APPARATUS FOR CALCULATING ROTATIONAL POSITION OF ROTARY MACHINE

摘要

In a system for driving an inverter, a superimposing element superimposes, on an output voltage of the inverter. The high-frequency voltage signal is correlated with a measured high-frequency component value of a current flowing in the rotary machine. A calculating element calculates a rotational angle of the rotary machine based on the measured high-frequency component value. A dead-time compensating element shifts a start edge and an end edge of an on duration for each of first and second switching elements of the inverter by a preset same time to compensate for an error due to dead time. A current manipulating element manipulates a current flowing in the rotary machine to maintain an accuracy of calculation of the rotational angle.