Energy Management in PV-Wind-Diesel-Battery Hybrid System Using MATLAB Simulink

Energy Management in PV-Wind-Diesel-Battery Hybrid System Using MATLAB Simulink

In modern energy systems, hybrid configurations combining solar PV, wind turbines, diesel generators, and battery storage are increasingly adopted for reliable, efficient, and sustainable power supply. This blog post explores the working of a PV-Wind-Diesel-Battery hybrid system designed and simulated in MATLAB Simulink, highlighting control strategies, system operations, and load management. -Energy Management in PV-Wind-Diesel-Battery Hybrid System Using MATLAB Simulink

System Overview

The simulated model integrates:

• Solar PV array connected via a bidirectional DC-DC (Bal) converter.

• Battery energy storage system with charge/discharge control.

• Wind generator (3 MW) with frequency conversion.

• Diesel generator (5 MW) providing backup power.

• Load management using breakers and control signals.

The setup aims to ensure power supply stability under varying irradiation and load conditions using effective energy management strategies.

Operating Modes

Case 1: Varying Irradiation Condition

• Under low solar irradiation, the battery discharges to compensate for reduced PV output.

• Under high irradiation, the battery charges using excess PV generation.

• Control logic generates a reference current based on PV current scaling, comparing it with actual battery current to regulate charging or discharging.

Case 2: Varying Load Condition

• High load demand triggers battery discharge to support the load.

• Low load demand prompts the battery to recharge.

• Reference currents are generated based on load power converted to current, regulating battery actions accordingly.

A mode selector switch toggles between Case 1 and Case 2 based on system conditions.

Control Strategy

1. Reference Current Generation:Based on PV current (Case 1) or load power (Case 2), a reference current is computed to control the battery’s behavior.

2. PI Controller & Duty Cycle:The reference current feeds into a PI controller to generate duty cycles that regulate the bidirectional converter, managing battery energy flow.

3. Inverter Control:

   • Utilizes P-MPPT (Perturb & Observe MPPT) algorithm.

   • Involves ABC to DQ transformation, feedforward compensation, and PI control loops to generate PWM signals.

   • Manages power delivery from PV to grid and connected loads.

Load and Breaker Management

• The model includes multiple load breakers:

  • Certain breakers remain closed throughout Case 1.

  • In Case 2, breakers operate on timed steps to simulate dynamic load connection and disconnection.

• Irradiation levels and load conditions are varied to observe system performance under both modes.

Wind Turbine Integration

• A 3 MW wind generator connects to the system through:

  • Dual converters converting rotor frequency (~2 Hz) to standard 50 Hz grid frequency.

  • AC to DC conversion, followed by DC to AC inversion for grid synchronization.

• The wind energy contributes to system power along with PV and diesel units.

Diesel Generator Functionality

• A 5 MW diesel generator supplements the hybrid system:

  • Operates in either P-control (real/reactive power control) or PV-control (real power and voltage control) modes.

  • Managed via acceleration (engine governor) control.

  • Integrated into the system’s common bus to supply power during deficits.

Simulation and Output Monitoring

• The simulation runs for 14 seconds representing a complete operational cycle.

• Scopes monitor:

  • PV power output.

  • Battery state (voltage, current, power).

  • Load power consumption.

  • Diesel and wind generator outputs.

• Load breakers, irradiation conditions, and battery operations are analyzed for both cases.

Conclusion

The PV-Wind-Diesel-Battery Hybrid System in MATLAB Simulink demonstrates effective energy management through dynamic load adjustment and environmental responsiveness. By integrating renewable and conventional sources with intelligent control, such systems can provide stable, efficient, and sustainable energy solutions for diverse applications.