Priority access of renewable resources such as offshore wind recommended by European energy directives, new market models and trading the electric energy among countries lead to new requirements on the operation and expansion of transmission grids. Since AC grid expansions are limited by legislative issues and long distance transmission capacity, there is a considerable attention drawn to appli...

The fast development of power electronics based on new and powerful semiconductor devices has led to innovative technologies, such as HVDC, which can be applied to transmission and distribution systems. The distribution voltage level is smaller than the transmission one, thus the power electronics are less expensive in distribution. The technical and economical benefits of this technology repre...

Recently, there has been a fast development and deployment of wind energy to meet the increasing electrical power demand and to limit the use of fossil fuels. More and more wind farms are planned far from shore because of good wind condition and less visual impact. This is so called offshore wind farm (OWF). In such a situation, high voltage direct current (HVDC) transmission is a favorable opt...

Because of high reliability and other characteristics, High Voltage Direct Current (HVDC) Light system had important applications in power transmission system. In order to ensure its operation safety, the fault diagnosis technologies based on observer were researched. The model of HVDC light system was introduced, and the types and characteristics of the system were analyzed. Several common fau...

HVDC circuit breaker with sufficient interruption capability and interruption speed, as a key technology to enable HVDC transmission in meshed multi terminal networks do not yet exist. AC circuit breakers in combination with a passive resonance path are used to build HVDC breakers even though the requirements for AC breaking strongly differ from requirements for DC current interruption. Current...

In this paper, a nonlinear controller for VSC-HVDC transmission system is proposed. The feedback linearization based nonlinear differential-geometric techniques is used to cancel nonlinearities and decouple the input control variables. A predictive current control (PCC) method is also proposed. It can predict the current reference for the next sampling instant rapidly and accurately. Comprehens...

One of the main objectives of the smart grid initiative is to enable bulk power transmission over long distance, with reduced transmission losses. Besides the traditional high-voltage alternating current (HVAC) transmission, with the advancement in power electronics, high-voltage direct current (HVDC) transmission is increasingly becoming important. One of the main factors impacting the transmi...

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...

In this paper an alternative railway power systems design based on an HVDC feeder is studied. The HVDC feeder is connected to the catenary by converters. Such an HVDC line is also appropriate for DC-fed railways and AC-fed railways working at public frequency. A unit commitment optimal power flow model has been developed and is applied on a test system. In this paper, the model is presented in ...

Large offshore wind farms are recently emerging as promising alternative power Sources. Long distances between offshore generation and onshore distribution grid demand new solutions for their connect alternative to conventional AC transmission above a certain cable length. This paper presents a new VSC transmission topology for HVDC grid connection of offshore wind farms.