Abstract— Synchronization systems are widely employed to connect multi-motor electric drive systems. Its main goal is to equalize the speeds of motors at different loads. In the current work, a comparative study between the different approaches of such synchronization systems has been done. Different indicators of three traditional synchronization systems were studied, modeled, calculated and discussed. These indicators affect the stability of the system and the synchronization system accuracy of operations. The three studied synchronization systems are: electrical shaft system, electromagnetic shaft system, and a capacitor-electromagnetic shaft system. Simulation is carried out using Matlab/Simulink. Simulation results show the differences, similarities, advantages and disadvantages of each of the three approaches. Therefore, the results may help choose the most suitable system for a certain application.