Power system operations and control: Difference between revisions

Revision as of 16:26, 31 May 2022

Revision as of 16:40, 31 May 2022

Line 13:

For a "traditional" [[vertical integration#Electric utilities|vertically integrated electric utility]] the main goal of the unit commitment is to minimize both the [[marginal cost]] of producing the unit electricity and the (quite significant for fossil fuel generation) start-up costs. In a "restructured" [[electricity market]] a [[market clearing]] algorithm is utilized, frequently in a form of an [[auction]]; the [[merit order]] is sometimes defined not just by the monetary costs, but also by the environmental concerns.{{sfn|Conejo|Baringo|2017|p=9}}

Unit commitment is more complex than the shorter-time-frame operations, since unit availability is subject to multiple constraints:{{sfn|Bhattacharya|Bollen|Daalder|2012|pp=47-52}}

* demand-supply balance need to be maintained, including the sufficient [[spinning reserve]]s for contingency. The balance need to reflect the transmission constraints;

* thermal units might have limits on minimum uptime (once switched on, cannot be turned off quickly) and downtime (once stopped, cannot be quickly restarted again);

* "must-run" units have to run due to technical constraints (for example, [[combined heat and power]] plants must run if their heat is needed;

* there is a limited amount of crews at the generation utility, restricting the number of units that can be started simultaneously.

== Hours-ahead operation ==