Magnetic System Study of a Compound-Structure Permanent-Magnet Synchronous Machine for HEVs

Abstract

The magnetic coupling problem is discussed for the six topologies of compound-structure permanent-magnet (PM) synchronous machine (CS-PMSM), and the radial-radial flux CS-PMSM is investigated as example. Taking Toyota Prius hybrid system as reference, a radial-radial flux CS-PMSM is designed. Owing to mechanical reason, the thicknesses of the PMs on the outer and inner sides of the outer rotor are quite different, which induces more coupling problem. The magnetic system of CS-PMSM is researched in two aspects: the combination of thicknesses of PM and outer rotor yoke and the effect due to armature reaction. It is concluded that the magnetic coupling problem can be solved by designing an appropriate outer rotor thickness. In order to evaluate the magnetic structure, a downsized radial-radial flux CS-PMSM prototype was designed and manufactured. Back electromotive force (BEMF), relations between torque and current, and efficiency of the prototype were measured, and the experimental results are in good accordance with the calculated results.Index Terms-Armature reaction, compound-structure permanent-magnet (PM) synchronous machine (CS-PMSM), dual mechanical port, hybrid electric vehicle (HEV), magnetic system.

Flexible Energy Conversion Control Strategy for Brushless Dual-Mechanical-Port Dual-Electrical-Port Machine in Hybrid Vehicles

“…The brushes and slip rings are eliminated and the rotor armature winding is moved to stator. In [19]~ [20], the MGM and PMSM parts are separated in axial direction, and the control of this system is investigated in [21]- [26]. In addition, the two parts can be integrated into one frame [27]- [29], and this structure is more compact.…”

“…For the regular winding, it is designed as an auxiliary winding and its flux only couples with the outer rotor, therefore, the electrical angle for regular winding can be detected only through outer rotor resolver. However, the electrical angle for modulation winding is determined by the relative position of outer and inner rotor according to the equation ( 2), and can be obtained by (20).…”

Emerging Multiport Electrical Machines and Systems: Past Developments, Current Challenges, and Future Prospects

“…For the dual-layer rotor topologies, the thickness of the yoke of the outer rotor has a significant influence on the coupling between the stator and inner rotor windings. In practice, the outer rotor yoke of the dual-layer PM rotor EVT is usually designed thick enough to achieve decoupled control of the outer machine (stator + outer rotor) and the inner machine (outer rotor + inner rotor) [113], which resembles that of the conventional PMSM. While the yoke thickness of the outer dual-layer squirrel-cage rotor is made thin to reduce weight and volume so the inner machine and outer machine are not magnetically separated anymore [16] and the electromagnetic behavior of the EVT differs from two IMs a lot.…”

Investigation of the Cooling and Thermal-Measuring System of a Compound-Structure Permanent-Magnet Synchronous Machine

“…The DRM transfers the torque from ICE to the reduction gear, and provides the speed difference between the ICE and the reduction gear; and the SM provides torque difference between the ICE and the reduction gear according to the requirements of vehicle load. Therefore, the CS-PMSM can realize the same function of the planetary gear unit, generator and motor in the Prius hybrid system [18][19][20]. The typical operating modes of the CS-PMSM under hybrid electric vehicle (HEV) operation conditions are analyzed [21].…”