1.College of Electrical Engineering，Zhejiang University，Hangzhou310027，China;2.Hunan Electric Power Company，Changsha410007，China

The accuracy of the synchronous generator model has great impact on power system stability study，and how to quickly and accurately determine the parameters of the generators in a power system is one of the most important issues in the field of power system modeling.In this paper，an online system-wide identification algorithm is proposed with the wide area measuring device and a complete mathematical model is developed for online identification multiple generators in a multi-machine system at the same time.And the multi-scenario parameter identification is proposed to improve the recognition accuracy to cope with the phasor measurement unit（PMU）measurement error.Multi-generator identification is a class of dynamic optimization problems，which is very time-consuming when solving large systems.A reduced-space interior point method is proposed to solve the parameter identification problem with small degrees of freedom，greatly reducing the computational time.Further，the scenario-decoupling strategy is proposed to solve the multi-scenario parameter identification in parallel.Two test cases show that the algorithm under discussion has higher accuracy and can quickly find the identified parameters compared with the traditional stand-alone identification algorithm.