Active-disturbance-rejection control-based high-speed railway traction network low-frequency oscillation suppression method

Abstract

The invention discloses an active-disturbance-rejection control-based high-speed railway traction network low-frequency oscillation suppression method. According to the method, a nonlinear active-disturbance-rejection controller is adopted for a motor train unit converter which is a strong-coupling nonlinear system; the nonlinear active-disturbance-rejection controller includes a tracking differentiator (TD), an extended state observer (ESO) and nonlinear state error feedback control laws (NLSEF); and the method is realized based on transient direct current control strategies of the active-disturbance-rejection controller. The method can be implemented with easiness; the functionality function of an active-disturbance-rejection control module is written according to the state space model of a rectifier; as for the tracking differentiator, a direct current link voltage value u<dcr> is set, when input signals change, a transition process is arranged, so that no overshoot tracking input signals do not exist in output in a limited time period; as for the extended state observer, middle direct-current voltage output u<dc> and input control quantity u are made to track the state and disturbance of a converter; and the disturbance is dynamically compensated, and error feedback control quantity u<0> is calculated. With the above method provided by the above technical schemes of the invention adopted, high robustness and excellent control quality of the controller can be realized, and the stability of a control system can be improved, and the problem of motor train unit-traction network electric quantity low-frequency oscillation can be solved with low cost.

Description

technical field [0001] The invention relates to the control of electronic power devices, in particular to a control method for suppressing low-frequency oscillation of rectifiers on the side of a train network. Background technique [0002] With the rapid development of high-speed railways, new "AC-DC-AC" electric locomotives have been widely used in electrified railway systems due to their advantages such as high power factor, high power, and large traction force. The control methods of traditional "AC-DC-AC" locomotives are mainly divided into two categories, indirect current control and direct current control. Indirect current control is represented by "phase amplitude control", and direct current control includes hysteresis current control, predictive current control and transient current control. Transient direct current control is a control strategy widely used in electric locomotives and high-speed EMUs, but the existing controllers are all based on linear PI control...

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Problems solved by technology

[0005] 1) Both the electric locomotive and the EMU in the study adopt the traditional PI control method, the control parameters are not easy to tune, and the PI control is sensitive to system disturbance;

[0006] 2) The four-quadrant converter is a typical nonlinear, multi-variable and strongly coupled system, which is sensitive to external disturbances and system parameter changes, and the traditional linear control method can no longer achieve the ideal control effect

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