Compensation of current measurement error in half-bridge PWM inverter for linear compressor

This paper proposes a novel compensation algorithm of current measurement error for single-phase linear compressor in home appliances. Current measurement error which may be problem, when use the DC link divided into two capacitors in half-bridge inverter, causes the unbalanced DC link voltage. In order to compensate the current measurement error, the synchronous reference frame transformation is used for detecting the measurement error. When the output current of the half-bridge inverter includes offset error, the d-axis current has a ripple of fundamental frequency. By using a PR(Proportional-Resonant) controller, first harmonic can be removed and can be compensated measurement error. The proposed compensation method can be easily implemented without much computation and additional hardware circuit. The validity of the proposed algorithm is verified through simulations.