This paper presents a control strategy based on a differential flatness approach for two boost choppers and one bidirectional buck-boost chopper connected in parallel, the goal being to stabilize the DC bus voltage at a constant level as well as to ensure a permanent availability of power distribution. Since the bidirectional buck-boost chopper can operate either in boost mode or in buck mode, the overall system is a switched system. The hybrid dynamical behavior is not due to the chopper switching frequency (since we consider the averaged model of each chopper), but to the transition from buck to boost mode and vice-versa of the bidirectional buck-boost chopper. We first give an in-depth study of the flatness property of each configuration of the switched system (the boost configuration, when the bidirectional buck-boost chopper operates in boost mode, resp., the buck configuration, when the bidirectional buck-boost chopper operates in buck mode) and demonstrate that both configurations are flat and moreover, that they admit the same flat output (which is independent of the discrete variable defining the switching). Finally, we establish a relation between the proposed flat output and the regulation of the DC bus voltage via an additional power load control loop. To demonstrate the effectiveness of the proposed control strategy, we present several simulation results.