Converter transformers are the key and the most important components in high voltage direct current (HVDC) power transmission systems. Statistics show that the failure rate of HVDC converter transformers is approximately twice of that of transformers in AC power systems. This paper presents an approach integrated with a two-dimensional cloud model and an entropy-based weight model to evaluate t...

This paper analyses reliability data of HVDC systems of Southern China Power Grid. The weak links of HVDC systems’ operational reliability are DC control and protection, valve hall and valve cooling system and transmission lines. Some improvement measures and HVDC system reliability technology are proposed in this paper.

Wind energy has huge potential to become major source of renewable energy for the modern world. For integrating wind farms to the AC grid, HVDC transmission systems have several advantages over AC transmission systems. This paper presents the design and control of voltage source converter based HVDC system for integration of wind farms in to AC grid. The designed VSC-HVDC system performance und...

This paper focuses on generic Type 4 wind turbine generators models, their applicability in modern HVDC connections and their capability to provide advanced ancillary services therefrom. A point-to-point HVDC offshore connection is considered. Issues concerning coordinated HVDC and wind farm control as well as the need of a communication link are discussed. Two possible control configurations a...

s : This paper proposes the improvement of power flow during transient condition of HVDC light using PI Controller. The Optimal design of PI controller for a HVDC light is a challenging task and time consuming using the conventional techniques. This work presents analysis of transient stability of HVDC link using PI controller, and the stability has been improved by optimized gains of PI contro...

The fault recovery of VSC-HVDC transmission system is often influenced by many factors, such as the reactive power compensation characteristics of the inverter and the dynamic performance of DC controllers. In this paper, the PSCAD/ EMTDC simulation tool is used to study the dynamic recovery performance of VSC-HVDC system for several different var compensating devices in VSC-HVDC inverter-Fixed...

This paper presents the performance analysis of DFIG based off shore wind farm feeding to large power system through a hybrid HVDC link. The hybrid HVDC link consists of a line commutated converter based inverter and voltage source converter based rectifier. The active and reactive power of off shore station is controlled using voltage source converter based rectifier controller and the dc line...

High Voltage Direct Current (HVDC) power transmission is employed to move large amounts of electric power. There are several possibilities to enhance the transient stability in a power system. One adequate option is by using the high controllability of the HVDC if HVDC is available in the system. This paper presents a control technique for HVDC to enhance the transient stability. The strategy c...

High Voltage Direct Current (HVDC) lines and grids interconnect AC grids to increase reliability, facilitate integration of electricity markets and connect offshore wind generation. To address the growing uncertainty in the operation of such systems and fully utilize HVDC control capabilities, this work proposes a semidefinite relaxation of a chance constrained AC optimal power flow (OPF) for i...

The intent of this research is to do studies on these HVDC lines and to determine if they improve dynamic performance. In attempting to do so, tools such as PSS/E and a MATLAB based tool, PSAT, will be used to construct multiterminal HVDC models on an IEEE 9-bus system and an IEEE 14-bus system. While studying the IEEE 9-bus system, a comparison will be done to see whether using HVDC lines will...