Dynamometer and method for simulating vehicle road load and/or inertial forces while providing compensation for the parasitic losses of the dynamometer

摘要

A dynamometer for testing engine powered vehicles including an induction motor coupled directly to the vehicle engine or the driven wheels thereof. A computer in response to the engine or wheel speed and the torque applied to or received from the engine or wheels by the motor provides a desired torque signal to a motor power controller to similate the road load and/or vehicle inertial forces encountered by the vehicle during actual operation and to compensate for the parasitic losses of the dynamometer. The motor power controller in turn applies a d.c. voltage to the motor when the desired torque signal is negative to cause the motor to absorb power from the engine or driven wheels and applies an a.c. voltage to the motor when the desired torque signal is positive to cause the motor to supply power to the engine or driven wheels in accordance with the parasitic losses and the road load and/or inertial forces to be simulated by the induction motor.