电机模拟器作为一种可编程的电力电子装置,在变频器系统级功能测试平台中具有广泛的应用前景。基于电机模拟器的变频器系统级功能测试平台是功率级硬件在环（Power Hardware-in-the-Loop,P-HIL）仿真平台的一种具体应用。P-HIL仿真平台中存在运行失稳风险与模拟精度不足这两大固有挑战,因而具体设计电机模拟器时需重点关注这两方面。影响电机模拟器系统运行稳定性与模拟精度的三个关键因素分别为P-HIL模拟算法的设计、电机模型的数字化求解以及电流放大接口的设计。因此本文着重从这三个方面展开分析与探讨,以永磁同步电机为模拟对象,并完成电机模拟器的设计与实验验证。针对三种应用较为广泛的P-HIL仿真系统的模拟算法,从稳定性、模拟精度这两个方面开展研究。通过对端口特性的定量评估,对比了理想变压器算法、部分电路复制算法和阻尼阻抗算法的模拟精度。其中理想变压器算法可获得最高模拟精度,但它的稳定性受负载阻抗影响较大,因此本文通过引入耦合阻抗提出了一种改进型理想变压器算法。基于选定的模拟算法与永磁同步电机的数学模型,对比了常用的前向Euler法、Adams-Basforth法和Runge-Kutta法的求解稳定性与求解精度。相较于两阶Adams-Basforth法和前向Euler法,四阶Runge-Kutta法具有更高求解精度与更宽数值求解稳定域,因而选用四阶Runge-Kutta法来实时求解永磁同步电机模型。为快速响应电机模型计算出的电流指令,需要为电机模拟器设计动态性能优异的电流放大接口,即电流控制型功率变换器。为使电流环既具有较快的响应速度与较小的超调量,引入了PDFF控制（Pseudo-Derivative-Feedback with FeedForward）作为功率变换器的电流控制策略。利用Si C MOSFET和IGBT变流器搭建了两台变流器对拖的实验平台,其中Si C变流器作为电机模拟器的电流放大接口,IGBT变流器作为变频器。实验结果验证了电机模拟器设计的合理性,及其在变频器功能测试中的有效性。
For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been *** photonuclear cross sections from evaluated or experimental d...
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For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been *** photonuclear cross sections from evaluated or experimental database are chosen as input *** checking the validity of the use of the data-based photonuclear algorithm,benchmarking simulations are presented in *** calculate photonuclear cross sections or reaction yield for ~9Be,^(48)Ti,^(133)Cs,and ^(197)Au and compare them with experimental data in the region of incident photon energy below ~30 *** Geant4 can hardly reproduce photonuclear experimental data,results obtained from the data-based photonuclear algorithm are found in good agreement with experimental *** application in estimation of specific activity of radioisotopes is further *** conclude that the developed data-based photonuclear algorithm is suitable for an accurate prediction of photoninduced neutron or proton productions.
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