The transverse flux synchronous machine (TFM) with permanent magnets combine high energy permanent magnets used in the design flow for flux concentration and three-dimensional distribution of magnetic flux. These electrical motors have a number of advantages that distinguish them from other types of electric motors. The most important is that there is no limitation between space needed for the magnetic material and space winding motor fittings, this increases design flexibility compared with electric motors with longitudinal flux, which for a high flux density, require significant currents. Another advantage of synchronous machine with transverse flux permanent magnet is that it can increase power density by increasing the number of pairs of poles or polar step decrease for a geometrical size time. With these advantages, is in agreement accepted that transverse flux motors with permanent magnets have a high power density compared to other types of electrical machines, the ratio being up to three to five times higher. Therefore, the transverse flux synchronous motors seem to be very suitable for direct-control applications, requiring high power density, without reducing motor performance. Besides these advantages, transverse flux synchronous motor generates a force due to variable reluctance magnetic variation. This can lead to noise and vibration of the motor and be managed by collaboration between motor designing and advanced digital control techniques. Another problem (which actually is not only a problem of the transverse flux machines) for the commercialization of transverse flux motor is generated by position sensor. Normally, the motors use a scaled sensor to the position control but it is expensive, requires a special mounting structure and tight tolerances for installation. Fortunately, the stator of TFM has a reluctance variation and it opens the possibilities of adapting induction type position sensor.

Collaboration between South Korea (Korea Research Institute Eletrotechnology - KERI - "Industry Applications Research Laboratory" - www.keri.re.kr/iarc/) and Romania (University Politehnica of Bucharest - UPB - Faculty of Electrical Engineering - Laboratory "Control of Electric Drive Systems with Digital Signal Processors - DSP_CED" - www.dsp-control.pub.ro) was performed in two parts.
· The first part was represented by the study of inductive position sensor applied to determine the transverse flux motor position - TFM (Transverse Flux synchronous motors having a greater energy density compared to other types of electrical machines), KERI, having great experience in the development of synchronous motors with transverse flux, and UPB doing research activities related to control of the transducers/without transducers - "sensorless" for different types of electrical machines.
· The second part was represented by the study methods of minimizing the traction force ripple of the synchronous transverse flux motor - TFM. Force ripple can be decreased, on the one hand, designing adequate the motor and, on the other hand, using adaptive control by minimizing the force ripple.

Traction force ripple (electromagnetic torque for rotating electric motors) was decreased, on the one hand, designing adequate motor (reducing the machine phase inductance values) and, on the other hand, by an adaptive control for minimizing the force using online parameter identification of the motor, by vector control and also of the motor, and by "sensorless" control without speed/position transducers.

Thus, the main objectives of the bilateral project SISFRMTFM, that were completed, can be summarized as follows:

- theoretical and experimental research solutions for estimating the parameters needed for the control of the transverse flux motor with high energy density (speed, position, electromagnetic torque, flux);
- achieving numerical simulations to validate the proposed estimation methods, define and test innovative strategies Sensorless control/Sensored - inductive position sensor control and minimize the force Ripple;
- choosing the optimum solution for controlling of the permanent magnet synchronous motor with transverse flux, and the issuing of a prototype (electrical motor, numerical DSP control).

Last update: October 26, 2009 .