This paper analyzed a comparative transient performance of different types of single machine power system connected to infinite bus under the presence of energy storage devices like Superconducting Magnetic Energy Storage (SMES) and Capacitive Energy Storage (CES). For Automatic Generation Control (AGC) loop, thermal unit is considered. The thermal unit is either single or double reheat turbine. PI controller is provided in the AGC loop. The power system AVR loop is provided with Conventional Power System Stabilizer (CPSS), the performances are compared under the presence of SMES and CES units. It is shown that CES based PI controlled AGC loop along with CPSS assists best transient performance of the power system in all cases under different operating conditions. The transient performances are carried out with different load variations.