A fault tolerance method for three-phase string winding topology open circuit fault with balanced modulation amplitude

Abstract

The invention discloses a three-phase series winding topological open circuit fault fault tolerance method for balanced modulation wave amplitude. When an open circuit fault occurs and any phase of the three-phase current is zero, the negative sequence current component that appears in the system is extracted and suppressed. Fault-tolerant operation of the motor after a fault is realized. After the positive-sequence and negative-sequence modulation wave components required to control the motor are superimposed, they are redistributed with the constraints of equal amplitudes, and finally the new command values ​​of each bridge arm after the open circuit fault occurs are obtained. The invention proposes for the first time a fault-tolerant control method that can ensure the normal operation of the motor after the bridge arm or winding open circuit fault occurs in the three-phase series winding topology, and effectively improve the amplitude imbalance after the modulation wave is superimposed; Simulation verification is carried out on the motor, and the effect of motor fault tolerance and modulation wave equalization control is remarkable.

Description

technical field [0001] The invention belongs to the field of motor control, and more specifically relates to a fault-tolerant method for three-phase series winding topology open circuit fault with balanced modulation wave amplitude. Background technique [0002] The gradual expansion of the application field of the electric drive system puts forward more and more stringent requirements on the performance of the motor system. As one of the core, the motor drive system needs a series of improvements in terms of power density, voltage utilization, reliability, power level, etc. The open-winding inverter topology has been widely used due to its higher voltage utilization rate and more control degrees of freedom. If the phase windings with the neutral point open are connected in series in sequence, an H-bridge with open winding can be obtained. The DC voltage utilization rate of the structure is the same, and the number of switching devices is reduced by nearly half, so the stru...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the object of the present invention is to provide a three-phase series winding topology open circuit fault fault-tolerant method that balances the amplitude of the modulation wave, aiming at solving the problem of negative sequence current in the three-phase series winding topology after the open circuit fault. The low-order torque ripple and the unbalanced modulation wave amplitude caused by the suppression process

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