To provide a controllable electrical inertia control device to the high-band be one which simulates the behavior of the inertial body having a set inertia by dynamometer.
An electrical inertia control device 5A is for simulating the behavior of the inertial body having a predetermined set inertia J _{The set} by dynamometer reduces the axial torque detection signal T ₁₂ from the host command torque signal T ^* generates a torque signal by multiplying the ratio of the moment of inertia J ₁ dynamometer for the signal to set the moment of inertia J _{the set} obtained Te, the inertia compensation torque by summing the torque signal and the axial torque detection signal J ₁ the inertia compensator 51A which generates a signal T _ref, the inertia compensation torque signal T _ref and by using a shaft torque detection signal T _12, the torque current so as to suppress the resonance of the mechanical system including the specimen and dynamometer comprising a resonance suppression control circuit 53A for generating a command signal _{T 1,} a.
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