3-Phase Unbalanced Star Connected Network using Simscape

Simscape model of a 3-phase unbalanced star network analyzing phase voltages, line currents, and neutral current behavior.

🔹 Overview

This project demonstrates a 3-phase unbalanced star (Y) connected network using MATLAB Simscape. It is designed to analyze the behavior of phase voltages, line currents, and neutral current under unbalanced load conditions.

🔹 Model Description

The model consists of:

• Three-phase AC voltage sources
• Unbalanced star-connected load (different impedance in each phase)
• Measurement blocks for:
• Phase voltages (VRN, VYN, VBN)
• Line voltages (VRY, VYB, VBR)
• Line currents (IR, IY, IB)
• Neutral current (IN)
• Scope for waveform visualization

🔹 Key Concepts Demonstrated

• Unbalanced three-phase system
• Star (Y) connection with neutral
• Effect of unequal load impedance
• Neutral current flow in unbalanced condition
• Voltage and current imbalance

🔹 Simulation Observations

• Phase voltages become unequal
• Line currents are different in each phase
• Neutral current is non-zero
• Voltage drops vary depending on load impedance
• System loses symmetry

🔹 Mathematical Relations

Line voltage:

V_L = √3 × V_Ph

Line current:

I_L = I_Ph

Neutral current:

I_N = I_R + I_Y + I_B ≠ 0

🔹 How to Run

1. Open the .slx file in MATLAB
2. Run the simulation
3. Observe voltage and current waveforms
4. Compare balanced vs unbalanced behavior

🔹 Applications

• Power distribution systems
• Fault analysis
• Load imbalance studies
• Electrical engineering laboratories