427 / 2017-04-27 16:24:44

Power Transformer Transient Modeling Considering the Effects of On-load Tap Changer

On-load tap changer; Transformer; Inductance matrix model; law of magnetic circuit; Symmetrical faults; Un-symmetrical faults; PSCAD.

Smart transformer is an integral part of the smart distribution grid which ensures the voltage optimization and responds the power grid fluctuations without interruptions. On-load tap changer (OLTC) is essential in regulating power transformers employed in electrical power systems and industrial applications. When studying power flow analysis, electromagnetic and electromechanical computer simulations by carrying out diagnostics on on-load tap changer it is found that the problem of assumption in conventional transformer that tap positions only effect the turn ratio still the same in case of single phase and three phase transformers because the real parameters of transformers, such as the transformer winding resistances and inductances, also vary with different tap positions.

In this paper single and three phase transformer models are represented which illustrates that winding resistance and inductance also have impact because of tap positions and also a case study is performed to assessed the performance of this transformer model in case of symmetrical and un-symmetrical faults. The model is simulated using PSCAD software in order to validate the developed model the output results are compared and presented in this paper to analyze transformers becomes more sensitive on the implications of various transient progresses. Thus it's vital to provide an applicable attention to the analysis and description of simulation with the usage of most accurate mathematical models, which permit us to review the behaviour of electrical device circuit without any risk.