Parameter Selection Method for Avoiding Control Interaction and Reducing Voltage Harmonics by Adopting C-type Filters on LCL Filter

This paper presents the method of avoiding resonance and reducing voltage harmonics by connecting a C-type filter to the capacitor section of an LCL filter which connected to the inverter. For this purpose, we set the parameters of the inverter and LCL filter. Then, various equations were employed to appropriately determine the values of the capacitor, inductor, and resistor of the C-type filter. Utilizing these configured values, the overall transfer function was represented using the transfer functions of the controller and filter. Subsequently, it was examined whether unstable resonance could be avoided when using the C-type filter. Furthermore, in the frequency domain, the Total Harmonic Distortion(THD) was utilized to assess how much the voltage harmonics decreased when the C-type filter was included, compared to when only the LCL filter was present.