This paper proposes a novel approach based on the eigenvalue method to investigate both transient and steady-state performance of a photovoltaic (PV) system connected to a large utility grid. A DC-to-DC boost converter is employed to step up the output DC voltage of the PV array. A DC-to-AC single-phase inverter is utilized to convert the higher DC voltage from the boost converter's output to the three-phase balanced voltages of utility's distribution system. The dynamic equations of the studied PV-utility's system are derived to examine the dynamic characteristics of the studied system under different operating conditions. The transient responses of the studied PV under different operating conditions are also examined. It can be concluded from the simulated results that the proposed methods are effective to explore the transient performance and dynamic characteristics of the studied combined PV-utility system under different disturbance conditions.