Abstract

The Louis-Hippolyte Lafontaine tunnel is defined as a critical infrastructure as it represents a major transportation link connecting the island of Montreal and the South Shore. Consequently, the daily operation of the tunnel is highly dependent on the stability of the electrical grid to maintain a proper power supply. Moreover, the changing electrical profile of the tunnel throughout the year is reflected differently on the grid. Hence, the scope of this work is to emulate and model a scaled-down version of the electrical system of the tunnel Louis-Hippolyte Lafontaine based on different operational scenarios. The system that is considered is simplified to the main electrical loads, which are the heating (purely resistive), lighting (mostly resistive) and ventilation fans. The modeling of the electrical profile is achieved using measurement-based data. To achieve the emulation of the ventilation fan, a drive system for a 2-hp induction motor is modeled in the MATLAB/Simulink environment and validated experimentally using open-loop voltage-over-frequency control under no-load condition. The results show proper speed control with the flux maintained constant under rated frequency in addition to accurate response to speed command change. To illustrate the changing operational profile of the tunnel throughout the year, the scaled-down electrical system is simulated and adapted to the corresponding profile of a summer day, a winter day and during an emergency event (diesel generator supply). For each distinctive day, the power characteristics at the point of common coupling are evaluated in regards to the respective electrical loads connected to the system. The analysis of the scaled-down simulated system has shown that the nature of the loads solicited in their respective scenarios has different impacts on the supply system. Through this research work, the scaled-down model of the Louis-Hippolyte Lafontaine tunnel electrical system showed similar power characteristics to what is observed on the actual system.