Patent ID: 6753665
Filing Date: 2004-06-22
Classification: F04B,G05B

Abstract:
A linear compressor driving apparatus for driving a linear compressor which has a piston and a linear motor for making the piston reciprocate and which generates a compressed gas by the reciprocating motion of the piston with an AC voltage being applied to the linear motor, said apparatus comprising:an inverter for outputting an AC voltage and an AC current to the linear motor; a resonance frequency information output means for outputting resonance frequency information which indicates a resonance frequency of the reciprocating motion of the piston; a voltage detection means for detecting an output voltage of said inverter to output a voltage detection signal; a current detection means for detecting an output current of said inverter to output a current detection signal; an inverter controller for controlling said inverter on the basis of the resonance frequency information so that said inverter outputs a sinusoidal-wave-shaped output voltage and a sinusoidal-wave-shaped output current whose frequencies each match the resonance frequency of the piston reciprocating motion; a timing detection means for detecting, as a specific phase timing, a phase timing at which a differentiated value of the output current of said inverter becomes zero; and a piston velocity calculation means for receiving the voltage detection signal and the current detection signal, and calculating a maximum amplitude of a piston velocity in the piston reciprocating motion on the basis of instantaneous values of the output voltage and the output current output from said inverter at the specific phase timing.