do not use common Null device (new for every use), it's ugly but it broke .ToCsv's cycle detector

csharp/Lib/Devices/AMPT/AmptStatus.cs

@@ -13,7 +13,7 @@ public class AmptStatus
     public DcBus? Dc { get; }
     public IReadOnlyList<DcBus> Strings { get; }
     
-    public static AmptStatus Null { get; } = new AmptStatus(null, Array.Empty<DcBus>());
+    public static AmptStatus Null =>  new AmptStatus(null, Array.Empty<DcBus>());
 }
 
 

csharp/Lib/Devices/Battery48TL/Battery48TlRecords.cs

@@ -34,5 +34,5 @@ public class Battery48TlRecords
     
     public IReadOnlyList<Battery48TlRecord> Devices { get; init; }
 
-    public static Battery48TlRecords Null { get; } = new Battery48TlRecords(Array.Empty<Battery48TlRecord>());
+    public static Battery48TlRecords Null =>  new Battery48TlRecords(Array.Empty<Battery48TlRecord>());
 }

csharp/Lib/Devices/Trumpf/TruConvertAc/AcDcDevicesRecord.cs

@@ -6,7 +6,7 @@ namespace InnovEnergy.Lib.Devices.Trumpf.TruConvertAc;
 
 public class AcDcDevicesRecord
 {
-    public static AcDcDevicesRecord Null { get; } = new AcDcDevicesRecord(null, Array.Empty<AcDcRecord>());
+    public static AcDcDevicesRecord Null => new AcDcDevicesRecord(null, Array.Empty<AcDcRecord>());
 
     public AcDcDevicesRecord(SystemControlRegisters? systemControl, IReadOnlyList<AcDcRecord> devices)
     {

csharp/Lib/Devices/Trumpf/TruConvertAc/AcDcRecord.Modbus.cs

@@ -75,13 +75,13 @@ public partial class AcDcRecord
     [InputRegister<Int16>(5141)]       internal readonly Double ActivePowerL2;
     [InputRegister<Int16>(5142)]       internal readonly Double ActivePowerL3;
     
-    [InputRegister(5231)]              internal readonly Double ReactivePowerL1;
+    [InputRegister<Int16>(5231)]       internal readonly Double ReactivePowerL1;
-    [InputRegister(5232)]              internal readonly Double ReactivePowerL2;
+    [InputRegister<Int16>(5232)]       internal readonly Double ReactivePowerL2;
-    [InputRegister(5233)]              internal readonly Double ReactivePowerL3;
+    [InputRegister<Int16>(5233)]       internal readonly Double ReactivePowerL3;
     
-    [InputRegister(5150, Scale = .01)] internal readonly Double GridCurrentL1;
+    [InputRegister<Int16>(5150, Scale = .01)] internal readonly Double GridCurrentL1;
-    [InputRegister(5151, Scale = .01)] internal readonly Double GridCurrentL2;
+    [InputRegister<Int16>(5151, Scale = .01)] internal readonly Double GridCurrentL2;
-    [InputRegister(5152, Scale = .01)] internal readonly Double GridCurrentL3;
+    [InputRegister<Int16>(5152, Scale = .01)] internal readonly Double GridCurrentL3;
     
     [InputRegister(5160, Scale = .1)]  internal readonly Double GridVoltageL1;
     [InputRegister(5161, Scale = .1)]  internal readonly Double GridVoltageL2;

csharp/Lib/Devices/Trumpf/TruConvertDc/DcDcDevicesRecord.cs

@@ -38,5 +38,5 @@ public class DcDcDevicesRecord
     public IEnumerable<AlarmMessage>   Alarms   => Devices.SelectMany(d => d.Status.Alarms  ).Distinct();
     public IEnumerable<WarningMessage> Warnings => Devices.SelectMany(d => d.Status.Warnings).Distinct();
 
-    public static DcDcDevicesRecord Null { get; } = new DcDcDevicesRecord(null, Array.Empty<DcDcRecord>());
+    public static DcDcDevicesRecord Null => new DcDcDevicesRecord(null, Array.Empty<DcDcRecord>());
 }

csharp/Lib/Units/Composite/Ac1Bus.cs

@@ -21,5 +21,5 @@ public sealed class Ac1Bus
         Power     = AcPower.FromVoltageCurrentPhi(voltageRms, currentRms, phi)
     };
 
-    public static Ac1Bus Null { get; } = FromVoltageCurrentFrequencyPhi(0, 0, 0, 0);
+    public static Ac1Bus Null => FromVoltageCurrentFrequencyPhi(0, 0, 0, 0);
 }

csharp/Lib/Units/Composite/Ac3Bus.cs

@@ -24,5 +24,5 @@ public sealed class Ac3Bus
         Frequency = frequency,
     };
 
-    public static Ac3Bus Null { get; } = FromPhasesAndFrequency(AcPhase.Null, AcPhase.Null, AcPhase.Null, 0);
+    public static Ac3Bus Null => FromPhasesAndFrequency(AcPhase.Null, AcPhase.Null, AcPhase.Null, 0);
 }   

csharp/Lib/Units/Composite/AcPhase.cs

@@ -41,7 +41,7 @@ public sealed class AcPhase
         Power   = AcPower.FromActiveReactiveApparent(activePower, reactivePower, apparentPower)
     };
 
-    public static AcPhase Null { get; } = FromVoltageCurrentPhi(0, 0, 0);
+    public static AcPhase Null => FromVoltageCurrentPhi(0, 0, 0);
     
     
   

csharp/Lib/Units/Composite/AcPower.cs

@@ -84,7 +84,7 @@ public sealed class AcPower
         };
     }
     
-    public static AcPower Null { get; } = FromVoltageCurrentPhi(0, 0, 0);
+    public static AcPower Null => FromVoltageCurrentPhi(0, 0, 0);
 
     public static AcPower operator +(AcPower left, AcPower right) => FromActiveReactive
     (
@@ -92,6 +92,12 @@ public sealed class AcPower
         left.Reactive + right.Reactive
     );
 
+    public static AcPower operator -(AcPower left, AcPower right) => FromActiveReactive
+    (
+        left.Active - right.Active,
+        left.Reactive - right.Reactive   
+    );
+    
     public static AcPower operator -(AcPower p) => FromActiveReactive(-p.Active, p.Reactive);
     
     

csharp/Lib/Units/Composite/DcBus.cs

@@ -17,5 +17,5 @@ public sealed class DcBus
       Power   = current.Value * voltage.Value,
    };
 
-   public static DcBus Null { get; } = FromVoltageCurrent(0, 0);
+   public static DcBus Null => FromVoltageCurrent(0, 0);
 }

csharp/Lib/Units/Power/DcPower.cs

@@ -12,5 +12,5 @@ public sealed class DcPower : AcPower
     public static implicit operator Double(DcPower d) => d.Value;
 
 
-    public static DcPower Null { get; } = new DcPower(0);
+    public static DcPower Null => new DcPower(0);
 }