Compact motor and drive system with high power density for mobile machines

Review of air-cooling strategies, combinations and thermal analysis (experimental and analytical) of a permanent magnet synchronous motor

“…Therefore, effective cooling is thus necessitated to safeguard the lifespan of the electric machine. 5,[20][21][22] The leading cause of losses occur in PMSM are collected and presented in Figure 1. In particular, the iron losses occur in the magnetic core of the stator include eddy current loss and hysteresis loss.…”

“…Thermal mapping of the electric motor, in particular winding insulation temperature, magnets' materials temperature, and the natural air convection cooling was investigated for the standstill operation as well as for the nominal operation of the electric motor. [20][21][22]60,66 Here, the 2-D FEM for heat transfer was used to predict the temperatures of winding insulation and magnet materials. Thermal analysis and cooling of the PMSM machine are very crucial for the performance of the machine since the temperature increasing would cause demagnetization of the permanent magnet materials.…”

“…Safe temperature range Demagnetization 6,17,[20][21][22][23]34,60,61,66,70 Up to 230 C for NdFeB Up to 350 C for SmCo Degradation of insulation 12,17,[20][21][22]60,66,67 155 C-220 C Polyurethane-polyester plus polyamide-imide as an insulation Decreased motor performance 21,32,43,60,63 Up to 150 C Decreased density of torque 31,60 Up to 150 C Degradation of bearings 29,61,67 70 C-110 C and for even >160 C For polyurea thickener with an ester base oil as a grease Increased consumption of energy 31,60 Up to 150 C Stresses developed in core, magnets and in sleeve 60 Up to 150 C Short circuit 6 Up to 150 C Figure 3. PMSM torque in respect to rotational speed for constant temperature characteristics, (temperature values are labelled on lines).…”

“…14 Rotor cooling using the helical water duct in the frame, where the radial fan is mounted on the shaft causes air stream to take away the heat as it passes through the axial ducts of the rotor core, is the effective solution. 7,[20][21][22] In this approach, the hot air is cooled as it passes through the helical water ducts in the frame. Inlet cooling water temperature is influential in controlling winding insulation temperature and thereby guarding the insulation life.…”