AC motor control device and AC motor driving system

摘要

The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.

主权项

1. An AC motor control device, comprising:
an inverter configured to apply a pulse width modulation voltage to an AC motor to drive the AC motor; a current detector configured to detect current in the AC motor; a controller configured to adjust the pulse width modulation voltage output by the inverter; and a state quantity calculating unit included in the controller and configured to calculate a state quantity of the motor; wherein the state quantity calculating unit calculates a setting value of the state quantity defined on either one of two axes orthogonal to each other in a rotary coordinate system of the motor, using at least one of state variables defined on the same one of the axes and the other one of the axes, and uses the calculated state quantity for driving control of the AC motor; wherein calculation of the state quantity setting values by the state variables defined on the same one of the axes and the other one of the axes is performed with a function formula using a constant featuring influence of the state variable on the state quantity, wherein the state variable is a parameter; wherein the function formula is a fractional expression of which a numerator includes a linear function in which the state variable defined on the same one of the axes is a parameter and of which denominator includes at least one of a linear function in which the state variable defined on the same one of the axes is a parameter and a linear function in which the state variable defined on the other one of the axes is a parameter; wherein a coil interlinkage flux is used as the state quantity; and wherein a motor current is used as the state variable.