Development of highly efficient building, integrated photovoltaic generator for use in detached houses and bigger photovoltaic plant

The project has resulted in the production of a prototype unit. The prototype unit is assembled in a wall mounted steel Box measuring 600mm x 400mm x 200mm. The unit is installed in a building at EnCon, the power supply is taken from a string of 1KW PV modules connected in series. On the output the unit is connected to the 230V Grid. In the design, achievement of high efficiency has been a high priority. As a consequence only few resources has been used on product optimization of the prototype unit. The prototype unit consist of 6 sub units each having their own Printed circuit board, the necessary connections are made by means of wires. The sub units are: 'input interface, output interface, display, control, step up and H bridge'. In order to optimize the efficiency the step up and H bridge subunits have been tested in each 3 configurations: configuration 1 - the design configuration -, configraution 2 - the one in which the prototype is installed at EnCon - and configuration 3 in which a higher efficiency is achieved by using a better core material for the chokes. Only one core with the better material was available, for this reason it was not possible to install the prototype in confiuration 3 at EnCon. A component cost price have been calculated for each sub unit based on a fictitious production batch of 100 pieces. The prototype - as it is now - is not suitable for mass production for that reason a production price including wages hasn't been calculated. In the actual prototype the efficiency is close to 96% (the goal for the project is 96% in the voltage range 300V - 350V and power range 100W - 1000W) in the voltage range 300V - 350V but only in the power range 1000W - 1300W. By lower power levels the efficiency shows a noticeable decrease. Hence the prototype doesn't meet the project goal for power levels lower than 1000W. Results obtained in laboratory tests shows that a optimized configuration - where both chokes in the H bridge and the on in the step up unit are made on the better core material - is likely have an efficiency of 96% (and in some cases higher) in the voltage range 250V - 350V and power range 500W - 1500W. The test period at EnCon showed that the simple and quickly performed adjustment - that the project only allowed - of the MPP routine wasn't sufficient to ensure optimum utilization of the solar energy, in all cases. During the project there have been no resources left for investigating EMC aspects