The Influence of VSC–HVDC Reactive Power Control Mode on AC Power System Stability

Abstract

Voltage source converter-based high-voltage direct current (VSC-HVDC) has the advantage of fast and independent controllability on active and reactive power. This paper focuses on effects of commonly proposed reactive power control modes, constant reactive power control and AC voltage margin control. Based on the mathematical model of single machine infinity equivalent system with embedded VSC-HVDC, the influence of VSC-HVDC with different reactive power control strategies on transient stability and dynamic stability of the AC system is studied. Then case studies were conducted with a realistic model of grid. The dynamic responses of AC/DC systems for different VSC-HVDC reactive power control modes were compared in detail. It is shown that compared to constant reactive power control, AC voltage margin control can provide voltage support to enhance the transient angle stability of an AC system. However, the fluctuant reactive power injected into a weak AC system may adversely affect power system oscillation damping for VSC-HVDC with AC voltage margin control, if the parameters of the controller have not been optimized to suppress the low-frequency oscillation. The results of this paper can provide certain reference for the decision of an appropriate VSC-HVDC reactive power control mode in practice.

Modern Power System Dynamics, Stability and Control

“…Ying Wang et al in [12] focus on effects of commonly proposed control modes for a voltage source converter (VSC)-based HVDC systems. The influence of VSC-HVDC with different reactive power control strategies on transient stability and dynamic stability of the AC system is studied.…”

Contingency Control Capability of an Optimized HVDC-Based VSC Transmission System

“…representing loss components of voltage magnitude are obtained from ( 23) and (24), respectively but derivatives for the loss angle components equals zero as a result of dc components, hence;…”

“…In a similar work, the control parameters of VSC were tuned using particle swarm optimization algorithm (PSO) for steady state and dynamic performance enhancement of VSC-HVDC system [23]. Wang et al, studied the effects of dissimilar reactive power control strategies on transient and dynamic stability of an ac system, with conclusion that oscillation control and voltage sustenance were influenced especially at the instance of grid disturbance [24]. It was concluded in [25] however, that VSC-HVDC have an impact on interdependency of power system dynamics and that further studies are required to fully understand their impact on system stability improvement and ancillary support services.…”

A Novel Adaptive Control Approach Based on Available Headroom of the VSC-HVDC for Enhancement of the AC Voltage Stability

“…VSC-HVDC technology is a promising solution for integration of future offshore wind farms into the existing AC system and also an attractive bulk power transmission structure in the next-generation networks [1]. VSC-HVDC can contribute to voltage stability improvement during severe disturbance [2][3][4][5][6][7][8][9][10][11][12][13], while the control schemes of the VSC-HVDC play an important role in the enhancement of the voltage stability [2][3][4][5][6][7][10][11][12][13]. In recent years, there are a number of research efforts focusing on the voltage stability of multi-terminal HVDC networks [2][3][4][5][6][7][8][9][10][11][12][13].…”

“…It is also found that the control schemes of VSC have an important effect on the voltage stability. Several control methods of the VSC-HVDC networks to provide voltage enhancement during the AC voltage drops are presented in [5][6][7][8][9][10][11][12][13]. However, in those papers, the limits of the reference reactive current are always selected corresponding to different control modes, which will restrict the capability of VSC for reactive support, especially under serious voltage falls.…”