In order to be competitive, companies aim at improving their technologies in terms of production process simplification and reduction in the overall price of products. However, the use of lower-cost materials and a simpler construction can often degrade the machine performance. One of the possible production process simplifications of electrical machines is the use of modular permanent magnet synchronous machines (MPMSM). Some analytical approaches to analyze machines with modular stator can be found in the literature but these fall in the accuracy or do not consider the U-Shape core structure. This paper presents an analytical model to estimate the no-load air-gap flux density distribution of a U-shape MPMSM with tooth-coil winding. The results were verified with 2-D finite element analysis showing good accuracy.