Recent Advances inElectrical & Electronic Engineering
S. Siva Sakthi
1,*
, R.K. Santhi
1
, N. Murali Krishnan
2
, S. Ganesan
1
and S. Subramanian
1
1
Department of Electrical Engineering, Annamalai University, Annamalai Nagar - 608 002, Tamil Nadu, India and
2
Department of Electrical and Electronics Engineering, Mailam Engineering College, Mailam - 604 304, Tamil Nadu,
India
Abstract: Background: The increasing concern of global climate change, the promotion of renewable
energy sources, primarily wind generation, reduces the power generation from conventional plants that
lead to the reduction in pollutant emission. The exploitation of wind power generation is rising
throughout the world. The objective of Unit Commitment (UC) is to identify the optimal generation
scheme of the committed units such that the overall generation cost is reduced, when subjected to a
variety of constraints at each time interval. The optimum generation planning in electrical power system
is difficult, since UC Problem has many variables and system and unit constraints of thermal generating
units. Nowadays, it is essential to include reliability analysis of the power system in operation strategy
of the generating units. Here, the generator failure and malfunction are considered in UC problem
formulation.
Methods: This paper presents a meta-heuristic algorithm based approach to determine the thermal
generation schedule with consideration of wind energy system. A novel evolutionary algorithm known
as Grey Wolf Optimization (GWO) algorithm is applied to solve the UC problem.
Results: The potential of the GWO algorithm is validated by the standard test systems. Besides, the
ramp rate limits are also incorporated in the mathematical problem formulation. In order to validate the
applicability of the GWO, the standard test system is used for demonstration.
Conclusion: The GWO algorithm is applied for the first time to solve wind integrated thermal UC
problem considering generator forced outage rates. The simulation results reveal that the GWO
algorithm has the capability of obtaining economical resolutions with good solution quality. The
implementation of algorithm for solving the chosen problem is simple and robust which indicates that
the GWO is a promising alternative for solving wind integrated thermal UC problems.
A R T I C L E H I S T O R Y
Received: March 14, 2017
Revised: August 18, 2017
Accepted: September 18, 2017
DOI:
10.2174/2352096510666171108155821
Keywords: Grey wolf optimization, ramp rate limit, reliability analysis, unit commitment, wind power generation, UC problem.
1. INTRODUCTION
The Unit Commitment (UC) is one of the vital divisions
of the thermal power generation scheduling. This is
significant because of today's energy paucity and economical
impact of power production company. UC problem
minimizes the total production cost while gratifying the
forecasted load demand and physical and running constraints
of the thermal generating units. The constraints include real
power generation limits, minimum up/down time, up/down
ramp limits and unit initial status. Here, we observe the
schedule of thermal generating units combined with wind
farm to meet the power requirement of each hour in the
planning horizon by considering the generator outages.
*Address correspondence to this author at the Department of Electrical and
Electronics Engineering, Krishnasamy College of Engineering and
Technology, Cuddalore - 607 109, Tamil Nadu, India; Tel:+919842016590;
E-mail: sivasakthi_gayu@yahoo.co.in
Abundant literatures have been reported for determining
thermal UC. Since the Wind Integrated UC (WIUC) is the
emerging research field, very few research reports have been
reported. Hence, the solution quality of WIUC problem can
be improvised by exploring the search space. This inspires to
develop a prominent method to determine the most feasible
UC schedule for WIUC.
The UC problem is formulated as a large-scale, non-
convex, mixed integer and non liner programming problem.
The finding optimum schedule of generating units is very
difficult within acceptable processing time and memory
requirement. The complete enumeration method can yield
exact solution of the UC problem. However, the excessive
computational time requirement makes it unsuitable for
realistic power systems. Numerous solution techniques have
been developed for solving UC problem and are classified as
traditional, artificial intelligence and hybrid methods.
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Recent Advances in Electrical & Electronic Engineering, 2018, 11, 58-68
RESEARCH ARTICLE
Thermal Unit Commitment Problem along with Wind Power Generation
by Considering Generator Outages