Tracing the flow of electricity becomes an important issue under deregulation system. It is more complicated compared to other fields due to norlinear nature of power flow and specific properties of electricity. Since the complexity of electricty transmission system, it is not straight forward to map out the contribution of particular generator to a particular line or loud. Thus there are several algorithms proposed to trace the power flow and loss through literatures. This paper will discuss the power flow and loss allocation using Modified Proportional Tree M-Lhod (MPTM). The method is based on Proportional Tree Method (PTM) and proportion sharing principle. After power flow solution is obtained, the test system is modeled like a tree, where the power flow tracing is started from a particular generator to a particular line or load through the routes that connected between them. It is also possible to appoint the losses at each transmission line to which generators. 4-bus and IEEE 14-bus test systems were used to illustrate the effectiveness of the method. Comparison with other method is also given.
