Abstract: The present invention discloses a ground fault detection system and method for an inverter. The ground fault detection method for the inverter includes a reference value setting step for setting a reference value for estimating a ground fault current and a reference value for deciding a ground fault, a ground fault current estimation step for comparing a current value obtained by adding up current values flowing through each phase of an output terminal of the inverter with the reference value for estimating the ground fault current, and estimating generation of the ground fault current when the calculated current value is larger than the reference value, and a ground fault phase decision step for deciding the phase in which the ground fault has been generated on the basis of a current difference value between start and end points of 0 vector sections of each phase or between start and end points of 7 vector sections of each phase.

Abstract: An inverter system for driving an induction motor is disclosed. The inverter system for driving an induction motor comprises: a rectifying circuit for rectifying a three-phase AC voltage and outputting the same; a smoothing circuit for smoothing the rectified voltage and outputting the same; a controller for detecting a DC link voltage of the smoothing circuit, determining a power failure mode, a normal mode or a power restoration mode according to the detected DC link voltage and predetermined elapsed time, and outputting a voltage pulse signal according to the mode; and an inverter for converting the DC voltage outputted from the smoothing circuit into an AC voltage of variable frequency and variable voltage according to the voltage outputted from the controller and outputting the converted AC voltage in order to drive the induction motor.

Abstract: An inverter system for driving an induction motor is disclosed. The inverter system for driving an induction motor comprises: a rectifying circuit for rectifying a three-phase AC voltage and outputting the same; a smoothing circuit for smoothing the rectified voltage and outputting the same; a controller for detecting a DC link voltage of the smoothing circuit, determining a power failure mode, a normal mode or a power restoration mode according to the detected DC link voltage and predetermined elapsed time, and outputting a voltage pulse signal according to the mode; and an inverter for converting the DC voltage outputted from the smoothing circuit into an AC voltage of variable frequency and variable voltage according to the voltage outputted from the controller and outputting the converted AC voltage in order to drive the induction motor.

Abstract: The present invention discloses a ground fault detection system and method for an inverter. The ground fault detection method for the inverter includes a reference value setting step for setting a reference value for estimating a ground fault current and a reference value for deciding a ground fault, a ground fault current estimation step for comparing a current value obtained by adding up current values flowing through each phase of an output terminal of the inverter with the reference value for estimating the ground fault current, and estimating generation of the ground fault current when the calculated current value is larger than the reference value, and a ground fault phase decision step for deciding the phase in which the ground fault has been generated on the basis of a current difference value between start and end points of 0 vector sections of each phase or between start and end points of 7 vector sections of each phase.