load disaggregation is important for the tasks such as load forecasting
demand side management and power security. The accuracy of the traditional methods subjects to the dimension of load signatures
the sampling frequency and the stability of load profile. In this paper
a Factorial Hidden Markov Model(FHMM)based load disaggregation method is proposed
which contains the load state disaggregation through extended Viterbi algorithm and the load allocation based on integer programming. The load is modeled as FHMM
and we extend the Viterbi algorithm to solve the FHMM directly. The proposed method is insensitive to the stability and accuracy of power data
so it is suitable for the residential and industrial devices. Meanwhile
through the sensitivity analysis of Viterbi algorithm
the relationship between the optimal states and the disturbance of the observation is established
which is significant for the reliability evaluation of the optimal states. This work is supported by National Natural Science Foundation of China(No. 61473218)and National Key Research and Development Program of China(No. 2016YFB0901904).