This document presents two closed loop control techniques for a SEPIC (single-ended primary inductor converter) DC-DC converter used with PV panels: 1) current mode control where the current is used as a reference and 2) PI control where the voltage is used as a reference. It describes the operation and design of the SEPIC converter, models the PV panel, and discusses each control strategy. Simulation results show the voltage and current waveforms for open loop, current mode control, and PI control of the SEPIC converter. In conclusion, current mode control provides better performance than PI control but has limitations on the reference current value.