Because the mover and stator of a doubly-fed linear motor are both equipped with three-phase windings, the motor enables contactless energy to be transferred from the stator to the mover. Thus, when a doubly-fed linea...Because the mover and stator of a doubly-fed linear motor are both equipped with three-phase windings, the motor enables contactless energy to be transferred from the stator to the mover. Thus, when a doubly-fed linear motor is used in the linear driving system of trains, neither an overhead line nor a third rail is needed. However, the doubly- fed motor will lead to more severe thrust fluctuation than the unilateral motors. In order to overcome this shortcoming, the thrust fluctuation of the doubly-fed motor should be analyzed. In this paper, an expression for motor thrust is derived. It points out that the slot effect caused by the slotted structure is the main reason for the increase of thrust fluctuation. The method of adopting unequal pole pitch and unequal slot numbers per pole per phase of stator and mover, is proposed to weaken the slot effect when designing the motor slot parameters. Three different motor models are simulated by ANSOFT. The proposed method results in a motor thrust fluctuation coefficient of 8.4%, compared to 49.4% for the conventional method. Therefore, the motor＇s thrust fluctuation is effectively suppressed by the proposed method.展开更多
This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried o...This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried on the test in transmission field. This paper introduces in detail the structure and characteristic of DSP system, and gives a design scheme of Doubly Fed Speed Control System of motor based on this chip.展开更多
文摘Because the mover and stator of a doubly-fed linear motor are both equipped with three-phase windings, the motor enables contactless energy to be transferred from the stator to the mover. Thus, when a doubly-fed linear motor is used in the linear driving system of trains, neither an overhead line nor a third rail is needed. However, the doubly- fed motor will lead to more severe thrust fluctuation than the unilateral motors. In order to overcome this shortcoming, the thrust fluctuation of the doubly-fed motor should be analyzed. In this paper, an expression for motor thrust is derived. It points out that the slot effect caused by the slotted structure is the main reason for the increase of thrust fluctuation. The method of adopting unequal pole pitch and unequal slot numbers per pole per phase of stator and mover, is proposed to weaken the slot effect when designing the motor slot parameters. Three different motor models are simulated by ANSOFT. The proposed method results in a motor thrust fluctuation coefficient of 8.4%, compared to 49.4% for the conventional method. Therefore, the motor＇s thrust fluctuation is effectively suppressed by the proposed method.
文摘This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried on the test in transmission field. This paper introduces in detail the structure and characteristic of DSP system, and gives a design scheme of Doubly Fed Speed Control System of motor based on this chip.
