The FMM has attracted considerable interest as a focal point in research due to its torque amplification properties. One line of inquiry within the FMM field focuses on increasing its output torque. To address this issue, scholars have proposed numerous innovative structural topologies for the FMM. This chapter explores the technical concepts and methodologies aimed at enhancing the performance of the FMM, based on flux modulation theory. Additionally, the FMM topologies associated with each performance enhancement strategy will be analyzed. Although it is not feasible to extensively cover all the new FMM topologies in this chapter, their core concepts will be clarified.