DC Active Power Filter-Based Hybrid Energy Source for Pulsed Power Loads

In this paper, design of a capacitor semiactive hybrid source for powering pulsed power loads based on dc power filter principle is presented. The system consists of an energy source connected directly to a load, supported by a bidirectional buck-boost dc-dc converter interfaced supercapacitor (SC). The converter is controlled such that the SC supplies the dynamic component of the load power, leaving the energy source to supply a near-constant power to satisfy average load demand. The control algorithm is adopted from the power filter theory, allowing to reduce the stress of an energy rich source despite operating under a high-power demanding load. Moreover, the SC-load voltage matching is not required and the control algorithm does not require load current sensing. Instead, energy source current of a much lower amplitude is necessary. The SC sizing methodology is proposed, and topology issues aiming to minimize the SC are discussed as well. Compared with a passive hybrid, the proposed system utilizes much lower capacitance at the expense of additional power electronics. Experimental results are presented to demonstrate the feasibility of the approach.