scholarly journals A Two-Level Desired Load Profile Tracking Algorithm for Electric Two-Wheeler Charging Stations

2021 ◽  
Vol 11 (6) ◽  
pp. 7814-7823
Author(s):  
D. N. Huu ◽  
V. N. Ngoc
Keyword(s):  
Power Systems ◽  
Tracking Algorithm ◽  
Effective Solution ◽  
Peak Shaving ◽  
Large Power ◽  
Load Profile ◽  
Load Leveling ◽  
The Cost ◽  
Two Wheeler ◽  
Charging Stations

In Vietnam and in other developing countries, two-wheeled electric vehicles are potential alternatives to gasoline-powered motorbikes. The growth in the number of Electric Two-Wheelers (E2Ws) requires a large power demand of charging load. In addition, the increasing spread in the appearance and penetration of rooftop photovoltaic (PV) power systems, with their intermittence and uncertain nature, poses technical challenges that need to be addressed. The coordination of PV rooftop operation and EV charging may be an effective solution to meet the emerging load demand from EVs, increasing solar power penetration while minimizing the cost of grid reinforcement or possible upgrades. In this paper, a two-level desired load profile tracking algorithm for PV integrated electric bicycles/electric motorcycle charging stations is proposed with the purposes of load leveling, valley filling, and peak shaving. The simulation results show that the proposed algorithm is an effective solution, significantly improving the load profile, especially when compared with uncontrolled charging and constant charging power scheme.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

2019 ◽  
Vol 14 (1) ◽  
pp. 5-11
Author(s):  
S. Rajasekaran ◽  
S. Muralidharan
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Firefly Algorithm ◽  
Transmission System ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Voltage Collapse ◽  
Facts Devices ◽  
The Cost ◽  
Bus System

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

scholarly journals A New Peak-Shaving Model Based on Mixed Integer Linear Programming with Variable Peak-Shaving Order

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 887
Author(s):  
Xianliang Cheng ◽  
Suzhen Feng ◽  
Yanxuan Huang ◽  
Jinwen Wang
Keyword(s):  
Linear Programming ◽  
Power Systems ◽  
Integer Linear Programming ◽  
Mixed Integer Linear Programming ◽  
Mixed Integer ◽  
Time Interval ◽  
Renewable Energy Resources ◽  
Load Curve ◽  
Peak Shaving ◽  
Model Based

Peak-shaving is a very efficient and practical strategy for a day-ahead hydropower scheduling in power systems, usually aiming to appropriately schedule hourly (or in less time interval) power generations of individual plants so as to smooth the load curve while enforcing the energy production target of each plant. Nowadays, the power marketization and booming development of renewable energy resources are complicating the constraints and diversifying the objectives, bringing challenges for the peak-shaving method to be more flexible and efficient. Without a pre-set or fixed peak-shaving order of plants, this paper formulates a new peak-shaving model based on the mixed integer linear programming (MILP) to solve the scheduling problem in an optimization way. Compared with the traditional peak-shaving methods that need to determine the order of plants to peak-shave the load curve one by one, the present model has better flexibility as it can handle the plant-based operating zones and prioritize the constraints and objectives more easily. With application to six cascaded hydropower reservoirs on the Lancang River in China, the model is tested efficient and practical in engineering perspective.

scholarly journals Coordination of Multiple Electric Vehicle Aggregators for Peak Shaving and Valley Filling in Distribution Feeders

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 352
Author(s):  
Saad Ullah Khan ◽  
Khawaja Khalid Mehmood ◽  
Zunaib Maqsood Haider ◽  
Muhammad Kashif Rafique ◽  
Muhammad Omer Khan ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Power Distribution ◽  
Distribution System ◽  
Energy Demand ◽  
Minimum Energy ◽  
Peak Shaving ◽  
Peak Period ◽  
Actual Distribution ◽  
Load Profile ◽  
System Load

