Using system dynamics simulation for assessment of hydropower system safety

Abstract

Hydropower infrastructure systems are complex, high consequence structures which must be operated safely to avoid catastrophic impacts to human life, the environment, and the economy. Dam safety practitioners must have an in‐depth understanding of how these systems function under various operating conditions in order to ensure the appropriate measures are taken to reduce system vulnerability. Simulation of system operating conditions allows modelers to investigate system performance from the beginning of an undesirable event to full system recovery. System dynamics simulation facilitates the modeling of dynamic interactions among complex arrangements of system components, providing outputs of system performance that can be used to quantify safety. This paper presents the framework for a modeling approach that can be used to simulate a range of potential operating conditions for a hydropower infrastructure system. Details of the generic hydropower infrastructure system simulation model are provided. A case study is used to evaluate system outcomes in response to a particular earthquake scenario, with two system safety performance measures shown. Results indicate that the simulation model is able to estimate potential measures of system safety which relate to flow conveyance and flow retention. A comparison of operational and upgrade strategies is shown to demonstrate the utility of the model for comparing various operational response strategies, capital upgrade alternatives, and maintenance regimes. Results show that seismic upgrades to the spillway gates provide the largest improvement in system performance for the system and scenario of interest.

A Deterministic Monte Carlo Simulation Framework for Dam Safety Flow Control Assessment

“…A more detailed description of the components, their operating states, and impacts is provided in Supplementary materials File S1. A simulation model of a hydropower system, described in detail in by King et al [9], was adapted for this case study with simplified components shown in Figure 14. The component interactions are represented through feedback loops that determine the system behavior.…”

“…Simulation model development using system dynamics simulation, as proposed by King et al [9], is described in the following section, which details how to develop the model to facilitate inputting of events (such as failures) and their parameters (such as the outage lengths). Next, a description of the Monte Carlo generation of simulation parameters is provided, followed by a description of the simulation process framework and event influence considerations in scenario analysis.…”

“…King et al [8] also suggest event timing, inflows, and outage lengths for each scenario can be explored through Monte Carlo simulation. King et al [9] present a system dynamics simulation model that represents, in detail, the components of a dam system and their interactions. The simulation model mathematically characterizes the system behavior using feedbacks and interactions within a hierarchical system of systems.…”

“…The approach can analyze high-level system behavior using low-level failures and events as inputs. However, the model described by King et al [9] is completely deterministic and does not provide a complete simulation framework capable of analyzing each of the potential combinations of events in an automated and systematic way. Another potential problem that has not yet been investigated is how to determine the start and end of a scenario, which depends on whether the preceding events in a scenario are influencing the events that follow.…”

Identifying Efficient Operating Rules for Hydropower Reservoirs Using System Dynamics Approach—A Case Study of Three Gorges Reservoir, China

“…Using the SD approach, Xu et al [38] constructed a water resources SD model to analyze the water resource sustainability of the Yellow River in China. King et al [48] used SD simulations to assess hydropower system safety. Yuan et al [35] developed a self-optimization system dynamics simulation model of real-time short term cascade hydropower system and extracted operation rules for short-term hydropower reservoir operation by SD simulation.…”