谈配电变压器节电的运行管理措施

本文简略地介绍如何组织变压器经济运行,变压器分接开关的节电运行和如何平衡变压器的三相负荷,调整负荷曲线,以降低变压器负载损耗,均衡变压器负荷。     

变压器经济运行节电技术分析

分析电力变压器容量与损耗的关系，提出计算，临界负荷电流的方法。在轻负荷时期，合理选择配电变压器的运行方式，达到降损节电的目的。     

半边山主变压器调整与经济运行分析

本文针对半边山矿区用电负荷的变化和主变压器供电方案的调整,进行了方案实施前后电能损耗等经济技术指标的计算分析,提出了主变压器运行方案要注重综合经济效益,以及达到经济运行的方法和措施。     

电力变压器经济运行方式分析与探讨

以30kVA和100kVA两台变压器为例，对电力变压器不同负荷下的损耗进行了分析，探讨了在各种条件下电力变压器应选择的经济运行方式     

变电所的节能措施

变电所的节能主要就是变压器的节电。本扼要地分析了变压器损耗与效率、无功功率、负荷波动的关系，然后提出了减少变电所综合损耗的技术措施。就如何抓好变电所的节能和变压器经济运行管理制定了实施方法。     

变压器短时合环故障分析

针对公司铁西变电所运行人员在进行母线倒负荷操作过程中，2台变压器合环瞬间出现负荷最高需量超过额定值的现象，分析了2台变压器合环过程中所存在的问题，找出故障产生的可能原因，为问题的解决提供了理论依据。     

TRT机组并网发电下总降变电站经济运行的研究与实践

通过分析某企业在运TRT发电并网工况和1~#总降变电站供电运行方式,依据TRT发电负荷和生产用电负荷情况,调整1~#总降变电站运行方式,停运一台20000 k VA主变压器,减少1#总降变电站主变压器基本容量电费和有功功率损耗电度电费支出而获得一定经济效益。     

昆钢220kV总降压站主变降容优化

昆明钢铁有限责任公司自2015年11月对生产组织结构进行调整后,生产用电负荷发生了较大的变化。根据公司远期规划分析,实际用电负荷与现有装机容量存在较大偏差,需进行节能改造,因此对昆钢220kV变电站主变降容,提高变压器的利用率并且降低电费支出。提出了改造方案,经分析确定主变降容,改造完成后经济效益可观。     

冶金变电站2~#主变压器缺相运行分析

本文通过计算，说明了变压器在缺相情况下，除同步电动机负序保护动作跳闸外，其他负荷为什么能正常运行的原因，为电力系统变压器缺相问题的分析、处理提供了依据。     

变电站供电经济运行方式研究与实践

通过对攀钢冷轧35 kV变电站运行方式、负荷情况及设备状况进行分析,在满足正常供电的前提下,提出了经济运行方式调整方案并实施完成,降低了变压器基本电费和损耗,取得了较大经济效益。     

Performance Evaluation of Precast Posttensioned Concrete Multibeam Deck

An innovative bridge construction utilizing on-site posttensioned precast concrete beams that are compressed together with full depth grouted shear keys and transverse posttensioning is the subject of this paper. In particular, the performance of the shear keys with regard to load transfer and water tightness constitutes the main issues of investigation. This paper presents the results of a live load testing program and associated finite-element analysis results of the as-built bridge. Live truck load test results help provide insights on the lateral (transverse direction) load distribution characteristics among the interconnected beams. The measured lateral distribution of the applied truck load among adjacent beams showed that the load was transferred primarily to the beams close to the truck load position, validating the effectiveness of the shear key details in transporting loads.     

Nonlinear Finite-Element Modeling of Batter Piles under Lateral Load

In this paper, a finite-element model is developed in which the nonlinear soil behavior is represented by a hyperbolic relation for static load condition and modified hyperbolic relation, which includes both degradation and gap for a cyclic load condition. Although batter piles are subjected to lateral load, the soil resistance is also governed by axial load, which is incorporated by considering the P-Δ moment and geometric stiffness matrix. By adopting the developed numerical model, static and cyclic load analyses are performed adopting an incremental-iterative procedure where the pile is idealized as beam elements and the soil as elastoplastic spring elements. The proposed numerical model is validated with published laboratory and field pile test results under both static and cyclic load conditions. This paper highlights the importance of the degradation factor and its influence on the soil resistance-displacement (p-y) curve, number of cycles of loading, and cyclic load response.     

