营口变压器的结构_0

营口变压器的结构
铁心
       营口变压器铁心的结构与营口变压器的差别不大。采用晶粒取向冷轧电工钢片，轭和柱采用45°全斜接缝。心柱用钢带或自干型绝缘粘带绑扎，也有用粘结剂将铁心胶合。
       营口变压器的铁心为防止因凝露而引起锈蚀，在铁心表面徐有耐热的防锈覆盖漆或树脂。
       在营口变压器运行时，铁心是产生振动和噪声的根源，绕组和底座等部件和铁心交接的部位需安置弹性零件(硅橡胶的撑条、压板和垫片等)，形成缓冲的结构，以便减小营口变压器的振动和噪声。
容量较大时，铁心中要有气道，气道尺寸为15-20mm。
 
绕组
       (1)浸渍式绕组，绕组的结构形式和营口变压器类似，耐热绝缘等级一般采用H级或F级，绕组除了浸漆处理之外，其表面还涂有附潮的覆盖漆。制造这种类型的绕组，工装设备比较简单，约为同规格浇注式营口变压器成本的80%。但是浸渍式绕组的营口变压器的绝缘性能比的差，防潮性能也差。
       为了改善浸渍式绕组的防潮性能，美国西屋公司推出了真空压力浸漆绕组的营口变压器。绕组的匝绝缘和层绝缘采用聚酯纤维纸隔板、绝缘筒和撑条采用聚酯玻璃布板(简)。采用箔式绕组，采用连续式绕组，撑条和垫块采用木梳式撑条绕组均是整段嵌在“木梳”的凹槽内。这种结构的绕组绕好后不用压紧，承受短路的轴向力较好。
       (2)环氧树脂厚绝缘浇注式绕组，绕组的结构形式可以西门子公司的“干福”产品为代表.绕组为铝箔绕制的F级圆筒式绕组，绕组采用以石英粉为填料的环氧树脂浇注的铝绕组。绕组的绝缘耐热等级为B级，环氧树脂包封层具有耐潮、阻燃和自熄性能。
 
温控装置
       在营口变压器运行中，如果遇到短路、过载、环境温度过高或冷却通风不够等情况时，就会使营口变压器过热，使绝缘迅速老化，缩短使用寿命。防止过热的有效方法就是在营口变压器上配装温度控制装置。营口变压器绕组的发热时间常数小(升温快)，故需设置过热保护。国内外营口变压器的温控保护装置一般采用以下4种型式：
 温控装置功能比较表种类功能盘式温度表可测量铁轭外侧空气上的空气温度，无保护功能膨胀式温控器可对旁边一相绕组进行过热保护，无显示功能PTC（正温度系数）热敏电阻温控装置可对三相绕组进行过热保护，无显示功能铂热电阻测温装置可显示三相绕组的温度，并可对它们进行过热保护 
The structure of dry-type transformers
 
Core
    Dry-type transformer core structure and oil-immersed transformer is not very different. The use of cold-rolled grain-oriented electrical steel, yoke and column using 45 ° miter joints. Center column with steel or self-adhesive dry-type insulation with banding, is also useful to core glue binder.
    Dry-type transformer core in order to prevent corrosion caused by condensation in the core surface coverage Xu paint or rust resistant resin.
    Running in the transformer, core is the source of vibration and noise, winding and base parts and core parts of the transfer of parts to be placed elastic (silicone rubber stays, clips and gaskets, etc.), to form the structure of the buffer in order to reduce the transformer vibration and noise.
Larger capacity, the iron heart to have airway, airway size is 15-20mm.
 
Winding
    (1) impregnated winding, winding and oil-immersed transformer structure is similar to commonly used thermal insulation Class H or Class F winding in addition to dipping treatment, the surface is also coated with paint coverage tide. Manufacturing this type of winding, tooling equipment is relatively simple, about the same size cast-type transformers of 80%. However, the impregnated winding insulation dry-type transformers oil-immersed than the poor, poor moisture performance.
    In order to improve the moisture performance of impregnated windings, Westinghouse introduced a vacuum pressure impregnation of dry-type transformer windings. Winding turn insulation and layer insulation of polyester fiber paper separator, insulating tube and stays polyester glass cloth board (Jane). Low use of foil windings, high pressure using a continuous winding, stays and stays pad using comb-type high-voltage windings are embedded in the whole "comb" of the groove. This structure not pressed after winding around the well, better axial force to withstand short circuit.
    (2) thick insulating epoxy resin casting winding, winding structure can be Siemens, "Gan" products represented. Low-voltage winding is wound F-grade aluminum cylindrical windings, high voltage windings with quartz powder as filler The epoxy resin cast aluminum windings. High voltage winding insulation class B heat-resistant, epoxy resin layer has resistant to moisture, fire-retardant and self-extinguishing properties.
 
Temperature control device
    Operation of the transformer, if you encounter a short circuit, overload, ambient temperature is too high or not enough cooling air, etc., they will make the transformer overheating, the rapid aging of the insulation and shorten life. Effective way to prevent overheating of the transformer is equipped with temperature control device. Dry-type transformer winding thermal time constant is small (fast heating), so need to set the overheat protection. Domestic dry-type transformer temperature protection device generally used the following four types:
 
Temperature control device feature comparison table
Types of functions
Disc thermometer to measure the iron yoke on the outside air temperature of air, without protection
Expansion type thermostat can be next to a relative low voltage winding temperature protection, no display
PTC (positive temperature coefficient) thermistor temperature control device can be carried out on three-phase low-voltage winding temperature protection, no display
Platinum resistance temperature device can display three-phase low-voltage winding temperature, and thermal protection for them