ﻃﺮاﺣﯽ ﯾﮏ ﺳﺎﺧﺘﺎر ﺣﻔﺎﻇﺖ دﯾﻔﺮاﻧﺴﯿﻞ ﺟﺪﯾﺪ ﺑﺮاي رﯾﺰﺷﺒﮑﻪﻫﺎي DC ﻣﺒﺘﻨﯽ ﺑﺮ ﻣﻮﻟﻔﻪﻫﺎي ﺟﺮﯾﺎن ﺧﻄﺎ

Design of a New Differential Protection scheme for DC Microgrids Based on Fault Current Components

در ﺳﺎلﻫﺎي اﺧﯿﺮ، اﻧﮕﯿﺰشﻫﺎي زﯾﺴﺖﻣﺤﯿﻄﯽ، اﻗﺘﺼﺎدي و ﻗﺎﺑﻠﯿﺖ اﻃﻤﯿﻨﺎن، ﺣﺮﮐﺖ ﺑﺴﻮي ﺑﻬﺮهﺑﺮداري ﺳﻠﻮﻟﯽ از ﺳﯿﺴﺘﻢ-ﻫﺎي ﻗﺪرت ﻫﻮﺷﻤﻨﺪ را در ﻗﺎﻟﺐ ﻣﻔﻬﻮم رﯾﺰﺷﺒﮑﻪﻫﺎ، ﺗﺴﺮﯾﻊ ﺑﺨﺸﯿﺪه اﺳﺖ. ﺑﺪﯾﻬﯽ اﺳﺖ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺳﻄﺢ ﭘﺎﯾﯿﻦ اﯾﻨﺮﺳﯽ، ﺗﻨﻮع ﻣﻨﺎﺑﻊ ﺗﻮﻟﯿﺪ ﺗﻮان ﺑﺎ ﻣﺸﺨﺼﺎت ﻓﻨﯽ ﻣﺨﺘﻠﻒ و ﻣﺪﻫﺎي ﻣﺨﺘﻠﻒ ﺑﻬﺮهﺑﺮداري ﺟﺰﯾﺮهاي و ﻣﺘﺼﻞ ﺑﻪ ﺷﺒﮑﻪ، ﺣﻔﺎﻇﺖ و ﮐﻨﺘﺮل رﯾﺰﺷﺒﮑﻪﻫﺎ ﺑﻪ ﭼﺎﻟﺸﯽ ﻧﻮﯾﻦ ﺑﺮ ﺳﺮ راه ﻣﺪﯾﺮان اﯾﻦ ﺳﻠﻮلﻫﺎي ﻫﻮﺷﻤﻨﺪ ﺗﺒﺪﯾﻞ ﺷﺪه اﺳﺖ. از ﺳﻮﯾﯽ دﯾﮕﺮ، ﺑﺎ ﯾﮑﭙﺎرﭼﻪﺳﺎزي ﺑﺴﺘﺮ اﻧﺪازهﮔﯿﺮي و ﻣﺨﺎﺑﺮاﺗﯽ ﭘﯿﺸﺮﻓﺘﻪ در رﯾﺰﺷﺒﮑﻪ ﻫﺎ، ﺣﻔﺎﻇﺖ ﻫﺎي دﯾﻔﺮاﻧﺴﯿﻞ، ﺑﻌﻨﻮان ﻣﻄﻤﺌﻦﺗﺮﯾﻦ ﻣﻨﻄﻖ ﺣﻔﺎﻇﺘﯽ، ﻣﯽﺗﻮاﻧﺪ ﻧﻘﺶ ﺣﯿﺎﺗﯽ را در ﺳﺎﺧﺘﺎر ﺣﻔﺎﻇﺘﯽ رﯾﺰﺷﺒﮑﻪﻫﺎ اﯾﻔﺎ ﻧﻤﺎﯾﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻣﺎﻫﯿﺖ رﺧﺪاد ﺧﻄﺎﻫﺎ در رﯾﺰﺷﺒﮑﻪ، ﺧﻄﺎﻫﺎي ﻣﻘﺎوﻣﺖ ﺑﺎﻻ ﯾﮏ ﻣﺸﮑﻞ اﺳﺎﺳﯽ در ﺑﮑﺎرﮔﯿﺮي ﺣﻔﺎﻇﺖ دﯾﻔﺮاﻧﺴﯿﻞ و ﺟﻬﺖ ﯾﺎﺑﯽ ﺧﻄﺎ ﺑﻪ وﺟﻮد آورده اﺳﺖ. در اﯾﻦ ﻣﻘﺎﻟﻪ از ﯾﮏ روش ﺟﺪﯾﺪ ﺑﺮاي ﺗﺸﺨﯿﺺ ﺳﺮﯾﻊ و دﻗﯿﻖ ﺧﻄﺎ در رﯾﺰﺷﺒﮑﻪ DC اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ، ﺑﻄﻮرﯾﮑﻪ ﺑﻪ درﺳﺘﯽ ﺧﻄﺎﻫﺎي داﺧﻠﯽ را از ﺧﻄﺎﻫﺎي ﺧﺎرﺟﯽ ﺗﺸﺨﯿﺺ داده اﺳﺖ، ﻫﻤﭽﻨﯿﻦ ﻋﻤﻠﮑﺮد اﯾﻦ اﻟﮕﻮرﯾﺘﻢ ﺟﺪﯾﺪ ﺑﻪ ازاي اﻓﺰاﯾﺶ ﻣﻘﺎوﻣﺖ ﺧﻄﺎ ﻧﯿﺰ ﻣﺸﺎﻫﺪه ﮔﺮدﯾﺪه و ﺑﺎ ﻋﻤﻠﮑﺮد ﺣﻔﺎﻇﺖ دﯾﻔﺮاﻧﺴﯿﻞ راﯾﺞ ﻣﻘﺎﯾﺴﻪ ﺷﺪه اﺳﺖ. اﺳﺎس روش ﺟﺪﯾﺪ اﺳﺘﻔﺎده از ﻣﻮﻟﻔﻪ ﺟﺮﯾﺎن ﻫﺎي ﺧﻄﺎ دو ﻃﺮف ﺧﻂ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ و رﺳﻢ آﻧﻬﺎ در ﺻﻔﺤﻪ  ﺑﺮاي ﺗﺸﺨﯿﺺ ﻧﻮع ﺧﻄﺎ ﻣﯽ ﺑﺎﺷﺪ. در اﯾﻦ ﻣﻘﺎﻟﻪ ﺷﺒﯿﻪ ﺳﺎزي ﺧﻄﺎي داﺧﻠﯽ و ﺧﺎرﺟﯽ در EMTP-ATP ﺑﻪ ازاي ﻣﻘﺎدﯾﺮ ﻣﺨﺘﻠﻒ ﻣﻘﺎوﻣﺖ ﺧﻄﺎ اﻧﺠﺎم ﺷﺪه و ﭘﯿﺎده ﺳﺎزي اﻟﮕﻮرﯾﺘﻢ ﺟﺪﯾﺪ و ﺣﻔﺎﻇﺖ دﯾﻔﺮاﻧﺴﯿﻞ ﻣﺮﺳﻮم ﻧﯿﺰ در MATLAB اﻧﺠﺎم ﻣﯽ ﺷﻮد. ﻧﺘﺎﯾﺞ ﺷﺒﯿﻪ ﺳﺎزي ﺑﯿﺎﻧﮕﺮ دﻗﺖ و ﺳﺮﻋﺖ ﻋﻤﻞ ﺑﺎﻻي روش ﺟﺪﯾﺪ ﺑﯿﺎن ﺷﺪه، ﻣﯽ ﺑﺎﺷﺪ.

Recently, environmental, economic and reliability oriented motivations facilitate cellular operation of smart power systems in the light of microgrid paradigm. Obviously, due to low inertia stack, high variety of generation units with various technical characteristics and different islanded and grid-connected operational modes, make the protection and control structures become new challenges. On the other hand, by integration of advanced metering and communication infrastructures in the microgrids, differential protection as the most reliable relaying logic, play a vital role in the protection structure of the microgrids. Owing to nature of occurring faults in the microgrids, high resistance faults have created a major problem in applying differential protection and directional fault. In this paper is used a new method for quick and accurate detection of fault in DC micro-grid, so that it detected internal fault from external fault, the performance of this new algorithm is also shown for increasing the fault resistance and compared with the conventional differential protection. The basis of new method is to use the Fault Component Current of the two sides of the study line and plot them on the plan to identify the type of fault. In this paper simulation of internal and external fault in EMTP-ATP for different values of fault resistance is done and the implementation of the new algorithm and conventional differential protection is done in MATLAB. The simulation results indicate the accuracy and high speed of the operation of the new expressed method.