Method of control of magnetic sound of alternating current rotating machine
A method for greatly reducing magnetic sound of an alternating current rotating machine compared with the past comprising superimposing an n−1-th order frequency in inverse turn on a multi-phase alternating current with reference to a basic frequency component of the multi-phase alternating current supplied to an armature of the alternating current rotating machine of multiple phases so as to reduce the n-th order harmonic components of the basic frequency component among radial direction magnetic vibrating forces generated in the radial direction in a core of the alternating current rotating machine.
1. A method of control of magnetic sound of an alternating current rotating machine comprising:
when designating an order of a basic frequency component of a multi-phase alternating current supplied to an armature of a multi-phase alternating current rotating machine as “1”;
adding, to said multi-phase alternating current, an (n−1)-th order (n is a natural number) radial direction vibration control use harmonic current having an inverse phase sequence from said basic frequency component;
so as to change, among radial direction vibration comprised of vibration radially generated about an axis of a shaft of said alternating current rotating machine due to vibrating force generated by said alternating current rotating machine or input to said alternating current rotating machine from the outside, n-th order harmonic radial direction vibration components in comparison with a case of not adding said radial direction vibration control use harmonic currents;
detecting said harmonic current components supplied to said armature; and
performing feedback control so that deviations of amplitude and phases between detected values of said harmonic current components and computed values of said radial direction vibration control use harmonic currents to be added to said multi-phase alternating current become 0 so as to obtain target values of said harmonic radial direction vibration components.
2. A method of control of magnetic sound of an alternating current rotating machine comprising:
when designating an order of a basic frequency component of a multi-phase alternating current supplied to an armature of a multi-phase alternating current rotating machine as “1”;
adding, to said multi-phase alternating current, an (n−1)-th order (n is a natural number) radial direction vibration control use harmonic current having an inverse phase sequence from said basic frequency component;
so as to change, among radial direction vibration comprised of vibration radially generated about an axis of a shaft of said alternating current rotating machine due to vibrating force generated by said alternating current rotating machine or input to said alternating current rotating machine from the outside, n-th order harmonic radial direction vibration components in comparison with a case of not adding said radial direction vibration control use harmonic currents;
said adding step comprising:
detecting said harmonic radial direction vibration components or electrical parameters associated with the same,
computing the amplitudes and phases of said radial direction vibration control use harmonic currents corresponding to the differences of said radial direction vibration components or electrical parameters associated with the same corresponding to the deviations between the detected values of said harmonic radial direction vibration components or the electrical parameters associated with the same and the target values of said harmonic radial direction vibration components or the electrical parameters associated with the same based on predetermined maps or equations showing relationships between said harmonic radial direction vibration components and said radial direction vibration control use harmonic currents, and
adding the computed values of said radial direction vibration control use harmonic currents to said multi-phase alternating current.