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一种广义水驱特征曲线的建立 总被引:2,自引:0,他引:2
广义水驱特征曲线能描述综合含水储量采出程度呈多种不同的凸、S、凹曲线类型。根据油水两相渗流原理,从归一化的油水相对渗透率出发,建立起累积产油、累积产水与综合含水率的积分相关关系,进而建立了累积产油、累积产水与归一化的油水相对渗透率的关系。通过构建积分函数,利用公式形式类比,建立了更一般形式的广义水驱特征曲线。理论分析和实例计算表明,所建立的广义水驱特征曲线与实际数据线性相关性更强,结果更可靠。 相似文献
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随着光伏发电和直流微电网的发展,以光伏电池作为主要电能来源的直流微电网将会有更多的研究应用, 然而光照强度和温度等变化使得光伏电池输出功率波动,这将引起直流母线电压剧烈波动,威胁直流微电网的安全稳定运行.针对光伏输出功率导致的母线电压波动问题,提出基于聚类经验模态分解 (EnsembleEmpiricalModeDecomposition,EEMD)进行频率分配的混合储能系统控制策略,将光伏原始输出功率中的高频分量作为超级电容响应的指令功率,提升了混合储能对电压波动的抑制效果,维持直流母线电压稳定.仿真试验结果表明,所提方法能够发挥超级电容响应速度快的优势,使超级电容响应高频波动功率,平抑直流母线电压波动,同时减少蓄电池充放电次数,延长蓄电池的使用寿命。 相似文献
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Gong Biyao Xing Tianzhang Liu Zhidan Wang Junfeng Liu Xiuya 《Mobile Networks and Applications》2022,27(4):1520-1530
Mobile Networks and Applications - Although federated learning has been widely used in collaborative training of machine learning models, its practical uses are still challenged by heterogeneous... 相似文献
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针对移动电站电源制式的多样化,设计了一种以STM32F103ZET为控制核心的同步电机通用型励磁控制系统,设计了低剩磁电压起励电路,满足了不同剩磁条件下的起励要求;针对独立电力系统的电压、频率波动较大造成采集精度下降的问题,引入了锁相环电路,实现了同步采样,提高了采样精度;采用参数自整定模糊PID的控制策略,通过IGBT功率器件进行励磁电压的PWM调节。实验结果表明,可以满足通用化的要求,具有较好的动、静态性能,调节速度快,完全符合规定的性能指标。 相似文献
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针对无线传感器网络中室外环境下的被动式目标定位问题,提出一种基于动态贝叶斯图的异构数据协同定位方法.该方法能够对异构无线网络数据相协调,完成目标被动式定位任务.首先深入分析了异构网络中可用于测距定位的三种基本被动式定位方法(基于信号强度模型,红外测距定位模型,粒子滤波定位),总结归纳了各方法的适用特点.其次,利用动态贝叶斯图,协调两种方法适用特点,推导出大规模室外被动式定位模型.仿真结果表明,笔者提出的异构数据协同定位方法能够完成被动式定位要求,与其他定位方法相比,定位精度较已有方法有所提升. 相似文献
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Design of the multi‐objective constrained nonlinear robust excitation controller with extended Kalman filter estimates of all state variables
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A new optimal back‐stepping robust adaptive control method for the military moving power station (MMPS) excitation system is proposed in this paper. Through the extended Kalman filter estimates of the state variables, the tracking of the operating point, and the back‐stepping technique, the proposed controller has been shown to improve system robustness to disturbances and dynamic uncertainties and minimise the effect of disturbances by solving the linear matrix inequality to obtain the optimal control law on all operating points. The simulation and experimental results show that the proposed control strategy can enhance the transient stability of the MMPS excitation system more effectively than other methods and can optimise the convergence rates of the state variables by modifying the values of the weighting matrices. Moreover, the terminal voltage of the MMPS can be sampled quickly by alternating current (AC) tracking comparison. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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在Abaqus/Standard平台建立TC4钛合金飞机壁板典型筋包结构超塑成形的三维有限元模型,探究表面缩沟和圆角破裂机理.结果表明:产生缩沟的主要原因为止焊剂涂覆范围偏小,尤其偏小2 mm以上时;圆角破裂的主要原因为圆角半径过小,最佳圆角半径与板料壁厚及理想减薄率相关,分析得到最佳圆角半径-壁厚预测方程.通过对TC4钛合金飞机壁板筋包超塑成形工艺优化,成功避免了缩沟和破裂的产生. 相似文献
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A wideband and high-efficiency 90°polarization rotator based on ultrathin planar metamaterial is presented. It consists of the metallic hexagonal patches on the top layer of the dielectric substrate and a metallic film on the bottom layer. Initially, the explanation of the physical mechanism for the polarization rotator is presented according to the anisotropy media theory. Thereafter, we have discussed the influences of the structure dimension on the performance of the proposed polarization rotator. And finally, the structure is also fabricated. Results of the test show that it exhibits over 90% polarization conversion ratio from 841GHz to 113GHz in the condition of normal incidence. 相似文献