions. Non-physical solutions were encountered...The time domain harmonic balance method is an attractive reduced order method of analyzing unsteady flow for turbomachines. However, the method can admit non-physical solutions. Non-physical solutions were encountered from a three-blade-row compressor configuration in a time domain harmonic balance analysis. This paper aims to investigate the root cause of the non-physical solutions. The investigation involves several strategies, which include increasing the number of harmonics, increasing the number of time instants, including scattered modes,including the rotor-rotor interaction, and the use of a new method-the approximate time domain nonlinear harmonic method. Numerical analyses pertinent to each strategy are presented to reveal the root cause of the non-physical solution. It is found that the nonlinear interaction of unsteady flow components with different fundamental frequencies is the cause of the non-physical solution. The non-physical solution can be eliminated by incorporating extra scattered modes or using the approximate time domain nonlinear harmonic method.展开更多
文摘为确保风电区域网内动态无功合理分布和电压达标,大量静止无功发生器(static var generator,SVG)被接入风场和风场汇流站,但由于SVG机间交互作用导致的设备负交互问题也开始显现。针对此类问题,首先分析H桥级联型SVG双机拓扑结构,针对双机载波异步条件下产生的机间高次谐波电压差进行数学推导,研究高次谐波环流对SVG内H桥子模块电容直流电压动态稳定性的影响。通过对各H桥子模块电容吸收有功功率差异的推导分析,发现非特征谐波与H桥子模块直流电压失衡之间的内在联系,指出当谐波环流导致非特征次谐波越限时,将会引发各H桥模块直流电压不平衡,并且提出一种直流电压均衡控制策略来解决SVG直流电压失衡的问题,实现各H桥子模块直流电压稳定,最后通过仿真验证了理论分析和所提控制策略的正确性。
基金National Natural Science Foundation of China(51976172)National Science and Technology Major Project (2017-II-0009-0023)+1 种基金China’s 111 project(B17037)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2023056)。
文摘The time domain harmonic balance method is an attractive reduced order method of analyzing unsteady flow for turbomachines. However, the method can admit non-physical solutions. Non-physical solutions were encountered from a three-blade-row compressor configuration in a time domain harmonic balance analysis. This paper aims to investigate the root cause of the non-physical solutions. The investigation involves several strategies, which include increasing the number of harmonics, increasing the number of time instants, including scattered modes,including the rotor-rotor interaction, and the use of a new method-the approximate time domain nonlinear harmonic method. Numerical analyses pertinent to each strategy are presented to reveal the root cause of the non-physical solution. It is found that the nonlinear interaction of unsteady flow components with different fundamental frequencies is the cause of the non-physical solution. The non-physical solution can be eliminated by incorporating extra scattered modes or using the approximate time domain nonlinear harmonic method.
