Research On The Calculation And Simulation Of Electrical Characteristies Based On BIPV

The consumption of energy in the world is stepping forward in the direction of new energy, high efficiency, low cost and environmental friendliness. Solar energy has been realized and found plenty of application in distributed generation since it was originally introduced to the connection to the power grid. It has terrific performances including ease of use, width of radiation, adequacy of radiating time and harmony of environment. It is undoubtedly one of the most recommended energy used in the field of distributed generation in National Long-term Development Planning. Building Integrated Photovoltaics (BIPV), by integrating the Photovoltaics component into buildings, can generate environment friendly electricity for building consumption. These features lead BIPV to one of the most studied areas in both smart building and smart grid all over the world.In the BIPV system, the PV systems are designed, constructed and maintained together with the building. The PV panels has dual roles:as parts of building exteriors and power generators. They can even improve the aesthetic of building. However, in the current building design practices, BIPV design is divided into multiple phases. Each phase is performed with respective software and engineers:e.g. the PV system and the building. The lack of design support for the correlated and complex design requirements for both the electricity system with photovoltaics and building, make the BIPV design become a weak point of BIPV’s applications. Lack of integrated information exchanges between two phases makes the inappropriate design of building electricity system, poor electricity power flow and electricity safety problems.In order to promote the development of BIPV industry, it is inevitably crucial to focus on the interaction effect between the electrical features of power system with photovoltaics and structure of building and then propose a reasonable regulation for the design, implementation, operation, maintenance and property management and supervision of BIPV. With the help of the financial support from the National Natural Science Fund Project (Project No:61202050), key project of Technology R&D (Project No:2013C01039), the building model and electrical model in BIPV are systematically studied based on BIM (Building Information Model) as the expression about physics and function of facility feature. In this thesis, the interaction effect between the electrical features of power system with photovoltaics and structure of building is systematically studied in respects of building of model, obtaining of data, integration of electrical simulation and the electrical optimization based on BIM. The main tasks of this work are listed below:(1) The design of BIPV were generally classified into two categories:Design of building and design of power system with photovoltaics. The architecture method of BIPV design was analyzed in detail. The implementation of BIPV design was divided into both construction of building model and construction of electrical model. Moreover, the electrical parameters of electrical model used for electrical simulation were integrated into the BIM.(2) The information related to BIM was acquired, including the topology of electrical system, information of electrical system, information of soil and grounding grid. The electrical models were filtered through the unique ID belonging to each in order to search through the whole electrical system and draw the conclusion of topology. The information obtained above was settled and separated into four categories:load device, supply device, distribution device and the correct connection between them. Moreover, the further processing was executed to obtain appropriate data format which would provide the electrical simulation with basic data support. According to the model for soil and grounding grid built on family module based on BIM, the electrical information was read out from electrical model through the programming interface provided by Revit SDK.(3) The integration with electrical simulation is achieved based on BIM for electrical system. The electrical system was built and then the relative electrical information was acquired which were both based on BIM. The power flow was analyzed in order to inspect the distribution of node voltage and line power. The short circuit was calculated through the entire nodes based on power flow. To find out the maximum value of short circuit current, the comparison through all nodes was investigated in detail. In order to guarantee the security of electrical system, grounding grid was designed to calculate the ground potential rise, touch voltage distribution and step voltage distribution. Meanwhile, the outcome of simulation was displayed in 3D.(4) Based on the IEEE-2000-80th standard, taking the satisfactory of touch voltage and step voltage into consideration, the cost of grounding grid was optimized aimed at proposing the most reasonable and economical design of grounding grid. The question about the optimal access point of photovoltaics was analyzed when the generation capacity was constant. The effect which the photovoltaics had on the contradictory relationship between minimum cost and minimum power loss was quantized from long term by using weight factor. Furthermore, the minimum cost and minimum power loss was normalized as goal function which was calculated for the optimal access by using genetic algorithm.This thesis proposed a design method of BIPV based on BIM to achieve the building of BIPV model. In this model, it not only provides information of building, but also provides information of electrical device which makes it possible to effectively simplify the complexity of model and the incompatibility between models. According to the storage function of BIM, the information is capable of being acquired automatically without inputting manually which effectively improves the accuracy of computation. The function of electrical simulation is designed to testify the reasonability of electrical design. Moreover, the optimization including grounding design and the access point is implemented to effectively reduce the cost of design.