配电变压器与有载分接开关匹配的基本原理

配电变压器与有载分接开关匹配的基本原理汪国民（遵义长征电器三厂）１．有载调压变压器的基本原理（１）变压器的基本原理单相变压器在理想状况下，可用以下公式表示：式中Ｕ１——一次侧绕组电压Ｕ２一一一二次侧绕组电压Ｎ１——一次侧绕组匝数Ｎ２——二次侧绕组匝数...     

有载调压变压器分接开关的运行和维护

指出有载分接开关运行中的注意事项,并从检修维护角度提出维护分接开关的注意事项.     

变压器有载调压分接开关的应用

变压器的电压调整是用分接开关切换变压器的调压分接头,从而改变变压器变比来实现的。调压方式可以分为3种：公共绕组中性点侧调压、串联绕组末端调压、中压侧线端调压,应根据变压器的电压、容量、运行方式要求进行选择。有载分接开关是保证在不切断负荷电流的条件下,     

无触点有载调压配电变压器光纤启动方案

提出一种以双向晶闸管(TRIAC)作为启动开关,基于光纤触发的无触点有载调压配电变压器启动方案。该方案中启动电路与变换分接头时的过渡回路共用1个支路:上电时该支路投入,启动变压器工作;变换分接头时,该支路投入,将过渡电阻串入分接头变换过渡回路,限制环流。启动或分接头变换完成后,TRIAC截止,该支路退出。双向晶闸管触发电路采用高压自取能随机触发方式,电路简单,工作可靠。针对该方案进行了主要电子元件的选型及参数的设计并进行了模拟实验。实验结果表明,该方案的电路设计及元件参数选择方法能满足无触点有载调压配电变压器对启动单元和过渡支路的要求。     

有载调压配电变压器节能应用研究

华南地区成品油管线输油站的10 kV配电变压器运行电压经常处于合格但偏高的状态,导致其空载损耗大幅上升.分析了少维护有载调压配电变压器节能原理,设计、制造了基于真空有载调压开关的S13型配电变压器,替换了东莞输油站一台S9型配电变压器.实际运行结果表明,有载调压配电变压器不但可以显著减少其空载损耗,还能大幅节约负载能耗,且可以在成品油管输线路的输油站推广应用.     

换流变用有载分接开关振动信号预处理方法研究

为提高换流变用有载分接开关(OLTC)状态诊断的准确性,开展换流变用OLTC振动信号预处理方法研究。通过对OLTC工作原理和现场噪声的分析,提出基于维纳滤波器的OLTC振动信号降噪方法和基于Teager能量算子-双门限法的OLTC振动信号阶段划分方法。在降噪方面,通过驱动电机电流信号划分噪声段和带噪信号段,基于噪声和带噪信号的频谱特征构建维纳滤波器,通过与降噪前的振动信号以及与其他降噪方法的比较,验证了该方法的有效性。在阶段划分方面,通过Teager能量算子放大振动脉冲与低频噪声的差异,通过对比观察法与所提方法在端点提取时存在的误差,验证了所提方法的有效性。文中提出的振动信号预处理方法,可为OLTC状态诊断提供高信噪比的振动信号和振动阶段信息。     

配电变压器防雷方式

由于雷击过电压、正逆变换过电压等因素,配电变压器的雷击损坏率一直很高,低压设备因雷击损坏的情况严重。本文通过对雷电损坏设备的机理分析,以及对多种接地防雷方式的优缺点进行分析比较,同时提出一种利用绕组绕接方式消除变换过电压的防雷方式,供广大电力人员参考。     

电力电子有载调压装置的控制系统设计

国内外现有的机械式和电力电子式有载调压变压器分接头的调节方式，具有结构复杂、体积大、调节速度慢、故障率高等不足。针对这些缺点，提出了一种新型的有载调压控制系统，该系统采用晶闸管组替代分接头调压开关，单片机作为控制单元，通过检测系统电压和电流，根据电力系统的安全、经济运行的需要，确定需要接通或断开变压器调压绕组的组数和分接头开关位置，然后根据电磁能量守恒原理在对电网无冲击的时刻触发相应的晶闸管开关。使调压过程中电压波形连续无冲击，为用户提供高质量的电能。     

