The study of the resilience of the gas distribution system in Iran

The substitution of the natural gas for other fossil fuels during last few years has led to a siginificant increase in its share in the energy mix. The main goal of this research is to investgate the resiliency of the Iranian gas distribution system using Lyapunov exponent. On cold days of the year, up to 85% of natural gas is consumed in the household sector. Therefore, temperature fluctuation, as a shock to the consumption of natural gas in the household sector, was considered as an indicator for measuring the resilience of the natural gas distribution system. In order to calculate the biggest Lyapunov power, the time delay and the encompassing dimension need to be calculated. To calculate the time delay, mutual information average function was used. Kao method was also used to calculate the encompassing dimension. Finally, Rosenstein method was used to calculate the biggest Lyapunov power. The results showed that the consumption of natural gas occurs in a chaotic process. Therefore, the gas distribution system is not resilent enough. Morevoer, regarding Lyapunov power before and after the subsidies reform, an improvement was observed in the resilence of the Iranian gas distribution system after the implementation of the law of subsidies reform in Iran.