| Abstract |
From the reasons for fossil fuel depletion and global environmental problem in recent years, power electronics devices with higher efficiency have been required. In industrial field, electric power of seventy percentages in Japan is used for the application systems of motors. The motor drive systems are divided into two types. One is constant speed applications such as fans and blowers. Another is variable speed control applications such as air conditioners and electric vehicles. In the constant speed applications, induction motors are exclusively used because they can be driven by directly connecting them to commercial three-phase power supply without starter. However, the induction motors are not good at efficiency and size compared with Permanent Magnet Synchronous Motors (PMSM). The PMSM with the cage winding driven by the commercial power supply has been proposed for the constant speed applications. However, by the variation of the amplitude of the source voltage, the large reactive current is generated. This paper presents a starting system of the PMSM for constant speed application driven by the commercial three-phase power supply. The starting system has an LC filter and a simple power converter. The power converter configuration which is called Simplified Matrix Converter (SMC) reduces the number of bidirectional switches to four from nine of general three-phase to three-phase matrix converter. Therefore, the system can realize cost reduction and downsizing. The authors propose the control scheme for starting the PMSM and stable drive at synchronous speed. The effectiveness of the proposed control system has been verified by experiments. |
