By the increased use of electric energy the importance of the electrical insulations became higher. The insulators are exposed to stresses, which must withstand for a long time. A cable section failure can result the loss of many consumers and significant material damage may occur. Corresponding maintenance can reduce the frequency of breakdowns.
My thesis deals with insulation diagnostics. Significant savings can be achieved and the security of supply is also increasing by achieving the well scheduled maintenance.
At the beginning of the thesis I overview stresses that affect the aging of insulators. Then I present the measurement methods used for measurement. One of the used methods is the modified full voltage response measurement (VR), the other is based on the series measuring of recovery voltages (RVM).
By using the VR and RVM methods I made measurements on new and aged PVC insulated cables. I compared the results, and I was looking for correlation between the two methods. In closing, I formulated suggestions to make better the measurement and evaluation.