System and method for modeling and simulating water distribution and collection systems including variable speed pumps

An apparatus comprising:

• a processor;
• a memory configured to store computer-executable instructions for execution on the processor, the computer-executable instructions implementing,
• a hydraulic model of a water distribution or collection system, the hydraulic model including link elements and node elements that define a configuration, at least one node element representing a variable speed pump (VSP), having a tank located on the VSP's discharge side that serves as the VSP's control node in the configuration or having a tank located on the VSP's suction side that serves as the VSP's control node in the configuration, and
• a hydraulic solver configured to initialize values of one or more hydraulic heads and link flows in the hydraulic model, compute system matrixes descriptive of the hydraulic model, solve the matrixes to determine new values of the one or more hydraulic heads, update link flows from current values to new values based upon the new values of the one or more hydraulic heads, repeat the operations of compute, solve and update until a change between current values to new values of link flows is less than a predetermined accuracy tolerance, cause the VSP to be set to an operating status of off, or to a variable speed mode of operation, depending on tank level at the VSP's control node in relation to a target level at the VSP's control node, when the VSP is set to a variable speed mode of operation use the new values of link flows and hydraulic heads to calculate at least one VSP speed at a time step, further repeat the operations of initialize, compute, solve, update, repeat, and use for time steps, with the VSP being set to each of the operating status of off and the variable speed mode of operation for at least some time steps, until a current time step is determined to be greater than a simulation duration;
• and
• a display configured to display results that include the at least one VSP speed at each time step.

A non-transitory computer-readable storage medium including instructions executable by a processor, the instructions when executed by the processor operable to:

• define a hydraulic model of a water distribution or collection system, the hydraulic model including link elements and node elements that define a configuration, at least one of the node elements representing a fixed-flow variable speed pump (VSP) having a tank located on the VSP's discharge side that serves as the VSP's control node in the configuration or having a tank located on the VSP's suction side that serves as the VSP's control node in the configuration;
• initialize values of one or more hydraulic heads and link flows in the hydraulic model;
• compute system matrixes descriptive of the hydraulic model;
• solve the matrixes to determine new values of the one or more hydraulic heads;
• update link flows from current values to new values based upon the new values of the one or more hydraulic heads;
• repeat the operations of compute, solve and update until a change between current values to new values of link flows is less than a predetermined accuracy tolerance;
• cause the VSP to be set to an operating status of off, or to a variable speed mode of operation, depending on tank level at the VSP's control node in relation to a target level at the VSP's control node;
• when the VSP is set to a variable speed mode of operation, use the new values of link flows and hydraulic heads to calculate at least one VSP speed at a time step;
• further repeat the operations of initialize, compute, solve, update, repeat, and use for time steps, with the VSP being set to each of the operating status of off and the variable speed mode of operation for at least some time steps, until a current time step is determined to be greater than a simulation duration;
• and
• include the at least one VSP speed in results of a simulation of the hydraulic model, the results displayed to a user.