oth have three phase currents weaving through the stator. How LSM's differ is that their rotor has two closely spaced direct current wires spaced regularly as the diagram below shows.The moving magnetic field is setup, but the induced currents setup are much smaller than in the LIM case. One reason is that the composition of the rotor may be different: it may be laminated or consist of a material of high electrical resistance. The DC currents are the important factor in LSM's. Look at the diagram below. (Note that the position of the rotor and stator are reversed. Also note the pattern of wires in the stator is A C' B A' C B' )From Applied Electromagnetism, page 578.The force acting on the rotor DC currents due to the track flux tends to to move the rotor to the right. (This can be shown using the right hand rule involving the vertical track flux lines. The horizonal track flux lines do not contribute to the propulsion.)The position of the DC rotor currents is very important. In the diagram above, the rotor currents coming out of the paper are aligned with the leftmost stator wire that is also coming out of the page. This produces the maximum force on the rotor. Now consider what will happen after the diagram's time frame:1. the rotor will move (in relation to its acceleration and velocity) 2. the stator's magnetic field will move (in relation to the frequency of the three phase currents) Now, after a small time interal, let's examine the relative positions of the rotor and stator. If the alignment is not the same as the figure, then the force on the rotor will not be the maximum. It should be clear that the Linear Synchronous Motor operates best at its sychronous speed. Indeed, if the rotor isn't moving close to the synchronous speed, then the LSM will not move the stator at all!If the rotor is close enough to the synchronous speed, then the LSM will be able to accelerate the rotor up to the synchronous speed.Note: the synchronous spee...
