Active damping control of multiple resonances for grid-connected inverter with long transmission cable

The long transmission cable with non-negligible parasitic capacitor and inductance is usually applied to transmit power energy in distributed generator system. As a result, LCL-type grid-connected inverter introduces the potential multiple harmonic resonances issue more sensitively compared with pure equivalent inductance of the cable. To eliminate these resonances, this paper focuses on active damping method which notch filter based on low pass filter (LPF-NF) is proposed without any additional sensor. Furthermore, compared with the existing active damping method based on series notch filter (SNF), the proposed LPF-NF can not only lessen computation burden relatively, but also preserve robustness and transient performance. Lastly, the effectiveness and correctness of the proposed LPF-NF is examined by comparative simulations.