_基于射线跟踪模型的3.5 GHz无线传播特性研究

说明：  matlab画三维凸包，根据一些离散点，效果非常好(Matlab draws three-dimensional convex hull, according to some discrete points, the effect is very good.)

本文首先分析了永磁同步电机矢量控制的发展概况，然后从机电能量转换的角度出发，解释三相永磁同步电机的机电能量转换原理，推导拉格朗日运动方程。此外，列写出永磁同步电机在三相静止坐标系和dq坐标系下的数学模型。基于Simulink建立了转速电流双闭环矢量控制系统的仿真模型，通过对仿真结果分析，验证了永磁同步电机矢量控制系统性能的优越性。(This paper first analyzes the development of permanent magnet synchronous motor vector control, and then explains the electromechanical energy conversion principle of three-phase permanent magnet synchronous motor from the perspective of electromechanical energy conversion, and deduce the Lagrange motion equation. In addition, the mathematical model of permanent magnet synchronous motor (PMSM) in three phase stationary coordinate system and dq coordinate system is listed. Based on Simulink, a simulation model of speed and current double closed loop vector control system is established. By analyzing the simulation results, the performance of PMSM vector control system is verified.)

该模型是对50kW、380V、50Hz三相三电平逆变器的两个相同电路进行建模。IGBT逆变器采用SPWM技术，(8kHz载频)将直流电源从a +/-200Vdc源转换为220V AC, 50Hz。逆变器通过75kVA 220/380V变压器输入50kW电阻负载。变频器输出采用L-C滤波器滤除主要产生于8kHz开关频率倍数(Fh=n*8000 +/-k*50Hz)附近的谐波频率Fh。逆变器所需的12个逆变脉冲由PWM发生器块产生。该系统以恒定的调制指标在开环中工作。 电路1使用三电平桥块对逆变器进行建模。电路2使用独立的IGBTs和二极管块。用开/关延时块模拟死区，仅在电路1上应用。(It is easy for us)

实现有源电力滤波器的电流跟踪控制，能够代替传统PI控制策略(Active power filter current tracking control can replace the traditional PI control strategy)

单相z源逆变器matlab仿真模型。(Matlab simulation model of single-phase Z source inverter)

逆流套管式换热器仿真小程序，工质物性调用refprop,所以需要自行嵌套refprop(Counter flow sleeve heat exchanger simulation small program, physical properties call RefProp, so need to self nest RefProp)

说明：  通过频谱来模拟波浪，程序为Jonswap谱的波浪模拟，可随意调整谱参数、时间间隔和模拟的时间长度(The wave is simulated by the spectrum, and the program is a wave simulation of the Jonswap spectrum. The spectral parameters, time interval and length of the simulation can be adjusted at will.)

abaqus经纬编织织物模型，umat子程序(ABAQUS warp and weft knitted fabric model, UMAT subroutine)

对等边直角三角形阵和立体三棱锥阵进行仿真建模，并进行了定向定位的误差分析，得到了相应的波形。(The simulation modeling of the equilateral triangle array and the stereoscopic three pyramid array is carried out, and the error analysis of directional positioning is carried out, and the corresponding waveforms are obtained.)

说明：  关于J2塑性流动理论的金属3的材料本构隐式子程序umat(Implicit Subprogram UMAT for Material Constitutive of Metal 3 in J2 Plastic Flow Theory)