Security-constrained Economic Dispatch with Linear/Nonlinear Energy Sources during Short-Term Emergency Period

In the last decade, renewable energy resources and energy storage systems (ESSs) played a pivotal role in the enhancement of the security of power systems. They exhibit great potential in power system operations: maintaining the load balance and improving power system security. This paper investigates the impact of linear and nonlinear energy resources on security-constrained economic dispatch (SCED) solution with different contingencies as a time-varying optimization problem. Linear ESSs are prominent in the literature on SCED. However, most of the previous studies do not take into account the impact of ESSs' nonlinear characteristic as highlighted in this paper. Therefore, the SCED problem should be discussed as a time-varying optimization problem. A new procedure is presented to handle time-varying optimization problems by finding the switching points and generator response equations. Not only this paper highlights the limitations of linear ESS characteristic and the effectiveness of using nonlinear characteristic of ESS in SCED solutions; illustrated on modified IEEE 6-bus and 14-bus systems, but also different optimization methods are used to validate the proposed procedure.