Five-phase system symmetrical component method

Abstract

The present invention discloses a five-phase system symmetrical component method. The method comprises the steps of: employing a linear transformation theory and number theory analysis to decompose afive-phase asymmetric system into five determined five-phase symmetric systems; decomposing a voltage and a current in a multi-phase symmetric circuit into symmetrical components so as to prove that each sequence of symmetrical components has independent property, namely, a certain sequence of currents only can cause a certain sequence of voltage drops, and there is no influence for other sequences of electric quantities; because each sequence of reactance in the motor is determined by the property of magnetic flux established by the sequence of currents, in order to show the property of eachsequence of reactance of a five-phase asynchronous motor, decomposing each-phase pulse vibration magnetic flux into two magnetic fluxes with opposite directions, and performing overlapping to allow the properties of the magnetic fluxes to determine the property of the reactance; and finally, obtaining each sequence of reactance through calculation or through corresponding experiments. The five-phase system symmetrical component method is an effective method for solving five-phase motor default phases and symmetrical short circuit, and is simple and accurate for calculation of initial values ofsteady-state transient short circuit current alternating current fundamental components.

Description

technical field [0001] The invention relates to the technical field of motor fault diagnosis, in particular to a five-phase system symmetrical component method. Background technique [0002] Five-phase asynchronous motors have many advantages over three-phase asynchronous motors. For example, under the condition of constant phase voltage, the current of each phase must decrease, which is very beneficial to reduce the capacity of power devices; when the number of phases of the motor increases, the amplitude of electromagnetic torque ripple output by the motor decreases and the frequency of torque ripple This makes the running performance of the motor greatly improved, especially when the motor is running at low speed; the five-phase asynchronous motor has a lot of control degrees of freedom, using this feature, the five-phase motor control system can be changed It is more flexible, which is beneficial to improve the performance of the control system; the five-phase motor has...

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Problems solved by technology

[0003] The many advantages of the five-phase asynchronous motor make its application prospect very broad. As the motor receives more and more attention, the research on the lack of phase of the five-phase asynchronous motor and related issues is also increasing. For example, when the five-phase When the motor has a rectified load, it is necessary to determine the "commutation" reactance and other issues. Whether using a two-phase static coordinate system or a two-phase rotating coordinate system, solving Parker's equation is generally more complicated than the research on three-phase motor related issues. Therefore, it is very useful It is necessary to find a simpler calculation method

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