Permanent Magnet and reluctance machines Projects List
The PM assisted synchronous reluctance machine is mainly a type of synchronous reluctance motors (SynRM) which is a family member of brushless AC machines consisting of the conventional dc permanent magnet machine, the permanent magnet synchronous machine and the cage induction machine. The members of this family have a standard three phase stator of induction machine with spatial sine wave rotating field. Generated torque is relatively smooth and as a result, the operation is quiet. A conventional three phase inverter can be used to drive the motors of this family if electronically controlled drive is desired. Most of the early work on the SynRM in 1960’s and 1970’s was related to the linestart machine. The requirement of a squirrel cage for line-start, along with some other manufacturing factors, compromised the rotor design and led to relatively poor performance compared to an induction machine. Because of this poor performance, SynRM was mainly ignored until late 1980’s. With the development of power transistor technology and vector control theory over.
This dissertation follows the style and format of IEEE Transactions on Industry Applications. 2 the past decays, the performance of SynRM has been drastically improved and this motor started to be seriously considered as a possible alternative to the other brushless machines (particularly an induction motor) in the variable speed industrial applications. By controlling the machine via a transistor voltage inverter, line-start feature was no longer necessary for SynRM. Therefore, the starting cage was removed from the rotor and it was designed such that gives the maximum saliency ratio. The main motivations for the renewed interest in the SynRM are:
1. Improved saliency ratio makes the SynRM competitive with an induction machine, particularly in terms of power factor and inverter kVA requirement.
2. Small to medium size high performance drives may have simpler control using the SynRM as compared to the field oriented controlled induction machine.
3. It can be operated stably down to zero speed at full load unlike an induction motor which may suffer overheating problems. In addition, SynRM appears to be more efficient at low speed than an induction machine.
4. By adding appropriate amount of magnet into the rotor core, efficiency improves without having significant back-EMF and without necessary change in the stator design.
Because of the existence of flux barriers, demagnetization is hard to occur if strong magnets are used. Demagnetization due to the machine overloading and high ambient temperature is a significant problem in IPMs. Before summarizing the main motivations for the work presented in this thesis, presenting the historical development of the machine can help the readers to have an 3 insight on the trend of SynRM evolution.
Permanent Magnet and reluctance machines