Dear Umair Shahzad

As stated in the attached chapter, The unit commitment problem is used to determine the start-up and shut-down schedule of all production units so that the electric demand is supplied and the total operating cost is minimized.

Then, once the commitment of the generating units is decided, the next step is to determine, for each hour of the planning horizon, the actual power output of each of the committed generating units that is needed to supply the demand and to comply with the limits imposed by the transmission network. This problem is denominated as Economic Dispatch (ED).

https://link.springer.com/content/pdf/10.1007%2F978-3-319-69407-8_7.pdf

Though with modern solar power generation of local residents and their supplied power to grid, are needed, area wise calculation with it consideration of solar generation too...

For a particular demand in the system having a number of generating units with known cost characteristics, Unit Commitment is based on minimization of cost of operation with the selection of units to be run with their level of generation. On the other hand, Economic Disptach is based on the principle of optimum operation of units, such as equi-incremental cost of generation for thermal units, while for hydro units if present, on the basis of usage of water allocated during the period.

If I understood your question correctly I can answer like this:

Unit commitment is a part of economic despatch. It decides the economic operation of partocular unit in a power station.

Economic despatch is concerned with economic transmission of energy genetated to load centres economically. Cost of generation is also included in the overall cost in economic despatch. Unit commitment will take care of cost of generation, availability etc. Economic despatch will ensure overall economy.

Economic Dispatch is a sub-problem of unit commitment. The economic dispatch is a mathematical optimization applied on generation units that exist in the network (i.e. integrated to the grid), while the unit commitment is to assume some units are off and some are on and select the best combination of generation scheduling.

Unit commitment is the process of determining when and which generating units in each power station to start and shut down. Economic transmission is the process of determining what individual energy outputs of the generating units should be scheduled at each point in time.

Chapter Unit Commitment and Economic Dispatch

Article Unit Commitment with Economic Dispatch

http://www.um.edu.uy/docs/7_unit_commitment_and_economic_dispatch_in_micro_grids.pdf

https://www.docsity.com/en/economic-dispatch-and-unit-commitment-explained/2625686/

https://shodhganga.inflibnet.ac.in/bitstream/10603/38951/7/07_chapter2.pdf

unit commitment and economic dispatch have the same objective of cost minimization. unit commitment has limited access and can minimize the generation/fuel cost it deals with the system operation up to utility end. More precisely UC provides best possible (in the sense of economy and power balance) pre-planned schedule to turn on/off units and also their power generation level based on 1. units' cost-characteristics (shutdown cost, startup cost, emission cost, fuel cost, maintenance cost) 2. their availability/non-availability conditions at upcoming particular time/interval and 3. percentage of reserve assigned to each unit. some constraints at generation level should also be satisfied like max./min power capacity of units, ramp rates, minimum up/downtime of units, etc.

Economic dispatch next checks for transmission network constraints like transmission loss, the transmission capacity of lines and voltage limits at buses, etc. and again optimizes the problem subject to these added constraints in such a way to find the modified schedule at minimum cost. This modified schedule is then finalized by power system operators in load dispatch centers for real-time operations.

Most of the time UC and ED problem is not solved back to back rather combined in the single formulation and optimized to achieve the objectives decided. So in literature, it looks indifferent. UCP is solved using utilities(GenCos) provided information whereas ED is solved using transCos provided information by PSOs

Unit commitment is an integer decision of keeping the unit on bar or otherwise , where as despatch is a continuous variable on the running units decided through UC . Both are to cause economy .

hence MILP , mixed integer linear programming etc etc

Unit Commitment is the process of selecting the units from the available generators to meet the power demand.

Economic dispatch is allocating the powers to meet the power demand.

Economic dispatch problem deals with optimal allocation of individual generating units which depends upon fuel cost.Unit commitment problem which deals in how many feasible combinations of allocation in power stations of the generating units to functioning most economically.

Unit commitment is to decide when and which generating power station to start up and shut down.economic dispatch is the process of deciding what the individual power o/p should schedule generating unit at each time.

Unit commitment is the process of deciding when and which generating units at each power station to Page 2 start-up and shut-down.

Economic dispatch is the process of deciding what the individual power outputs should be of the scheduled generating units at each time-point.

Generally, unit commitment is defined to optimize the ON/OFF status of generating units to meet the forecasted loads and reserve requirements, so as to provide a least-cost power generation schedule.

The economic load dispatch is an online process of allocating generation among the available generating units to minimize the total generation cost and satisfy the equality and inequality constraints. Since the civilization increases day by day the demand of electricity increases in the same ratio.

Under the UC model, the objective is to schedule generating units while total cost is minimized, demand is supplied, and the technical and security constraints, as the main ingredients of the UC problem, are met. Hence, the constraints, including Start-Up/shut down Costs, Power Bounds, Ramping Limits, Security Constraints, and Power Balance, should be considered in a typical planning horizon (24 h).

In general, for a given period of time, the ED problem attempts to determine the output power of every generating unit so that all demands can be met at the lowest cost while still satisfying the different technical requirements for each generating unit.

(Conejo, Antonio & Baringo, Luis. (2018). Unit Commitment and Economic Dispatch. 10.1007/978-3-319-69407-8_7. )