新形势下水电站接机发电面临的安全隐患

结合雅砻江流域锦屏水电站工程实际,分析了新形势下水电站在接机发电期间的安全隐患,并从物、人及管理的因素入手,提出了若干应对与防范措施,以减少和避免事故的发生,促进电力安全生产。

基于OKR的巨型水电站精细化接机发电实践

水电站接机发电是一项较复杂的综合组织管理过程,贯穿设计、制造、建设到发电运行维护各阶段,需要进行严密组织策划与过程质量管控,以及高效的信息共享与工作协同。以往主要依靠线下组织、会议跟踪以及人工统计,如何进行全方位精细化组织策划准备,将信息化管控融合到组织管理与质量管控过程,并通过高效协同与事务跟踪实现设备高质量无缝接管值得研究探讨。本文主要阐述巨型水电站通过创新电力生产准备模式,基于OKR任务分解管理思路,依靠任务跟踪、信息共享、知识管理的综合管理信息平台,对水电站接机发电全生命周期过程进行精细化组织管控。

浅论工会在服务中心工作中发挥的作用——基于乌东德水电站接机发电案例分析

建设职能是工会组织的四项基本职能之一,在新时代,面对新形势新问题,工会组织要持续探索并找准赋能中心工作的着力点,优化发挥建设职能的方式方法,引导广大职工当好主人翁,建功新时代,推动中心工作高标准、高质量完成。

浅谈如何加强基层党组织建设——基于乌东德水电站接机发电案例分析

党的基层组织是党在社会基层组织中的战斗堡垒,是党的全部工作和战斗力的基础。基层党组织建设好坏,直接关系到党与人民群众的血肉联系以及党的方针、路线能否得到顺利贯彻落实,因此加强基层党组织建设,是推动党建工作走向深入的基础。乌东德电厂党委以党的政治建设为统领,坚持党的领导,在增强基层党组织政治功能、组织功能、服务群众能力以及推动党建与中心工作融合等方面进行了积极探索,为实现“两新两高”精品工程目标提供了政治保障,注入了强大动力。

Effects of Uncertainties in the Position and Orientation of Both the Transmitter and Receivers on Marine Controlled-Source Electromagnetic Data

Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.

Connecting Wind Turbine Generator to Distribution Power Grid--A Preload Flow Calculation Stage

A distribution grid is generally characterized by a high R/X （resistance/reactance） ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in such a way that power flows from transmission system via distribution system to consumers. But in a situation when wind turbines are connected to the distribution grid, the power source will change from one source to two sources, in this case, network is said to be active. This may probably have an impact on the distribution grid to whenever the wind turbine is connected. The best way to know the impact of wind turbine on the distribution grid in question is by carrying out load flow analysis on that system with and without the connection of wind turbines. Two major fundamental calculations： the steady-state voltage variation at the PCC （point of common coupling） and the calculation of short-circuit power of the grid system at the POC （point of connection） are necessary before carrying out the load flow study on the distribution grid. This paper, therefore, considers these pre-load flow calculations that are necessary before carrying out load flow study on the test distribution grid. These calculations are carded out on a test distribution system.

Direct Power Control of Variable Wind Speed Based on the Doubly Fed Asynchronous Machine

In this work, the authors propose the study of a wind speed variable based on the DFAM （double fed asynchronous machine）. The model of the turbine is drawn from the classical equations describing the operation of a variable wind speed. The torque generated by the turbine is applied to the DFAM directly connected on the network side and the stator via a bidirectional converter side rotor. This configuration allows velocity variations of ±30% around the synchronous speed and the converter is then sized to one third of the rated power of the machine. The DFAM is controlled by a control vector ensuring operation of the wind turbine power coefficient maximum.

Influence of Design Parameters on Cogging Torque in Directly Driven Permanent Magnet Synchronous Wind Generators

In order to reduce the cogging torque, this paper investigates the influence of some parameters on the cogging torque developed by directly driven permanent magnet synchronous wind generators. Based on the remanent magnetic flux densities, the cogging torque is computed by using finite element method. It is shown that many parameters have influence on cogging torque and the slot and pole number combination has a significant effect on cogging torque. A simple factor has been introduced to indicate the effect of the slot and pole number combination. Some practical experience to reduce the cogging torque was applied to 2 MW three phase permanent magnet synchronous generator at rated speed of 37.5 rpm for wind energy conversion. The simulation and experiment results verify the effect of the proposed method.

Dipole-moment-induced effect on contact electrification for triboelectric nanogenerators

Triboelectric nanogenerators （TENGs） have been demonstrated as an effective way to harvest mechanical energy to drive small electronics. The density of triboelectric charges generated on contact surfaces between two distinct materials is a critical factor for dictating the output power. We demonstrate an approach to effectively tune the triboelectric properties of materials by taking advantage of the dipole moment in polarized polyvinylidene fluoride （PVDF）, leading to substantial enhancement of the output power density of the TENG. The output voltage ranged from 72 V to 215 V under a constant contact force of 50 N. This work not only provides a new method of enhancing output power of TENGs, but also offers an insight into charge transfer in contact electrification by investigating dipole-moment-induced effects on the electrical output of TENGs.

Multiple target implementation for a doubly fed induction generator based on direct power control under unbalanced and distorted grid voltage

This paper presents a multiple target implementation technique for a doubly fed induction generator （DFIG） under unbalanced and distorted grid voltage based on direct power control （DPC）. Based on the mathematical model of DFIG under unbalanced and distorted voltage, the proportional and integral （PI） regulator is adopted to regulate the DFIG average active and reactive powers, while the vector P1 （VPI） resonant regulator is used to achieve three alternative control targets： （1） balanced and sinusoidal stator current; （2） smooth instantaneous stator active and reactive powers; （3） smooth electromagnetic torque and instantaneous stator reactive power. The major advantage of the proposed control strategy over the conventional method is that neither negative and harmonic sequence decomposition of grid voltage nor complicated control reference calculation is required. The insensitivity of the proposed control strategy to DFIG parameter deviation is analyzed. Finally, the DFIG experimental system is developed to validate the availability of the proposed DPC strategy under unbalanced and distorted grid voltage,