Ripple content on DC side – Rooftop solar system

Ripple current is the small unwanted residual direct current (dc) power supply which has been derived from an alternating current (ac) source. This ripple is due to incomplete suppression of the alternating waveform within the power supply. PV modules produce Pure DC Voltage and Current without any ripple, however inverter operation influence the voltage on the DC side, and  have a backlash on the PV generator voltage. Depending on the inverter topology and with or without transformer, the ripple on the DC side may appear very different. Even an old style transformer inverter has some very low AC 2x50Hz ripple on the DC side. That’s due to the energy flow in the inverter. There is no standard available for ripple control, however the  ripple content must not exceed 3% .