MATLAB Simulation of 2 MW PV Battery Grid system
- lms editor
- Dec 10, 2024
- 3 min read
MATLAB Simulation of 2 MW PV Battery Grid system
Components of the 2 MW PV Battery Grid System
The simulation model integrates several key components designed to work together in harmony to supply and manage power. Here's a closer look at the system setup:
Main Grid and TransformerThe main grid is rated at 154 MW, with a voltage of 34.5 kV. A transformer is used to step down the voltage to 400 V to connect with the rest of the system. This is necessary for the efficient transfer of energy from the PV and battery sources to the grid.
Load at the Point of Common Coupling (PCC)The load is set at 1.6 MW and is connected to the system through the Point of Common Coupling (PCC). This is where the grid, the PV system, and the battery interact to supply energy.
PV and Battery IntegrationThe photovoltaic (PV) system is connected directly to the DC link, while the battery is connected via a bidirectional converter. This allows both the battery and the PV system to supply power to the grid and store excess energy when required.
Battery System and Solar Panel Configuration
The battery plays a crucial role in storing energy generated by the PV system. In the simulation:
The battery is rated at 2 MW, with a nominal voltage of 300 V, and a capacity of 6.6 kAh. This battery system is specifically designed to integrate with the 2 MW PV power generation.
Solar panels in the system have a power output of 444 W each, with a voltage of 72.9 V and a current of 5.6 A at maximum power. The simulation uses 712 strings of panels to generate a total of 2 MW.
PV System Current and Battery Charging
The battery’s charging current is generated based on the current from the PV system. This involves taking a percentage of the PV power and combining it with the battery’s charging requirements to generate a reference current. This reference current is processed by a PWM (Pulse Width Modulation) generator to control the battery’s charging and discharging cycles.
Inverter Control and Power Flow
The inverter plays a key role in converting DC power from the PV system and battery into AC power that can be fed into the grid. The inverter is controlled by a PWM method, with a specific focus on injecting only real power into the grid (reactive power is set to zero). The inverter’s voltage and current are measured, transformed from ABC to DQ form, and then processed by a controller to ensure proper power flow.
Power Transformation and Control
To effectively manage power in the system, the voltage and current measurements are first converted from their ABC form into DQ form using a power transformation technique. A Phase-Locked Loop (PLL) is employed to generate the necessary reference signals, which are then used to ensure that the real power injected into the grid is consistent with the system’s requirements.
Simulation Results: Energy Generation and Load Management
During the simulation, the system is tested under varying irradiation conditions to observe its behavior. Key findings include:
PV Power Generation: At maximum irradiation (1000 W/m²), the PV system generates 2 MW, with the current reaching 4000 A. This power is then fed into the grid or stored in the battery.
Battery Charging: When the PV system generates power in excess of the load demand, the battery enters charging mode, absorbing power. During this time, the battery current is negative, indicating energy storage.
Battery Discharging: Under reduced irradiation conditions (500 W/m²), the battery switches to discharging mode to supply power back to the grid. The battery provides around 100 kW to the system while the grid supplies additional power to maintain load demand.
Load Power and Grid Interaction
Throughout the simulation, the load power fluctuates based on the available solar power and the battery’s state of charge (SOC). The system is designed to maintain a balance between power generation and consumption, ensuring that the load receives a continuous supply of power regardless of fluctuations in solar radiation.
When the battery is charging, it takes in power from the PV system, and the grid remains in a passive state.
When irradiation drops, the battery discharges to support the load, while the grid compensates for any remaining power requirements.
Conclusion: System Performance and Power Balance
The MATLAB simulation demonstrates the flexibility and reliability of a 2 MW PV-battery grid integration system. By carefully managing power generation from the solar panels, storage in the battery, and distribution to the grid, the system ensures a steady power supply to the load under varying conditions. The simulation also highlights how changes in irradiation impact the battery’s charging and discharging modes, as well as the overall power balance between the battery, grid, and PV system.
Comments