||This thesis proposes the Transformer Management System(TMS) by developing the Intelligent Transformer Terminal Unit (iTTU) to perform the function of real time monitoring of transformer operation condition. For the abnormal operation conditions of a transformer such as overloading or customer electricity tampering, the system will report the transformer abnormal condition to the control station.|
In this thesis, the iTTU is designed by integration of power supply, sampling circuit of temperature measurement, computing processor for power consumption calculation and communication module. The iTTU measures the power delivery and oil temperature. The data of power delivery and oil temperature are then transmitted back to the TMS marter station by either the wired communication of power line carrier (PLC) or the wireless communication of ZigBee. The embedded system is also designed to retrieve the customer power consumption, which is stored in the Data Collection Unit (DCU) of AMI system. By comparing the electricity delivered by a transformer and the electricity consumed by all customers served by a transformer, the iTTU can detect the electricity tampering. In addition, when overloading occurs, demand response function can be activated by iTTU to perform the customer load shedding to solve the transformer overloading problem. After iTTU report the warning message back to the TMS marter station. The abnormal operation condition of a transformer can therefore be displayed on the automated mapping system to show the geographic location of transformer with the warning message.
This thesis also analyzes the load characteristics of distribution transformers and by deriving its load patterns according to the customer monthly energy consumption. With the temperature sensitivity of various types of customers served by a transformer, the peak loading of a transformer can therefore be estimated. In case the potential overloading problem, the demand response strategy can be derived for the direct control of customer loads. With the imformation of transformer power delivery, the connectivity of transformers and the customers served can be adjusted to enhance the operation efficiency of transformers.