In this paper, a coordination method of multiple electric vehicle (EV) aggregators has been devised to flatten the system load profile. The proposed scheme tends to reduce the peak demand by discharging EVs and fills the valley gap through EV charging in the off-peak period. Upper level fair proportional power distribution to the EV aggregators is exercised by the system operator which provides coordination among the aggregators based on their aggregated energy demand or capacity. The lower level min max objective function is implemented at each aggregator to distribute power to the EVs. Each aggregator ensures that the EV customers’ driving requirements are not relinquished in spite of their employment to support the grid. The scheme has been tested on IEEE 13-node distribution system and an actual distribution system situated in Seoul, Republic of Korea whilst utilizing actual EV mobility data. The results show that the system load profile is smoothed by the coordination of aggregators under peak shaving and valley filling goals. Also, the EVs are fully charged before departure while maintaining a minimum energy for emergency travel.

Gas Turbine Recuperator Technology Advancements

1972 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
Heat Exchanger ◽  
Power Systems ◽  
Gas Turbine ◽  
Substantial Reduction ◽  
Liquid Fuels ◽  
Cycle Space ◽  
Fuel Savings ◽  
Efficient Heat Transfer ◽  
The Cost ◽  
Turbine Design

Because of intense development in the aircraft gas turbine field over the last 30 years, the fixed boundary recuperator has received much less development attention than the turbomachinery, and is still proving to be the nemesis of the small gas turbine design engineer. For operation on cheap fuel, such as natural gas, the simple cycle-engine is the obvious choice, but where more expensive liquid fuels are to be burned, the economics of gas turbine operation can be substantially improved by incorporating an efficient, reliable recuperator. For many industrial, vehicular, marine, and utility applications it can be shown that the gas turbine is a more attractive prime mover than either the diesel engine or steam turbine. For some military applications the fuel logistics situation shows the recuperative gas turbine to be the most effective power plant. For small nuclear Brayton cycle space power systems the recuperator is an essential component for high overall plant efficiency, and hence reduced thermal rejection to the environment. Data are presented to show that utilization of compact efficient heat transfer surfaces developed primarily for aerospace heat exchangers, can result in a substantial reduction in weight and volume, for industrial, vehicular, marine, and nuclear gas turbine recuperators. With the increase in overall efficiency of the recuperative cycle (depending on the level of thermal effectiveness, and the size and type of plant), the cost of the heat exchanger can often be paid for in fuel savings, after only a few hundred hours of operation. Heat exchanger surface geometries and fabrication techniques, together with specific recuperator sizes for different applications, are presented. Design, performance, structural, manufacturing, and economic aspects of compact heat exchanger technology, as applied to the gas turbine, are discussed in detail, together with projected future trends in this field.

Expectations and Recent Experience for Gas Turbine Reliability, Availability, and Maintainability (RAM)

2007 ◽  
Author(s):  
Robert F. Steele ◽  
Dale C. Paul ◽  
Torgeir Rui
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Advanced Technology ◽  
Recent Experience ◽  
Reliability Growth ◽  
Market Place ◽  
New Product Introductions ◽  
Low Emission ◽  
The Cost

Since the early 1990’s there have been significant changes in the gas turbine, and power generation market place. The ‘F-Class’ Gas Turbines, with higher firing temperatures, single crystal materials, increased compressor pressure ratios and low emission combustion systems that were introduced in the early 1990’s have gained significant field experience. Many of the issues experienced by these new product introductions have been addressed. The actual reliability growth and current performance of these advanced technology machines will be examined. Additionally, the operating profiles anticipated for many of the units installed during this period has been impacted by both changes in the anticipated demand and increases in fuel costs, especially the cost of natural gas. This paper will review how these changes have impacted the Reliability, Availability, and Maintainability performance of gas turbines. Data from the ORAP® System, maintained by Strategic Power Systems, Inc, will be utilized to examine the actual RAM performance over the past 10 to 15 years in relation to goals and expectations. Specifically, this paper will examine the reliability growth of the F-Class turbines since the 1990’s and examine the reliability impact of duty cycle on RAM performance.

Sign in / Sign up

Export Citation Format

Share Document