Magnetic pole initial position detecting device and magnetic pole position detecting device of DC excitation method

摘要

To provide a magnetic pole initial position detection device using a direct-current excitation method, capable of acquiring a magnetic pole initial position of a rotor of a synchronous motor in a short period of time, and a magnetic pole position detection device including the same.SOLUTION: A magnetic pole initial position detection device 1 for detecting a magnetic pole initial position of a rotor of a synchronous motor 2 includes: a direct-current excitation command generation section 11 configured to generate a first command for causing a constant excitation current with a current phase fixed to a first phase to flow through the synchronous motor 2; a torque-zero determination section 12 configured to determine whether or not a torque generated in the rotor of the synchronous motor 2 is zero when the excitation current based on the first command flows through the synchronous motor 2; and a magnetic pole initial position acquisition section 13 configured to acquire the magnetic pole initial position of the rotor of the synchronous motor 2 on the basis of a rotor actual position in the vicinity of a point in time when the torque-zero determination section 12 determines that the torque is zero, the number of pole pairs of the synchronous motor 2, and an excitation phase during direct-current excitation under the first command.SELECTED DRAWING: Figure 1