The Design Of Micro-grid Microcomputer Relay Protection System Based On DsPIC33CH

With the rapid development of the country and the continuous improvement of people's quality of life,the demand for power resources is increasing.In order to meet the power demand of different industries and regions,the power industry has derived a multi energy structure power generation system.In the past,solar energy,wind energy and geothermal energy,which were not paid attention to before,have gradually become the indispensable important resources of power grid.As an important supplement to the large power grid,how to effectively ensure its safe operation is the key.However,due to the energy diversity and unstable power generation of microgrid,the protection of microgrid is quite different from that of traditional large grid.It is difficult and important to study reliable and fast protection.In recent years,the government has promulgated the standards and specifications on Microgrid,and scholars are committed to the research of protection theory and simulation,so there is a lack of consideration and Research on the hardware part.Therefore,the research of microgrid protection unit has important theoretical significance.This paper first introduces the energy types of distributed generation,analyzes the characteristics of its energy,and then leads to the types of corresponding distributed generation and puts forward the basic requirements and performance requirements of microgrid grid connection protection by analyzing the main grid connection modes of different power sources.Secondly,the advantages and disadvantages of hardware collocation scheme of microprocessor protection unit based on independent microprocessor and DSP Microprocessor are introduced.Combined with the working environment and grid connection mode of micro power supply,a hardware configuration scheme based on dspic33 ch microprocessor,high-precision ADC module and reliable communication design is proposed.Finally,combined with the protection function and operation characteristics of microgrid,the overall control logic flow is proposed.According to the input characteristics of analog signal,the enhanced filtering algorithm is introduced.The control flow and algorithm examples of common current protection,low voltage protection and differential protection aregiven.Finally,a relatively complete microcomputer relay protection unit is formed.