B2 型地铁列车直接转矩控制方法研究
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Abstract
Traction system is the core component of urban rail transit vehicles and the source of
train power. Traction motor, as an important part of the traction system, plays a decisive role
in the direction and speed of the train. Direct Torque Control (DTC) has become an important
way of motor frequency conversion speed regulation because of its advantages of simple
Control structure, high system stability and fewer parameters required in the speed regulation
process. It is a popular direction of motor speed regulation research at present. However, after
the motor runs for a period of time, the stator resistance is easily changed due to the heating
up, which leads to the deviation of the stator flux calculation. Moreover, the Bang-Bang
regulator used can only be adjusted when it reaches the specified limit, which has certain
passivity and limitations. In order to make the control system more accurate and rapid, this
thesis based on B2 type subway train traction motor YQ-190-13B, aiming at the deficiencies
of direct torque control, designed an improved scheme, and through Matlab/Simulink
simulation and PLC simulation experiment, the improved scheme was verified.
Firstly, induction motor speed regulation development process and speed regulation
method are summarized, motor model and inverter model under different coordinate system
are established, and the relationship between each part of the direct torque control system is
described, which provides theoretical support for further research.
Secondly, based on the above theoretical basis, this paper introduces the hexagon flux
trajectory direct torque control system (DSC) and circular flux trajectory direct torque control
(DTC) system of principle and structure, and the flux linkage and torque calculation module,
flux from the control module and switch selection table module in detail in this paper. At the
same time, the DSC system and DTC system are simulated on the Matlab/Simulink software,
and the electromagnetic torque, stator current and speed of the two control systems at
different speeds are compared and analyzed.
Then, aiming at the shortcomings of direct torque control technology, a control method
combining space vector pulse width modulation and direct torque control (SVM-DTC) was
designed. PI controller was used to replace the traditional Bang-Bang controller, and the ideal
voltage vector was synthesized from adjacent voltage vectors. The simulation modeling of
SVM-DTC system is carried out on Matlab/Simulink software, and the simulation results are
compared with THE DTC system. The results show that the improved scheme can effectively
reduce the electromagnetic torque ripple, and improve the response speed, anti-interference
ability and dynamic performance of the system.
Finally, for SVPWM module of SVM-DTC system, the ladder diagram control program
is written on TIA V16 software, and the simulation experiment of SVPWM module is carried
