Frequency-domain modelling of sub-synchronous torsional interaction of synchronous machines and a high voltage direct current transmission link with line-commutated converters

Electrical Damping Assessment and Stability Considerations for a Highly Electrified Liquefied Natural Gas Plant

“…The loop resulting from the described phenomena can be stable when the torsional vibrations on the TG unit naturally damp following the transient event. The loop can be unstable when such vibrations keep increasing over time with insufficient or negative damping [9,11].…”

“…The loop resulting from the described phenomena can be stable when the torsional vibrations on the TG unit naturally damp following the transient event. The loop can be unstable when such vibrations keep increasing over time with insufficient or negative damping [9,11]. The overall damping of each TG unit supplying an island-operated grid is the sum of the shaftline inherent mechanical damping plus the electrical damping resulting from the above-mentioned electro-mechanical loop [24].…”

“…Limited literature has been published about SSTI phenomena in LNG plants [5][6][7][8]. Differently, numerous studies can be found on SSTI for High Voltage Direct Current (HVDC) applications [9][10][11][12][13]. In this context, SSTI is categorized as the evolution of the Sub-Synchronous Resonance (SSR) phenomenon [14][15][16][17][18].…”

Impact of DFIG‐based wind farm integration on sub‐synchronous torsional interaction between HVDC and thermal generators

“…A new SSTI problem emerging in Inner Mongolia, a province in Northern China was introduced in [14], and preliminary analysis was made by the complex torque coefficient approach and electromagnetic transient (EMT) simulations. The authors of [15] built a model of a system that includes an LCC-HVDC transmission link closely connected to a synchronous generator used to perform the analysis of SSTI in the frequency domain. In [16], the SSTI problems caused by an HVDC system were analysed intensively on the basis of eigenvalue analysis method and EMT simulations.…”

“…In [16], the SSTI problems caused by an HVDC system were analysed intensively on the basis of eigenvalue analysis method and EMT simulations. However, the HVDC rectifier side of the studied system in [10][11][12][13][14][15][16] is only in the form of TG, not bundled wind-thermal energy. The above publications have not studied that the impact of wind power integration on the SSTI between TGs and HVDC.…”