pof_transformer_11_20kv {CNAIM} R Documentation

## Current Probability of Failure for 6.6/11kV and 20kV Transformers

### Description

This function calculates the current annual probability of failure for 6.6/11kV and 20kV transformers. 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 30 in CNAIM (2017).

### Usage

```pof_transformer_11_20kv(
hv_transformer_type = "6.6/11kV Transformer (GM)",
utilisation_pct = "Default",
placement = "Default",
altitude_m = "Default",
distance_from_coast_km = "Default",
corrosion_category_index = "Default",
age,
partial_discharge = "Default",
oil_acidity = "Default",
observed_condition = "Default",
reliability_factor = "Default"
)
```

### Arguments

 `hv_transformer_type` String. Refers to the high voltage transformer type the calculation is done for. Options: ```hv_transformer_type = c("6.6/11kV Transformer (GM)", "20kV Transformer (GM)")```. The default setting is `hv_transformer_type = 6.6/11kV Transformer (GM)`. `utilisation_pct` Numeric. The max percentage of utilisation under normal operating conditions. `placement` String. Specify if the asset is located outdoor or indoor. A setting of `"Outdoor"` means the asset is located in an outside environment, and a setting of `"Indoor"` means the asset is located in an indoor environment. A setting of `"Default"` will result in either an indoor or an outdoor environment setting that depends on the specification of `asset_type`. See page 107-108, table 25A in CNAIM (2017) for default environments. `altitude_m` Numeric. Specify the altitude location for the asset measured in meters from sea level.`altitude_m` is used to derive the altitude factor. See page 107, table 23 in CNAIM (2017). A setting of `"Default"` will set the altitude factor to 1 independent of `asset_type`. `distance_from_coast_km` Numeric. Specify the distance from the coast measured in kilometers. `distance_from_coast_km` is used to derive the distance from coast factor See page 106, table 22 in CNAIM (2017). A setting of `"Default"` will set the distance from coast factor to 1 independent of `asset_type`. `corrosion_category_index` Integer. Specify the corrosion index category, 1-5. `corrosion_category_index` is used to derive the corrosion category factor. See page 107, table 24 in CNAIM (2017). A setting of `"Default"` will set the corrosion category factor to 1 independent of `asset_type`. `age` Numeric. The current age in years. `partial_discharge` String. Indicating the level of partial discharge. Options for `partial_discharge`: ```partial_discharge = c("Low", "Medium", "High (Not Confirmed)", "High (Confirmed)", "Default")```. See page 138, table 159 in CNAIM (2017). `oil_acidity` Numeric. Measured in mg KOH/g. See page 138, table 160 in CNAIM (2017). `temperature_reading` String. Indicating the criticality. Options for `temperature_reading`: ```temperature_reading = c("Normal", "Moderately High", "Very High", "Default")```. See page 139, table 161 in CNAIM (2017). `observed_condition` String. Indicating the observed condition of the transformer. Options for `observed_condition`: ```observed_condition = c("As New", "Good", "Slight Deterioration", "Poor", "Very Poor", "Default")```. See page 120, table 73 in CNAIM (2017). `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 69 in CNAIM (2017).

### Value

Numeric. Current probability of failure.

### Source

DNO Common Network Asset Indices Methodology (CNAIM), Health & Criticality - Version 1.1, 2017: https://www.ofgem.gov.uk/system/files/docs/2017/05/dno_common_network_asset_indices_methodology_v1.1.pdf

### Examples

```# Current probability of failure for a 6.6/11 kV transformer
pof_transformer_11_20kv(hv_transformer_type = "6.6/11kV Transformer (GM)",
utilisation_pct = "Default",
placement = "Default",
altitude_m = "Default",
distance_from_coast_km = "Default",
corrosion_category_index = "Default",
age = 10,
partial_discharge = "Default",
oil_acidity = "Default",