Control method for predicting virtual flux linkage by Vienna rectifier model

Abstract

The invention discloses a control method for predicting a virtual flux linkage by a Vienna rectifier model. The method comprises the steps of firstly, sampling voltages of upper and lower capacitors of a direct-current side, and obtaining given power P* after a direct-current voltage increment obtained by direct-current voltage negative feedback passes through a PI controller; obtaining a three-phase input current iabc and a switch state Sabc at a moment k, and obtaining a virtual flux linkage psi g of a voltage of a network side at current moment and a phase angle omega t of the voltage of the network side through a virtual flux linkage observer; calculating a given value psi*s of a virtual flux linkage of a line; then, online predicting a virtual flux linkage psi s (k +1) of the line atthe moment (k+1) by the prediction model; and finally, obtaining an optimal voltage vector control switch bridge through a minimization value function, and controlling the virtual flux linkage of theline to track the given value so as to obtain an expected control effect. According to the method, a voltage sensor of an alternating-current side of a rectifier is effectively eliminated, so that theanti-interference performance of the system to the voltage disturbance of the network side is greatly improved while the system cost is reduced.

Description

technical field [0001] The invention relates to a Vienna rectifier model prediction virtual flux linkage control method, which belongs to the field of power electronics. Background technique [0002] The Vienna rectifier is a three-level rectifier with high reliability, high power density, and low cost. Therefore, it is more and more widely used in high-power occasions such as electric vehicle charging piles, wind power generation, and aviation DC power supply systems. At present, the research on the control method of Vienna rectifier mainly focuses on vector control (Vector control, VC) and model predictive control (Model predictive control, MPC). The main idea of ​​vector control is to use coordinate transformation to transform the input current to the dq coordinate system for decoupling control, which usually has good steady-state performance, but its control effect depends heavily on the parameter setting of the PI controller, so the dynamic performance is poor, and at t...

AI Technical Summary

Problems solved by technology

However, due to the need to use grid-side voltage-related information, the MPCC control effect is directly related to the grid-side voltage quality, so the anti-interference performance is poor, and it is difficult to meet the control requirements when the grid-side voltage is distorted or disturbed.

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