  This paper proposes a programmable multi-input buck-boost structure method,
which can enhance the operation tolerance for the PV array under extremely
harsh climatic conditions. The proposed structure based on a traditional two
switches buck-boost converter can connect PV panels in parallel and cascade
flexibly, and also enable the individual operation of each PV panel. The active
switches can be programmed to change the connection structures as well as
achieve the maximum power point track of PV panels simultaneously. The paper
presents the programming method for an exemplified scalable structure converter
for two PV panels. The simulation has been established in MATLAB/Simulink to
validate the performance of the proposed converter in terms of multiplexing
function, wide operating range of PV panels, and low switching stress.