Optimal regulator-based control of electronic power transformer for distribution systems

This paper presents the design of a linear-quadratic-regulator (LQR) with integral action to improve dynamic performance of an electronic power transformer for distribution systems (DEPT). The integral action is added to cancel the steady-state errors knowing that the standard LQR provides only proportional gains. This controller is designed to achieve the following four control objectives: (1) to keep the input currents sinusoidal and in phase with the input voltages to achieve unity input power factor, (2) to maintain the dc-link voltage at a reference value, (3) to maintain the output voltages at a constant value and (4) to keep the output voltages sinusoidal and symmetric. The DEPT model which includes the integral action in the d–q rotating frame is built and linearized around a set point. The system is tested for dc-link reference voltage, load and input voltages variations, respectively. The validity of the built model and the proposed control strategy is demonstrated by simulation results based on MATLAB/SIMULINK.     

新型配电网电压互感器的研究

为消除配电网中常见的铁磁谐振现象，防止其对配电网电压互感器造成的严重危害，国内外一些研究工作主要从电压互感器外部着手来解决谐振问题，起到了一定效果，但仍存在不同程度的问题。通过借鉴这些研究工作的经验和不足，提出在互感器内部进行改进：在电压互感器开口三角内部短接形成稳定绕组、高压绕组中性点对地串接零序绕组和铁心采用平面形六柱四绕组及对称式四柱四绕组结构等新措施，探讨设计新型原理的电压互感器。从消谐原理、等值电路等方面进行理论分析，表明以上改进措施能够有效防止和消除铁磁谐振，且制样机挂网运行效果良好，证明了新型原理电压互感器研究的成功。     

Coordinated control of OLTC and multi‐CEMSs for overvoltage prevention in power distribution system

The high degree of penetration of residential rooftop photovoltaic systems causes the overvoltage problem in power distribution systems. This paper aims to introduce demand‐side management for a distribution system for overvoltage prevention. A real‐time overvoltage prevention coordination scheme between an on‐load tap changer (OLTC ) and multi‐community energy management systems (multi‐CEMSs ) is proposed. The main objectives of this control are to relieve the stress in the OLTC tap operation using household schedulable loads and to maximize customer profit in each CEMS . The load scheduling performed by each CEMS is formulated as a combinatorial, nonlinear, time‐series scheduling optimization problem and is solved by a sequential search method named voltage‐ranking‐based load combination search algorithm. The effectiveness of the proposed method is validated in a model distribution system with1800 customers. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Theory and application of distribution electronic power transformer

Three-phase and 4-wire Distribution Electronic Power Transformer's (DEPT's) operation principle is analyzed in this paper. Based on the analysis, the control scheme is established. In this control scheme, the input stage is controlled as a three-phase balanced current source and makes the primary current sinusoidal and power factor easily adjusted. While the output stage is controlled as a three-phase balanced voltage source and keep the load voltage sinusoidal and nominal. In order to meet the requirement of the single phase or unbalanced loads, each phase is an independent voltage source. With the proposed control strategy, the characteristics of DEPT are studied by simulations. And further detailed simulations are carried out to validate the power quality control function of DEPT. The results show that DEPT has very good static and dynamic performances, and it can not only realize the functions of conventional power transformer, but also can prevent from voltage sags, swells, flickers and harmonics infecting the loads while avoid loads impacting the primary system.     

基于有限体积法的油浸式变压器绕组温度分布计算

针对变压器内部产热散热的对流换热过程,并考虑到变压器内部系统的非齐次性,采用有限体积法(FVM)将支配流动与传热的控制偏微分方程对微小控制体积积分,构造一组离散的控制方程,结合系统的初始条件和边界条件,求解一类自然油循环电力变压器温度场,仿真计算绕组温度分布.并与实验室温升用试验变压器不同条件下的实测数据进行对比验证,...