Motor control system and power steering system

A power steering system comprising:

• a motor control system for driving a motor having a phase number n of three or more, motor control system comprising:
• an inverter that drives the motor;
• and
• a control calculation unit that calculates a current command value indicating a current to be supplied to the motor from the inverter on the basis of a target current command value given from the outside as a control target of the motor, and feeds back an actual current detection value indicating a current supplied to the motor from the inverter to the current command value to feedback-control the inverter, wherein
• the control calculation unit includes
• a voltage control calculation unit that calculates a voltage command value indicating a voltage to be applied to the motor from the inverter on the basis of a current deviation between the current command value and the actual current detection value,
• a torque ripple compensation calculation unit that adds a compensation value for compensating a torque ripple in the motor to a signal value on an upstream side in a signal flow that passes through the voltage control calculation unit, and
• the torque ripple compensation calculation unit includes
• a phase compensator that calculates a compensation value component in the voltage control calculation unit on the basis of an actual angular velocity value indicating an angular velocity at which the motor rotates, and
• an inverse characteristic calculation processor that calculates a compensation value component for compensating the torque ripple on the basis of an inverse characteristic of an open loop transfer function in the feedback control, and
• a current limit calculation unit configured to limit the target current command to a predetermined value or less, wherein the current limit calculation unit is upstream of the torque ripple compensation calculation unit,
• wherein the inverter is configured to control the motor based on the current command value;
• a motor controlled by the motor control system;
• and
• a power steering mechanism driven by the motor.