【作者】 张鼎；

【导师】 常文森； 李云钢；

【作者基本信息】 国防科学技术大学 ， 控制科学与工程， 2010， 博士

【摘要】 磁浮列车悬浮控制系统的电源是重要的车载变流设备,其装机容量和瞬态性能对悬浮控制性能有重要影响。试验中发现,磁浮电源在重载时,输出电压和输出电流大幅波动,由此引发过流保护,容易损坏电源,严重影响列车的正常运行。为解决上述问题,本文研究磁浮电源与负载的相互影响、磁浮电源的稳压控制技术及其性能参数的设计方法。首先,建立由磁浮电源及悬浮控制系统组成的大系统的模型;然后,以此模型为基础,分析悬浮控制系统在各种工况下对电源输出电流和输出电压、以及电源控制系统的稳定性的影响,指出磁浮电源控制系统失稳的原因是悬浮控制系统具有负阻抗特性,其解决方法是增大变换器的输出电容或减小电容的等效串联电阻;最后,提出抑制磁浮电源和悬浮控制系统相互影响、降低电源输出电压纹波的方法,包括改进电源的控制算法和次级电路的参数、改进悬浮功放的控制方式和输入电容的参数等。实验表明,采用上述方法后,输出电压的波动幅度减小10%以上。然后,研究与悬浮控制系统性能关系密切的装机容量、输出电流变化率及输出电压等三项参数的设计和优化方法。第一,分析磁浮电源的静态和动态输出功率与悬浮功耗的关系,并据此提出装机容量的设计准则:其额定值等于额定静态输出功率与最大动态输出功率之和;其最大值等于最大静态输出功率与最大动态输出功率之和。通过限制动态输出功率的变化范围、改善磁浮列车的起浮策略等方法可节省装机容量40%。第二,分析磁浮电源的输出电流变化率与电磁铁电流变化率的关系,据此提出输出电流变化率的设计准则:其额定值等于电磁铁电流的最大变化率。通过提高电源输入电压、改进电磁铁连接方式及降低悬浮控制系统的动态功耗可使输出电流变化率指标下降50%。第三,提出依据电源的瞬时输出功率和最大动态功率指标设计输出电压的方法,并将该方法应用于低速磁浮列车磁浮电源的输出电压指标的设计。最后,研究磁浮电源变换器的实现和性能测试问题。先设计磁浮电源变换器的主要性能参数并研制出60kW工程化样机,有针对性地研究了拓扑结构优化、电磁兼容设计及数字控制器实现等方面的内容。然后,通过单磁浮架供电实验测试磁浮电源变换器样机的稳态性能和动态性能,实验数据表明,试制的磁浮电源达到了设计性能要求。最后,所研制的磁浮电源成功实现对整车悬浮控制系统供电。由于实际列车上都配有蓄电池,实验测试镍氢蓄电池或镍镉蓄电池与磁浮电源输出并联时的输出特性,实验表明镍氢蓄电池的输出响应速度更快,适合作为辅助电源。更多还原

【Abstract】 The power supply for maglev levitaion systems (called as maglev power convertor, MPC) is an important power convertor equipment on the vehicle. Installed capability and transient performance are the key features of MPC, which greatly affect the performance of the maglev control systems (MLS). In the experiments, the output voltage and current of MPC changes greatly and even becomes unstable under the condition of over loading. This phenomenon will lead to the over-current protection of the MPC, the failure of the MPS and then affect the running of maglev trains. To solve these problems, the interaction influence between MLCS and MPCs,the regulation control technology of the output voltage, and the design method of the performance parameters of MPC are researched in this paper.Firstly, the whole system consisting of the MPC and MLCS is modeled. On the basis of this model, the influence of the MLCS to the output voltage and current of MPCs and the stability of the maglev power control system (MPCS) are analyzed under various working-conditions, which points out that the main reason why MPCS becomes unstable is that the impedance of the MLCS is negative. It can be solved by increasing the capacitance or decreasing the equivalent series resistance of the output capacitor of MPC. Finally, the methods of suppressing the interaction between MPC and MLCS, and minimizing the ripple of the output voltage are proposed, which include optimizing the control law and improving the output stage circuit of the MLPS, optimizing the switching mode and increasing the input capacitance of the maglev chopper, and so on. The experimental results show that the fluctuation of the output voltage and the current can be decreased by 10% using these methods.Secondly, the methods of designing and optimizing the performance parameters of MPCs, including installed capacity, output voltage and slew rate of output current, are studied. First of all, the relationship between the steady/dynamic output power and the levitation power loss are investigated. On the basis of this, the design criterion of the installed capacity is proposed: the nominal installed capacity can be chosen as the sum of the rated steady power and the maximum dynamic power, and the maximum installed capacity should equale to the sum of the maximum steady power and maximum dynamic power. This requirement can be reduced by 40% with the strategy of restricting the range of the dynamic output power and improving the levitation-up algorithm. Secondly, the relationship betweent the slew rate of output current and the electromagnet current is studied. The results show that the design criterion of slew rate of output current that the nominal slew rate of output current should equal to the slew rate of the electromagnet current, which can descend 50% by modifying the format of the connectin between the electromagnet and the maglev amplifier, and by saving the dynamic powe loss of MLCS. Finally, the practical design criterion of the output voltage according to the instant ouput power and the maximum dynamic power of MPC is proposed, and the application to the low-speed maglev train shows that this method is available. Finally, the implementation and experiments of the MPCs are performed. A 60kW engineering demo convertor is designed and developed according to the proposed design criteria. Its steady and transient performance is separately tested in the system of a single maglev bogy and a whole train. The results show that the required performance is fully satisfied. Considering that auxiliary power supplyment is widely equipped on the vehicles, the output performance of the designed MPC parallel with Ni-H or Ni-Cd battery is tested. The experimental results illustrate that the response speed of Ni-H battery is faster, and it can be used as the auxiliary power supplyment for the maglev trains.更多还原