Fault-tolerant control method of machine-side converter based on d-axis current injection

Abstract

The invention discloses a d-axis current injection-based side converter fault-tolerant control method. According to the method, d-axis given current is adjusted by combining the system operation condition; a sector division manner is selected to carry out sector division; the influences, in each sector, of a faulty switch tube and the changes of basic voltage vectors before and after the fault aredetermined; the basic voltage vector of each sector and the action time of the basic voltage vector before the fault are determined; the action time of the basic voltage vectors influenced by the faulty switch tube is adjusted; the conduction time of the three-phase switch tube is determined; and the conduction time of the switch tube and a triangular carrier are modulated, the PWM pulse of the switch tube is determined, and the on / off of the switch tube is determined, so as to complete the d-axis current injection fault-tolerant control. According to the method, the sizes and phases of zero-current hoop sections of fault-phase current are changed through changing the d-axis injection current of generators, so that the influences caused to the system by faulty switch tubes are decreased and the performance of the side converters after the fault are improved.

Description

technical field [0001] The invention relates to a fault-tolerant control method of a machine-side converter based on d-axis current injection, belonging to the field of power conversion and control. Background technique [0002] As the key and core of the wind power generation system, the failure or loss of function of the converter system will seriously threaten the overall operation performance of major equipment, and even bring fatal effects, leading to catastrophic accidents. Therefore, it has important theoretical and practical significance to establish a wind power generation system with high reliability and strong fault-tolerant performance to avoid the secondary failure of the system caused by the failure of the converter, and has a strategic impact on national economic construction and national defense security. [0003] The existing machine-side PWM converter fault-tolerant methods are divided into two categories: hardware fault-tolerant control and software fault-...

AI Technical Summary

Problems solved by technology

The above method does not accurately compensate for the impact of the faulty switching tube on each sector, and also compensates for the sectors that are not affected by the switching tube failure, which belongs to overcompensation

The paper "PWM Rectifier Fault-Tolerant Control System Based on NCAV and Circuit Equivalent Replacement" proposed a fault-tolerant control method for PWM rectifiers based on equivalent circuits, but this method did not accurately compensate for the impact of faulty switching tubes on each sector. And in the sectors affected by multiple fault vectors, no compensation is performed, which belongs to undercompensation

The paper "A Rectifier Fault-Tolerant Control Method Based on Space Vector Control" proposed a space vector-based rectifier fault-tolerant control method. This method does not establish a unified sector division function, and cannot implement fault tolerance for multiple bridge arm switch tube failures. Although the precise compensation of a single switching tube can be realized, the negative impact of the faulty switching tube on the system is not considered, and the effect of fault-tolerant control is not optimal.

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