Unity AI Insights: Snow Event Flag Calculation

Last Modified on 2025-05-08 20:44:23 +0200

In this article:

Overview
Calculation Logic
Inputs and Outputs

Overview

This calculation combines all relevant information available to create a “smart event” for snow.

Importance: for accurate and organized snow events
Schedule: runs daily after classifier is finished running (after 5AM next day) for a given PV site
Relevant sites: PV sites with AI Insights
Historical data needed: day of and day prior, with the caveat that Inverter Classifier is an input which needs at least 3 months of historical data to get a given day’s classification label and probability

Calculation Logic

In the images below, you’ll see the logic for opening and closing these types of events:

Inputs and Outputs

Inputs - Signals

Segment Apcode	Mloc Apcode	CalcType	CalcPeriod	MType	Notes
Site	AmbientTemperature	Final	siteTR	Temperature	day prior and of
Site	AmbientTemperature	CascadeFlag	siteTR	Temperature	day prior and of
Site	SunAzimuthAngle	Calculated	siteTR	Angle	day of
Site	SunHeightAngle	Calculated	siteTR	Angle	day of
Site	SnowEventFlag	Calculated	siteTR	Flag	day prior; need to know whether an event is already open or not
Inverter	ActivePower	ValidationFlag	siteTR	Power	day of
Inverter	FinalClassification	Calculated	1D	Inverter Classifier	day of
Inverter	Snow	Calculated	1D	Inverter Classifier	day of; classification probability of snow
Inverter	PerformanceIndex	Calculated	siteTR	Percent	day of
SatelliteWeatherStation	SolidPrecipitation	Mean	siteTR	Precipitation	day prior and of

Inputs - Configuration Parameters

Parameter	Value	Notes
`AMB_TEMP_THRESHOLD`	5.0	While there is precipitation, the mean of the ambient temperature must be below this threshold to be considered low temperature.
`PI_AVAILABILITY_THRESHOLD`	0.25	Performance Index must be available during the day for at least this proportion of time
`PI_THRESHOLD`	0.75	The given time is considered to have low Performance Index (PI) if the mean of PIs from all inverters is less than this threshold.
`PRECIPITATION_THRESHOLD`	3.0	The sum of precipitation must be above this threshold to be considered precipitation occurred.
`SNOW_PROBABILITY_THRESHOLDS`	{ "HIGH_THRESHOLD": 0.8, "MEDIUM_THRESHOLD": 0.4, "MEDIUM_STD_THRESHOLD": 0.2, }	Thresholds that classify the snow probability as high, medium/variable, or low. Refer to image of logic.

Outputs - Signals

Segment Apcode	Mloc Apcode	CalcType	CalcPeriod	MType	Unit	Notes
Site	SnowEventFlag	Calculated	siteTR	Flag	-