During the steady-state period of low-voltage ride-through in renewable energy integrated power grid with faults

inappropriate active and reactive current injections can lead to system instability

causing static voltage stability issues. This paper extends the normal steady-state static voltage stability analysis method to the low-voltage ride-through period of new energy generator

analyzes its mechanism

and defines the static stability index for short circuit faults. Firstly

considering the low-voltage ride-through control strategy of the renewable energy generator

the critical current value for voltage stability during the low-voltage ride-through period of a single renewable energy source integrated power grid is obtained. A low-voltage ride-through static voltage stability margin index (LTSVSMI) is defined. Difference is compared in static stability characteristics between new energy generators during low-voltage ride-through period and in the normal steady state

and there are significant differences between the two stability limits. Secondly

to calculate the stability index for an asymmetric fault in a single renewable energy integrated power grid

the negative-sequence and zero-sequence networks are treated as additional impedances connected to the fault point

and the impact of asymmetric faults is analyzed. In a multi-source renewable energy power grid

the fault ports are specially treated according to symmetric and asymmetric fault types

and the influence of other renewable energy sources is incorporated into virtual impedances

extending the application of the method to multi-source renewable energy integrated power grids. Finally

a single renewable energy source grid-connected system and a multi-source renewable energy grid-connected system are simulated based on the IEEE 33-node distribution network to validate the correctness of the derived results.