Analysis of reconfigurable tap changing transformer model through analog emulation

Emulation of power systems is a viable alternative to traditional digital methods as it provides certain advantages such as physically realizable solutions and faster computation times. Accurate analog models of power systems components are required in order to realize an analog computation engine for power systems. Prior research in this field has modeled generators, transmission lines and loads. Other components have significant influence on the power systems, such as tap changing transformers. Effects of tap changing transformers on voltage stability have been a continuing area of research. In this paper, a circuit model design to emulate the behavior of a tap changing transformer is validated. It is important to demonstrate how this reconfigurable analog model may be utilized in load flow studies. Such demonstration is presented by comparing steady-state emulation and simulation results for a test case in which a power system experiences slow gradual changes in load.