pof_cables_60_30kv {CNAIM}

Current Probability of Failure for 30-60kV cables

Description

This function calculates the current annual probability of failure per kilometer for a 30-60kV cables. The function is a cubic curve that is based on the first three terms of the Taylor series for an exponential function. For more information about the probability of failure function see section 6 on page 34 in CNAIM (2021).

Usage

pof_cables_60_30kv(
  cable_type = "60kV UG Cable (Gas)",
  sub_division = "Aluminium sheath - Aluminium conductor",
  utilisation_pct = "Default",
  operating_voltage_pct = "Default",
  sheath_test = "Default",
  partial_discharge = "Default",
  fault_hist = "Default",
  leakage = "Default",
  reliability_factor = "Default",
  age
)

Arguments

cable_type

String. A sting that refers to the specific asset category. See See page 17, table 1 in CNAIM (2021). Options: cable_type = c("30kV UG Cable (Gas)", "60kV UG Cable (Gas)", "30kV UG Cable (Non Pressurised)", "60kV UG Cable (Non Pressurised)", "30kV UG Cable (Oil)", "60kV UG Cable (Oil)") . The default setting is cable_type = "60kV UG Cable (Gas)".

sub_division

String. Refers to material the sheath and conductor is made of. Options: sub_division = c("Aluminium sheath - Aluminium conductor", "Aluminium sheath - Copper conductor", "Lead sheath - Aluminium conductor", "Lead sheath - Copper conductor")

utilisation_pct

Numeric. The max percentage of utilisation under normal operating conditions.

operating_voltage_pct

Numeric. The ratio in percent of operating/design voltage.

sheath_test

String. Only applied for non pressurised cables. Indicating the state of the sheath. Options: sheath_test = c("Pass", "Failed Minor", "Failed Major", "Default"). See page 153, table 168 in CNAIM (2021).

partial_discharge

String. Only applied for non pressurised cables. Indicating the level of partial discharge. Options: partial_discharge = c("Low", "Medium", "High", "Default"). See page 153, table 169 in CNAIM (2021).

fault_hist

Numeric. Only applied for non pressurised cables. The calculated fault rate for the cable in the period per kilometer. A setting of "No historic faults recorded" indicates no fault. See page 153, table 170 in CNAIM (2021).

leakage

String. Only applied for oil and gas pressurised cables. Options: leakage = c("No (or very low) historic leakage recorded", "Low/ moderate", "High", "Very High", "Default"). See page 157, table 182 (oil) and 183 (gas) in CNAIM (2021).

reliability_factor

Numeric. reliability_factor shall have a value between 0.6 and 1.5. A setting of "Default" sets the reliability_factor to 1. See section 6.14 on page 73 in CNAIM (2021).

age

Numeric. The current age in years of the cable.

Value

DataFrame Current probability of failure per annum per kilometer along with current health score.

Source

DNO Common Network Asset Indices Methodology (CNAIM), Health & Criticality - Version 2.1, 2021: https://www.ofgem.gov.uk/sites/default/files/docs/2021/04/dno_common_network_asset_indices_methodology_v2.1_final_01-04-2021.pdf

Examples

# Current annual probability of failure for
# "60kV UG Cable (Non Pressurised)", 50 years old
pof_cables_60_30kv(cable_type = "66kV UG Cable (Non Pressurised)",
sub_division = "Lead sheath - Copper conductor",
utilisation_pct = 80,
operating_voltage_pct = 60,
sheath_test = "Default",
partial_discharge = "Default",
fault_hist = "Default",
leakage = "Default",
reliability_factor = "Default",
age = 50)