Sun Hexu

Application of Adaptive Fuzzy Sliding-Mode Controller for Heat Exchanger System in District Heating

The temperature control system of heat exchanger in district heating is a nonlinear system with strong heat inertia and large time lag. Classical PID control dissatisfies static characteristics and dynamic characteristics of the system during its control process. According to this case, an adaptive fuzzy sliding mode controller is designed based on stability theory of Lyapunov for the system. Simulation results show that the system with adaptive fuzzy sliding mode controller has better rapidity, strong robustness and high control precision, as compared with the system of PID control. The controller is very suitable for the temperature control system of heat exchanger. It is also suitable for other temperature control system of industrial processes. Therefore it has a high value of application.

Study on Torque Ripple Attenuation for BLDCM Based on Vector Control Method

In this paper, a novel id*=0 vector control method for a BLDCM with neither sinusoidal nor trapezoidal back-EMF (the main part is considered as sinusoidal with high-order harmonics) is proposed. By this method, the iq for a constant torque to produce is calculated through coordinate transformation, and the reference iq is tracked by vector control in the dq0 frame. The simulation results show that this control technique can effectively minimize the torque ripple caused by high-order harmonics of the back-EMF.

Optimal control in variable-speed pumping stations

This paper presents a kind of optimal control method for variable-speed pumping stations with similar parallel pumps, and gives the minimum total power consumption. The optimal control method is given for the fixed total flow. The optimal control method is to keep the same load for each pump. The conclusion can also be applied to the energy optimization of other general devices.

Dynamic modeling research on the SRD based on Ansoft and simpoloer

This paper proposes a new modeling method for switched reluctance motor drive system (SRD) based on Maxwell and Simplorer. A 1.5KW four phase 8/6 pole switched reluctance motor (SRM) is selected as prototype. This method uses Ansoft/Rmxprt to calculate the initial value and optimize the performance of motor , and puts motor model into Maxwell 2D to make static and transient analysis by finite element method. Then asymmetrical half-bridge power converter circuit and control circuit are established in Simplorer, which is with SRM to constitute integrated co-simulation system . The simulation results show the modeling method accuracy and practically , and laid the foundation for the SRD control strategy.

Design for wireless networked control systems with time-delay and data packet dropout

The paper presents a model of a class of wireless network systems with delay and data dropout. The optimal state estimator is designed for the system by using time-varying Kalman filter on the basis of the presented model. Then, a design approach to feedback control of optimal state is presented. And the separation principle of state feedback controller and state observer is guaranteed by carrying the additional information in data packet. Finally, the stability of closed-loop NCSs is proven by applying MJLS theory.

Effects of Manganese Substitution in the Nd2Co17-xMnx Compounds on Structural and Magnetic Properties

The structural and magnetic properties of the Nd2Co17-xMnx(x≤14) compounds have been investigated by means of x-ray diffraction and magnetization measurements. The Nd2Co17-xMnx (x≤14) compounds have a rhombohedral Th2Zn17-type structure. The unit-cell volume increases with increasing x. The Curie temperature and the saturation magnetization of these compounds show a marvellous drop with increasing x. The spin reorientation is observed at about 190 K in the Nd2Co15Mn2 compound.

Optimal switch in variable-speed fan stations

This paper presents a kind of optimal switch method for variable-speed fan stations with the same model fans. The optimal switch method is given for the changing total flow. The conclusion can also be applied to the energy optimization of other general devices.

Optimal switch for a common system

A common system consists of the same creatures or the same model man-made machines, and the power consumption of this system includes several factors. The optimal switching method is given for this system, and the minimum total power consumption is given also.

Optimal switch in variable-speed pumping stations

This paper presents a kind of optimal switch method for variable-speed pumping stations with similar parallel pumps, and gives the minimum total power consumption. The optimal switch method is given for the changing total flow. The conclusion can also be applied to the energy optimization of other general devices.

Simplification of Motion Controller Based on DSP IO Space and CPLD

A method is designed for the simplification of multi-function motion controller, based on the DSP I/O space and CPLD. The core technology is the use of the rich I / O space of the DSP and the powerful logic capabilities of CPLD. Using this method, the reuse of the DSP bus can be achieved. Compared with the traditional motion controller, the simplified motion controller significantly reduces both the hardware resources and the complexity of the motion controller. It increases the reliability and versatility of the motion controller. Development cycle is shorter and easier to maintain. This method is suitable for real-time signal processing.