By default, projection runs will use the model objects (control, demand diagram, electricity tariff, etc ) defined in the baseline default simulation, as specified in the Default Model tab of the Baseline Object window. These objects are referred to as default objects.
It is possible to switch the default objects during a projection run based on the current simulation date or current weather forecast. These objects are referred to as switch objects.
A switch script is required for the switching to be enabled. A switch controller (optional) and switch objects (optional) can be used in conjunction with the switch script:
- The switch controller object is created and edited in InfoWorks WS Pro, and is used to set up links to weather feeds and to set up calendar data.
- The switch script is a ruby script and is defined in the Switch Options tab of the Baseline Object Window. It can be edited via the Switch Script dialog in the IWLive Pro Administrator.
- The switch objects are defined on the Switch Options tab.
If the baseline has an associated switch script, the simulation will substitute default objects for switch objects as per the script. The purpose of switching is to allow a user to change the projection run simulation environment based on the instructions of the switch script.
Default / Switch objects are defined per baseline and can be one or more of the following types:
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Control - contains the operational aspects of modelling the water supply system. The control data describes the initial state of the water supply network at the start of a simulation and the policy for controlling the network during the simulation.
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Demand Diagram - contains one or more demand categories which define the demand pattern for an individual type of consumer.
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Demand Scaling - allows adjustment of a group of demands and transfer flows (grouped by area and / or demand category) by a percentage. This can be used to model changes in demand, for example forecast increase in demand, without altering the values for individual nodes.
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Electricity Tariff - allows users to take into account the cost of various control strategies when working out the optimum control strategy for a system.
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UPC Scenario - contains details of structures, sensors and rules that together determine flows throughout the network. If there are several scenarios, each one represents one possible way in which the network can be controlled.
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Energy CO2 Factors - allows energy losses in the network (due to friction and minor losses in pipes, losses at control valves and losses at customer taps) to be calculated as a Carbon Dioxide (CO2) equivalent in an attempt to perform sustainability analysis.
Switch objects would normally have been set up in InfoWorks WS Pro, however they can be selected or deselected for the current baseline when modifying the baseline in the IWLive Pro Administrator application.