Follow these steps:

1. Data Collection: Gather all the necessary data for the PV-DG system, such as the PV array characteristics (rated power, efficiency, temperature coefficient), inverter specifications (rated power, efficiency), and location of the PV-DG installation in the network.

2. PV-DG Modeling: Develop a mathematical model for the PV-DG system that represents its behavior and its interaction with the distribution network. The most common model used for PV-DG is the PV generation model, which relates the PV output power to the solar irradiance and temperature.

3. Integration into Load Flow: Modify the load flow algorithm to include the PV-DG system. Usually, the load flow algorithm is based on the backward/forward sweep method, and you'll need to extend it to accommodate the PV-DG model.

- At each bus where the PV-DG is connected, add the PV-DG model equations to calculate the PV output power based on the solar irradiance and temperature.

- Modify the power flow equations to consider the power injections from the PV-DG system.

- Update the nodal equations to include the PV-DG power injections and modify the voltage and power calculations accordingly.

4. Initialization: Set initial values for the PV-DG system variables, such as solar irradiance and temperature, based on available data or assumptions.

5. Iterative Solution: Solve the modified load flow equations iteratively until convergence is achieved. The iterative process involves updating the PV-DG system variables and recalculating the load flow solution until the system reaches a steady state.

6. Sensitivity Analysis: Perform sensitivity analysis by varying the PV-DG system parameters (e.g., size, location) to determine the optimal placement and sizing. This analysis can be done using optimization techniques or by manually evaluating different scenarios.

7. Validation: Validate your load flow results by comparing them with measured data or other validated simulation models. Ensure that the PV-DG integration satisfies the desired performance criteria, such as voltage limits, power losses, and system stability.

Hope it helps

Thank you for this detailed information