**7. Discussion**

Stealth false data injection attacks create huge damage to a power system. Such kinds of attacks should be detected for a smooth and reliable power flow in a smart grid. The proposed model was applied for the detection of such attacks. The model was based on a dummy measurement. The meters in the smart grid send the actual measurement and the dummy measurement. There are two techniques in the proposed model, namely, the fixed dummy value model and the variable dummy value model.

Both techniques were validated through the experimental results. The first technique of the fixed dummy value model could detect FDI attacks. However, at the same time, this technique has some limitations. When the attacker does not attack the dummy value of measurement, i.e., only the actual measurement is attacked, the control room is not able to detect that attack. The second technique of the proposed model, such as the variable dummy value model overcomes the limitation and the FDI attacks that were left unnoticed by the fixed dummy value model were detected by the variable dummy value model, as validated by the results.

The proposed model does not require the installation of any extra buses or transmission lines. There is no need to install any extra meters. Therefore, the model can be effectively applied to a smart grid and is economically efficient. From the viewpoint of long-term operation, the proposed model can be applied to make a smart grid more protected and secured. In the future, an extension of this work can be done to practically implement the model for a smart grid, which will protect the smart grid from FDI attacks. Some other methods can be adopted to set the dummy values of the power in the future. The probability of launching the attack can be minimized in this way.
