Damping of Subsynchronous Control Interactions in Large-Scale PV Installations Through Faster-Than-Real-Time Dynamic Emulation

Abstract

Large-scale photovoltaic (PV) power plant has witnessed a dramatic increase in the integration into transmission and distribution network, manifesting subsynchronous control interaction (SSCI) when the host grid is weak. In this work, the oscillation modes of a typical PV network are analyzed, and a faster-than-real-time (FTRT) emulation is proposed for predicting the SSCI and consequently mitigating its impacts on AC grid by taking the effective active/reactive power control action. The electromagnetic transient (EMT) simulation is utilized to model the PV panels and converter stations to reflect the actual dynamic process. Meanwhile, the AC grid undergoes transient stability (TS) simulation to obtain a high speedup over real-time, and consequently, a power-voltage interface is adopted for the coexistence of different simulation methods. The reconfigurability and parallelism of the field-programmable gate arrays (FPGAs) enable the EMT-TS co-emulation strategy to run concurrently. With a remarkable 122 FTRT ratio, the proposed hardware emulation can provide an effective solution before the SSCI causes serious disruption following its detection. The hardware emulation results are validated by the off-line simulation tool Matlab/Simulink ® and TSAT ® in the DSATools TM suite.INDEX TERMS AC/DC grid, dynamic simulation, electromagnetic transient, faster-than-real-time, fieldprogrammable gate arrays, hardware emulation, parallel processing, predictive control, PV generation.

Analysis of sub‐synchronous resonance between DC‐side dynamics of large‐scale PV plants and nearby synchronous generators shaft

“…The SSOs originated from PV converters' operating conditions integrated into the transmission and distribution systems and are studied in [41]. Although a comprehensive small‐signal analysis of PV plants is performed in this paper, only a single‐mass shaft model is used for the synchronous generator; thus, the impact of large‐scale PV plants on the torsional modes of nearby synchronous generators is not considered.…”