an electrical drive system includes an electric motor having an armature , which is mounted on a stator , and a rotor , wherein aligning stator flux with rotor flux enables current to flow in the armature without inducing torque on the rotor shaft . the disclosed operation may be used , for example , in testing the electrical drive system . the electric drive system can carry full rated current yet produce little or no torque , thereby increasing the current that can be tested during electrical drive test procedures without producing undesired forces or motion . the method may be used , for example , in heating the electric motor , for example for de - icing .