An inverter in a power generation system converts a direct current that is input from a direct-current-side device into an alternating current for power supply. The inverter includes a control apparatus and a communications apparatus. The control apparatus controls the inverter to convert the direct current that is input from the direct-current-side device into an alternating current for power supply. The communications apparatus is coupled to the control apparatus, and sends a networking information request signal used to request networking information to the direct-current-side device in the power generation system through a direct-current power line, where a frequency of the networking information request signal is within a first frequency band. The communications apparatus also receives the networking information from the direct-current-side device; and sends a control signal to the direct-current-side device, where a frequency of the control signal is within a second frequency band.