added helper method for max alternator power

VectoCommon/VectoCommon/InputData/DeclarationInputData.cs

@@ -33,6 +33,7 @@ using System;
 using System.Collections.Generic;
 using System.Data;
 using System.IO;
+using System.Linq;
 using System.Xml;
 using TUGraz.VectoCommon.BusAuxiliaries;
 using TUGraz.VectoCommon.Exceptions;
@@ -971,6 +972,15 @@ namespace TUGraz.VectoCommon.InputData
 		IList<IBusAuxElectricStorageDeclarationInputData> ElectricStorage { get; }
 	}
 
+	public static class ElectricSupplyDeclarationDataHelper
+	{
+		public static Watt GetMaxAlternatorPower(this IElectricSupplyDeclarationData electricSupply)
+		{
+			return electricSupply.Alternators?.Select(alt => alt.RatedCurrent * alt.RatedVoltage)?
+				.Max();
+		}
+	}
+
 	public interface IElectricConsumersDeclarationData
 	{
 		bool? InteriorLightsLED { get; }