Shen WANG – 道木研究室


研究テーマ / Research topic


English ver. Japanese ver.


To deal with the energy&environmental issue caused in the process of using fossil fuel, electric power system are introducd extensively and have taken the place of many fuel conbustion applications. Specifically, applications of electric motor drive system gains great progess in transportation field due to high-efficiency and low-pollution compared with conventional gasoline vehicle. Addition to predominant use in Electric Vehicle(EV), motor drive system are also adopted in ship propution, electric aricraft fields.

Safety is considered as a crucial factor in eletric application in the transportation field before. a Permanent Magnet Synchronous Motor(PMSM) is mostly adopted in motor drive applications dual to its structural simplicity as shown in the figure below and standarized manufacture process. However, once unexpected problem such as open circuit or short circuit happens in one or more phase winding of a PMSM, failture of the drive system working cannot be avoided due to its inherent poor fail-safe ability. However, fail-safe ability can be significantly improved by adding one more set of three-phase winding to the existed one sharing same structure of a PMSM, and in this way, a synchronous dual-three phase motor(dual-three phase motor) is obtained and shown beside the PMSM picture below.

Redundancy of phase winding enables the dual-three phase motor good potential of fail-safe. Neverthless, as a result of complex phase windings, magnetic coupling exists between the two three-phase sets shown in the figure below. The coupling causes deterioration of torue response of a dual-three phase motor drive system as overshoot as well as delayed reponse dynamics can be confirmed from the figure next to the left one below. So it is necessary to establish a well-behaved dual three phase motor drive system regardless of coupling for extensive applications of this kind.

state feedback from control theory is adopted in this research to solve the coupling problem mentioned. Since the dynamics or characteristics of coupling can be described by a math model, we can estimate the coupling in every conrol period by the model. Then, we eliminate the influence of coupling by deploying another compensation cammand based on the calculation result of model, as shown in the figure below. In this way, coupling is cancelled out the compenstation and an indepentant control of both two subsystem can be achieved.

Simulation result shown below verified the effectiveness of the proposed method against coupling. As from the result, overshoot and delay in response no more appear comparing with the torque response result without proposed method.