In my thesis, I focus on the low voltage distribution network. I examine the effects of the distibuted generation on the system and I will focus on the thermal ageing due to short-time overloads. In the first part of my thesis the processes responsible for the cyclic overloads are described. I will introduce in detail the influences of the thermal ageing on the electric parameters of the distribution cables. Then, I will create my own measurement process, and with that I will simulate these effects. Cable samples will be created from a low-voltage distribution cable applied by electricity provider companies. The samples will be exposed to accelerated ageing on two different temperatures. After every 3 hour, I will measure different mechanical and electrical parameters on the samples, and I will follow the changes in these values. As a mechanical parameter I will measure the hardness of the jacket of the cables through the ageing process. As electrical parameters, I will focus on the capacity and dissipation factor, and they will be measured both on the jacket and on the conductors. I will determine, that how many hours of ageing in the lower temperature equals with different ageing times in the higher temperature. I will calculate activation energy on the process encountered during my measurements. My thesis will end with the description of my results and with the conclusion.