Title |
Study on Avoiding Control Interaction Conditions Through Virtual Impedance Control with Reinforcing Damping on LCL Filter |
Authors |
곽효근(Hyo-Geun Kwak) ; 이효(Hyo Lee) ; 심재웅(Jaewoong Shim) |
DOI |
https://doi.org/10.5370/KIEE.2024.73.9.1499 |
Keywords |
Grid-connected inverter; Control Interaction; LCL filter; Virtual Impedance; Damping resistor |
Abstract |
This paper introduces the method of avoiding control interaction conditions by using virtual impedance control and connecting a R-damper to the capacitor section of an inverter containing an LCL filter connected to the power system. For this purpose, we set the parameters of the inverter and LCL filter. Then, equations were employed to appropriately determine the values of the damping resistor of the filter and virtual impedance. Utilizing these configured values, the overall transfer function was represented using the transfer functions of the inverter and filter. Subsequently, it was examined whether unstable resonance, as compared to the system impedance, could be avoided when using the virtual impedance control and adding resistor to filter. Furthermore, in the frequency domain, We assess how much the voltage harmonics decreased when the virtual impedance and damping resistor was included, compared to when only the LCL filter was present. |