diff --git a/Electric/ConnectionTriangleStar.cs b/Electric/ConnectionTriangleStar.cs
new file mode 100644
index 0000000..96a2b4d
--- /dev/null
+++ b/Electric/ConnectionTriangleStar.cs
@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Calculations.Electric
+{
+    /// <summary>
+    /// Calculations parameters if winding of synchronous/asynchronous motor/generator/transformer change connection between star and triangle
+    /// </summary>
+    public class ConnectionTriangleStar
+    {
+
+        /// <summary>
+        /// Calculate voltage in triangle from star voltage
+        /// </summary>
+        /// <param name="Voltage">Voltage in Star</param>
+        /// <returns>Voltage in Triangle</returns>
+        public static decimal VoltageStarToTriangle(decimal Voltage)
+        {
+            return Voltage / (decimal)Math.Sqrt(3);
+        }
+
+        /// <summary>
+        /// Calculate voltage in star from triangle voltage
+        /// </summary>
+        /// <param name="Voltage">Voltage in Triangle</param>
+        /// <returns>Voltage in Star</returns>
+        public static decimal VoltageTriangleToStar(decimal Voltage)
+        {
+            return Voltage * (decimal)Math.Sqrt(3);
+        }
+
+        /// <summary>
+        /// Calculate current in triangle from star current
+        /// </summary>
+        /// <param name="Current">Current in Star</param>
+        /// <returns>Current in Triangle</returns>
+        public static decimal CurrentStarToTriangle(decimal Current)
+        {
+            return Current * (decimal)Math.Sqrt(3);
+        }
+
+        /// <summary>
+        /// Calculate current in star from triangle current
+        /// </summary>
+        /// <param name="Current">Current in Triangle</param>
+        /// <returns>Current in Star</returns>
+        public static decimal CurrentTriangleToStar(decimal Current)
+        {
+            return Current / (decimal)Math.Sqrt(3);
+        }
+
+
+
+    }
+}