Hybrid Solar–Wind Traffic Light System using MATLAB Simulink | Dc Microgrid

Video thumbnail Watch simulation overview
matlab projects illustration

Introduction

In the era of rapid urbanization and escalating energy demand, traditional traffic light systems powered by grid electricity contribute significantly to operational costs and carbon emissions, particularly in off-grid or remote locations. The integration of renewable energy sources offers a sustainable, cost-effective, and environmentally friendly alternative. A hybrid solar-wind traffic light system combines photovoltaic (PV) panels and small-scale wind turbines to generate reliable power for LED-based traffic signals, ensuring uninterrupted operation even during variable weather conditions.

Solar energy provides abundant daytime generation, while wind power — enhanced by vehicle-induced airflow on highways — complements generation during low-sunlight periods, nighttime, and cloudy days. This hybrid approach improves energy reliability, reduces dependence on fossil-fuel-based grid power, lowers maintenance expenses, and aligns with global sustainability goals such as UN SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action).

The primary objective of this project is to design, model, and simulate a standalone hybrid solar-wind powered traffic light system using MATLAB Simulink. The simulation evaluates system performance under real-world irradiance, wind speed variations, and traffic-dependent load profiles. Key performance indicators include power balance, battery state-of-charge (SoC), system autonomy, energy yield, and LED illumination stability. This work demonstrates the technical feasibility of renewable-powered intelligent transportation systems, offering a scalable solution for smart cities, rural roadways, and energy-constrained regions.

Methodology

The methodology adopts a systematic simulation-based approach using MATLAB/Simulink (Simscape Electrical and Simulink libraries) to model, integrate, and analyze the hybrid renewable energy system for traffic light application. The step-by-step process is outlined below:

  1. System Architecture Definition The proposed standalone system comprises:
    • Solar PV array (with MPPT controller)
    • Small vertical-axis or horizontal-axis wind turbine coupled to a permanent magnet synchronous generator (PMSG)
    • DC-DC boost converters for both sources
    • Hybrid charge controller / power management unit
    • Battery energy storage system (lead-acid or lithium-ion)
    • Bidirectional DC-DC converter (for battery charging/discharging)
    • DC bus feeding high-efficiency LED traffic lights (red, yellow, green signals with adaptive dimming)
    • Backup logic for low SoC or extreme conditions
  2. Modeling of Renewable Sources
    • Solar PV Model: Implemented using the single-diode five-parameter model (or Simulink PV Array block). Inputs include solar irradiance (G in W/m²), ambient temperature (T in °C), and panel specifications (Voc, Isc, etc.). Perturb & Observe (P&O) or Incremental Conductance MPPT algorithm extracts maximum power.
    • Wind Turbine Model: Aerodynamic power is calculated using the standard wind power equation P = 0.5 × ρ × A × v³ × Cp(λ, β), where Cp is the power coefficient. A PMSG-based wind energy conversion system (WECS) is modeled with rectifier and boost converter. Wind speed data (average + turbulence from vehicle movement) is used as input.
  3. Power Electronics and Energy Management
    • DC-DC converters (boost topology) regulate output to a common DC bus (typically 24V or 48V).
    • A rule-based or fuzzy logic energy management system prioritizes solar → wind → battery → load shedding (dimming LEDs or switching non-critical signals).
    • Bidirectional converter controls battery charging/discharging to maintain DC bus voltage stability.
  4. Traffic Light Load Modeling
    • LED signals modeled as variable resistive/capacitive loads with realistic power consumption:
      • Red: ~15–25 W
      • Green: ~15–20 W
      • Yellow: ~10–15 W
    • Adaptive control logic (timer-based sequence + possible vehicle density sensing) adjusts brightness or cycle timing to reduce average power demand.
  5. Battery Storage and Backup
    • Generic or detailed battery model (Simscape) with SoC estimation using coulomb counting.
    • Depth of discharge (DoD) limited to 50–80% for longevity.
  6. Simulation Environment Setup
    • Developed in MATLAB/Simulink (R2023b or later recommended).
    • Real-time environmental data: Typical meteorological year (TMY) irradiance and wind speed profiles (sourced from local weather databases or synthetic generation).
    • Simulation duration: 24 hours to multiple days for autonomy analysis.
  7. Performance Evaluation
    • Key metrics analyzed:
      • Energy balance (generation vs. consumption)
      • Battery SoC dynamics
      • Loss of power supply probability (LPSP)
      • Excess energy dumped
      • System efficiency and LED uptime
    • Parametric studies: Variation in PV size, wind turbine rating, battery capacity, and geographic location.
  8. Validation & Optimization
    • Model validated against published hybrid renewable benchmarks.
    • Optimization performed manually or via Simulink Design Optimization toolbox to minimize cost and maximize reliability.

This simulation-based methodology enables rapid prototyping, sensitivity analysis, and performance prediction without hardware implementation, making it ideal for academic projects, feasibility studies, and preliminary design of renewable energy traffic light systems.