基于改进大气衰减算法的地形抛物模式研究

地形抛物模式（TPEM）被广泛用于对流层电磁波传播损失的数值模拟,对于大气吸收衰减量计算,该模式使用固定的大气衰减率沿传播路径进行积累,这与实际的海面大气状况不符并会产生计算误差。文章针对这一不足,基于水汽密度的垂直递减关系式,引入随高度变化的大气衰减率计算关系式对TPEM进行了改进,并利用某次试验记录对改进前后TPEM的计算结果进行了对比验证,结果表明改进后的TPEM可更有效、准确地模拟电磁波传播。     

TPEM 在炼厂老旧装置日常生产维护管理中的运用尝试

全员设备管理（ TPEM）理念形成较久且推行甚广，但其在生产工艺苛刻，连续性强，且具有高温、高压、易燃、易爆、易中毒特点的炼油化工型企业老旧炼油装置中是否可行，尚需尝试。为此通过制度建设、理念宣传和理论结合实践经验进行的全员参与多重监督的模式探索，使该先进理念在装置的日常运行维护中得到有效推行，同时也提升了老旧炼化装置的设备管理水平。     

A two-point estimate method for uncertainty modeling in multi-objective optimal reactive power dispatch problem

Due to nonlinear and discrete variables and constraints, optimal reactive power dispatch (ORPD) is a complex optimization problem in power systems. In this paper, the purpose is to solve multi objective ORPD (MO-ORPD) problem considering bus voltage limits, the limits of branches power flow, generators voltages, transformers tap changers and the amount of compensation on weak buses. The objectives of this paper are real power losses and voltage deviations from their corresponding nominal values, which are conflicting objectives. Because of the stochastic behavior of loads, the MO-ORPD problem requires a probabilistic approach. Hence, in this paper, a two-point estimate method (TPEM) is proposed to model the load uncertainty in MO-ORPD problem. Moreover, the proposed method is compared with some other methods such as deterministic approaches and Monte Carlo simulations (MCS). The obtained results approve the efficiency of the proposed methodology. The proposed models are implemented and solved using GAMS optimization package and verified using IEEE 14-bus and IEEE 30-bus standard test systems.