Branches assignments to WeatherStation and XYCurve

The ability add weather-dependent limits was added in Version 23.

Branch objects have various field associated with them which are used as part of the Weather-Dependent Limits which are accessed on the Weather-Dependent Limits dialog.

There also similar weather-related fields for Substation and Generator objects.

Branch Weather-Related Fields

Each Branch can be assigned to a WeatherStation object directly by the user by entering the Name of a WeatherStation object in the branch field WeatherStation. This WeatherStation will then be used for all weather related values for the Branch. If the WeatherStation is not specified for a branch, then the branch will look at the terminal bus substations and make appropriate calculations of an average, max, or vector sum average. The branch object has a fields that perform lookups into the assigned WeatherStation object (or terminal substations WeatherStation objects) to show the associated weather information for the branch.

The branch object also has fields for specifying a list of XYCurves that describe the temperature-dependent MVA limits for the branch. See the topic XYCurve, XYCurvePoint, XYCurveX Objects for more details on how to define XYCurves. There are entries for specifying XYCurves for use for normal limits and also an entry for a list of XYCurves for post-contingency limits. Finally there are YES/NO fields to designate whether these XYCurves should even be used.

These fields are described in the following table.

Field	Type	Type
WeatherStation	String Enterable	WeatherStation object to which the user has assigned the substation
TemperatureLimitNormalUse TemperatureLimitCTGUse	String Enterable	YES or NO. Specify YES to use the TemperatureLimitNormal XYCurves (or TemperatureLImitCTG XYCurves)
TemperatureLimitNormalName TemperatureLimitCTGName	String Enterable	A comma-delimited list of names of XYCurves that will impact this Branch. Multiple curves are allowed because there may be multiple devices that impact the limit of this branch. For example, a Current Transformer (CT) may be on a particular branch that imposes a different limit on the line as compared to the conductor limit. The limit that is calculated by PowerWorld Simulator will be the minimum limit across all these curves. The x value of the curves is assumed to be temperature WS_TempC (Celsius temperature). The TemperatureLimitNormalName refers to XYCurves that will be used to determine the TemperatureLImitNormal result, while the TermperatureLimitCTG are XYCurves for the TemperatureLImitCTG result.
TemperatureLimitNormal	Single Float	Uses the WS_TempC value and looks up the MVA limits based on the list of Limit XYCurves specified in TemperatureLimitNormalName field. If no curves are specified, then value is blank If 1 curve is specified, then value returns the lookup for that curve using WS_TempC If multiple curves, then value performs the lookup on all curves using WS_TempC and then returns the minimum value across all curves.
TemperatureLimitCTG	Single Float	Same as TemperatureLimitNormal, but uses the TemperatureLimitCTGName XYCurves instead.
WS_TempF WS_TempC WS_DewPointF WS_DewPointC WS_Humidity WS_WindChillF WS_WindChillC WS_HeatIndexF WS_HeatIndexC WS_InsolationPerc	Single Float	Various values taken from a WeatherStation If a WeatherStation is specified then this weather station's value is used. If a WeatherStation is not specified, then the terminal bus substations will be checked and if both values are valid then the maximum value is returned, otherwise if only one is valid then this valid value is returned.
WS_CloudCoverPerc	Single Float	Cloud Cover Percentage (between 0 and 100). An entry of blank means there is not a valid value for this quantity. If a WeatherStation is specified then this weather station's value is used. If a WeatherStation is not specified, then the terminal bus substations will be checked and if both values are valid then the average value is returned, otherwise if only one is valid then this valid value is returned.
WS_WindSpeedmph WS_WindSpeedKnots WS_WindSpeedMsec WS_WindSpeedkmph	Single Float	Wind Speed in miles per hour, knots, meters per second, or kilometers per hour. We only store a single value internally and so the final one read will be kept. An entry of blank means there is not a valid value for this quantity. If a WeatherStation is specified for the branch then this weather station's value is used. If a WeatherStation is not specified, then the terminal bus substations will be checked and if both values are valid then the vector summation of values is done and the resulting magnitude divided by 2 is returned, otherwise if only one is valid then this valid value is returned.
WS_WindDirection	Single Float	Wind Direction in degrees. (90 = From East; 180 = From South; 270 = From West; 360 = From North. Only show 0 if wind speed also 0.) An entry of blank means there is not a valid value for this quantity. If a WeatherStation is specified for the branch then this weather station's value is used. If a WeatherStation is not specified, then the terminal bus substations will be checked and if both values are valid then the vector summation of values is done and the resulting vector direction is returned, otherwise if only one is valid then this valid value is returned.