APPARATUS AND METHOD FOR CONTROL OF PERMANENT MAGNET SYNCHRONOUS MACHINE

摘要

PROBLEM TO BE SOLVED: To drive a permanent magnet synchronous machine satisfactorily in all regions by a method, wherein the permanent magnet synchronous machine is changed over by using the output of a first excitation means in a start or a low-speed operation, and the synchronous machine is changed over by using the output of a second excitation means at intermediate- speed and high-speed operations. SOLUTION: A first magnetic pole position estimating means 55 calculates an estimate value 1' or the magnetic pole position of a synchronous machine. By using a before-start magnetic-pole position estimating part 55A, an estimation value 11' of the magnetic pole position before the start of a permanent magnet-type synchronous motor 3 is estimated. By using an low-rotation magnetic-pole position estimating part 55B, an estimate value 12' of the magnetic pole position after the start of the permanent magnet synchronous motor 3 is estimated. A second magnetic-pole position estimating means 56 detects the phase of the output signal Vu of a dq-axis current control means 51 whose phase is identical to that of an applied voltage to the synchronizing machine, and the estimate value 2' and a speed m2 of a magnetic-pole position are calculated and a speed deciding means 58 connects a switch means 57 to a terminal 57A from which the estimation value 11' before the start is output when the synchronous machine is started according to the speed m of the synchronous machine, and it connects the switch means 57 to a terminal 57C in an intermediate-speed operation and a high-speed operation, in which the speed m1 after the start of the synchronous machine is larger than m0.