Dual Interval Optimization Based Trading Strategy for ESCO in Day-ahead Market with Bilateral Contracts

Being capable of aggregating multiple energy resources, the energy service company(ESCO) has been regarded as a promising alternative for improving power system flexibility and facilitating the consumption of renewable resources in the electricity market. Considering the uncertain variables in day-ahead(DA) market trading, an ESCO can hardly determine their accurate probability distribution functions. Traditional interval optimization methods are used to process these uncertain variables without specific probability distribution functions.However, the lower and upper bounds of the intervals may change due to extreme weather conditions and other emergent events. Hence, a dual interval optimization based trading strategy(DIOTS) for ESCO in a DA market with bilateral contracts(BCs) is proposed. First, we transfer the dual interval optimization model into a simple model consisting of several interval optimization models. Then, a pessimistic preference ordering method is applied to solve the derived model. Case studies illustrating an actual test system corroborate the validity and the robustness of the proposed model, and also reveal that ECSO is critical in improving power system flexibility and facilitating the ability of absorbing renewable resources.

Bilateral Contract for Load Frequency and Renewable Energy Sources Using Advanced Controller

Reestablishment in power system brings in significant transformation in the power sector by extinguishing the possession of sound consolidated assistance.However,the collaboration of various manufacturing agencies,autonomous power manufacturers,and buyers have created complex installation processes.The regular active load and inefficiency of best measures among varied associates is a huge hazard.Any sudden load deviation will give rise to immediate amendment in frequency and tie-line power errors.It is essential to deal with every zone’s frequency and tie-line power within permitted confines followed by fluctuations within the load.Therefore,it can be proficient by implementing Load Frequency Control under the Bilateral case,stabilizing the power and frequency distinction within the interrelated power grid.Balancing the net deviation in multiple areas is possible by minimizing the unbalance of Bilateral Contracts with the help of proportional integral and advanced controllers like Harris Hawks Optimizer.We proposed the advanced controller Harris Hawk optimizer-based model and validated it on a test bench.The experiment results show that the delay time is 0.0029 s and the settling time of 20.86 s only.This model can also be leveraged to examine the decision boundaries of the Bilateral case.

Effects of Hydrogen Storage System and Renewable Energy Sources for Optimal Bidding Strategy in Electricity Market

This work suggested a novel model for obtaining optimum bidding/offering strategy to improve the benefits in case of big users.Aiming this regard,several electrical energy resources including:micro turbines,green power sources(wind turbine and photovoltaic system),power storage unit such as Hydrogen storage system with fuel cell,as well as mutual treaties are taken into account in offered model.Considering various models for uncertain parameters based on their natures such as power demand,electricity market tariffs,solar irradiation,temperature and wind speed is one of the contributions of the proposed model.Uncertainty of power demand is modeled by robust optimal method whereas remain uncertain parameters are incorporated in model by stochastic method.Considering of wind speed cased is made by Weibull distribution.While,normal distribution is utilized for production of cases for electricity market tariffs,solar irradiation and temperature.In order to reduce the bidding error loss,the storage devices are corporate with green energy in power unbalanced conditions.Combined-integer linear programming method is applied for handling of pricing method profiles that have strength against considered uncertainties on power demand of big user.The obtained results confirm,the entire electrical energy supplement expenditure of big user in absence of demand uncertainty is$39.63 whereas it is augmented up to$49.47 to achieve robustness vs.demand uncertainty.Also,using of hydrogen storage system by considering the reliability index is reduced the bidding price of the system.

Measuring Enrichment Liability in the Context of Unfinished Construction Projects

Most aspects of construction projects mainly fall under contractual regime. However, when things go wrong such as when the project is abandoned for various reasons, they may create two different scenarios： a contract that is breached and a fixed structure that is left on the land which may constitute an incomplete benefit that is acquired by one of the parties. The transfer of such benefit is initially made with a legal ground, but that ground has since ceased to exist. If some aspect of that benefit cannot be recovered under a contract, enrichment rules may be competent to solve the problem. How to measure the different aspects of that enrichment is however a problem that may have different interpretations according to different conceptions of the foundations of enrichment liability in a particular legal system. This article explores the measures of enrichment in such cases of failed bilateral contracts scenarios working from South African perspective. It argues that in cases of failed bilateral contracts generating an enrichment situation, sanctioning a dual measure of enrichment in a legal system may be an appropriate avenue.

A Novel Approach for a Two Area Load Frequency Control in a Competitive Electricity Market Adopting Unscheduled Interchange Price

This paper proposes a novel price based load frequency control scheme for a two area system, using an Unscheduled Interchange (UI) price signal, which is ideal and suitable for electricity market. The Government of India has introduced Availability Based Tariff (ABT) structure with an intention of ensuring grid security and to regulate grid indiscipline through Central Electricity Regulatory Commission Regulation. After the introduction of this regulation, the over or under injection by the generating companies (GENCOs) during off peak or peak hours are demoralized and the frequency is maintained at the nominal value. In this paper, the GENCOs instead of reacting to this price signal manually, an automated mode of frequency control is deployed in each area using UI price signal to achieve fast response to load change. The Distribution Company (DISCO) Participation Matrix (DPM) has also been employed in this work to relate the scenario under deregulation of electricity market. The proposed scheme has been verified for different cases by simulating it on a two area system, each having four GENCOs and one DISCO in MATLAB/SIMULINK environment. From the results, it is clearly observed that if the proposed method is employed by all GENCOs, it will certainly enhance the control of system frequency and at the same time throw down the UI liability of market participants. It also ensures that the GENCOs and DISCOs strictly adhere to the bilateral contract following the DISCO participation matrix.

Transmission Cost Allocation by Power Tracing Based Equivalent Bilateral Exchanges

The allocation of transmission cost provides important references and signals for system expansions and investments.This paper proposes a power tracing based equivalent bilateral exchange(PTEBX)method in which network users are responsible for not only their induced power flows,but also power flows induced by whom they have equivalent bilateral exchanges with.The equivalent bilateral exchanges are recognized based on the power tracing.To evaluate the performance of different methods of allocating transmission cost,seven criteria are put forward that take into consideration characteristics of power systems.Theoretical analysis is then conducted to certify whether the methods satisfy the criteria.The results indicate that only the PTEBX method is able to satisfy all the seven criteria.Numerical examples based on the IEEE-30 system are presented to further demonstrate the applicability of the proposed method.

Load frequency control in deregulated power system with wind integrated system using fuzzy controller

This paper presents the analysis of load frequency control （LFC） of a deregulated two-area hydro-thermal power system using fuzzy logic controller, with doubly fed induction generators （DFIGs） integrated into both the control areas. The deregulation of power sector has led to the formation of new companies for generation, transmission and distribution of power. The conventional two-area power system is modified to study the effects of the bilateral contracts of companies on the system dynamics. Deregulation creates highly competitive and distributed control environment, and the LFC becomes even more challenging when wind generators are also integrated into the system. The overall inertia of the system reduces, as the wind unit does not provide inertia and isolates from the grid during disturbances. The DFIGs integrated provide inertial support to the system through modified inertial control scheme, and arrests the initial fall in frequency after disturbance. The inertial control responds to frequency deviations, which takes out the kinetic energy of the wind turbine for improving the frequency response of the system. To enhance the participation of the doubly fed induction generator （DFIG） in the frequency control, optimal values of the speed control parameters of the DFIG-based wind turbine have been obtained using integral square error （ISE） technique. The dynamics of the system have been obtained for a small load perturbation, and for contract violation using fuzzy controller.