变电站工程
一、变电站基础 | Substation Fundamentals
二、变电站主要设备 | Major Substation Equipment
三、变电站设计与布局 | Substation Design & Layout
四、变电站土建工程 | Substation Civil Works
五、变电站施工 | Substation Construction
Characters: Electrical Commissioning Engineer (电气调试工程师 CE) / · Characters: Electrical Supervisor (电气主管 ES) / QC Inspector (QC检验员 QI)
Transformer Specialist (变压器专家 TS) The 150 MVA, 220/33 kV power transformer is rigged and set on its foundation. The impact recorder shows the acceleration during transport stayed within the 3G limit — no issues. Now we need to start the oil processing. What's the sequence?
150MVA/220/33kV电力变压器已就位固定在基础上。冲击记录仪显示运输加速度在3G 限值内——没问题。现在开始油处理。什么顺序？
First, we do a vacuum leak test on the assembled transformer — pull vacuum to less than 1 mbar and hold for 24 hours. The leakage rate must be below 0.5 mbar per hour. If it passes, we proceed to hot oil circulation. We heat the oil to 65°C, circulate it through the transformer windings for 48 hours to remove moisture from the insulation paper. After circulation, we drain the hot oil, pull vacuum again to less than 1 mbar for 48 hours, then vacuum-fill with degasified and dehydrated oil. The oil must meet the specification: moisture below 10 ppm, dielectric strength above 60 kV, and dissolved gas content below 1%.
首先做组装好的变压器真空泄漏试验——抽真空到1毫巴以下保持24小时。泄漏率必须 低于每小时0.5毫巴。通过后做热油循环。油加热到65°C，在绕组中循环48小时除去 绝缘纸水分。循环完后排油、再抽真空到1毫巴以下48小时、然后用脱气脱水油真空 注油。油指标必须满足：水分低于10ppm、耐压高于60kV、含气量低于1%。
That's a 5-6 day process minimum. While the oil processing runs, can I start the bushing and radiator installation, or should we wait?
最少5-6天。油处理期间能开始装套管和散热器，还是等？
Install the radiators, conservator, and piping now — they're part of the vacuum system. But the HV and LV bushings should be installed after the vacuum drying is complete, just before oil filling. Installing bushings earlier risks moisture ingress through the bushing seals. And once oil filling is complete, we need to let the transformer sit for at least 72 hours before any electrical testing — the oil needs time to fully impregnate the insulation.
现在装散热器、储油柜和管路——它们是真空系统的一部分。但高低压套管要在真空 干燥完成后、注油前装。早装套管有通过密封进潮的风险。注油完成后至少静置72小时 才能做电气试验——油需要时间充分浸渍绝缘。
We've completed the grounding grid installation for the substation — 2,800 meters of copper conductor in a 10×10 meter grid pattern, with 48 ground rods at the intersections, all exothermic welded. Ready for the ground resistance test.
变电站接地网安装完成——2800米铜导体10×10米网格、48根接地极在交叉点、全部 放热焊接。可以做接地电阻测试了。
Let me review the welding inspection records first. Each exothermic weld must be visually inspected — no porosity, no slag, the conductor must be fully embedded in the weld metal. Did you do the hammer test on 10% of the welds? I see you have 340 weld points total, so I need to see 34 hammer test records.
先看焊接检查记录。每个放热焊点须目视检查——无气孔、无夹渣、导体完全包裹在 焊料中。10%焊点做了锤击试验吗？总共340个焊点，需要看到34个锤击试验记录。
All done. The hammer test records are here — all 34 passed with no cracks or separation. The visual inspection log shows 338 passed, 2 welds were rejected and re-welded — they had surface porosity. Those two have been re-inspected and passed. We're at 100% weld acceptance.
全做了。锤击试验记录在这——34个全通过，无裂纹无分离。目视检查日志显示338个 通过、2个因表面气孔拒收重焊——这两个已复检通过。焊点合格率100%。
Good. Now, the ground resistance test. We use the fall-of-potential method. Place the current electrode 200 meters from the substation fence and the potential electrode at 62% of that distance — about 124 meters. The target resistance for this 220 kV substation is less than 0.5 ohm per the design specification. What's the reading?
好。现在接地电阻测试。用电压降法。电流极离变电站围栏200米、电压极在62%处 ——约124米。这个220kV变电站目标电阻设计规范要求低于0.5欧姆。读数多少？
First measurement: 0.42 ohm. Let me take two more at different probe positions to confirm... 0.44 ohm and 0.41 ohm. Average 0.42 ohm. Well below the 0.5 ohm target. The soil here is moist clay — that helps. I'll prepare the test report with the resistance curve and the soil resistivity data for your signature.
第一测：0.42欧姆。换探棒位再测两次……0.44欧姆和0.41欧姆。平均0.42欧姆， 远低于0.5欧目标。这儿是湿黏土——有帮助。准备试验报告附电阻曲线和土壤电阻率 数据给你签。