SBIR-STTR Award

A hybrid power plant, consisting of a diesel generator, a batteryfor energy storage, a photovoltaic array or other renewableenergy source, and an inverter/battery charger, will beeconomically feasible in the near future both within the UnitedStates and throughout the developing world where rural areas arestarving for quality power. At present diesel generators runcontinuously; the new hybrid power plants will transfer powersources between the diesel generator and the inverter at leastdaily. The planned Phase I research methodically approaches thecontrol of the inserter so that the transfer of power is a smoothprocess. An adaptive controller for the inverter/battery chargerwill measure and store the characteristics of a diesel generatorin the field and adjust the transfer of power by operating theinverter in parallel with the diesel generator for a few secondsat each power transfer. The success of Phase I will bedemonstrated with computer simulations that predict properoperation both in the steady state and during all powertransfers. Anticipated Results /Potential Commercial Applications as described by the awardee: The unit under investigation willprovide a low cost solution for the field installation of hybridpower plants. In Phase II, a family of products spanning thepower range from 50 to 250 kW will be available for prototype andsmall production runs. In Phase III, under company sponsorship,production tooling and value engineering will be added to thehybrid power plant to generate marketplace attractions intechnology and price.

Currently, diesel generators are the primary source of electric power in remote areas where the cost of constructing long power lines exceeds the cost of fuel delivery. Advances in photovoltaics (PV) technology now make it cost effective to build and operate a hybrid power plant. A trimode power processor fulfills an important control function in remote village applications of PV. It optimizes the use of three sources of energy, PV, diesel, and battery, by minimizing diesel fuel consumption and by using the maximum power available from the PV array. The positive impact of applying the trimode power processor with a newly invented power quality enhancement controller was demonstrated with detailed computer simulations in Phase I. The simulations illustrated how battery charging will be used in a control strategy to apply the optimum load to the diesel generator. The processor reduces the fuel consumption of the diesel generator to a minimum by presenting itself as the perfect electrical load to the generator. In Phase II, hybrid systems will be developed that combine the energy sources from PV, batteries, and diesel-generators, and a 50 kW three phase unit will be tested to prove its worthiness in actual field conditions. Economical feasibility will be demonstrated for small power plants in many parts of the world. Anticipated Results/Potential Commercial Applications as described by the awardee: The application of PV energy at remote locations where reliability of supply requires a diesel generator will be less costly to operate by reducing the run time of the diesel generator. The numerous benefits include longer times between maintenance for the diesel engine and better power quality from the generator.