PS 1: Question 3 Advantages and disadvantages of each thermal philosophy A transformer is a complex protective object. Life time management and condition based monitoring needs more information. To determine the loss of life or the condition of the whole transformer due to: Dielectric stresses Chemical stresses Thermal stresses Dynamic stresses Sensor setup adapted to an economical cost-value ratio

Measuring quantities: On-line Monitoring Concept for Power Transformers Important Parameters to provide an Early Warning System and Life Management Support by means of On-line Monitoring Information about: Measuring quantities: Load and operation conditions and history  voltage (HV), load current (HV), tap changer position Transient conditions  peak values of voltage (HV) Thermal aging /Hot-spot calculation  oil temperature and load current (HV) Condition of insulation and oil  H2 in oil, moisture in oil Efficiency of cooling system  oil temperatures, top and bottom Load tap changer condition  position, counter, power consumption of motor drive Operation time of pumps and fans  circuit state of pumps and fans

On-line Monitoring Concept for Power Transformers Example of Hardware for Monitoring Applications Based on a powerful data logging device Data storage capacity 256 MByte..1 GByte Analog Inputs Digital inputs and outputs Virtual channel for calculations Event controlled storage Remote access by Modem, GSM, LAN Alarms by means of digital outputs, SMS or E-mail 1 Interface LAN - TCP/IP 2 Interfaces RS232 Example of a data logging device

On-line Monitoring Concept for Power Transformers Remote Monitoring, Example of a Network Configuration Remote Monitoring Computer Display of measurements in diagrams Down-load of stored data ASCII-export for MS-Office applications OPC-Server