Suppression method of low frequency oscillation of high-speed rail based on model control of self-feedback correction device

Abstract

The invention discloses a method for suppressing low-frequency oscillation of high-speed rail based on model control of a self-feedback correction device. The method comprises the following steps: firstly constructing an expression of the current and voltage dynamic characteristics of the AC side of a single-phase pulse rectifier, and decoupling the dq two-phase through a second-order generalized integrator. The discrete current prediction model in the rotating coordinate system; the uncertainty of grid-side parameters and the uncertainty of the discrete and sampling process are analyzed for the obtained prediction model; combined with the analysis results, a self-feedback correction device is designed to eliminate the uncertainty caused by the uncertainty. The feedback term is substituted into the prediction expression, and the control voltage is obtained by solving the cost function; the control pulse can be obtained by the SPWM modulation of the control voltage. The invention can make up for the shortcomings of high model accuracy dependence and poor current decoupling effect in the traditional model predictive control, and can make the grid-side current have a smaller distortion rate to ensure the power quality and system stability of the vehicle-to-grid coupling system.

Description

technical field [0001] The invention belongs to the technical field of control of single-phase pulse rectifiers for EMUs, in particular to a method for suppressing low-frequency oscillation of high-speed rails based on self-feedback correction device model control. Background technique [0002] Since 2008, the low-frequency oscillation phenomenon of the locomotive-traction network system has occurred successively in many EMUs or electric locomotives in my country. The phenomenon of low frequency oscillation of the vehicle network is manifested in that when multiple locomotives of the same type are raised at the same power supply feeder at the same time, the catenary network voltage fluctuates greatly and abnormally, the phase difference of the network voltage and network current occurs, and the instantaneous value envelope of the voltage (or current) waveform presents a low frequency. cyclical fluctuations. When the low-frequency oscillation occurs, the grid-side voltage an...

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Problems solved by technology

However, 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 it is difficult to achieve a good control effect by using traditional control methods.

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