A compound-wound motor (a motor having both a series and a shunt field) in which the series field has the greater effect on the motor characteristics. The shunt, or parallel, field attempts to hold the speed of the motor constant as the load changes, but the series field causes the motor to speed up as the load increases.

In a flat compounded motor, the effects of the two fields cancel, and the motor speed remains relatively constant as the load changes. In an overcompounded motor, the series winding has the greater effect, and the motor tries to speed up as the load increases.