Cooperative Current Limiting Control between Grid Forming Converters in Power Electronic Equipment System
With the rapid development of new energy,the scenarios of 100%power electronic equipment networking and independent operation are gradually increasing.Due to the lack of inertia and damping of traditional synchronous genera-tor,they are sensitive to external interference when the grid forming converters based on different control types provide voltage and frequency support for the system.Under the condition of large load disturbance,the system has obvious over-current problems.To solve this problem,firstly,we devised an overcurrent suppression method based on Current Satura-tion Algorithm for single grid forming converter to limit its transient overcurrent.Secondly,we proposed a cooperative current limiting control method based on different control types for multi-port converters,which solved the problem of ex-cessive output current caused by disturbance when networking composed of grid forming converters and realized the smooth switching between current limiting control and normal working mode.At the same time,we built a small signal model of the system and used the root locus to analyze the influence of the main control parameters on the system stabili-ty.Finally,we built a controller-level-hardware-in-the-loop test platform and performed hardware-in-the-loop tests on the theoretical analysis and the proposed method to verify the effectiveness and superiority of the proposed method.
power electronic equipment networkinggrid forming convertercooperative controlcurrent limitingstability analysis