pof_cables_132kv {CNAIM}

Current Probability of Failure for 132kV cables

Description

This function calculates the current annual probability of failure per kilometer for a 132kV 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_132kv(
  cable_type = "132kV 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("132kV UG Cable (Gas)", "132kV UG Cable (Gas)", "132kV UG Cable (Non Pressurised)") . The default setting is cable_type = "132kV 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 157, table 184 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 157, table 185 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 157, table 186 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 158, table 187 (oil) and 188 (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
# "132kV UG Cable (Non Pressurised)", 50 years old
pof_cables_132kV_non <-
pof_cables_132kv(cable_type = "132kV 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) * 100

paste0(sprintf("Probability of failure %.4f", pof_cables_132kV_non),
" percent per annum")