A comparative safety assessment for direct current and direct current with hybrid supply power systems in a windfarm service operation vessel using system- theoretic process analysis

Research output: Contribution to conferencePaper

Abstract

As windfarms are moving further offshore, their maintenance has to be supported by the new generation Service Operation Vessels (SOV) with Dynamic Positioning capabilities. For the SOV safe operations it is crucial that any hazardous scenario is properly controlled. Whilst international regulations require the implementation of Failure Modes and Effects Analysis (FMEA) for SOV power systems, FMEA has been criticised for not addressing properly failures in control systems. In this study, System-Theoretic Process Analysis (STPA) is employed for identifying the hazardous scenarios in terms of Unsafe Control Actions (UCAs) in Direct Current (DC) and DC with batteries power systems. Then the identified UCAs are ranked based on their risk. The results demonstrate that the number of hazardous scenarios derived by the STPA increases in a power system with batteries in comparison to a conventional DC power system, thus depicting higher complexity of this system. However, the increase in overall risk is small and within acceptable limits, whilst the risk reduces for a number of UCAs leading to Diesel Generator overload sub-hazard.

Conference

ConferenceEuropean STAMP Workshop & Conference
Abbreviated titleESWC
CountryFinland
CityEspoo
Period18/09/1920/09/19
Internet address

Fingerprint

Electric power systems
Failure modes
Dynamic positioning
Hazards
Control systems

Keywords

  • windfarm service operation vessels
  • safety
  • blackouts
  • diesel-electric propulsion
  • hybrid diesel-electric propulsion

Cite this

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title = "A comparative safety assessment for direct current and direct current with hybrid supply power systems in a windfarm service operation vessel using system- theoretic process analysis",
abstract = "As windfarms are moving further offshore, their maintenance has to be supported by the new generation Service Operation Vessels (SOV) with Dynamic Positioning capabilities. For the SOV safe operations it is crucial that any hazardous scenario is properly controlled. Whilst international regulations require the implementation of Failure Modes and Effects Analysis (FMEA) for SOV power systems, FMEA has been criticised for not addressing properly failures in control systems. In this study, System-Theoretic Process Analysis (STPA) is employed for identifying the hazardous scenarios in terms of Unsafe Control Actions (UCAs) in Direct Current (DC) and DC with batteries power systems. Then the identified UCAs are ranked based on their risk. The results demonstrate that the number of hazardous scenarios derived by the STPA increases in a power system with batteries in comparison to a conventional DC power system, thus depicting higher complexity of this system. However, the increase in overall risk is small and within acceptable limits, whilst the risk reduces for a number of UCAs leading to Diesel Generator overload sub-hazard.",
keywords = "windfarm service operation vessels, safety, blackouts, diesel-electric propulsion, hybrid diesel-electric propulsion",
author = "Victor Bolbot and Romanas Puisa and Gerasimos Theotokatos and Evangelos Boulougouris and Dracos Vassalos",
year = "2019",
month = "9",
day = "18",
language = "English",
note = "European STAMP Workshop & Conference, ESWC ; Conference date: 18-09-2019 Through 20-09-2019",
url = "https://www.aalto.fi/en/events/issaveswc-2019",

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TY - CONF

T1 - A comparative safety assessment for direct current and direct current with hybrid supply power systems in a windfarm service operation vessel using system- theoretic process analysis

AU - Bolbot, Victor

AU - Puisa, Romanas

AU - Theotokatos, Gerasimos

AU - Boulougouris, Evangelos

AU - Vassalos, Dracos

PY - 2019/9/18

Y1 - 2019/9/18

N2 - As windfarms are moving further offshore, their maintenance has to be supported by the new generation Service Operation Vessels (SOV) with Dynamic Positioning capabilities. For the SOV safe operations it is crucial that any hazardous scenario is properly controlled. Whilst international regulations require the implementation of Failure Modes and Effects Analysis (FMEA) for SOV power systems, FMEA has been criticised for not addressing properly failures in control systems. In this study, System-Theoretic Process Analysis (STPA) is employed for identifying the hazardous scenarios in terms of Unsafe Control Actions (UCAs) in Direct Current (DC) and DC with batteries power systems. Then the identified UCAs are ranked based on their risk. The results demonstrate that the number of hazardous scenarios derived by the STPA increases in a power system with batteries in comparison to a conventional DC power system, thus depicting higher complexity of this system. However, the increase in overall risk is small and within acceptable limits, whilst the risk reduces for a number of UCAs leading to Diesel Generator overload sub-hazard.

AB - As windfarms are moving further offshore, their maintenance has to be supported by the new generation Service Operation Vessels (SOV) with Dynamic Positioning capabilities. For the SOV safe operations it is crucial that any hazardous scenario is properly controlled. Whilst international regulations require the implementation of Failure Modes and Effects Analysis (FMEA) for SOV power systems, FMEA has been criticised for not addressing properly failures in control systems. In this study, System-Theoretic Process Analysis (STPA) is employed for identifying the hazardous scenarios in terms of Unsafe Control Actions (UCAs) in Direct Current (DC) and DC with batteries power systems. Then the identified UCAs are ranked based on their risk. The results demonstrate that the number of hazardous scenarios derived by the STPA increases in a power system with batteries in comparison to a conventional DC power system, thus depicting higher complexity of this system. However, the increase in overall risk is small and within acceptable limits, whilst the risk reduces for a number of UCAs leading to Diesel Generator overload sub-hazard.

KW - windfarm service operation vessels

KW - safety

KW - blackouts

KW - diesel-electric propulsion

KW - hybrid diesel-electric propulsion

UR - https://www.stamp-workshop.eu/

M3 - Paper

ER -