In this paper the implementation of the particle swarm optimization algorithm for the maximum power point tracker (PSO MPPT) of a panel array, under partial shading is analyzed. Unlike most studies where partial shading has been analyzed on the structure of the Buck and Boost converter, this article implements the PSO MPPT in the Dual Active Bridge Series-Resonant (DABSR) DC-DC converter. The analyzed converter has many advantages with the typical structures such as: galvanic isolation, bidirectional power flow and high efficiency. The modulation and the control strategy are presented. Since in partial shading the power delivered by the panels is decreased, two command signals are used to power control transfer: the duty ratio (DR) and the phase shift angle (PSA). The DR controls the PV voltage and the PSA the power flow respectively. In the PSO MPPT algorithm, the swarm particles are the power references which has to transfer by the converter, and the maximum power is the objective function that the swarm must reach. Simulation results using the PSIM software validate the modulation and the control strategy for a 750W prototype.