Analytical Approach for Fast Frequency Response Control of VSC HVDC

Abstract

The importance of the auxiliary control of power electronic devices such as HVDC and FACTs is growing owing to the increase in the generation capacity of renewable energy sources. This paper presents a temporary frequency support strategy using the electrostatic energy in voltage-sourced convertertype high-voltage direct current systems. An analytical derivation for selecting the optimal droop constant to improve the frequency nadir was established. The optimal droop constant was derived via system frequency response analysis by using the support termination time. Furthermore, the optimality of the support was computed using numerical equations. Modified outer control loops were implemented in the master controller to utilize the proposed method in voltage-sourced converter control. The effect of the fast frequency support control strategy was verified via a time-domain electromagnetic transient program simulation based on case studies. To examine the practical applicability of the proposed strategy, the parameter robustness was investigated by performing deviated system parameter simulations. The results validated the proposed strategy.INDEX TERMS Droop constant, fast frequency support control (FFSC), frequency nadir, primary frequency response, system frequency response, VSC HVDC.

Targeted Fast Frequency Response by Decomposing Frequency into Transient and Steady-State Deviations

“…If not appropriately moderated, this may give rise to a frequency second dip, which may lead to even a lower frequency nadir [20]. References [14], [15], [20]- [24] focus on preventing the frequency second dip while improving the frequency nadir using energy storage systems. However, these solutions are less attractive for practical applications due to the high cost and large-scale capacity requirements [22].…”

Decentralized Cooperative Active Power Control for Small-Scale Grids with High Renewable Penetration through VSC-HVDC

“…With advances in semiconductor devices and control methods, a large-capacity operation is also possible for VSC-HVDC. It can change the power transfer direction faster than LCC-HVDC [26][27][28][29][30][31]. Recently, solutions for improving grid stability based on the VSC-HVDC have been studied.…”