Two methods of inertia simulation, energy compensation method and torque control method, using work of electromotor during brake application are discussed in comparison in this paper. Mathematical models are described. Experiment under various brake conditions unfolds the rule of some key factors of energy compensation including working period of electromotor, start point and ending condition of compensation. Comparison experiment shows advantages of the energy compensation method over its counterpart. Limitations as well as corresponding solutions are discussed in the end.