The invention discloses a grid-connected control method for a multi-
machine parallel virtual synchronous
inverter. When each virtual synchronous
inverter is connected to a main power network in parallel, the
voltage synchronization between each virtual synchronous
inverter and the main power network can be realized by using the
phase angle compensation amount and the
angular frequency synchronouscompensation amount. In addition, the current
virtual inertia of each virtual synchronous inverter is adjusted to the target
virtual inertia by utilizing the equivalent
reactance between each virtualsynchronous inverter and the main power network and the maximum
angular frequency compensation amount, so as to achieve the purpose of suppressing
power oscillation between each virtual synchronous inverter and the main power network. Therefore, when each virtual synchronous inverter is connected to the main power network, the synchronization between the output
voltage of each virtual synchronousinverter and the
voltage of the main power network is ensured, and the
power oscillation problem caused by each virtual synchronous inverter can be avoided when each virtual synchronous inverter can not be connected to the main power network. In addition, the invention discloses a grid-connected control device for a multi-
machine parallel virtual synchronous inverter, which has the effect as above.