Zhang Zongqing

Bio: Zhang Zongqing is an academic researcher from Beijing Institute of Technology. The author has contributed to research in topics: Magnetic levitation & Electromagnetic coil. The author has an hindex of 2, co-authored 2 publications receiving 5 citations.

High-flatness permanent magnet linear motor planar coil

Abstract: The present invention discloses a high-flatness permanent magnet linear motor planar coil. Because a common planar coil cannot satisfy the high-precision requirement in application occasions such as precision positioning and the like, a flat cutting is provided for making a single-phase coil, the single-phase coil is processed and assembled according to a special mode, and a high-precision planar coil is obtained. The high-flatness permanent magnet linear motor planar coil is mainly used for the planar coil of a permanent magnet motor.

Disturbance Observer Based Robust Sliding Mode Control of Permanent Magnet Synchronous Motor

Abstract: This paper addresses speed control of permanent magnet synchronous motor under load torque perturbations. The mathematical model is derived using park’s transformation. The load torque disturbance is considered unknown bounded, and states variables are available in feedback. In order to achieve robust speed performance, sliding mode control (SMC) is introduced. However, it is noted that conventional SMC does not provide satisfactory performance under load torque disturbances. To end this, a novel control strategy called disturbance observer SMC (DOSMC) is formulated. It includes an observer that offers a tool to vanish the effect of load torque. The DOSMC technique has two distinguished characteristics: first, the design gains are needed to be greater than the maximum limit of disturbance estimation error instead of disturbances, second; the proposed observer estimates load disturbances and provide a compensator to update sliding surface and control input. The stability analysis of overall control system is verified using Lyapunov theorem. Simulations in MATLAB/Simulink proves efficacy of the proposed scheme.

Linear coreless winding, preparation technology and linear permanent magnet motor with winding

Abstract: The invention discloses a linear coreless winding. A wire of the winding is a strip-shaped copper sheet with the section long edge perpendicular to the movement direction of the linear motor, the strip-shaped copper sheets are concentrically wound to form a coil, and a plurality of coils are arranged adjacent to each other so as to form a linear winding structure; a concentrated winding can be adopted in the structure, and interference-free arrangement of end parts of the coils can be realized; or the coils are obtained through further processing, wherein the end parts of the coils are all located on one side of an effective part, and the coils are called an upper coil (100); the upper coil is overturned by 180 degrees along a geometric symmetry line to obtain lower coils (200, 300); the upper coil (100) and the lower coils (200, 300) are alternately arranged with each other to form the linear winding. The invention further discloses a preparation method of the winding and a linear permanent magnet motor with the winding. According to the linear coreless winding disclosed by the invention, an eddy current path is effectively cut off, the eddy current loss of the winding is inhibited, the copper cross section ratio in the air gap space is obviously improved, the power density of the motor is effectively improved, and the weight of the motor is reduced.

Control of magnetic levitation positioning stage with an eddy current damper

Abstract: To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic arrays,four stators and displacement sensors.The dynamics model of this stage was a complex nonlinear,strong coupling system which made the control strategy to be a focus research.The nonlinear controller of the system was proposed based on the theory of differential geometry.Both simulation and experimental results show that either the decoupling control of the movement can be realized in horizontal and vertical directions,and the control performance was improved by the damper,verifying the validity and efficiency of this method.

Dynamic simulation of a rigid-flexible coupling positioning stage base on modified floating frame of reference formulation

Abstract: A rigid-flexible coupling positioning stage (RFCPS) is proposed in this study for long-stoke-high-precision (LSHP) positioning, and its dynamic model is established. The structure of the RFCPS contains three parts: the working stage, the frame and the flexure hinge group. The flexure hinges can provide micro deformation to compensate the positioning error cause by the friction of the mechanical bearing. In order to consider the deformation of the flexure hinges, the flexible multi-body system dynamic analysis method is adopted to establish the dynamic model of the RFCPS. The investigation of the principle model demonstrates that the floating frame of reference formulation (FFRF) has higher accuracy than the absolute nodal coordinate formulation (ANCF) for the deformation analysis of the RFCPS. Sequentially, a finite element based model (FE model) is established by using the FFRF. Numerical simulation results shown that the results of the FE model is consistent to the analytical solution, and the deformation of the flexure hinges is effectively obtained. The establishment of the dynamic model lays the foundation for structural optimization and control system design of the RFCPS.