## 5 Model Application
Figures 15 and 16 depicts the voltage profiles for a selected number of buses, where minimum voltage violation is detected for scenario 1 and 2, respectively. In order to keep the bus voltage above the minimum voltage level, load shedding is implemented at the affected buses. The left plots in Figures 15 and 16 show the voltage profiles of the affected buses for the computation where voltage violations were detected and no countermeasures were employed to avoid this violation, while the right plots show the voltage profiles after implementing load shedding at the affected buses. As can be seen in the right plots of Figures 15 and 16, the bus voltages recover to a value above the minimum voltage threshold after load shedding is implemented. However, due to load shedding some customers connected to the affected buses are not supplied with enough electricity (see Figures 6 and 7). Figure 8: Time evolution of gas supply and pressure at the cross border import (CBI) node for the computed scenarios  
Figure 10: Time evolution of regasification rate and pressure at the liquefied natural gas (LNG) terminal for the computed scenarios. Figure 9: Time evolution of gas supply and pressure at the production field for the computed scenarios. Figure 11: Time evolution of flow balance (sum of inflow minus sum of outflow) and line pack for the computed scenarios. Figure 12: Time evolution of withdrawal rate and pressure at underground gas storage (UGS) facility for the computed scenarios. Figure 13: Time evolution of load and pressure of failed GFPPs in scenario 1. Regarding the CBE_1 station, due to the pressure drop at the station (see Figure 17), the flow is restricted around 21:00 because the threshold pressure of 30 (bar-g) is reached. This is the only way to  
Figure 16: Time evolution of bus voltages before load shedding (**left**) and after (**right**) for scenario 2. Load shedding was applied at 15 buses. Among these buses are the 4 buses from scenario 1, which are shown in this figure. Figure 5:0 Time evolution of load and pressure of failed GFPPs in scenario 2. Figure 5:1 Time evolution of bus voltage before load shedding (**left**) and after (**right**) for scenario 1. All four buses where load shedding was applied are shown in this figure. keep minimum delivery pressure at that exit point; otherwise problems would arise downstream due to too low pressure. Figure 17, shows the drop in flow (around 8 (Msm\({}^{3}\)/d) ) at CBE_1 station due to the pressure restriction. Moreover, the difference between scenario 0 and scenario 2 shows the gas system reaction to the electric side disruption. In Figure 11, it can be seen that the flow balance of the gas network in scenario 2 is more negative (the gas system loses more gas) than in scenario 0 until 18:00. This is caused by the increase in gas demand of GFPPs due to the disruption of the lignite power plant and the loss of power generation from wind turbines. The increase in gas demand of GFPPs leads to a pressure drop in two GFPPs, followed by the disconnection of the power plants from the network (see Figures 7 and 14). The pressure and load profiles for failed GFPPs are given in Figure 5:2 The disconnection of the generators affects the loading of the gas system in a positive way. Moreover, the line pack starts to recover after 18:00 (see Figure 11). The scenario results indicate clearly that the disruptions taking place in the gas network that affect GFPPs also affected the operability of the power network. After failure of each GFPP, the power model calculates the new generating profiles for all power plants and sends these profiles to the gas model. In scenario 1, the closure of 4 GFPPs due to low pressure levels in the gas system caused voltage violations in the electricity network at peak demand hour (19:00-20:00) because of the high amount of power transmission from relatively distant generators in order to compensate the missing generating capacity. This violation in voltage levels caused 954 (MW) of load shedding during 2 h (see Figures 6 and 15).