Dynamic ramping model including intraperiod ramp-rate changes in unit commitment

The discrete unit commitment problem with min‐stop ramping constraints optimizes the daily production of thermal power plants, subject to an operational reactivity of thermal units in a 30‐minute delay. Previously, mixed integer programming (MIP) formulations aimed at an exact optimization approach. This paper derives matheuristics to face the short time limit imposed by the operational constraints. Continuous relaxations guide the search for feasible solutions exploiting tailored variable fixing strategies. Parallel matheuristics are derived considering complementary strategies in parallel. Tests were performed on more than 600 real‐life instances. Our parallel matheuristic provides high‐quality solutions and outperforms the MIP approach in the time limits imposed by the industrial application. This paper illustrates a special interest for matheuristics in industrial highly constrained problems: many tailored neighborhood searches can be derived from an MIP formulation, and their combination in a parallel scheme improves the solution quality as well as the consistency of the heuristic.

show abstract

“…Ramping constraints were complexified in Correa‐Posada et al. () and Morales‐España et al. () to have more realistic formulations.…”

Section: Related Workmentioning

confidence: 99%

Parallel matheuristics for the discrete unit commitment problem with min‐stop ramping constraints

Dupin

Talbi

2018

Int Trans Operational Res

View full text Add to dashboard Cite

show abstract

“…The formulation of coupling constraints of SGs' minimum uptime/downtime via introducing auxiliary binary variables can be found in [38]. The formulation of power ramp up/down constraints of a generator over a dispatch interval under automatic generation control can be found in [39].…”

Section: Generator Dispatch Formulationmentioning

confidence: 99%

System Strength and Inertia Constrained Optimal Generator Dispatch Under High Renewable Penetration

Yan

Saha

et al. 2020

IEEE Trans. Sustain. Energy

View full text Add to dashboard Cite

System strength and inertia inherently provided by synchronous generators (SGs) empower a power system to ride through voltage and frequency disturbances. The requirements of system strength and inertia were not enforced in the National Electricity Market (NEM) of Australia since SGs dominated the generation fleet in the past. However, the increasing wind and solar generation continuously displaces SGs and consequently reduces system strength and inertia in the NEM. This paper proposes a formulation of system strength and inertia constrained generator dispatch to reassure NEM operational security in light of emerging high renewable penetration. A fault current iterative solver is developed to evaluate system strength, in which the current limitation and voltage control logics of inverter-based generators, and the fault current contribution from VAR compensators are properly modelled in the phasor domain. The system strength contribution factor of an SG is defined to linearize system strength constraint for unit commitment (UC). System and sub-network inertia constraints are also formulated for the UC to limit the rate of change of frequency (RoCoF) in the event of generator/interconnector trip. The proposed generator dispatch formulation can fully meet system strength and inertia requirements in the NEM.

show abstract

“…∆ uc max represents the vector of maximal feasible variation of control variables between two successive dispatch intervals, which mainly refers to the power increase or decrease of an SG/SS over a dispatch interval under secondary frequency control using AGC. The detailed formulation of SG/SS generation ramp up/down constraints in the load tracking operation can be found in [32]. mainly refers to the set of coupling constraints of the minimum uptime and downtime of every SG/SS/SC, which can be formulated via introducing auxiliary binary variables according to [33].…”

Section: A Unit Commitment 1) Problem Statementmentioning

confidence: 99%

Zonal Inertia Constrained Generator Dispatch Considering Load Frequency Relief

Yan

Muljadi

et al. 2020

IEEE Trans. Power Syst.

View full text Add to dashboard Cite

Synchronous generators are operating for less time than before or being decommissioned in the National Electricity Market (NEM) of Australia, due to the proliferation of asynchronous wind and solar generation. Sub-networks of the NEM will face inertia shortages in the near future. This paper develops a formulation of zonal inertia constrained generator dispatch for power systems with a diversified generator portfolio including synchronous generators, synchronous condensers, inverter-interfaced generators and energy storages. Zonal inertia constraints are formulated in unit commitment and optimal power flow to limit the rate of change of frequency (RoCoF) in the event of network separation. Load frequency relief is also considered to reduce the ramp rate requirement of primary reserve. The proposed formulation can reduce the average cost of primary reserve and maintain zonal inertia adequacy to constrain RoCoF in case of the trip of the interconnector(s). Index Term-Inertia, load frequency relief, unit commitment, optimal power flow, renewable energy, power system.

show abstract

Dynamic ramping model including intraperiod ramp-rate changes in unit commitment

Cited by 10 publications

References 5 publications

Parallel matheuristics for the discrete unit commitment problem with min‐stop ramping constraints

Parallel matheuristics for the discrete unit commitment problem with min‐stop ramping constraints

System Strength and Inertia Constrained Optimal Generator Dispatch Under High Renewable Penetration

Zonal Inertia Constrained Generator Dispatch Considering Load Frequency Relief

Contact Info

Product

Resources

About