Grid connected PV Wind and Battery with Fuzzy MPPT
Overview of the System Components
Wind Energy Conversion System (WECS)
The WECS includes:
Wind Turbine
Permanent Magnet Synchronous Generator (PMSG)
Rectifier
Boost Converter
The boost converter output is connected to a DC bus maintained at 400V, with the wind turbine's maximum power rating at 3kW. The fuzzy MPPT algorithm controls the boost converter by adjusting the duty cycle based on the rectifier's voltage and current inputs.
Fuzzy MPPT Algorithm for WECS
The fuzzy MPPT algorithm involves:
Calculating power change (ΔP) and voltage change (ΔV) over time.
Deriving the error (slope of the power curve).
Using the error and its change as inputs for the fuzzy logic controller.
Generating a duty cycle to control the boost converter's MOSFET.
Solar PV System
The solar PV system, rated at 2kW, also connects to the DC bus via a boost converter controlled by a fuzzy MPPT algorithm. This algorithm follows a similar process to the WECS, adjusting the duty cycle based on PV voltage and current to maximize power output.
Battery Energy Conversion System
The battery system (220V, 40Ah) is connected through a bi-directional converter, which maintains the DC bus voltage at 400V and allows power flow in both directions based on system needs. The bi-directional converter is controlled by a voltage control method, using a PI controller to maintain the reference voltage.
Grid Integration
The system integrates with the grid (230V RMS, 50Hz), supporting two loads (1000W initially, adding another 1400W after 2 seconds). The grid-tied inverter, controlled by a current control method, adapts based on the PV current and battery SOC. When the PV output is low, or the battery SOC is less than 10%, the grid supplies power to the load.
Simulation Model and Results
Simulation Setup
Wind Speed: Initially 12 m/s, decreasing to 10.8 m/s after 2 seconds.
Solar Irradiation: Varies every 0.3 seconds, starting at 1000 W/m², then 500 W/m², dropping to 10 W/m², and returning to 1000 W/m².
AC Load: 1000W initially, increasing to 2400W after 2 seconds.
DC Load: Set at 1000W.
Results
PV System Performance
PV Power and Current: Initially at 2000W, dropping to 1000W with reduced irradiation, and reaching 0W at 10 W/m².
PV Voltage: Maintained at around 245V, dropping to 50V under low irradiation.
WECS Performance
Rectifier Power: Initially 3000W, dropping to 2100W with decreased wind speed.
Battery Performance
Battery Current: Shows significant variations based on system conditions, charging and discharging as needed to balance the power supply.
Grid Interaction
Grid Power: Fluctuates based on the load and generation conditions, providing power to the system when PV and wind outputs are low.
Load Voltage and Current
Load Voltage and Current: Maintained consistently, with variations reflecting changes in the power supply sources.
Key Observations
Inverter Operation: Inverter voltage and current remain in phase when supplying power to the grid and out of phase when drawing power from the grid.
System Efficiency: The fuzzy MPPT algorithm effectively maximizes power extraction from both PV and wind sources, ensuring optimal system performance.
Conclusion
The integrated system using fuzzy MPPT algorithms for both solar and wind energy conversion successfully manages power generation and distribution, maintaining stability and efficiency. The simulation results highlight the system's ability to adapt to varying conditions, ensuring reliable power supply and grid interaction.
Comments