Parallel-Connected Converters with Innovative Control

"This Small Business Innovation Research Phase I project intends to develop a solar-based expandable, parallel-connected power system with robust maximum power point tracking (MPPT) capability.Solar energy is regarded as an important resource of power energy in the future. As the need for flexible, scalable solar power requirements increases, and in an effort to avoid redesign of solar based power system, a modular infrastructure of powerprocessing management is implemented for maximum utilization of the available power from multi-channel solar array sources. In the proposed system, dither signal is adopted to avoid the trapped-in instability of MPPT controller, and switching cycle,sampling signal and dither signal are synchronized to achieve robust MPPT control. Two-level shared-bus configuration is elaborated to allow the paralleled channels operate in different modes without interaction between each other. Also such structure hasthe advantage of the flexibility for power expansion and near uniform current sharing. Finally, the potential instability sources and their corresponding solutions, redundant shared-buses for fault-tolerance are also presented in this proposal.The trend toward utilizing natural energy and long-term cost/schedule benefits will make the proposed system accepted by the spacecraft and electric propulsion power systems. Also, it is believed that in the very future such systems have the potential tobe extended to