Study on Active Control of Short-Circuit Current by Renewable Energy Considering Voltage Stability

In large receiving-end power grids in load-intensive areas, the problem of main grid short-circuit current exceeding the equipment's interrupting capacity is prone to occur. The grid-connected operation of massive renewable energy units further raises the short-circuit current level in sensitive areas, while medium and low voltage power grids may simultaneously have insufficient short-circuit current, resulting in the inability to configure backup protection. Therefore, with the participation of renewable energy units in the active control of short-circuit current as the core, the influence of low voltage ride-through parameters of renewable energy units on their output short-circuit current characteristics was studied and verified, and then a fast calculation expression for the short-circuit current at the fault point was established. On this basis, in order to avoid voltage problems caused by changes in low voltage ride-through parameters of renewable energy, a single section online decision-making and day-ahead decision-making of short-circuit current considering voltage stability are proposed, and a collaborative active control framework for short-circuit current between the dispatching master station and renewable energy plants is established. The results of different cases based on actual power grids show that the proposed short-circuit current control method involving renewable energy units can ensure voltage stability while controlling the short-circuit current.