Research on Control Strategy of 2-phase Interleaving Magnetic Integrated VRM

A kind of 2-phase interleaving coupled magnetic integrated VRM is studied and the corresponding passivity-based control strategy is put forward. The model of this kind of magnetic integrated VRM is constructed, and the performance of this 2-phase interleaving magnetic integrated VRM of passivity-based control is verified by simulation experiments. The results proved that this kind of passivity-based control strategy can decrease the steady state current ripple and the dynamic output voltage under load disturbance.

Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers

To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were conducted.Simulation and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met.

Simulation research on effect of magnetic nanoparticles on physical process of magneto–acoustic tomography with magnetic induction

Magneto–acoustic tomography with magnetic induction(MAT-MI) is a multiphysics coupled imaging technique that is combined with electrical impedance tomography and ultrasound imaging. In order to study the influence of adding magnetic nanoparticles as a contrast agent for MAT-MI on its physical process, firstly, we analyze and compare the electromagnetic and acoustical properties of MAT-MI theoretically before and after adding magnetic nanoparticles, and then construct a two-dimensional(2 D) planar model. Under the guidance of space-time separation theory, we determine the reasonable simulation conditions and solve the electromagnetic field and sound field physical processes in the two modes by using the finite element method. The magnetic flux density, sound pressure distribution, and related one-dimensional(1 D), 2 D, and three-dimensional(3 D) images are obtained. Finally, we make a qualitative and quantitative analysis based on the theoretical and simulation results. The research results show that the peak time of the time item separated from the sound source has a corresponding relationship with the peak time of the sound pressure signal. At this moment, MAMPTMI produces larger sound pressure signals, and the sound pressure distribution of the MAMPT-MI is more uniform, which facilitates the detection and completion of sound source reconstruction. The research results may lay the foundation for the MAT-MI of magnetically responsive nanoparticle in subsequent experiments and even clinical applications.

Applications of state estimation in multi-sensor information fusion for the monitoring of open pit mine slope deformation

The traditional open pit mine slope deformation monitoring system can not use the monitoring information coming from many monitoring points at the same time, can only using the monitoring data coming from a key monitoring point,and that is to say it can only handle one-dimensional time series.Given this shortage in the monitoring, the multi-sensor information fusion in the state estimation techniques would be intro- duced to the slope deformation monitoring system,and by the dynamic characteristics of deformation slope,the open pit slope would be regarded as a dynamic goal,the condi- tion monitoring of which would be regarded as a dynamic target tracking.Distributed In- formation fusion technology with feedback was used to process the monitoring data and on this basis Klman filtering algorithms was introduced,and the simulation examples was used to prove its effectivenes.

Delay-dependent stability of discrete-time interconnected systems

This paper studies the delay-dependent stability problem of discrete-time interconnected systems with time-varying delays.By using vector Lyapunov function approach and linear matrix inequalities (LMIs),new stability conditions are derived.These results proposed in this paper are all at subsystems level.After comparing with the existing results,it is shown that these conditions are less conservative.A numerical example is presented to demonstrate the effectiveness of the results.

Research on hybrid power filter of 6 kV power grid in coal mine

Studied the harmonic control of the 6 kV power grid in a coal mine substation.Taking harmonic suppression and reactive power compensation into account, and complyingwith the economic and efficient technical line of the smart grid, a new hybrid activefilter was proposed and applied to the power grid in the coal mine with the advantagessuch as large capacity, low cost and low loss.In order to improve detection speed and reducethe succeeding errors to improve the filtering performance of the active power filter,the DFT (Discrete Fourier Transform) sliding window algorithm based on coordinatetransformation and improved hysteresis control method was proposed.The Matlab simulationresults show that the hybrid active filter is satisfactory, can improve the grid powerfactor and can meet the requirements of improving the power quality in the coal mine.

Further improvement of stability criterion and BRL for Markovian jump systems with interval time-varying delay

这份报纸处理延期依赖者为 Markovian 的随机的稳定性和围住的真实词根(BRL ) 跳有间隔的线性系统变化时间的延期。由构造某新 Lyapunov functionals 并且使用 Jensens 不可分的不平等方法，免费 weighting 矩阵方法，凸的联合方法和延期分解综合地来临，一些不太保守的延期依赖者稳定性标准和 BRL 被建立。数字例子被给显示出建议方法的有效性。