At 15:30 on January 17, the stator core magnetization test of Unit 5 of Lijiaxia Hydropower Station, which was constructed by the Mechanical and Electrical Installation Branch of the Fourth Bureau of Sinohydro, passed the stator core magnetization test at one time and officially entered the offline stage.
The purpose of the stator core magnetization test is to confirm the electrical performance quality of the stator core silicon steel sheet manufacturing and on-site stacking, and check whether there is a short circuit between the iron sheets and whether the insulation is good. In addition, the core magnetization test can also release the gap between the iron sheet through vibration and heat generation, so as to achieve the purpose of pressing the core in the next step.
The generator set of Lijiaxia Hydropower Station is manufactured by Dongfang Electric Co., Ltd., with a stator core inner diameter of 11.8 meters, an outer diameter of 12.8 meters and a height of 2.83 meters, which is made of more than 290,000 0.5 mm silicon steel sheets, with a total weight of more than 450 tons.
In order to ensure the successful completion of the test, before the start of the test, the Lijiaxia Project Department organized all personnel and relevant parties to carry out safety technology disclosure, explained the test content, work points, precautions and organizational division of labor in detail, so that each operator understood their responsibilities and safety precautions, and carried out a comprehensive cleaning and inspection of the stator core.
During the test process, the operators perform their own responsibilities and carefully do a good job in test monitoring and inspection. After 90 minutes of intense busyness, the stator core magnetization test of Unit 5 of Lijiaxia Hydropower Station passed smoothly at one time. The test data show that the maximum temperature difference between the core and the unit, the maximum temperature rise of the core, and the temperature difference between the stator tooth (groove) of the core are excellent and far exceed the design temperature difference of the manufacturer, which has been unanimously affirmed by the power plant, the owner, the supervisor and the manufacturer.
Picture and text of this issue: Jiao Xiaolong
Editor of this issue: Yang Shuaishuai
Review of this issue: Zhang Huaiqiang
China Hydropower Fourth Bureau Mechanical and Electrical Installation Company