【作者】 陈杰；

【导师】 刘志刚；

【作者基本信息】 北京交通大学 ， 电气工程， 2013， 博士

【摘要】 随着城市轨道交通的快速发展,对城轨列车辅助供电系统的高品质输出和运行可靠性提出了更高要求。论文在深入调研、分析国内外辅助供电系统的研究与应用现状基础上,围绕辅助供电系统高品质波形控制及无互联线并联关键技术开展了研究工作,取得了以下研究成果。在三相四线制分裂电容逆变器拓扑中引入中线电感,提出基于改进型谐振控制器的高性能波形控制技术：基于电感电流重构,采用PADE近似,构建了连续域下包含时延的电流闭环模型,给出了新颖的电流内环设计方法；引入改进型谐振控制器,并首次提出基于改进型谐振控制器的电压外环设计方法。波形控制技术通过降低逆变器的基波、谐波阻抗并抑制分裂电容偏压,实现了复杂负载条件下的高品质波形输出。通过分析改进型谐振控制器多种离散方式的谐振点偏移现象及相应频率特性,得出偏移量与采样频率、谐振频率间的定性关系,提出了最优离散方法的选取原则。为了能采用阻性下垂法改善传统下垂法均流性能与电压调节性能间的固有矛盾,提出了基于改进型谐振控制器的逆变器主动输出阻抗控制技术,并对传统功率计算方法进行改进,引入全周期自适应控制,改善了阻性下垂法的动态性能和鲁棒性。针对参数不一致及复杂负载条件下的并联技术,通过增大有功比例下垂系数解决了参数不一致下的均流问题,并结合系统阻抗补偿和d轴电压补偿,抑制了泵类负载等引起的电压跌落；提出三相独立的有功下垂和一体化的无功下垂,解决了不平衡负载下的均流和相角漂移问题；提出结合低通和高通滤波器的阻性虚拟阻抗技术,在宽频带内增加逆变器谐波阻抗,实现了非线性负载下的谐波均流并抑制了谐振点偏移。提出基于掷骰子法的随机启动策略,构建了掷骰子法的概率模型,解决了无互联线下的并联系统启动问题。针对一般小信号建模法在城轨辅助并联系统应用中的缺陷,提出了一种新的小信号建模法,将并联点电压表示为各变流器参数的函数,从而充分考虑各变流器间的耦合,提高了小信号模型的准确性。在此基础上,研究了下垂系数、功率计算方法、线路阻抗、负载特性等对并联系统稳定性和动态性能的影响。论文进行了大量仿真和实验,充分验证所提理论和方法的有效性。图153幅,表16个,参考文献187篇。更多还原

【Abstract】 With the unbelievable development of urban rail transit, there is increasing demands for high performance waveform control and reliability of the auxiliary power system. Based on the application and research status at domestic and abroad, the dissertation is focused on high performance waveform control, as well as the wireless parallel technology of auxiliary power supply, deriving the achievements as follows:The dissertation introduces neutral inductor into the conventional3-phase-4-line inverter with split capacitors, and comes up with the improved resonant controller, for the realization of high quality AC output. Based on inductor current reconstruction and PADE approximation, an equivalent model of current loop is built, with the consideration of time-delay in continuous domain. Based on the model, the parameter selection criterion is presented; An improved resonant controller is also brought out, together with the parameter selection criterion of voltage loop with such controller for the first time. The high performance waveform control is realized by the elimination of unbalanced voltage across the split capacitors and the reduction of the fundamental and harmonic impedance. By analyzing the frequency error of the resonant spot under different discretization approaches, the qualitative relationship is derived, which is between frequency error and sampling frequency, and among various resonant frequencies. Due to the analysis above, the optimal selection of discretization approach is presented.For the application of resistive droop approach, which is the key to improving the inherent contradiction of inductive droop approach, between the realization of better balanced current output and the improvement of voltage adjustment capability, the dissertation comes up with a novel active impedance control scheme, with the existence of improved resonant controller. What’s more, revised power calculation approach and full period adaptive control mechanism are adopted for the improvement of the dynamic and steady characteristics of such resistive droop approach. Under different circuit parameters of the paralleled inverters, balanced current output is realized by the increase of active power damping coefficient. With the compensation of system impedance voltage and d-axis voltage, the voltage droop caused by pumping load is eliminated. With the theory of independent active power droop and universal reactive power droop, the unbalanced current output and angular displacement owing to unbalanced3-phase load are eliminated. With resistive virtual impedance technology combines low-pass and high-pass filter, the harmonic impedance in wide frequency range is increased, and the frequency error of the resonant spot under nonlinear load is further eliminated. A random value approach, like the dicing mechanism, is applied during the starting up of paralleled inverters. The probability model of such approach is built, and such approach finally plays a key part in the solution of starting up dilemma.Oriented to the disadvantages of conventional paralleled auxiliary inverters small-signal mode, the dissertation presents a novel small-signal model, in which the paralleled voltage is expressed as the function of parameters of the inverters. With such novel model, it is possible for the consideration of the coupling among all the inverters, hence the accuracy of the model is increased. On such basis, the influence on stability and dynamic performance of paralleled system form the droop coefficient, the power calculation approach, the line impedance and load characteristics are analyzed.For all of the theories, models and approaches above, there are corresponding simulated and experimental results, explaining their applicability and validity.更多还原