This paper proposes a 12-stator slot/4-rotor pole (12/4) synchronous reluctance (SynRel) machine with integral slot concentrated windings (ISCW), a segmented stator, and a skewed rotor, namely the 12/4 ISCW machine. The proposed 12/4 ISCW machine exhibits comparable torque performance when compared to the case of adopting an integral slot distributed winding (ISDW) with the same total stack length. A comparison study is conducted on the 12/4 ISCW machine, a 24/4 ISDW machine, and 6/4 fractional slot concentrated winding (FSCW) machines. Then a torque prediction method and a continuous maximum torque per ampere (MTPA) control based on the polynomial fitting model (PFM) are proposed for SynRel machines, to provide fast and accurate calculation of the real-time inductances and torque. Magnetic saturations are also considered in the PFM, which is why the PFM has great potential in the maximum-current-per-torque control of SynRel machines. Finally, a prototype of the proposed 12/4 ISCW SynRel machine is manufactured and experimental validations are carried out.