Voltage Source Converters (VSC) have for the first time been used for HVDC transmission in a real network. Experience from the design and commissioning of the transmission shows that the technology has now reached the stage where it is possible to build high voltage converters utilising Insulated Gate Bipolar Transistors (IGBTs). Operation and system tests have proved that the properties that h...

Concepts for possible use of high temperature superconductors in millimeter/submillimeter wave cavities, mode convertors and waveguides are described. Reduction of the ohmic loss in the cavities could remove a major constraint on the power produced by high frequency gyrotrons. Significant benefits could be obtained without the need for ultra high values of cavity Q. Improved mode convertor perf...

The need for ultra low-power, area efficient and high speed analog-to-digital converters is pushing toward the use of dynamic regenerative comparators to maximize speed and power efficiency. The objective of this paper is to design and implementation of delay efficient and low power consumption double-tail dynamic comparator in successive approximation analog to digital convertor. The conventio...

An efficient model has been developed to simulate High Voltage Direct Current (HVDC) Converters in real-time transient simulators. Real time performance of 45 μs per solution step has been achieved for a 12-pulse monopolar converter and 81 μs for the bipolar converter using a single processor Pentium Pro 200 MHz desktop computer. The HVDC converter model is solved simultaneously with the power ...

Several offshore wind farms are planned in a number of locations in Northern Europe. The introduction of offshore wind power brings the wind power into a new era, characterized by larger size of the farms, 200 – 1000 MW are planned, and increasing distances from the grid. Cable transmission is the only solution for the transmission from the farm to the shore. Often land cables are also required...

Existing mechanical HVDC breakers are capable of interrupting HVDC currents within several tens of milliseconds, but this is too slow to fulfill the requirements of a reliable HVDC grid. HVDC breakers based on semiconductors can easily overcome the limitations of operating speed, but generate large transfer losses, typically in the range of 30 percent of the losses of a voltage source converter...

In this paper HVDC is investigated for its ability to supply a passive industrial system. The objective of the paper is to assess the potential and limitation of the use of dc distribution in the industrial power system. The performance of the dc supplied distribution system is compared with pure ac supplied distribution system of simi lar ratings under balanced faults on the grid side and moto...

Experiments have been conducted on a dual electric grid thermionic device to investigate an alternative method of space charge mitigation in a thermionic energy convertor (TEC). Two electric grids, the attractor and deflector grids, provide opposing electric fields to overcome space charge while minimizing power losses to the attractor grid. Electron beams are formed in the electrode gap provid...