Research On Applications Of SiC Power Devices In The Permanent Magnet Synchronous Motor Drive

Rapidly developments in applications such as hybrid electric vehicles, aerospace, electric traction and household electric appliance raise higher requirements in permanent magnet synchronous motor, demanding higher efficiency, higher power density and higher reliability. Power electric devices are main conponents of motor drive system, playing an important role in efficiency, power density and reliability. Silicon Carbide device has advantages in fast switching speed, high blocking voltage and high temperature tolerance, therefore we can foresee the improvement of efficiency, power density and dynamic proformance in motor drive designed by Si C power devices. With the development of Si C power electric device manufacturing technology, researchers are more and more focused on its applications in permanent magnet synchronous motor drive.The paper introduces the structure of PMSM and coordinate transformation. On the basis, the paper continues to establish mathmatic model of PMSM based on coordinate transformation, and then analyse the principle of voltage vector control and space vector control strategy. This paper analyses pratical application problems caused by applying Si C power device in detail.In motor drive using phase-leg configure, high dv/dt during fast switching transient of one device will affect the operating behavior of its complementary device, which is called crosstalk, resulted in extra swithing power loss and even power devices failure. The paper discusses the problems caused by fast switching of PMSM drive based on Si C devices, and analyses the mechanism causing crosstalk interference. The paper studies specificity of fast switching crosstalk problems in PMSM drive using phase-leg configure, and explains the method of crosstalk suppression and shows suppression experiment results. By analysing the influence of parasitic inductors on power device safely-working in fast switching method, this paper plots the tolerance to parasitic parameter when switching speed is faster, and explains the suppression method of parasitic inductor effect and suppression experiment results.Finally, the paper analyses the loss of power electric device in PMSM drive, which demonstrate effeciency advantage by using Si C device instead of Si device. A 1k W PMSM drive prototype is also built to verify the theoretical explanation.