Modelling of a 25 kV-50 Hz railway infrastructure for harmonic analysis

2019-04-17T10:28:46+00:00December 20th, 2018|Power Electronics & Converters, Publications|

This paper presents a methodology for the modelling of a 25 kV-50 Hz railway infrastructure, for frequencies from 0 to 5 kHz. It aims to quantify the amplifications of current and voltage harmonics generated by on-board converters into the infrastructure. A circuit is developed to model the skin effect in the overhead line for time-domain simulations. A new approach, based on state space representation and transfer functions, is also proposed to analyse the interactions between trains.

Study of Turn-to-Turn Electrical Breakdown for Superconducting Fault Current Limiter Applications

2018-11-06T16:01:51+00:00November 2nd, 2018|High Voltage Substation Equipment, Publications|

The rational insulation design of a resistive superconducting fault current limiter (r-SCFCL) requires data gathered from experimental setups representative of the final apparatus. Therefore, an experimental study was performed to characterize the electrical breakdown (BD) of liquid nitrogen (LN2) in the peculiar conditions of a quenching superconducting device.

Arc appearance and cathode spot distribution in a long gap high-current vacuum arc controlled by an external axial magnetic field

2018-11-15T16:33:23+00:00October 31st, 2018|High Voltage Substation Equipment, Publications|

An experimental study of a high-current vacuum arc (VA) generated between two static CuCr25 contacts spaced 20 or 30 mm apart was conducted to characterize the arc appearance and the cathode spot (CS) distribution.

HVDC protection criteria for transient stability of AC systems with embedded HVDC links

2019-02-18T09:48:48+00:00October 15th, 2018|Publications, Supergrid Architecture & Systems|

The objective of this study is to propose a methodology for the transient stability assessment of a simple but representative AC grid in case of DC fault. After validation of the methodology, some HVDC link protection criteria are defined in terms of the Critical Time to Return to Operation. These criteria will be helpful for the design of HVDC protection systems or for the sizing of future HVDC links in order to respect the constraints of the existing protection strategies.

Electrical properties of epoxy systems based on ionic liquids

2018-11-07T16:13:21+00:00October 12th, 2018|High Voltage Substation Equipment, Publications|

In accordance with their interesting properties, ionic liquids (ILs) have attracted in the recent years a great interest in the material field. Recently, few authors have demonstrated the reactivity of ionic liquids towards epoxy in order to form new epoxy-based networks...

Advanced Electrical characterisation of high voltage 4H-SiC PiN diodes

2019-02-15T17:16:32+00:00September 6th, 2018|Power Electronics & Converters, Publications|

This paper reports the design, the processing, the static characterisation, the switching behaviour and the high current stress test of 10 kV aimed 4H-SiC bipolar diodes. The actual breakdown voltage of the selected devices is between 7 kV and 8 kV. The switching characterisations show a good behaviour with a t rr of only 90 ns. No degradation was observed after the application of 10 000 high current pulses during the stress tests.

Models of AC and DC cable systems for technical and economic evaluation of offshore wind farm connection

2019-01-10T10:06:53+00:00September 3rd, 2018|High Voltage Substation Equipment, HVDC Cable Systems, Publications|

Accurate cable modeling is a recurrent issue for electric architecture evaluation and design, especially in specific contexts, like offshore wind farms. This paper proposes optimal analytical cable models for the technical and economic assessment of offshore wind generation systems.

Space Charge Measurements for HVDC GIS Spacer using the Thermal Step Method

2018-09-11T14:29:58+00:00August 31st, 2018|High Voltage Substation Equipment, Publications|

High voltage direct current (HVDC) technologies are currently emerging to develop new energy transmission networks able to integrate renewable energy sources with remote locations from consumers. Gas Insulated Substations (GIS) have been widely used in alternating current (AC) transmission due to their low footprint and high reliability.