电工技术学报2024，Vol.39Issue(9)：2771-2783,13.DOI:10.19595/j.cnki.1000-6753.tces.230178
基于多电平滞环电流控制的牵引供电系统可控宽频带阻抗测量技术
Controllable Broadband Impedance Measurement Technology of Traction Power Supply System Based on Multilevel Hysteresis Current Control
摘要
Abstract
With the increasing mileage of electrified railways and the number of new electric locomotives,the power electronics characteristics of traction power supply system in China become more and more obvious,which can easily cause wide-band oscillation phenomenon.A lot of research shows that this phenomenon is caused by the input/output characteristics mismatch of electric locomotive and traction power supply system,and this mismatch can be regarded as the impedance characteristics mismatch of"vehicle-network".Therefore,accurately obtaining the impedance characteristics of traction power supply system is of great significance for revealing the mechanism of wide-band oscillation in electrified railway and improving the reliability of railway power supply.However,the impedance mathematical modeling method relies on the derivation of mathematical formulas,which requires to know the detailed parameters inside the system,and the traction power supply system has complex structure,numerous components,dynamic topology changes,and the actual impedance of components may deviate from the production design parameters.The impedance characteristics obtained by impedance measurement are closer to reality.Therefore,this paper focuses on the research of controllable wide-band impedance measurement technique for traction power supply system,and the main research contents are as follows: A controllable wide-band impedance measurement device embedded with energy storage unit is proposed,which mainly includes:boost transformer,cascaded H-bridge,bidirectional DC-DC converter,super capacitor.Among them,bidirectional DC-DC converter and super capacitor form energy storage unit together,which provides stable DC voltage for cascaded H-bridge to generate wide-frequency harmonic current.Its power level can be flexibly expanded by increasing the number of modules. A multilevel hysteresis current control method is proposed,which uses the characteristic that the output voltage level of each port changes with the direction of output current,combined with the calculated minimum number of modules and the current trend of error current,dynamically adjusts the output voltage of each module,limits the error current within the target range,so that the output harmonic current is as close as possible to the reference current,and improves the harmonic current output effect.Based on Matlab/Simulink,the control method is simulated and verified.Several current disturbance waveforms and Fourier analysis results with representative frequency bands are given.The simulation results show that this control method can generate wide-frequency harmonic current in the range of 10 Hz～5 kHz. A hardware-in-the-loop experimental platform is built to further verify the controllable wide-band impedance measurement device embedded with energy storage unit and multilevel hysteresis current control method.The experimental results show that the proposed method can quickly obtain the wide-band impedance characteristics of traction power supply system.The measurement range is 10 Hz～5 kHz,which greatly improves the measurement efficiency and can adapt to the measurement demand of time-varying impedance.Through the above analysis,we can draw the following conclusions:(1)The proposed device topology does not contain resistance,has low energy loss,does not need to worry about serious heating due to resistance during measurement process,and has modular structure,convenient expansion and flexible application.(2)The multilevel hysteresis current control method can inject harmonic current with controllable frequency band and amplitude into traction power supply system at one time,which can adapt to the measurement demand of time-varying impedance.(3)Compared with traditional hysteresis current control method,under the same tracking accuracy condition,this method greatly reduces switching times of power devices,avoids dead zone effect at same time,and has good application potential.关键词
牵引供电系统/阻抗测量技术/多电平滞环电流控制/谐波扰动Key words
Traction power supply system/technology of impedance measurement/multilevel hysteresis current control/harmonic disturbance分类
信息技术与安全科学引用本文复制引用
陈司懿,胡海涛,肖冬华,潘鹏宇,宋依桐..基于多电平滞环电流控制的牵引供电系统可控宽频带阻抗测量技术[J].电工技术学报,2024,39(9):2771-2783,13.基金项目
国家自然科学基金项目(52107125)和四川省自然科学基金重大项目(2022NSFSC0001)资助. （52107125）
