Interoperability of voltage source converters in dc grids

Review of dc–dc converters for multi‐terminal HVDC transmission networks

“…The emergence of voltage source converter high-voltage dc (VSC-HVDC) in the early 1990s [10,12,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] that can reverse dc power without any difficulty (power reversal is achieved without the need to reverse the dc voltage) has reinvigorated research into generic multi-terminal HVDC networks. Recent consideration of offshore wind farms by many European countries with real possibilities of building offshore multi-terminal HVDC networks and inter-regional dc grids, has encouraged serious research and development effort from major HVDC manufacturers and academia [1,8,12,[43][44][45][47][48][49][50][51][52][53][54][55][56][57][58][59]. These efforts include all technology chains which are necessary for practical realisation of multi-terminal HVDC networks, such as dc switchgear (dc circuit breakers and fast disconnectors) and high-voltage dc-dc converters [44,47,[60]…”

Interoperability of Modular Multilevel Converters and 2-level Voltage Source Converters in a Laboratory-Scale Multi-Terminal DC Grid

“…Thus, European Transmission System Operators (TSOs) require that future MT HVDC systems should be based on a technical foundation allowing for multi-vendor solutions in a similar way as in traditional ac systems. For reliable operation of such multi-vendor systems it is critical to ensure interoperability between installations from different manufacturers [6], [7], [11]. This implies that HVDC converter stations commissioned separately at different times during the development of a MT HVDC system should be able to operate together without causing problems due to differences in topologies or control system implementations.…”

“…However, in the context of HVDC transmission, the concerns regarding converter interoperability seems to have increased substantially with the introduction of the MMC, which has expanded the number of possible configurations and topologies that can potentially coexist in the same system. An example of simulation-based analysis for confirming successful interoperability of HVDC converter terminals with different topologies was provided in [11].…”

“…Indeed, the theoretical framework and the tools suitable for analysis of these two critical aspects of interoperability will differ significantly. For example, investigation of potential interoperability issues related to operation of different converter topologies in the same system would require very detailed models, which in practice restricts the analysis to time-domain simulations or experimental testing, as in [11], [12], [13]. By contrast, it can be expected that interoperability issues related to the control strategies of the HVDC converter terminals, and especially interactions associated with the outer control loops and their tuning can be analyzed by average models, as discussed in [14]- [19].…”

Impedance computation for power electronic converters with Hilbert transform

“…These grids have the voltage source converter (VSC) topology (e.g. two level, modular multilevel or other configurations) as the main agent acting on the power flow control [1]- [5]. A large number of models for converters and elements of the power electronics based network has been developed in the frequency domain to study the behaviour and the stability of the system with the Nyquist criterium [6]- [10].…”