Distributed Voltage and Current Control of Multi-Terminal High-Voltage Direct Current Transmission Systems

Abstract

High-voltage direct current (HVDC) is a commonly used technology for long-distance power transmission, due to its low resistive losses and low costs. In this paper, a novel distributed controller for multi-terminal HVDC (MTDC) systems is proposed. Under certain conditions on the controller gains, it is shown to stabilize the MTDC system. The controller is shown to always keep the voltages close to the nominal voltage, while assuring that the injected power is shared fairly among the converters. The theoretical results are validated by simulations, where the affect of communication time-delays is also studied.<p>QC 20150519</p

Distributed Controllers for Multiterminal HVDC Transmission Systems

“…The 2 nd author is also affiliated with the Centre for Autonomous Systems at KTH. This work extends the manuscripts presented in [5], [2]. The Authors are with the ACCESS Linnaeus Centre, KTH Royal Institute of Technology, 11428 Stockholm, Sweden.…”

“…To overcome this potential issue, a novel controller is proposed. The proposed controller takes inspiration from the control algorithms given in [3], [5], [24], and is given by…”

Control strategies for automatic generation control over MTDC grids

“…A number of primary control algorithms, which operate on the milliseconds to seconds scale, and secondary control algorithms, which act on the seconds to minutes scale, have been developed for MTDC grids, typically for the regulation of the voltages and DC grid power transfers (Hendriks et al, 2007;Beerten and Belmans, 2013;Egea-Alvarez et al, 2013;Arags-Pealba et al, 2014;EgeaAlvarez et al, 2012;Zonetti et al, 2014;Andreasson et al, 2013). A range of primary control algorithms exist for sharing power between areas.…”

A tool for power flow analysis of a generalized class of droop controllers for high-voltage direct-current transmission systems

“…One way to deal with this issue, that prevails in practice, is the use of hierarchical control architectures [1]- [3]. Usually, at the top of this hierarchy, a centralized controller called tertiary controlbased on power flow optimization algorithms (OPFs)-is in charge of providing the inner controllers with the operating point to which the system has to be driven, according to technical and economical constraints [1].…”

“…The ever increasing use of power electronic devices in modern electrical networks, in particular the presence of constant power devices (CPDs), induces a highly nonlinear behavior in the systemrendering the analysis of existence and stability of equilibria very complicated. Since linear, inherently stable, models, are usually employed for the description of primary control of dc grids [3], [6], [7], little attention has been paid to the issues of stability and existence of equilibria. This fundamental aspect of the problem has only recently attracted the attention of power systems researchers [8]- [10] who, similarly to the present work, invoke tools of nonlinear dynamic systems analysis, to deal with the intricacies of the actual nonlinear behavior.…”