Due to the complexity and particularity of double-reheat unit's boiler construction

the dynamic characteristics of reheat steam temperature changes greatly compared with the unit with single reheat cycle.On the simulation platform of ultra-supercritical(USC)1 000 MW unit with double-reheat that adopts APROS software and virtual controller VDCS

the reheat steam temperature model identification program was established

and disturbance test for the reheat steam temperature system was also carried out

combining the differential evolution algorithm with the generalized loss function definition.The transfer function models of reheat steam temperature with disturbance of flue gas damper opening degree

flue gas recirculation damper opening degree and spray dereheating valve opening degree were obtained

under conditions with 100%ECR and 75%ECR load.The results show that

the reheat steam temperature model has high identification accuracy

and the transfer function model can well explain the dynamic characteristics of the reheat steam temperature under different disturbances.It is of great significance to formulate the control strategy of reheat steam temperature of actual units.