For any motor text say that, the rotor field follows the stator field with a certain torque angle. And in case of generator, the stator field follows the rotor field with a negative load angle. The underlying principle is that one field is attracted to another, say in motor the lagging rotor field is attracted to stator field. But why cant the motor action be driven by field repulsion rather than field attraction. For example in motor action, why cant rotor field be leading stator field and be repelled by it to cause motion? This in theory would still cause rotation.