Study On Energy Recovery Inverter Device For Regenerative Braking In Urban Railway

In order to alleviate the traffic pressure of the urban population, the urban railway is a kind of transportation which is expected to reach the 6000km total mileage of urban rail transit operation in 2021.The urban railway is clean , fast and safe, and does not occupy urban land area. Urban rail transit has the characteristics of fast speed and short station spacing, so frequent regenerative braking brings great potential for energy utilization. For the regenerative braking energy utilization device, the inverter feedback device has been a research hotspot in recent years, which has been included in one of the national major science and technology support program during the "the 11th Five-Year Plan". This paper mainly does the research and design of the inverter feedback device. According to the hardware-in-the-loop simulation on the DSP-dSPACE platform, the digital control algorithm of the inverter feedback device is verified while it's connected with the train simulation; and finally the design and construction of the mini watt hardware platform of the inverter feedback device designed is completed.Firstly, the research background and significance of the research on the energy utilization of urban railway and the semi-physical simulation will be introduced, and the merits and demerits of several existent types of regenerative braking energy utilization device and its application and production status of domestic and overseas are summarized in recent years;then, this paper introduces the recent research of the higher learning institution on the regenerative braking energy utilization system, and finally indicates that inverter feedback device cooperate the existing braking resistor would be the main research direction.Secondly, by analyzing the asynchronous motor mathematic model and characteristics of traction train, the traction, coasting drifting and brake conditions of the train work on the DC traction power supply system are simulated, which lays the foundation for the semi-physical simulation research of inverter feedback device.Thirdly, aiming at the filtering link and the control system are important in the design of the inverter feedback device. After the analysis of the different current feedback control, this paper proposes to use the coordinate optimization digital system method without damping control to suppress the resonance peak of the LCL filter. For the control system, the double closed-loop control without inductance parameter can optimize the feedforward decoupling control. And based on the test data of Chengdu metro DC voltage of traction network, this paper supposes to adjust the threshold value of the device start and stop in time, and the concrete formula is given after the theoretical analysis. The simulation of inverter feedback device is built in the Matlab/Simulink platform, including the main circuit, PLL phase-locked loop module, optimized double closed-loop control module and the SVPWM modulation module.Finally, the design accuracy of the control algorithm and inverter feedback device are further verified by using the DSP-dSPACE hardware-in-the-loop simulation platform, and the hardware design and construction of the miniwatt platform are completed.