Techniques for reduction of electric motor torque pulsation

A method of arranging and operating an electric motor system for an electrified vehicle, the electric motor system including a permanent magnet motor (PMM) and a controller, the method comprising:

• providing the PMM including:
• forming a hollow cylindrical stator defining a circular inner portion with a plurality of slots, defined between a respective plurality of ferromagnetic teeth, and having a plurality of electromagnetic coils arranged in the plurality of slots, respectively;
• and
• forming a cylindrical rotor disposed within the stator and defining a circular outer portion having N pairs of permanent magnets arranged thereabout to define N rotor poles, respectively, wherein N is an even integer greater than or equal to four;
• and
• providing a controller configured to control the PMM to mitigate or eliminate magnetic cogging by controlling each pair of electromagnetic coils to stagger or offset a stator magnetic field generated by the pair of electromagnetic coils relative to the rotor magnetic poles, wherein the controller utilizes N/2 times as many switching transistors to individually control each electromagnetic coil of each pair of electromagnetic coils to receive a different current magnitude,
• wherein the magnetic cogging is caused by a periodic strength of a magnetic field resulting from a periodic layout of the electromagnetic coils and the ferromagnetic stator teeth, and wherein the controller is configured to control the PMM to mitigate or eliminate the magnetic cogging when the electromagnetic coils are energized.