Distributed Market Clearing Approach for Local Energy Trading in Transactive Market

This paper proposes a market clearing mechanism for energy trading in a local transactive market, where each player can participate in the market as seller or buyer and tries to maximize its welfare individually. Market players send their demand and supply to a local data center, where clearing price is determined to balance demand and supply. The topology of the grid and associated network constraints are considered to compute a price signal in the data center to keep the system secure by applying this signal to the corresponding players. The proposed approach needs only the demanded/supplied power by each player to reach global optimum which means that utility and cost function parameters would remain private. Also, this approach uses distributed method by applying local market clearing price as coordination information and direct load flow (DLF) for power flow calculation saving computation resources and making it suitable for online and automatic operation for a market with a large number of players. The proposed method is tested on a market with 50 players and simulation results show that the convergence is guaranteed and the proposed distributed method can reach the same result as conventional centralized approach.Comment: Accepted paper. To appear in PESGM 2018, Portland, OR, 201

Design of auction-based approach for market clearing in peer-to-peer market platform

This paper designs a market platform for Peer-to-Peer (P2P) energy trading in Transactive Energy (TE) systems, where prosumers and consumers actively participate in the market as seller or buyer to trade energy. An auction-based approach is used for market clearing in the proposed platform and a review of different types of auction is performed. The appropriate auction approach for market clearing in the proposed platform is designed. The proposed auction mechanism is implemented in three steps namely determination, allocation and payment. This paper identifies important P2P market clearing performance indices, which are used to compare and contrast the designed auction with different types of auction mechanisms. Comparative studies demonstrate the efficacy of the proposed auction mechanism for market clearing in the P2P platform.Comment: 6 page

Two-Step market clearing for local energy trading in feeder-based markets

Recent innovations in Information and Communication Technologies (ICT) provide new opportunities and challenges for integration of distributed energy resources (DERs) into the energy supply system as active market players. By increasing integration of DERs, novel market platform should be designed for these new market players. The designed electricity market should maximize market surplus for consumers and suppliers and provide correct incentives for them to join the market and follow market rules. In this paper, a feeder-based market is proposed for local energy trading among prosumers and consumers in the distribution system. In this market, market players are allowed to share energy with other players in the local market and with neighborhood areas. A Two-StepMarket Clearing (2SMC) mechanism is proposed for market clearing, in which in the first step, each local market is cleared independently to determine the market clearing price and in the second step, players can trade energy with neighborhood areas. In comparison to a centralized market, the proposed method is scalable and reduces computation overheads, because instead of clearing market for a large number of players, the market is cleared for a fewer number of players. Also, by applying distributed method and Lagrangian multipliers for market clearing, there is no need for a central computation centre and private information of market players. Case studies demonstrate the efficiency and effectiveness of the proposed market clearing method in increasing social welfare and reducing computation time.Comment: 6 page

Distributed Load Scheduling in Residential Neighborhoods for Coordinated Operation of Multiple Home Energy Management Systems

Recently, home energy management systems (HEMS) are gaining more popularity enabling customers to minimize their electricity bill under time-varying electricity prices. Although they offer a promising solution for better energy management in smart grids, the uncoordinated and autonomous operation of HEMS may lead to some operational problems at the grid level. This paper aims to develop a coordinated framework for the operation of multiple HEMS in a residential neighborhood based on the optimal and secure operation of the grid. In the proposed framework customers cooperate to optimize energy consumption at the neighborhood level and prevent any grid operational constraints violation. A new price-based global and individualized incentives are proposed for customers to respond and adjust loads. The individual customers are rewarded for their cooperation and the network operator benefits by eliminating rebounding network peaks. The alternating direction method of multipliers (ADMM) technique is used to implement coordinated load scheduling in a distributed manner reducing the computational burden and ensure customer privacy. Simulation results demonstrate the efficacy of the proposed method in maintaining nominal network conditions while ensuring benefits for individual customers as well as grid operators

Enhancing scalability of peer-to-peer energy markets using adaptive segmentation method

