Wide utilization of converter-based interfaces in AC-DC hybrid power system requires precise modeling and simulation for complicated and large-scale control system. However

this process can be accelerated by fine-grained parallel algorithm

hence improving the simulation efficiency. A fine-grained parallel algorithm for large-scale control system simulation is proposed

and a large-scale control system simulation on graphics processing unit(GPU)is accelerated. First

in order to generate massive computing threads

the control system is modeled by a directed graph(DG)with preliminary control elements. Second

by introducing a DG layering algorithm

the control elements are divided into different layers

which can be computed by fine-grained parallel strategies on GPU. Finally

through precise adjustment for thread structure and optimal utilization of shared memory

the computing threads are mapped to GPU cores with highest degree of parallelism. In order to validate the accuracy and acceleration of the proposed algorithm

an IEEE 13-bus distribution system with distributed energy resources integration is provided. Simulation results indicate that the proposed method significantly accelerates transient analysis of control system(TACS)on GPU. In addition

no scale limits are added to the proposed algorithm with adequate computing resources. This work is supported by State Grid Corporation of China.