This paper presents both eigenvalue calculations and dynamic simulations to determine dynamic stability of multiple photovoltaic (PV) modules connected to a large utility grid. Each PV subsystem is connected to the utility grid through a DC-to-DC boost converter and a DC-to-AC three-phase inverter. The dynamic equations of the combined multiple PV systems are derived in detail to examine the dynamic behavior of the studied system under different operating points. System eigenvalues are calculated for determine stability margin of the studied PV system under various operating conditions. Transient responses of the studied PV system subject to sudden disturbances are also examined. It can be concluded from the simulated results that the proposed analyzed schemes are very effective to determine dynamic stability limits and transient behaviors of the studied grid-connected multiple PV systems under different operating points and various disturbance conditions.