Control strategy for power flow management in a PV system supplying electrical loads in an air-conditioned bus

The price of fossil fuels is constantly escalating. Fossil fuels are also the major cause of air pollution and global warming. Renewable energy sources appear to be a suitable alternative as they are abundant and pollution free. However, the major drawback of replacing fossil fuels completely with renewable energy sources, especially solar energy, is that the renewable energy sources tend to be inadequate in meeting the energy demands in certain situations and are also not wholly reliable under all circumstances. This paper presents a novel strategy to feed the electrical loads in a bus using solar energy. The already existing bus electrical system which is powered by the alternator coupled to the bus engine, is integrated with Photovoltaic (PV) cells in order that minimum energy is drawn from the fossil fuels. An efficient power flow management strategy is incorporated together with a Maximum Power Point Tracking (MPPT) algorithm such that the solar energy augments the power supplied from the bus engine and thereby reduces fuel consumption in the process. This control strategy is formulated using State of Charge (SoC) of the battery as the criterion.