Abstract: Due to the small capacity and weak regulation energy of island grid，it is very easy to cause system

collapse. When the isolated grid collapses，it is necessary to establish the grid through its internal black start power

supply without relying on the external public grid. In recent years，with the rapid development of energy storage

technology，more and more energy storage systems are incorporated into the isolated grid to regulate the power load balance in the isolated grid，which makes it possible for the energy storage system and the traditional diesel

generator to complete the black start of the power grid together. Take the actual isolated grid black start as an

example，the power supply network architecture of isolated grid black start power supply was introduced，and the

unified droop control strategy based on virtual impedance for building large-scale energy storage system black start

power supply in isolated mode was analyzed under the premise of solving the internal circulation of multi machine

parallel system and aiming at the parallel voltage source of energy storage converter，the simulation model was

constructed and verified.

      Key words: isolated grid；energy storage；diesel generator；black start；droop control；virtual impedance；

power sharing strategy