【作者】 许爱国；

【导师】 谢少军；

【作者基本信息】 南京航空航天大学 ， 电力电子与电力传动， 2009， 博士

【摘要】 随着经济的发展,城市化进程的加快,我国城市轨道交通发展迅速。城市轨道交通车辆再生制动可节约能源,符合节能减排的要求,但是目前再生制动能量利用率低下,多余的能源被电阻消耗掉,不但不能节能,反而增加了城市轨道交通线路通风散热系统的负担,因此研究城市轨道交通再生制动能量利用技术,提高再生制动能量利用率,符合城市轨道交通发展的方向,对节能减排和可持续发展具有很重要的意义和实用价值。本文首先建立城市轨道交通系统再生制动能量分析模型,并以南京地铁1号线车辆数据为依据进行仿真研究,揭示了城市轨道交通车辆再生制动能量特征,即城市轨道交通车辆再生动能量具有幅值高、时间短的特点,功率冲击较大。城市轨道交通再生制动能量分析模型为研究再生制动能量利用技术提供了有力的分析与验证工具。再生制动能量处理问题产生的根本原因是城市轨道交通供电系统采用了不可逆的整流电路,因此本文提出一种新型能馈式轨道交通牵引供电变流方案,采用双向阶梯波合成变流器实现城市轨道交通系统的供电与再生制动能量回馈。阶梯波合成变流器具有开关频率低、开关损耗小、电磁兼容性好、输入谐波少、总谐波含量低、滤波器体积小等优点,特别适合城市轨道交通系统的大功率能馈供电。为了实现阶梯波合成变流器的快速调节,本文提出了一种新的顺序采样空间矢量调制(SVM)技术,采用该技术后,阶梯波合成过程中等效采样点从传统的每周期6个提高到每周期24个,提高了调制环节的带宽,减小了调制环节的延时,为提高阶梯波合成变流器的动态性能提供了有利的技术基础;在分析变换器模型的基础上,提出了一种SVM调制延时补偿办法,采用该补偿办法后,降低了dqo坐标系下两相系统的耦合,提高了变换器带宽,为实现dq轴电流解耦控制和有功功率、无功功率的独立控制提供了必要的基础;提出了阶梯波合成变流器的瞬时值闭环控制策略与参数设计方法,为提高和优化阶梯波合成变流器的动态性能提供了必要的依据,为城市轨道交通供电系统直流母线的动态调节提供技术保障。在3kW实验平台上进行了实验,实验结果表明该双向阶梯波合成变流器除了开关频率低、电流波形正弦性好以外,还具有快速的动态调节性能。在分析了再生制动能量全功率回馈电网与再生制动能量全储存方式的优缺点基础上,本文提出了一种新型的能馈与储能相结合的再生制动能量吸收方案,利用能馈系统回馈大部分能量,减少储能系统的容量、体积以及成本,利用储能系统为脉冲能量提供一定缓冲,减小再生制动能量对电网的冲击以及能馈系统的设计容量,提高能馈系统的容量利用率。研究了三种容量配置方法,并研究了两种控制器实现方式,以实现两个系统的功率容量配合。通过仿真模型研究了能馈系统与储能系统的能量分配与电网电压特性。为了配合提出的能馈牵引供电系统,缓冲脉动功率对电网的冲击,本文最后研究了基于超级电容器的储能系统。提出了一种模块化储能系统功率变换方案,采用该模块化方案一方面可以使储能系统适用于多种供电电压等级的城市轨道交通系统,另外一方面还可降低储能模块的超级电容器串联个数,提高了超级电容器组的可靠性;针对多模块输入串联结构的储能系统,提出一种具有输入均压能力的双向变换器闭环控制策略,保障多模块串联结构在双向变换器场合的应用;储能单元电压均衡措施是保证超级电容器串联应用的高效与可靠的关键技术,本文在分析现有均衡电路的基础上提出了一种新型的电压均衡电路,根据均衡速度的需要,该均衡电路可开环控制也可闭环控制,控制方法都比较简单,不需要对多个电容器单元进行电压检测与决策控制就可以实现电压的自动均压。通过仿真和实验研究验证了提出的超级电容储能系统关键技术的可行性。更多还原

