CONTROLLING APPARATUS FOR SINGLE-PHASE GRID INVERTERS USING LLCL FILTERS

摘要

The present invention relates to an apparatus to control a single-phase grid inverter by using an LLCL filter. According to the present invention, the apparatus comprises: a damping component generation unit feeding back a capacity current flowing in a capacity of an LLCL filter to generate a damping component; an operation unit operating a current command value of a system side current inputted to a system side and the generated damping component to generate a current command value to which the damping component is reflected; a current control unit receiving a phase component calculated from DC power of the system side and the current command value to which the damping component is reflected to generate a voltage command value by using a proportional-resonance controller and a repetition control unit; and a pulse wavelength modulation (PWM) control unit performing PWM control of a switching device of an inverter according to the generated voltage command value. According to the present invention, since the inverter is controlled by reflecting the damping component to remove resonance occurring by the LLCP filter, the resonance is removed without using an actual resistor, and thereby power loss caused by resistance is not caused, stable current control is enabled, and an excellent harmonic wave reduction performance is exhibited.