ElectricMotorData.EfficiencyMapLookupTorque: Fixed bug when only one level is...

ElectricMotorData.EfficiencyMapLookupTorque: Fixed bug when only one level is limited by battery, but the other is not.

VectoCore/VectoCore/Models/SimulationComponent/Data/ElectricMotor/ElectricMotorData.cs

@@ -53,10 +53,18 @@ namespace TUGraz.VectoCore.Models.SimulationComponent.Data
 			var r1 = a.EfficiencyMap.LookupTorque(electricPower, avgSpeed, maxEmTorque);
 			var r2 = b.EfficiencyMap.LookupTorque(electricPower, avgSpeed, maxEmTorque);
 
-			if (r1 == null && r2 == null) {
+			if (r1 is null && r2 is null) {
 				return null;
 			}
 
+			// if one of the values is limited by EM, but the other is not (is null): use maxEmTorque instead
+			if (r1 is null) {
+				r1 = maxEmTorque;
+			}
+			if (r2 is null) {
+				r2 = maxEmTorque;
+			}
+
 			var retVal = VectoMath.Interpolate(a.Voltage, b.Voltage,
 				r1, r2, voltage);
 			var elPwr = LookupElectricPower(voltage, avgSpeed, retVal, true);