【Abstract】 With the rapid economical development and China’s accelerating urbanization process, urban railway transit system grows flourish. On the urban rail trains, regenerative brake is usually used. It can save energy and meets the trends of energy saving and emission reducing. But now, the regenerating energy is of a low utilization rate, and the extra energy is wasted in heat. The wasted energy can even cause increasing aerator load of the tunnel. So, to improve the utilization rate of the regenerating energy and to save more energy, it’s important and valuable to have a research on regenerating energy feeding to utility and buffering method. And this also goes with the direction of the urban railway transit’s development.Firstly, the simulation model of the urban railway transit system for the analysis of regenerating energy is set up, and simulation study was carried out based on the data of the Nanjing Metro Line 1. The characteristic of the regenerating energy of the train set is discovered, which can be represented as high amplitude, shortly lasting time and highly power strike. The simulation model and results are helpful tools to the whole study for analysis and validation.Sencondly, as the problem of regenerating energy handling is caused by the unidirectional rectifier of the traction power supply, a new type of regenerating traction power supply with the ability of feeding the regenerating energy back to the utility is carried out, which adopts bidirectional rectifier. A new type bidirectional converter based on staircase-synthesize converter structure, which is also called mulitypulse converter and is characterized with low switching frequency, low switching losses, low EMI, low hamonics and low filter volume, is proposed in the paper. Thus, it’s more suitable for high power conversion of the tranction power supply. To improve the regulation performance, a new sequential SVM technique is also proposed, which make the number of converter’s adjustable switching events improving from 6 to 24 during a fundamental periode. It enlarges the bandwidth and reduces the time delay of the modulation link, and this gives an important foundation to improve the converter’s dynamic regulation performance. With the analysis of the converter’s transfer function model, a time-delay compensation method is brought out, which can reduce the system coupling made by the time delay of SVM link and can help the close loop controller to realize the decoupling current control and independent regulation of active power and reactive power. An instantaneous-value feedback control algorithm of the converter is introduced and the optimization of the controller parameters’selection is also described in detail to improve the dynamic performance, which makes the converter suitable for the urban rail transit with high regulation performance of the DC supply voltage. A 3kW protytype is also built up. The experimental results validate the fesibility of the bidirectional converter and control algorithm and prove that the converter is characterized with not only low switching frequency and sine current waveform but also fast dynamic regulation.Thirdly, a new hybrid traction power supply system is proposed based on the analysis of the merits and demerits of both regenerative power supply and storage method to handle the whole regenerating energy, which is composed with a regenerative power converter and an energy storage device. The most energy of the regenerating energy is feed back to the utility and this can reduce the energy storage capacity, device volume and costs. The energy storage device provides a peak power buffer and limits the peak power feeding back to the utility to a lower level to reduce the power shock, and this can also reduce the converter’s capability of the power supply and improve the utilization rate of the converter’s power capability. Three types of capacity configuration are proposed and two types of realization of the control algorithm are also provided in detail. Simulation is carried out based on the urban rail transit model. The regenerative energy’s flow is studied and the DC supply voltage’s deviation is also observed.Lastly, to cooperating with the regenerative power supply and reduce the energy’s strike on the utility, a new scheme of energy storage system based on ultracapacitor is proposed. A modular energy storage topology is brought out, which can make the energy storage system adaptive to different supply voltage system and also reduce the number of the ultracapacitor connected in series and then improve the reliability of the energy storage system. The control algorithm of the bidirection DC/DC converter in the energy storage system, with the ability of input voltage balance when the converters are connected with inputs in series, is analyzed in detail. It makes the series-input power conversion topology applicable in the bidirectional power conversion. The voltage equallization is a key technology to improve the ultracapacitor stack’s capacity and reliability. On the analysis of the existing equalization methods, a new type voltage equalization circuit is also proposed, which can be open-loop controlled or close-loop controlled according to needs of equalization speed. The circuit is simple and can realized automatic voltage equalization with no needs of voltage sensing network and voltage comparising circuits. Simulation and experiment studies are carried out to validate the fesibility of the key technology of the energy storage system.更多还原