The back emf in a motor is normally subtracted from the supply voltage but in a PM Vernier machine it is directly proportional to the torque. I am finding it difficult to fully get the concept.
Thanks Julia. can you please suggest me some book/paper regarding gamma-delta axis calculation method of torque and voltage as the in the above paper it uses that and it has given some references but those references are of japan iee which i cannot access at the moment.