According to different motor models, there are two types of S1 curve (continuous duty system) in the operating stage from static to rated operating point: using the maximum torque allowed in temperature and using constant torque (usually using constant torque). The power will increase with the speed according to the torque type. This is followed by a period of constant power, during which field weakening occurs. The field weakening range is limited by the voltage limit value. The overload capacity is generally implemented according to the S6 (40%) work system.
The selection of dynamometer needs to consider the following factors:
For the rated power, rated speed, maximum speed, overload factor, etc. of the tested motor, it is generally required that the S1 curve of the dynamometer can cover the peak curve of the tested motor. If in order to save costs, or the dynamometer selection is difficult, you can also consider using the dynamometer's S6 curve to envelope the peak curve of the tested motor, but you must consider that the dynamometer's overload time cannot exceed the design requirements.