Drive system and control method

A drive system comprising:

• a rotor phase detection circuit that is disposed to be able to detect a phase of a rotor of a synchronous motor and outputs phase information indicating the detected phase;
• a phase estimation circuit that generates an initial phase command of defining a position of the rotor of the synchronous motor by using a correction amount for correcting a phase error;
• a phase error adjustment circuit that generates the correction amount for adjusting a phase error of an initial magnetic pole position of the synchronous motor by using a phase error of an initial phase command at a timing defined by the phase information;
• and
• a drive control circuit that controls driving of the synchronous motor by using the initial phase command obtained by adjusting the phase error,
• wherein the phase estimation circuit includes
• an initial magnetic pole position estimation circuit that generates a phase command value by using the correction amount and an estimation result of the phase of the rotor,
• an initial phase command generation circuit that acquires a detection phase corresponding to the phase of the rotor detected by the rotor phase detection circuit, and
• a calculation processing circuit that generates the phase Δθ corresponding to an integral value of a speed command on the basis of the speed command of the synchronous motor.