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The performance of stepper motor is closely related to the driving method. Stepper motor subdivision drive is used to transform Servo system of CA6140 lathe. With this method, it can reduce the motor step angle, thereby decreasing machine pulse equivalent to improve the precision of servo control and precision machining.
In order to solve the larger harmonic measurement errors of capacitor voltage transformer (CVT), this paper puts forward a new method of Y-Δ equivalent conversion and cascaded transfer function combining with Bode diagram to study the transmission characteristics of harmonic component for CVT. Simulation work based on MATLAB of the influence of the key circuit parameters on the harmonic transmission...
Line-start permanent magnet synchronous motor has many advantages, but it has two important defects are poor starting torque and synchronization capability. This paper presents a pole-changing of line-start permanent magnet synchronous motor which has a 6/8 pole-changing stator winding. A new structure of stator winding is designed to realize pole-changing. This motor can eliminate braking torque...
Static excitation systems have been widely used in large synchronous generators and field flashing is needed to set the initial electromagnetic field for the generator voltage buildup. In order to meet the requirements for the large synchronous generator field flashing, the selection of the field flashing circuit and rotor winding time constant, the coordinated control of the field flashing system...
This paper presents a dynamic model predictive voltage control (DMPVC) method for the single-input dualoutput (SIDO) flyback converter. In this converter, cross regulation is one of the most critical issues because its primary winding is shared by its secondary windings so that the two output voltages are interacted with each other. The proposed method has the ability to reduce cross regulation significantly,...
This paper presents mechanisms of the voltage spike and the diode freewheel phenomenon caused by the diode reverse recovery in the commutation of doubly salient brushless DC generator (DSBLDCG). An analytical solution for the voltage spike is derived on the basis of a simplified model of the diode reverse recovery. Some factors that influence the spike size, such as the rotating speed, field current...
This paper studies a new type of hybrid excitation claw pole alternator (HECPA), and the shape of the claws is modified to be right-angled trapezoid. Firstly, the structure characteristics and working principle of the HECPA are discussed. The paper studies the air gap magnetic field regulation principle on the basis of magnetic field distribution analysis. Then, both the static and the transient 3-D...
A 3-phase E-core axial field flux-switching permanent magnet machine (AFFSPMM) is investigated on basis of 3-D finite element method (FEM). It is found that the high self-inductance is valuable to reduce the short-circuit current, and the demagnetization of PMs caused by the short-circuit armature currents can be eliminated due to the parallel magnetic circuits of PMs and armature windings. The fault-tolerant...
In this paper, an open-circuit fault tolerant strategy for a five-phase permanent magnet synchronous machine (PMSM) is proposed based on the theory of keeping the magneto-motive force constant under both healthy and faulty conditions. According to the principle, the corresponding modified current vectors of healthy windings under three different open-circuit faults are derived, respectively. Then,...
In this paper, a Dual-Redundancy Brushless DC Motor (DR-BLDCM) servo system is introduced. To achieve a performance of fast response and high tracking accuracy, we adopt a hybrid PI controller with incomplete feed-forward compensation for position loop. The characteristics of the torque and power loss are analyzed under the unbalanced operations. Also, the reasons and effects of unbalanced operations...
The levitation control of Bearingless motor depends on the bias magnetic field provided by the torque winding. Bearingless induction motor (BIM) became one of the earliest and most widely used types. In order to suspend the rotor of bearingless induction motor, a complete control method for radial suspension force was proposed in this paper. Firstly, the principle of suspending the rotor was analyzed...
The levitation control of Bearingless motor depends on the bias magnetic field provided by the torque winding. Bearingless induction motor (BIM) became one of the earliest and most widely used types. In order to suspend the rotor of bearingless induction motor, a compensation control method for radial suspension force was proposed in this paper. Firstly, the principle of suspending the rotor was analyzed...
To ensure the transient performances of the singlephase induction motor with three parallel-connected windings, the simulated and experimental researches are carried out detailedly in this paper. At first, the transient simulation model of the motor is established and the simulation analysis is performed. Then the experiments are performed on the prototype motor, to verify the validity of the above...
To ensure the starting performance of the single-phase induction motor with three parallel-connected windings, the transient performances and starting methods are studied in this paper. At first, the transient mathematical model of the motor is established according to the electromagnetic relations, and the simulation analysis is performed. Then two starting methods are proposed and studied. The first...
As the high-voltage repetition-frequency pulse power supply is widely used in industry, thyristor series switch technology has developed rapidly. In this paper, a synchronous drive circuit with high-voltage isolation ability is designed. A pulse generator is also designed which can generate different pulses by setting different parameters. The generator can be controlled remotely by the optical fiber...
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