NRTO now serves as a tool to evaluate the Columbia River hydro system's distribution of generation on a within-hour basis.

BPA also plans to incorporate the Synexus NRTO as the optimizer in its more automated Generation Management System (GMS) logic. By setting optimal base points at the beginning of each hour, NRTO will be used by Duty Schedulers to more accurately optimize the federal hydro system generation. NRTO will also be used by Corps of Engineers and Bureau of Reclamation Project Operators to choose the most efficient combination of units to meet their generation obligations.

NRTO works as a stand-alone application, or in conjunction with the Synexus Vista Decision Support System ("Columbia Vista") which has recently been installed and customized for BPA. Vista is the world's premier software system for hydropower scheduling. It determines the global optimum generation schedule for a cascade or group of cascades over the long term (one or more years), as well as in the short-term planning horizon of one to two weeks on a one-hour time resolution.

Scheduling precision can now be further optimized to include detailed within-hour operations by using NRTO. The software was designed as a workbench solution for continual, user-friendly application by Duty Schedulers and plant operators.

The NRTO model allows users to evaluate unit dispatch options while simultaneously meeting generation requests and observing imposed operating constraints. For example, a project operator can look half an hour ahead (in six 5-minute ‘snapshots') and determine the best way to meet the distinct generation requirements anticipated for each interval – while minimizing the number of unit-commitment changes that would be required over the half-hour period. Factors such as constraints on unit dispatch order, unit operating efficiencies, and the effects on head of the generation decision, are all taken into account.

Synexus designed the NRTO software so that Duty Schedulers can also use it to evaluate system-load allocations among selected hydroelectric projects. By using the same tool for both duty schedulers and project operators, overall functionality of both groups of users is enhanced.

NRTO uses continuous real-time data feeds to ensure that current conditions are always reflected in the dispatch solutions it generates. As well, NRTO can respond to either a generation target or a total-flow target as the primary objective. Secondary objectives can also be specified, such as spinning reserve requirements and/or scheduled spill flows. A future option will also allow the user to specify reactive power targets.

BPA Duty Schedulers have been undergoing advanced NRTO training and are impressed with how user-friendly the application is. Tom Murphy, NRTO project manager at Bonneville Power, says simply that “It is a great model!” Full implementation is scheduled for early in 2004 at key projects in the Columbia River system.

The project's next phase, to be conducted later this year, will see Synexus fully integrate its Vista global solution with the NRTO detailed resolution – including considerations of start costs, dynamic conditions, cascade effects and dynamic real-time feeds to the control system.

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