An Analog Circuit Approach for Optimal Damping of Inter-Area Oscillations using Wide Area Control of Power Converters

This paper proposes an electric circuit analogy approach to represent the electromechanical dynamics of a power transmission network using virtual passive elements. A participation factor analysis on this simplified circuit provides optimal location for the placement of HVDC or FACTS devices into the network. These devices can also be represented by appropriate passive elements (i.e., RLC) to introduce damping, synchronizing, and inertia effects in the system. The optimal damping can be easily determined using the analogous ‘maximum power theorem’ to obtain a value for the virtual resistance ‘R’ in the analog network. This value of R directly corresponds to the controller gain in the real network. A case study of three machine nine bus system is presented in this paper to show such applications. This control design procedure is not only simple and intuitive, but has beneficial effect on the system dynamics even with detailed models.