The main objective of work is to calculate eddy current losses in the solid iron body of the rotor for one claw pole generator, which is connected to rectifier (Fig. 1). For this purpose, a 3D time transient analysis in JMAG is performed to analyze 3D eddy currents losses in the rotor. End winding is precisely modeled to consider eddy currents in end regions of the rotor. This study shows how JMAG can save a lot of time for one complicated 3D model with eddy currents consideration.
The first part of the study is to model precisely the claw pole generator with real end winding configuration and rotor solid iron body. Skin mesh of JMAG is used in the rotor to model the skin effect. Extruded mesh is applied for meshing to decrease number of elements and reduce simulation time. Second step is to run the model and evaluate the results. In order to read rotor eddy current losses at steady state condition we need to simulate 9 electrical periods, which is long time for 3D simulation. We use time reduction technique in JMAG to decrease simulation time almost 80 %.
Two simulations are analyzed using JMAG:
Simulation shows eddy currents distribution and eddy current losses distribution in the rotor of claw pole generator (Fig. 2).
The transient time is considerably decreased, which help to save time especially for large model and parametric calculations and optimization (Fig. 3). The accuracy of all magnetic and results.
Fig. 1 Claw pole generator model with mesh in JMAG (left) and used electric circuit in JMAG (right)
Fig. 2 Eddy currents distribution in the solid iron rotor (left) and eddy current losses distribution in the solid iron rotor (right)
Fig. 3 Circuit current versus time (left) and eddy current losses versus time in the solid iron rotor (right) – Blue lines are without time reduction techniques in JMAG and red lines with time reduction technique in JMAG
The main objective of work is performance analysis of a single sided linear induction motor with consideration of translational motion (Fig. 1). For this purpose, a 2D time transient analysis in JMAG is performed to calculate thrust forces at different speeds. Large air region area is considered around the moving part (primary) to take into account end effects fields.
Accurate modeling of linear induction motor in JMAG is first step in simulation. Moving parts and stationary parts should be determined in the model. The sliding mesh is modeled in JMAG to simulate linear motion in JMAG. Optimum size for air region is considered around the model for accurate modeling of end effects and minimum number of mesh elements.
Thrust force with and without time reduction technique in JMAG is shown (Fig. 2). Using time reduction technique in JMAG makes simulation time to be shorter and reach steady state thrust force faster. Average steady state thrust force versus speed is shown in Fig. 3.
Magnetic flux distribution is shown in Fig. 4, which end effects flux leaks outside of moving part core in opposite direction of motion.
Fig. 1 Linear induction motor with mesh in the air gap
Fig. 2 Thrust force versus time without time reduction technique (red line) and with time reduction technique (black line)
Fig. 3 Average thrust force versus speed
Fig. 4 Magnetic flux distribution – leakage flux caused by end effects is shown