Grid-connected PV Wind with Battery System
System Overview
Our system integrates:
Hybrid Solar PV Generator: Connected to the grid through a boost converter and controlled using the incremental conductance method.
Wind Turbine: Equipped with a Permanent Magnet Synchronous Generator (PMSG) and a rectifier to convert AC to DC. A Maximum Power Point Tracking (MPPT) algorithm is used to optimize power extraction.
Battery Storage: Connected to the DC bus through a bi-directional DC-DC converter, which is managed by a voltage controller to maintain a stable voltage.
Grid Connection: Managed via an inverter and an LCL filter, with control based on the reference current generated from PV and battery sources.
Simulink Model and Control
Wind Turbine System
The wind turbine is modeled to convert wind energy into electrical power using a PMSG. The output is rectified and boosted to connect with the common DC bus. The MPPT algorithm used here ensures maximum power extraction from the wind energy.
PV System
The PV panels are rated at around 2000 watts and are controlled by a boost converter using the incremental conductance method. This control strategy optimizes power output under varying irradiance conditions.
Battery Storage
The battery, rated at 28V with a 20Ah capacity, is connected to the DC bus via a bi-directional DC-DC converter. This converter is regulated by a voltage controller to ensure that the DC bus voltage remains at 400V.
Grid Connection
The grid connection involves an inverter and an LCL filter. The inverter’s operation is controlled by generating a reference current based on the power from PV and battery sources. The inverter’s control logic is designed to either import or export power to the grid as needed.
Irradiance and Wind Speed Variations
The simulation involves varying irradiance levels and wind speeds:
Irradiance: Changes every 0.3 seconds between 1000 watts/m², 500 watts/m², and 100 watts/m².
Wind Speed: Adjusted from 0 to 10 meters/second at specific intervals.
Results and Discussion
PV System Performance: The PV system responds to irradiance changes by adjusting the power output, as expected. For higher irradiance, the power output reaches up to 2000 watts, while lower irradiance levels reduce the power output.
Wind Turbine Performance: The wind turbine produces varying power outputs based on wind speed. For example, at 12 meters/second, the system generates approximately 2.6 kW, while lower speeds yield reduced power outputs.
Battery Charging: Battery charging rates fluctuate with the available power from the PV and wind systems. For instance, when the wind power is high, the battery charges at a higher rate, which decreases as the wind power reduces.
Inverter and Grid Interaction: The inverter's output current is sinusoidal, indicating proper control and synchronization with the grid. The grid connection adapts to the power levels from the PV and wind systems, managing the flow of energy efficiently.
Conclusion
The MATLAB simulation of a grid-connected PV-wind system with battery storage demonstrates effective integration and control of renewable energy sources. The system maintains stability and optimizes power output through advanced control strategies and MPPT algorithms.
Comments