Design of synchronous reluctance motor and drive fed by low voltage

In day by day, electric energy consumption rapidly increases and limited energy sources decrease at the same rate. In this case, the use of efficient systems and/or alternative energy sources have become inevitable. The use of such energy sources increases the importance of solar and wind power because of high energy potential. The geographical location of our country makes solar energy potential considerably higher compared to many countries. The average annual sunshine time of Turkey is 2741 hours (7.5 hours per day) and its average total irradiation is 1527 kWh/m2-year (4.18 kWh/m².day) according to Solar Energy Potential Atlas of Turkey (GEPA). Compared to other regions, Southeastern Anatolia Region is the region that benefits most from solar energy. Additionally, the agriculture irrigation needs are high for this region. In some cities of this region, the electricity outages are performed by the energy distribution company due to the accumulated depts and so agricultural lands are damaged due to lack of irrigation. Therefore, the pump systems which can operate directly by solar energy are important for these type regions. Nowadays, many solar-powered irrigation systems are available. These systems consist of solar panel, battery, drive, motor and pump. All of these products are manufactured by independent company. The IMs and DC motors are widely used in photovoltaic systems. Recently, brushless DC motors are preferred because of their high efficiency. However, a boost converter must be used to increase the voltage levels generated by photovoltaic panels because they are lower than the voltage level of the available commercial motor. In addition, the battery pack and battery charge management system are needed in these systems. The system installation costs increase and the system reliability reduces because of the battery. Also, it must be operated at the maximum power point to obtain higher efficiency from system. For this purpose, maximum power point tracking (MPPT) must be performed. The system can be operated by using only the panel, motor and drive without battery pack, battery management system and boost converter. Thus, the system cost can be significantly reduced. In addition, the durability of the system will be increased by eliminating the problems such as maintenance and low life of the battery. The motor and its drive must be redesigned to operate without need the other devices. In addition, it must be controlled by a modified MPPT algorithm which can adjust the motor speed reference. In this thesis, Synchronous Reluctance Motor (SynRM) having standard motor case was designed for low voltage level which can be produced by PV panel. The motor has been optimized by using Genetic Algorithm (GA) optimization technique. Additionally, motor drive and control algorithm were designed and developed for this motor. Production costs and robustness of SynRM rotor will be much higher compared to other motors because the motor does not contain magnets and windings on its rotor. In addition, these motors have virtually constant efficiency and torque independent of the speed. An MPPT algorithm has been added to the motor drive to ensure motor to run at maximum speed continuously and analyzed in simulation environment. However, the prototype motor has been experimentally tested under low voltage level DC source. Consequently, more efficient, more compact and user friendly system has been obtained in this thesis.