Since the use of photovoltaics in the domestic and industrial sector is increasing, the reliability and safety of photovoltaic systems is becoming more and more important. One of the crucial issues for safety is the formation of a hot-spot, which can reach several hundred degrees Celsius in less than thirty minutes. For this reason, a fire may occur under prolonged exposure. However, a method for hot-spot detection during operation, based solely on current-voltage characteristics, has not yet been established because the detailed formation mechanism of these hot-spots is different for every sample. We have proposed electro-thermal coupled model to reproduce the temperature distribution in a solar cell with a hot-spot that is caused by a reverse bias voltage due to a local partial shade. This time, we propose an improved model using current FB (feedback).