ApplicationofExtendedforPowerQualit.pdf

Article ID: 1007-1172( 2007) 02-0257-06 Application of Extended Kalman Filter to the Modeling of Electric Arc Furnace for Power Quality Issues J IN Zhi-j ian(金之俭) , 　WAN G Feng-hua * (王丰华) ,　ZH U Zi-shu(朱子述) ( Dept. o f Electr ical Eng . , Shanghai Jiao tong Univ . , Shanghai 200030, China) Abstract: Electr ic ar c furnaces ( EAFs) r epr esent one o f t he most disturbing lo ads in the subtr ansmission or t rans- mission electr ic power sy stems. Ther efor e, it is necessary to build a pr actical model to descr ipt the behavior of EAF in the simulation of pow er system for pow er quality issues. T his paper dea ls with the modeling of EAF based on the combinat ion o f ext ended Kalman filter t o identify the par ameter of ar c cur rent and the pow er balance equa- tion t o obt ain the dynamic, multi-valued u- i char acter istics of EAF load. The w hole EAF systems ar e simulated by means of pow er system blo ckset in Mat lab to v alidate the propo sed EAF model. This model can a lso be used t o assess the im pact o f the new plant or highly v ary ing nonlinear lo ads t hat exhibit chaos in pow er sy st ems. Key words: electr ic ar c furnace ( EAF) ; ex tended Ka lman filter ; pow er quality ; chaos CLC number: TM 924. 4　　　Document code : A Received date: 2005-09-28 * E-mail : fhwang7723@ sj tu . edu. cn Introduction Elect ric arc furnaces ( EAFs) are more and mor e applied in iron and steel indust ry. T he basic oper at ing principle of EAF is that an electr ic arc is st ruck from one or more elect rode to a metallic charg e w ith the thermal energy dissipated to melt and ref ine the ir on and steel r aw mater ial fo r the pr oduct ion of quality steel . It is energ y ef ficient and economical. How ever, the operat ion of EAF can cause se- vere pow er quality problems on the elect rical net , such as harmonics, inter-harmonics, f licker and voltag e imbalances etc. Therefore, it is necessary to build a practical model fo r the EAF employed in the simulat ion of w ho