Accurate　modeling　of　electric　arc　furnaces　(EAF)　is　important　for　studying　the　impacton　power　quality　of　EAF　and　developing　relevant　management　measures　in　the　power　grid.　However,　the　existing　research　mainly　treats　the　electric　arc　as　a　nonlinear　electrical　component,　neglecting　the　coupling　of　electric　and　physical　parameters　in　the　electric　arc.　Thus,　reflecting　the　electro　thermal　physical　nature　of　the　arc　is　challenging,　resulting　in　a　deficiency　in　simulation　accuracy.　This　paper　proposes　an　improved　AC　arc　furnace　model.　The　voltage　and　current　of　the　arc　are　defined　as　electrical　characteristics,　while　the　temperature　and　pressure　that　characterize　the　arc　state　are　defined　as　physical　parameters.　The　coupling　mechanism　between　the　electrical　and　physical　parameters　is　determined　based　on　the　electronic　continuity　equation,　Ohm＇s　Law,　the　magnetic　compression　force　balance　equation,　and　the　instantaneous　energy　balance　equation.　A　general　model　is　constructed　that　reflects　harmonics　and　voltage　fluctuations　of　AC　electric　arc　furnaces　more　accurately.　Its　mathematical　expressions　are　given　as　follows:(Formula　Presented)For　the　unknown　parameters　in　the　models:　A,　B′,　rc;　and　L0　can　be　estimated　and　determined　through　mechanistic　analysis;　b,　b1,　and　b2　can　be　identified　using　arc　furnace　transformer　parameters　and　existing　arc　temperature-related　research　to　construct　an　arc　temperature　curve.　The　data　amount　is　reduced,　making　it　more　practical　for　engineering　applications.　Measured　data　from　two　steel　mills’　50t　and　55t　electric　arc　furnaces　are　used　to　verify　the　model.　The　results　indicate　that　the　simulated　AC　arc　temperature　varies　with　the　arc　current,　exhibiting　an　alternating　characteristic　and　a　double-frequency　relationship.　The　thermal　inertia　of　the　arc　induces　a　lad　in　the　peak　temperature　relative　to　the　peak　current.　The　pressure　in　the　arc　column　fluctuates　around　atmospheric　pressure.　Furthermore,　considering　the　arc’s　electrical-physical　coupling　characteristics,　the　simulation　accuracy　of　the　electrical　characteristics,　such　as　harmonic　voltage,　harmonic　current,　and　voltage　fluctuations,　has　been　further　improved　compared　to　existing　methods.　©　2024　China　Machine　Press.　All　rights　reserved.