The Monitoring And Evaluating System Of Grid-connected Wind/Solar Generation System

In the modern world, the increasingly serious environmental problems and worldwide energy crisis have become more and more urgent problem of human. Environmental pollution and Energy depletion have already become an important problem in the development of the world. However, the development and utilization of renewable energy provides an effective solution. In recent years, new energy generation technology has become the hot topic of research. Experts and scholars in many countries have done very deep exploration and research on it, especially the wind power and solar photovoltaic power generation technology. With the continuous development of new energy power generation technology, more and more distributed generation systems are connected to the grid. Because of the randomness and uncertainty, the output power of distributed generation system will fluctuate. Therefore, the distributed generation system has much influence on the grid after connected to the grid. This thesis designs a monitoring and evaluating system of grid-connected wind/solar generation system on the basis of experimental generation system to evaluate the effects on power quality of distributed generation. The main research is as follows:Firstly, the wind and solar hybrid generation system has been built is presentted in detail, including the structure, selection and parameter of each part. Then, develop a monitoring and evaluating system of grid-connected wind/solar generation system based on the generation system. The data communication program, the data storage program and the visual interfaces are developped in detail. Then the visual interface part of the monitoring and evaluating system is presentted.Secondly, evaluate the steady state power quality after distributed generation system is connected to the grid by the monitoring and evaluating system of grid-connected wind/solar generation system. Select voltage and harmonic this two parameters to evaluate power quality. And new steady state power quality evaluation indexes are proposed in consideration of the distributed power generation system. Study and analyze the voltage and harmonic data using different visual interfaces. Contrast the data of point of common coupling before and after the distributed generation system is connected to the grid. Then, evaluate the power quality. It can directly display the evaluation results using data curve and can display the historical data with and without the distributed generation system for data research.Finally, in the process of power fast fluctuations and power grid fault, evaluate the steady state power quality using the monitoring and evaluating system. The output power of distributed generation changes for meteorological reasons or system switching. So, research the impact on power quality of the point of common coupling in the change process. Then, new evaluation indexes of transient state power quality are proposed which are more suitable for the grid with distributed power generation system.Evaluate the impact of the output power changes through monitoring the data of meteorological conditions and power quality. Then, simulate that the power grid occurs and evaluate the islanding detection capability of grid-connected inverter.