Projekter pr. år
This paper aims to disseminate the results of the COBRAcable research project. At first, expandable plans of an existing PtP link into a multi-terminal HVDC (MTDC) in the world are listed and compared with COBRAcable expansion plan. Two main factors are discussed, i.e. DC voltage operating range of the expanded system and the implementation of DC grid control concept. An analytic approach to redesign the existing link’s operating range to reflect the one for MTDC system is explained. Furthermore, an additional DC grid control layer is proposed in order interface between the coordinated MTDC control and converter control. By using this interface, the replacement of the existing PtP link’s converter control system when this link is expanded into an MTDC system can be avoided.
Apart from mitigating the expansion challenges, additional studies related with the AC-side impact of the converter control are also discussed. These studies are useful for both PtP and MTDC operations, because the same converter is connected with the same AC network. It is found that the converter can contribute to the long-term frequency stability of the AC system by changing the active power level through this converter. However, an active power gradient (APG) control should be carefully considered to avoid risking the AC system in the other side of the link. Furthermore, a new power factor control method is proposed. The proposed power factor control mitigate the challenge of the conventional control approach during active power reverse direction event.
|Titel||Proceedings of CIGRE Symposium Aalborg 2019|
|Forlag||CIGRE (International Council on Large Electric Systems)|
|Status||Udgivet - jun. 2019|
|Begivenhed||CIGRE Symposium Aalborg 2019 - Aalborg, Danmark|
Varighed: 4 jun. 2019 → 7 jun. 2019
|Konference||CIGRE Symposium Aalborg 2019|
|Periode||04/06/2019 → 07/06/2019|