<p>To achieve smooth switching between grid-connected and islanded operation of microgrid, a smooth switching control strategy based on the consistency theory for multi-machine parallel PV energy storage VSG system is proposed. This distributed control strategy can be synchronized without relying on phase-locked loop; the control is more flexible and simple. The consistency theory is used to make phase angle and voltage amplitude between DGs consistent. Meanwhile, grid synchronization controllers are designed to ensure the phase angle and voltage amplitude of leading DG is synchronized with grid, the rest of other DGs can be made to be consistent with the leading DG when they turn from islanding to grid connection. Finally, Simulation model and experimental platform for smooth switching control strategy of multi-machine parallel PV energy storage VSG system based on consistency theory approach are established. The test results show that the consistency theory-based multi-machine parallel PV energy storage VSG system has stronger robustness in switching compared with state-following method/direct switching method. Meanwhile, this method not only can realize secondary regulation frequency and voltage in the transient and steady state but also can realize power precise distribution of the system.</p>