Bingyi Zhang

Study on Low Voltage High-power Multi-branch Permanent Magnet Synchronous Motor

There are many disadvantages in the systems which driven by high voltage AC motors. People are looking for the solutions to these problems for many years. In this paper, a novel idea that adopting general low voltage converters supply power to multi-branch permanent magnet synchronous motor (PMSM) is reported. The stator windings of this multi-branch PMSM are designed into multi branches, and these branches compose independent windings which are leaded out three-phase output-ends. In this way, the stator current can be separated. A sample PMSM has been manufactured and some experiments have been made on it.

Study on starting performance of a novel wound rotor line-start PMSM with WMW

A novel WRLS-PMSM (wound rotor line-start permanent magnet synchronous motor) with WMW (weak magnetic winding) on rotor is proposed in this paper. The WMW installed under the starting winding is to restrain the braking torque of PMSM in the process of starting. Mathematical model of WMW and magnetic circuit is established. In order to do simulation analysis of this type of motor, a prototype of 22kw is designed. This paper analyzes the weak magnetic effect of WMW when its main dates change such as number of turns and wire gauge. The analysis results and mathematical model can provide the basis for design. This paper does research in the induced voltage and weak magnetic current change rule of WMW under the diode of single guide using the FEA method. This paper also studies the relationship between the specific dimensions of starting winding on rotor and performance parameters, for example, starting torque, generating and braking torque, pull-in torque, starting current, etc. Study the relationship between external series resistance and asynchronous torque. Study the difference of asynchronous torque when magnetic circuit structure is symmetrical or not.

Analysis and comparison of three-phase variable frequency PMSM with single-phase induction motor in household appliances

The single-phase induction motor which used in household appliances has problems such as low efficiency and poor power factor. In order to solve issues, this paper proposes a three-phase variable frequency PMSM in household appliances which is supplied with the single-phase power. By comparing the performance of the three-phase variable frequency PMSM with the single-phase induction motor through the theory and experimental analysis, the result indicates that the three-phase variable frequency PMSM can not only be suitable for the field of household appliances, simultaneously it achieves a high efficiency and power factor and it also obviously improves other performances of the motor.

Application of Multi-motor Synchronous Drive System Based on Fuzzy-PID Control on Fiber Spinning Production Line

According to the accurately synchronous technical requirement of fiber spinning multi-motor system, this paper presents a Fuzzy-PID control method which is established on the basis of deviation compensation principle. Master-slave control strategy is also presented in this paper. In the system, programming and debugging by using SIMENS s7-200PLC, designing the deviation compensation controller in the PLC. And PROFIBUS technology is applied to communication in the multimotor drive system. To compare the Fuzzy-PID control method with the traditional PID control method, the experimental results are given to show the excellent performance of Fuzzy-PID control method.

Study on unit combination type direct-driven submersible permanent magnet motor

Conventional submersible motor manufacturing process, operation and repair difficult technology, puts forward a submersible direct drive the super thin unit combination type permanent magnet motor. This paper introduces the composition and structure characteristic of the motor. Through establishing 2D finite-element analysis model of the submersible motor and curve fitting by parameter calculations, the relationship curve between the air magnetic bridge width and the leakage flux coefficient is given out. The waveform of the air-gap magnetic field and the harmonic content are analyzed with the finite element method to obtain the waveform deviation factor-pole eccentricity curve and the optimal eccentricity. Then get the curve between the no-load back-EMF with the groove depth of stator yoke based on a series of finite element calculations. At last, the 3D finite element calculation results verify the motor stator, rotor structure optimization design effectiveness. The structure of the unit combination type permanent magnet synchronous motor is feasible, and can be widely applied to the submersible screw pump system.

Analysis on starting performance of a novel wound rotor Line-start Permanent Magnet Synchronous Motor

Under the cranes working conditions, a Wound Rotor Line-start Permanent Magnet Synchronous Motor (WRLSPMSM) is designed in this paper. Rotor external resistance can be connected to the prototype, and rotor resistance determines when the maximum torque appears. So this paper puts forward a method to improve the starting performance, which PWM chopping is adopted to control rotor external DC fixed resistance. Because the number of rotor external AC resistance is limited, the starting torque has fluctuation when rotor external AC resistance is switched. Rotor external DC fixed resistance is controlled by PWM chopper technology. Regulate the rotor external DC fixed resistance rapidly to reduce torque ripple and realize speed stepless. Detailed theoretical analysis shows that starting torque is mainly affected by asynchronous torque and generated braking torque, and also according the analysis determines the value of rotor external DC fixed resistance. Meanwhile considering the influence of slots per pole per phase q on cogging torque, which easily disturbs the systems precise controlling during the low speed running, the fraction-slot winding is adopted in the prototype. The PWM chopping control method makes the starting process safer and more convenient than asynchronous motor.

Study on PMSMs with wide Flux-weakening Speed Range for New Energy Electric Vehicles

This paper analyzes the permanent magnet synchronous motor used for electric vehicle, and the influence of the built-in “V” type size parameters on direct axis inductance, quadrature axis inductance as well as PM flux linkage. The research is about the change rule of permanent magnet torque and reluctance torque. In the view of the optimal driving system, it summarizes the design method for rotor magnetic circuit structure of PMSM used for electric vehicle, and analyzes the influence on Flux Weakening ability of the main electromagnetic parameters. It also includes the design of two sets of prototype of 25 kW with different rotor structure. Experimental results of the speed regulation characteristic curve and efficiency MAP verify the feasibility of the design rules proposed in this paper.

Research on variable frequency low-speed high-torque squirrel cage induction machine for elevator

This paper attempts to present the structures and characteristics of variable frequency low-speed high-torque squirrel cage induction machine for elevator (VFLHSCIM). The structures of rotor sheet and stator winding are analyzed. And how the rotor resistance influences the performance of the motor is presented. Moreover, a prototype is tested, and the experimental results are analyzed.

Study of sliding mode variable structure control system for a novel gearless windlass balance oil pumping unit driven by low-speed and high-torque PMSM

The paper studies sliding mode variable structure control system for a novel gearless windlass balance oil pumping unit(GWBOPU) driven by low-speed and high-torque permanent magnet synchronous motor (PMSM). By analyzing the correlative relationships of the motor and the load, a mathematics model for GWBOPU is established. Base on this model, a speed sliding mode controller is designed by regarding the load speed as the control object. To guarantee the higher operating performance of the system, the running speed is also planned and designed according to different operating conditions. The simulation and experiment results show the control system has satisfied dynamic performance and strong robustness to disturbances.