Metrological Qualification of PD Analysers for Insulation Diagnosis of HVDC and HVAC Grids

Fernando Garnacho; Fernando Álvarez; Alf-Peter Elg; Christian Mier; Kari Lahti; Abderrahim Khamlichi; Eduardo Arcones; Joni Klüss; Armando Rodrigo Mor; Pertti Pakonen; José Ramón Vidal; Álvaro Camuñas; Jorge Rovira; Carlos Vera; Miran Haider

doi:10.3390/s23146317

Metrological Qualification of PD Analysers for Insulation Diagnosis of HVDC and HVAC Grids

Sensors (Basel). 2023 Jul 11;23(14):6317. doi: 10.3390/s23146317.

Authors

Fernando Garnacho^{1

2}, Fernando Álvarez², Alf-Peter Elg³, Christian Mier⁴, Kari Lahti⁵, Abderrahim Khamlichi^{1

2}, Eduardo Arcones², Joni Klüss³, Armando Rodrigo Mor⁶, Pertti Pakonen⁵, José Ramón Vidal¹, Álvaro Camuñas², Jorge Rovira¹, Carlos Vera², Miran Haider³

Affiliations

¹ Fundación para el Fomento de la Innovación Industrial, FFII-LCOE, Eric Kandel Street 1, Getafe, 28906 Madrid, Spain.
² Department of Electrical and Electronic Engineering, Automatic Control and Applied Physics, School of Industrial Design and Engineering (ETSIDI), Universidad Politécnica de Madrid (UPM), Ronda de Valencia 3, 28012 Madrid, Spain.
³ RISE Research Institutes of Sweden, 501 15 Borås, Sweden.
⁴ Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands.
⁵ Department of Electrical Engineering, Tampere University (TAU), Korkeakoulunkatu 3, 33720 Tampere, Finland.
⁶ Instituto de Tecnología Eléctrica, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.

Abstract

On-site partial discharge (PD) measurements have turned out to be a very efficient technique for determining the insulation condition in high-voltage electrical grids (AIS, cable systems, GIS, HVDC converters, etc.); however, there is not any standardised procedure for determining the performances of PD measuring systems. In on-line and on-site PD measurements, high-frequency current transformers (HFCTs) are commonly used as sensors as they allow for monitoring over long distances in high-voltage installations. To ensure the required performances, a metrological qualification of the PD analysers by applying an evaluation procedure is necessary. A novel evaluation procedure was established to specify the quantities to be measured (electrical charge and PD repetition rate) and to describe the evaluation tests considering the measured influence parameters: noise, charge amplitude, pulse width and time interval between consecutive pulses. This procedure was applied to different types of PD analysers used for off-line measurements, sporadic on-line measurements and continuous PD monitoring. The procedure was validated in a round-robin test involving two metrological institutes (RISE from Sweden and FFII from Spain) and three universities (TUDelft from the Netherlands, TAU from Finland and UPM from Spain). With this round-robin test, the effectiveness of the proposed qualification procedure for discriminating between efficient and inappropriate PD analysers was demonstrated. Furthermore, it was shown that the PD charge quantity can be properly determined for on-line measurements and continuous monitoring by integrating the pulse signals acquired with HFCT sensors. In this case, these sensors must have a flat frequency spectrum in the range between several tens of kHz and at least two tens of MHz, where the frequency pulse content is more significant. The proposed qualification procedure can be useful for improving the future versions of the technical specification TS IEC 62478 and the standard IEC 60270.

Keywords: GIS; HVDC–HVAC transmission and distribution grids; cable insulation; condition monitoring; insulation testing; off-line measurement; on-line measurement; partial discharges; qualification procedure; standardisation.

Grants and funding

The research presented in this paper has received funding from the project 19ENG02 FutureEnergy of the EMPIR programme, co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.