Изолационното превантивно тестване е важна мярка, за да се гарантира безопасната работа на оборудването . чрез напрежение, издържащи на тестове, условието за изолация на оборудването може да бъде схванато, скрити дефекти вътре в изолацията могат да бъдат открити своевременно и подготовка за навременна профилактика може да се избегне опасност.} icestans volt and dc Често използвани методи за тестване на силата на изолацията в захранващото оборудване .
Изолационен превантивен тест
Preventive insulation testing of electrical equipment is an important measure to ensure the safe operation of the equipment. Through testing, the insulation condition of the equipment can be grasped, hidden defects inside the insulation can be discovered in a timely manner, and eliminated through maintenance. In severe cases, replacement is necessary to avoid insulation breakdown during operation, which can cause irreparable losses such as power outages or equipment щети .
Изолационните превантивни тестове могат да бъдат разделени на две категории:
One type is non-destructive testing, also known as insulation characteristic testing, which measures various characteristic parameters at lower voltages or using other methods that will not damage the insulation. It mainly includes measuring insulation resistance, leakage current, dielectric loss tangent value, etc., in order to determine whether there are defects inside the insulation. Experimental results have shown that Този метод е ефективен, но в момента не може да се разчита единствено на надеждно да се определи електрическата якост на изолацията .
The other type is destructive testing, also known as withstand voltage testing. The voltage applied in the test is higher than the operating voltage of the equipment, and the insulation test is very strict, especially to expose concentrated defects with high danger and ensure that the insulation has a certain electrical strength, mainly including DC withstand voltage, AC withstand voltage, etc. The Недостатък на теста за издържане на напрежението е, че той може да причини определено увреждане на изолацията .
DC издържа на тест за напрежение
The DC withstand voltage test has a high voltage and plays a special role in detecting certain local insulation defects. It can be conducted simultaneously with the leakage current test. Compared with AC withstand voltage test, DC withstand voltage test has the advantages of lightweight testing equipment, minimal insulation damage, and easy detection of local defects in the equipment. Compared with AC withstand voltage test, the main disadvantage of DC withstand voltage test is that the voltage distribution inside the insulation is different between AC and DC, and the test of insulation by DC withstand voltage test is not as close to reality as AC test.
Влиянието на постоянен ток издържа на тест за напрежение върху омрежени захранващи кабели
Cross linked polyethylene insulation material is generated by cross-linking process of cross-linked polyethylene plastic, belonging to integral insulation material. Its dielectric constant is 2.1-2.3, and it is generally not affected by temperature changes. Under direct current voltage, the electric field strength in the insulation layer is distributed proportionally according to the insulation resistivity, and the distribution на изолационното съпротивление е неравномерно (в производствения процес на омрежени полиетиленови пластмаси неминуемо се присъстват в основния материал поради причини за процеса, които имат малко изолационно съпротивление и се разпределят радиално по протежение на изолационния слой, с неравномерно разпределение) ., следователно, електрическото поле за разпределение на кръстосано полиетилово потул inconsistent breakdown characteristics. The DC withstand voltage test not only fails to effectively detect insulation defects such as water branches in cross-linked polyethylene insulation materials, but also, due to the effect of space charges, further develops and expands the existing weak points inside the insulation, gradually deteriorating the insulation performance and forming an accumulation effect of internal insulation degradation. This can easily cause the cable to explode shortly after being put into operation in certain areas that should not have problems under AC voltage. In addition, certain parts of the cable, such as the cable head and middle head, may have certain defects under AC voltage, but they will not break down during DC withstand voltage testing.
AC издържа на тест за напрежение
The AC withstand voltage test is very strict in testing insulation and can effectively detect more dangerous concentrated defects. It is the most direct method for assessing the insulation strength of electrical equipment, and has a decisive significance in determining whether electrical equipment can be put into operation. It is also an important means to ensure the insulation level of equipment and avoid insulation accidents.
The AC withstand voltage test may sometimes exacerbate some weak points in the insulation. Therefore, before the test, it is necessary to conduct tests on the insulation resistance, absorption ratio, leakage current, and dielectric loss of the test sample. If the test results are qualified, the AC withstand voltage test can be carried out. Otherwise, it should be Разгледани навреме и тестът за напрежение на променлив ток трябва да се проведе, след като всички индикатори са квалифицирани, за да се избегне ненужна повреда на изолация .
Wuhan UHV е специализиран в производството на производствоРезонанс на серията (известен също като резонанс на серията с променлива честотаи се занимава с индустрията за електрически измервания в продължение на много години . Нейните продукти имат първокласно качество и добре дошли клиенти, за да дойдат и да закупят .