The Effect of FRT Behavior of VSC-HVDC-Connected Offshore Wind Power Plants on AC/DC System Dynamics

Abstract

Future power systems will contain more converterbased generation, among which voltage-sourced converter VSC-HVDC connected offshore wind power plants (WPP). Their interaction with the onshore system influences power system dynamics in the transient stability time-frame. The respective protection and control methods which cause this interaction must be taken into account in grid-integration studies performed today.This paper gives insight about the effect of typically required fault ride through (FRT) and post-FRT measures of VSC-HVDC connected offshore WPPs on the combined AC and HVDC system dynamics. Several important sensitivities are addressed, among which 1) FRT implementation, 2) the post-fault active power recovery rates, 3) the AC network dynamic characteristics, and 4) the HVDC topology.The analysis is first performed as a proof of concept on a small benchmark system, and subsequently generalized to a realistic dynamic model of the future Northwestern European power system. The results of this paper can be used as reference for understanding the effects of large-scale VSC-HVDC connected offshore WPPs on the stability of the onshore interconnected power systems.

Enhanced Voltage Control of VSC-HVDC-Connected Offshore Wind Farms Based on Model Predictive Control

“…The details of the proposed MPC-EVCS are presented in Section V. To be noticed, the control period of the proposed EVCS is in seconds. Considering the real-life implementation, the coordination between the EVCS and existing FRT control scheme [17]- [20] of a wind farm should be in place. The FRT control should have the highest priority.…”

“…For VSC-HVDC connected OWFs, a considerable number of studies have been done for the fault ride through (FRT) / low voltage ride through (LVRT) control strategies due to the lower short circuit power contribution from power electronic interfaced WTGs and VSCs [17]- [19].…”

Impact of VSC Control Strategies and Incorporation of Synchronous Condensers on Distance Protection Under Unbalanced Faults

“…The value of I Q is obtained from [32] and it can be expressed as I Q = −2.5 |v + | + 2.25 (0 ≤ I Q ≤ 1). To enhance the fault-ride-through operation of the VSCs, both VSCs are equipped with a dynamic braking resistor on the DC side to drain the excess electrostatic energy according to [33]. Synchronous condensers SC1 and SC2 are equipped at the PCC of these two converters.…”

Cyber-physical energy systems modeling, test specification, and co-simulation based testing

“…In zone A , the FRT controller must engage internal component protection and while is shall prevent entering zone B . The protection and additional control measures that need to be taken are implemented as a finite state machine, hence a discrete controller [30]. The corresponding test system comprises the IEEE 9-bus transmission system, the SuT and the WTG.…”