| CPC H02P 21/14 (2013.01) [H02P 21/0003 (2013.01); H02P 21/22 (2016.02); H02P 25/022 (2013.01)] | 10 Claims |

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10. A dead-time compensation apparatus for a permanent magnet synchronous motor (PMSM), comprising:
a detection unit, configured to acquire current sampling time d-axis currents and current sampling time q-axis currents corresponding to current sampling time three-phase stator currents of the PMSM, wherein the d-axis and the q-axis are coordinate axes in a dq coordinate system, the current sampling time d-axis currents are components of the current sampling time three-phase stator currents in the d-axis, and the current sampling time q-axis currents are components of the current sampling time three-phase stator currents in the q-axis;
a filtering unit, configured to perform low-pass filtering on the current sampling time d-axis currents and the current sampling time q-axis currents to obtain current sampling time filtered d-axis currents and current sampling time filtered q-axis currents;
an angle acquisition unit, configured to acquire, according to vector angles of current sampling time three-phase current vectors, the current sampling time filtered d-axis currents, and the current sampling time filtered q-axis currents, included angles between the current sampling time three-phase current vectors and the d-axis;
the angle acquisition unit being further configured to acquire current sampling time angles θ of the current sampling time three-phase current vectors in an αβ coordinate system according to the included angles between the current sampling time three-phase current vectors and the d-axis;
a polarity acquisition unit, configured to acquire polarities of the current sampling time three-phase stator currents according to the current sampling time angles θ; and
a compensation unit, configured to acquire current sampling time compensation voltage values according to current sampling time pre-compensation voltage values, current sampling time pre-compensation pulse width modulation (PWM) duty ratios, a current sampling time compensation PWM duty ratio, and the polarities of the current sampling time three-phase stator currents;
wherein the vector angles of the current sampling time three-phase current vectors are current sampling time rotor angles of the PMSM;
wherein the acquition of the included angles between the current sampling time three-phase current vectors and the d-axis comprises: calculating the included angles between the current sampling time three-phase current vectors and the d-axis according to a third equation, the third equation being:
ψ=arctan(id/iq),
wherein ψ is the included angle between the current sampling time three-phase current vector and the d-axis; id is the current sampling time filtered d-axis current; and iq is the current sampling time filtered q-axis current; and
wherein the acquition of the current sampling time angles θ comprises: calculating the current sampling time angles θ of the current sampling time three-phase current vectors in the αβ coordinate system according to a fourth equation, the fourth equation being:
θ=ψ+ω,
wherein ψ is the included angle between the current sampling time three-phase current vector and the d-axis; and ω is a current sampling time rotor angle of the PMSM.
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