This paper proposes an adaptive segmentation method as a market clearing mechanism for peer-to-peer (P2P) energy trading scheme with large number of market players. In the proposed method, market players participate in the market by announcing their bids. In the first step, players are assigned to different segments based on their features, where the balanced k-means clustering method is implemented to form segments. These segments are formed based on the similarity between players, where the amount of energy for trade and its corresponding price are considered as features of players. In the next step, a distributed method is employed to clear the market in each segment without any need to private information of players. The novelty of this paper relies on developing an adaptive algorithm for dividing large number of market players into multiple segments to enhance scalability of the P2P trading by reducing data exchange and communication overheads. The proposed approach can be used along with any distributed method for market clearing. In this paper, two different structures including community-based market and decentralized bilateral trading market are used to demonstrate the efficacy of the proposed method. Simulation results show the beneficial properties of the proposed segmentation method

Distribution feeder loads classification and decomposition

Load in distribution networks is normally measured at the 11kV supply points; little or no information is known about the type of customers and their contributions to the load. This paper proposes statistical methods to decompose an unknown distribution feeder load to its customer load sector/subsector profiles. The approach used in this paper should assist electricity suppliers in economic load management, strategic planning and future network reinforcements

Advances in power system small signal stability analysis considering load modeling and emerging generation resource

With the increasing complexity of the power system, electromechanical oscillations are becoming one of the major problem. Several blackouts have been reported in the past due to insufficient damping of the oscillatory modes. The starting point to avoid catastrophic behaviors would be to simulate actual power system and study the response of the system under various outages leading to blackouts. Recently, it has been identified that appropriate modeling of the load is necessary to match the actual system behavior with the computer simulated response. This research throws some insight into the detailed load modeling and its impact on the system small signal stability. In particular, Composite load model is proposed and its effect on the system small signal stability is investigated. Modeling all the loads in a large power system would be a cumbersome job and hence the method for identifying the most sensitive load location is also proposed in the thesis. The effect of load modeling on the eigenvalue movement is also investigated. The low damped electromechanical modes are always undesirable in the large inter-connected power systems as they might get excited under some event leading to growing oscillations. Proper damping of these modes is essential for effective and reliable system operation. Power system stabilizers have been proved to be an effective way of damping these electromechanical modes. The optimal number and location of PSS to effectively damp the modes via improved Differential algorithm is proposed. Moreover, the effect of TCSC, series compensated FACTs device, on enhancing the system damping is investigated. A fixed order model matching technique is presented to design a damping controller for the TCSC. With the increasing global pressure for reducing carbon emissions, there is a great amount of interest in the renewable sources of energy, particularly Wind Energy Conversion Systems. Of all the present methods of wind generation systems, Doubly Fed Induction Generation (DFIG) based wind farms are gaining popularity. The comparison of various methods of wind generation techniques is presented. In particular, the impact of DFIG based wind farms on the system small signal stability is investigated in this work. Co-ordinated tuning of the controllers is performed using Bacterial Foraging Technique, which is another member of Evolutionary algorithms. Damping controller for the DFIG system is proposed to enhance the damping of the electromechanical modes. Results have proved the effectiveness of the control methodology. The contributions made in this thesis could be utilized to promote the further development of the damping controllers for large power systems

Decoupled controller for single-phase grid connected rooftop PV systems to improve voltage profile in residential distribution systems

Unity power factor injection from single-phase PVs located towards the end of a residential feeder leads to voltage rise problems. Also, unbalanced current injection due to variable solar insolation results in voltage unbalancing and makes the situation worst. This paper proposes a decoupled controller for a single-phase PV inverter to improve the voltage profile of the distribution feeders. The proposed controller consists of the following components: voltage regulator (to control the amount of reactive power injection), Outer voltage control loop (slow controller to set the reference for the inner current loop), inner current control loop (to control the PV inverters) and modified second order generalised integrator (to generate fundamental frequency). A sample distribution systems consisting of several PVs located in all three phases and a three-phase induction motor load is considered. The real-time Hardware-in-the-Loop (HIL) simulations are performed to test the efficacy of the proposed controller scheme. Results show the improvement in voltage regulation of different buses