主权项 |
1. A motor control device for controlling a three-phase AC motor by using dq-three-phase coordinate conversion, the motor control device comprising:
a phase correction amount calculation unit for calculating a phase correction amount by using a detected motor speed and a q-axis current command initial value, which is a value obtained by dividing the torque command by the torque constant; a rotor phase angle correction unit for adding or subtracting the phase correction amount to or from a detected rotor phase angle of the motor to calculate a corrected rotor phase angle; and a coordinate conversion unit for performing coordinate conversion between parameters on a dq coordinate system and parameters on a three-phase coordinate system on a basis of the corrected rotor phase angle, wherein the phase correction amount calculation unit comprises a storage unit for storing a speed coefficient NA, a first reference speed NB, a phase correction amount limit value NL, a current coefficient TA, and a reference current rate TB as predetermined parameters; a speed correction term calculation unit for calculating a speed correction term on a basis of:
Speed correction value=min[NA×max{0,(N−NB)},NL] where N represents the motor speed; a current correction term calculation unit for calculating a current correction term on a basis of:
Current correction value=TA×min[1,max{0,(Tr−TB}] where Tr represents an initial q-axis current command rate that is a percentage of a q-axis current command initial value with respect to a maximum current outputtable by an inverter that converts DC power into AC power to supply the AC power as a drive power for the motor; and an output unit for outputting, as the phase correction amount, a value obtained by multiplying the speed correction term and the current correction term together. |