A HYDROPOWER INFRASTRUCTURE SIMULATION MODEL FOR ASSESSMENT OF RESILIENCE

摘要

Many of Canada's hydropower infrastructure systems are reaching the end of their serviceable life. Major investments in the coming years will be required to renew and upgrade these critical infrastructure systems. It is important that decision makers have a good understanding of current system performance in order to optimize operations and develop strategies for re-engineering these systems in the future. Resilience is a dynamic numerical measure of system performance and adaptation capacity that covers the time from the beginning of an undesirable event to full system recovery from it. Using resilience as a metric to measure system performance offers a major advantage over traditional methods that seek to estimate probabilities, which are essentially a static measure of risk that does not take time variance into consideration. Simulation lends itself well to estimating system resilience as it can be used to investigate system response over time under different operating conditions. This paper presents a system dynamics simulation technique which can be utilized to quantify dynamic resilience. System dynamics facilitates: (a) detailed representations of complex system structures, allowing the modeller to ensure all components affecting system resilience are included in the model, and (b) easy modification of the system structure for comparison between different alternatives for infrastructure upgrades or operations strategies. Simulation outputs of system performance over time can be used to estimate the dynamic resilience of both individual system components and the system as a whole in response to various operating conditions. The system dynamics modelling approach presented in this work considers interactions between natural, engineered and human system components. The approach is applied to a hydropower system but a similar methodology could be utilized for other civil infrastructure systems. Four model sectors are utilized to represent the system structure: (1) the controller, (2) mechanical and electrical actuators, (3) physical infrastructure, and (4) sensors and information relay. Simulation provides a useful technique for quantification of system resilience, allowing for an improved understanding of the system structure and its vulnerabilities under different operating conditions. The proposed methodology can be utilized to provide informative comparisons between various investment alternatives for infrastructure renewal.