Fault-tolerant control method of high-power four-quadrant converter based on predictive control

Abstract

The present disclosure provides a predictive control-based high-power four-quadrant converter fault-tolerant control method, which obtains the parameter data of the converter after the faulty bridge arm and the reused bridge arm are connected through bidirectional thyristors; blocks the switching signal of the faulty bridge arm, Reorganize the switching state of the converter according to the obtained parameter data; traverse all the combined switching states to predict the system state at a certain moment in the future; aim at the minimum weighted sum of the grid-side cost function and the machine-side cost function, and obtain the most Optimum combined switch state; control the converter according to the optimal combined switch state; this disclosure overcomes the phenomenon of aggravated capacitor voltage imbalance existing in traditional solutions, and avoids the secondary fault and control precision drop caused by it. Under the condition of not restricting the degree of freedom of the switching state, it fully guarantees the continuous operation of the converter system in the event of a fault, and better improves the reliability and stability of the electric drive system.

Description

technical field [0001] The present disclosure relates to the technical field of converter fault-tolerant control, in particular to a predictive control-based fault-tolerant control method for a high-power four-quadrant converter. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. [0003] The three-level neutral-point-clamped (3L NPC) back-to-back converter has the advantages of small grid-side voltage / current harmonic distortion, low dv / dt value, and small grid-side filter size. , Widely used in industrial motor drive systems. However, the converter system in applications such as high-performance electric drive works for a long time under harsh working conditions such as high voltage, high current, strong electromagnetic interference, time-varying load, and limited heat dissipation, often due to power switching caused by semiconductor devices and ...

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Problems solved by technology

[0006] In order to solve the deficiencies of the prior art, the present disclosure provides a fault-tolerant control method for high-power four-quadrant converters based on predictive control, which effectively overcomes the aggravated phenomenon of capacitor voltage imbalance in traditional solutions and avoids the resulting In order to solve the problems of secondary faults and control accuracy drop, a new fault-tolerant control method for bridge arm multiplexing was established without limiting the degree of freedom of the switch state, which fully guaranteed the continuous operation of the converter system under fault conditions and better improved the The reliability and stability of the electric drive system avoids huge economic losses caused by converter failures in applications such as electric vehicles

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