调整不平衡负荷减少电能损耗

论述三相不平衡负荷产生的危害，通过对三相不平衡电流附加线损的计算，说明调整不平衡负荷的重要性。     

Load Transfer in Rammed Aggregate Piers

Predicting the load–settlement and load–transfer behaviors of rammed aggregate piers are important aspects of design. Use of advanced engineering models, however, can be complex involving uncertainty in selection of nonlinear constitutive model parameters for the aggregate and surrounding matrix soils and in selection of in situ stress fields. For purposes of simpler design calculations, this paper uses the closed-form approximate solution and the boundary-element method using both elastic (i.e., neglecting interface slip) and elastic–plastic soil–pier interface (i.e., considering interface slip) to predict load–settlement and load–transfer for rammed aggregate piers. Unlike previous studies that evaluate load–settlement and load–transfer for stiff, slender piles (e.g., concrete and steel piles) or fully penetrating granular piles, this paper focuses on floating rammed aggregate piers having slenderness ratios (L/D) of 3–10 and pier–soil stiffness ratios (Ep/Es) of 5–80. Predictions of load–settlement and load–transfer as a function of depth are compared to three full-scale instrumented load tests. Based on the calibrated models, equations for predicting load–settlement response and load–transfer as functions of Ep/Es, and L/D are presented with example calculations.     

Temperature Correction and Strut Loads in Central Artery Excavations

Braced excavations for the Central Artery/Tunnel project in Boston, Mass. include several instrumented sections for monitoring excavation and ground response to soil removal and strut installation. Strain in the struts is measured using thermally matched vibrating wire strain gauges (VWSGs). This paper presents issues related to strut load interpretation using VWSG data and the difficulties and errors associated with the use of field data. The paper presents a procedure to separate earth load from thermal load induced in the struts due to temperature variation throughout construction. The procedure is an extension of a method that uses measured temperature and corresponding load change to compute a thermal (temperature change induced) load coefficient. The procedure emphasizes the dependency of the thermal load coefficient on construction stage and support configuration. A numerical analysis is presented to support the proposed procedure. Strut loads and earth pressure diagrams are presented using the proposed procedure. Comparisons are made between measured loads and the design load envelope developed prior to construction.     

“均压”烧结新技术的评述与展望

首次提出了均压烧结的概念；分析了和均压烧结技术提高烧结放产质量的机理；介绍了给上部料层加压和为下部料层减压的试验结果；展望了均压烧结技术在攀钢运用的必要性与可行性。     

负载换相变频软启的电气原理

文中主要介绍了同步电机负载换相变频软启系统的电气原理。描述了同步电机的一般模型,分析了断续换流和负载换相的实现方法,以及如何从断续换流向负载换相过渡。     

Reliability Verification Using Proof Pile Load Tests

Proof pile load tests are an important means to cope with uncertainties in the design and construction of pile foundations. In this paper, a systematic method to incorporate the results of proof load tests not conducted to failure into the design of pile foundations is developed. In addition, illustrative acceptance criteria for driven piles based on proof load tests are proposed for use in a reliability-based design. Finally, modifications to conventional proof test procedures are studied so that the value derived from proof tests can be maximized. Whether or not a proof test is conducted to failure, its results can be used to update the probability distribution of the pile capacity using the method proposed in this paper. Hence, contributions of the proof test can be included in foundation design in a logical manner by considering several load test parameters such as the number of tests, the test load, the factor of safety, and test results. This adds value to proof load tests and warrants improvements in the procedures for acceptance of pile foundations using proof load tests. A larger test load for proof tests, say 1.5 times the predicted pile capacity, is recommended since it will yield more information about the capacity statistics and thus allow for more economical designs.     

Wash Load and Bed-Material Load Transport in the Yellow River

It has been the conventional assumption that wash load is supply limited and is only indirectly related to the hydraulics of a river. Hydraulic engineers also assumed that bed-material load concentration is independent of wash load concentration. This paper provides a detailed analysis of the Yellow River sediment transport data to determine whether the above assumptions are true and whether wash load concentration can be computed from the original unit stream power formula and the modified unit stream power formula for sediment-laden flows. A systematic and thorough analysis of 1,160 sets of data collected from 9 gauging stations along the Middle and Lower Yellow River confirmed that the method suggested by the conjunctive use of the two formulas can be used to compute wash load, bed-material load, and total load in the Yellow River with accuracy.     

热连轧机负荷分配方法的分析和综述

热连轧的负荷分配是生产过程优化的基础，本文简介了我国发明的综合等储备负荷分配方法和今井一郎的能耗法，通过与引进方法对比说明我国发明方法的先进性，推广到热连轧机上应用的可行性。