Linear motor control apparatus and compressor equipped with the same

A linear motor control apparatus, configured to control a linear motor, including a winding to which an AC voltage is applied and a mover which is connected to an elastic body, the linear motor control apparatus, comprising:

• a controller configured to perform:
• an operation mode (1) which linearly increases amplitude of a voltage command value while keeping a frequency of the AC voltage substantially constant, and
• an operation mode (2) which changes the frequency of the AC voltage while keeping the amplitude of the voltage command value substantially constant,
• wherein the linear motor is configured to drive a piston having a stroke, the piston attached to the mover,
• wherein the controller is configured to execute the operation mode (1) and the operation mode (2) in order of the operation mode (1) and the operation mode (2),
• wherein the controller is configured to:
• execute the operation mode (1) immediately after a start of the linear motor,
• set a stroke range of the piston at the start of the linear motor regardless of a load at the start,
• where a stroke command is linearly increased from zero and a stroke command value deviates from a stroke detection value depending on whether the driving frequency substantially coincides with a resonance frequency of the mover,
• estimate a position of at least one of the mover or the resonance frequency of the mover after amplitude of the position of the mover is linearly increased to a predetermined value or more in the operation mode (1), and
• change the frequency while keeping the amplitude of the voltage command value substantially constant, and then increase the amplitude of the voltage command value in the operation mode (2).