Flexible Time-Stepping Dynamic Emulation of AC/DC Grid for Faster-Than-SCADA Applications

Dynamic simulation of the integrated AC/DC grids plays a crucial role in the energy control center. In this work, a faster than supervisory control and data acquisition (FT-SCADA) emulation based on flexible time-stepping (FTS) algorithm is proposed for the energy control center to predict and mitigate the impacts after serious disturbances using field-programmable gate arrays (FPGAs). To gain a high acceleration over SCADA/real-time, the FTS-based dynamic emulation is applied to the AC grid, which is the IEEE 118-bus system where a $9^{th}$-order synchronous machine model is adopted. Meanwhile, the electromagnetic transient (EMT) emulation revealing the exact performance of the DC grid provides an insight into the impact on its AC counterpart. A power-voltage interface is inserted between the AC and DC grids since distinct emulation strategies are utilized, and the EMT-dynamic co-emulation is able to run concurrently on FPGA boards due to their massive parallelism. Three case studies are emulated to demonstrate the efficacy of the proposed algorithm, and a minimum of 101 times faster-than-SCADA/real-time can be achieved. Hence, following the occurrence of a disturbance, the FT-SCADA/RT emulator will generate an optimal solution in advance to maintain the stability of the hybrid AC/DC grid. The results of the FTS-based FT-SCADA/RT emulation are validated by the off-line transient stability simulation tool TSAT of the DSATools suite.