نور الهدى علي جاسم الكريطي

The cables are one of the significant and crucial elements in the low voltage (LV) distribution network. As is common knowledge, most LV cable networks were built decades ago. Since then, distributed generation has increased significantly due to the spreading of consumer- side renewable sources. Moreover, the recent rise in new appliances and electric vehicles can cause an unbalanced load on distribution cables [1] , [2] . These short-term overloads lead to temperature elevation above rated operating limits, which may lead to damage that can decrease the lifetime of cables [1] , [3] . Also, the short- circuit current creates heat dissipation over the cable. However, the degradation of the components is not equal. To monitor the effect of these short-term temperature rises, this publication describes the change in electrical properties of low-voltage cables due to short-term cyclic artificial ageing. This study investigates the impact of cable structure on the dielectric parameters of cable specimens. Each 50 cm length of four cable samples was prepared and subjected to an accelerated ageing test in a temperature-controlled oven.

The distribution generation technologies are advancing rapidly, with more significant generation units (small wind farms, solar photovoltaic farms) linked to the medium-voltage grid. The smaller generation units, in contrast, are directly connected to the LV grid. This form of link calls into question the distribution grid's ability to accommodate additional loads as it was designed many decades ago, as these new loads can affect the lifetime of low voltage distribution cables. Moreover, a significant load variance can increase current flow in the cables, increasing their temperature and reducing their lifetime. The consequences of these overloads usually are undetectable if the fuse does not blow. So, a more precise prediction of the cable's lifetime should be made by calculating and tracking the cable's temperature. However, it is necessary to understand how low voltage cables are affected by thermal overloads. The current work proposed investigating the effect of the cable structure on the ageing of low voltage distribution cables. The first part of this work will deal with the theoretical background of the distribution generation cables and the degradation phenomena, and the dielectric insulation testing measurements. The second part deals with the experimental part, where the first step is to make the baseline (reference point) to the samples used in the experiments. The baseline measurement was done using the capacitance and dissipation factor (Tan δ) measurement. The second step is changing the cable structure by removing the outer insulation layers. The last step is doing the thermal ageing process on the samples to study the effect of the ageing cycles on the material structure and compare the results with those we get in the reference values. The obtained results demonstrated that the changing of cable structure affects its dielectric properties, which was seen in the dissipation loss factor and capacitance measurements. Moreover, after the ageing, the results observed that changing the structure affects the ageing behaviour of the PVC low voltage cable. That change is seen by comparing the results before and after the ageing process.

اجتيازنا دورة طرائق التدريس الخاصة بتطوير مهارات الكوادر التدريسية المقامة في جامعة الفرات الاوسط التقنية- مركز التعليم المستمر

اجتياز اختبار صلاحية التدريس الخاص بالكوادر التدريسية المقام في جامعة الفرات الاوسط التقنية / مركز التعليم المستمر

المشاركة في ورشة العمل الخاصة بكيفية ادارة حساب الباحث في مستوعبات سكوبس والمقامة بتاريخ 15/12/2025 بالشراكة بين وزارة التعليم العالي والبحث العلمي وشركة السفير لدعم الباحثين العراقيين.