This paper investigates the impact of embedded Voltage Source Converter-based High Voltage Direct Current (VSCHVDC) links on AC grids transient stability. Firstly, using Transient Energy Functions (TEF), it is demonstrated that VSC-HVDC links controlled to track constant power references, do not inherently improve transient stability of the surrounding AC grid as an AC line naturally does. Then, a control law using the feedback linearization technique on a simple but representative power system is derived. The control law highlights and combines the three main actions the VSC-HVDC link can offer to enhance rotor angle stability: fast power reallocation, injection of synchronising power and injection of damping power. The control law is implemented and validated in EMT simulation. It is then shown that an HVDC link can assure the synchronisation of different AC areas even if no AC transmission lines interconnect them. Through another case study, it is shown how the HVDC link can help to share dynamic frequency reserves in order to not jeopardise the stability of the system. A last example investigates the effect of a DC fault on AC transient stability and how the control can help improving the system response.
Juan Carlos Gonzalez-Torres, SuperGrid Institute 69100 Villeurbane, France
Gilney Damm, Laboratoire des signaux et systèmes (L2S), 91190 Gif-surYvette, France
Valentin Costan, EDF Lab Paris-Saclay, 91120 Palaiseau, France
Abdelkrim Benchaib, SuperGrid Institute 69100 Villeurbane, France
Françoise Lamnabhi-Lagarrigue, Laboratoire des signaux et systèmes (L2S), 91190 Gif-surYvette, France
Published in IET Research Journals, pp. 1–12 © The Institution of Engineering and Technology 2020