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This paper presents the feasibility and design of a Microgrid (MG) for Demand Response (DR), demand peak shaving, and energy arbitrage using a real-world test case, located in Texas. The real-world study MG consisted of natural gas generators and a Battery Energy Storage System (BESS) as principal Distributed Energy Resources (DERs). HOMER Pro® software was used as a simulation test bed to conduct techno-economical assessment of the considered MG system. The MG's preliminary design involved sizing of the DERs accounting for the current and prospective loading conditions in that MG. Sensitivity analysis was performed to identify the most economical MG design that will lead to the lowest costs and highest cost savings. Obtained results from these simulations are discussed in the paper.

With high penetration of distributed generation (DG) into distribution systems, an unintended bulk DG tripping as a consequence of severe disturbances such as 3-phase faults in the transmission system is a concern since it can further cause unintended operation of transmission distance relays. To address this matter, this paper presents a novel protection scheme based on support vector machine (SVM) approach. The proposed scheme detects bulk DG tripping following a fault in the power transmission system, and then makes sure there is no follow on distance relay maloperation. It is also able to detect a fault if it happens during the blocking period and hence unblock the relay operation correspondingly. Wide-area (WA) measurements obtained from phasor measurement units (PMUs) are used, in addition to local measurements, to improve the scheme selectivity. The New-England 39 bus system is used to test the proposed scheme. Simulation results are discussed and illustrated.

A challenge raised in today's power system is assessing the system protection security and dependability after the topology has been changed due to relay operation upon the occurrence of cascading faults or intentional operator switching action. This paper proposes an automated setting calculation module which could be used to review the adequacy of the distance relay settings following network topology changes. The calculation procedure is broken down into blocks which could be processed in parallel in order to improve the computation speed. A new concept called distance of impact is proposed to reduce the computational burden by conducting the calculations on a limited portion of the network affected by the topology change. The module performance is tested on a synthetic IEEE 118-bus and real-life Alberta transmission operator systems. A sensitivity analysis in the form of N-2 contingency impact on the network relay settings coordination is conducted on the test systems.

Traditional power system protection principles, schemes, and technologies are continuously being challenged by the proliferation of highly distributed stochastic renewable energy sources (RES). In the presence of such massive penetrations of intermittencies and uncertainties in the electricity grid, the dependability and security of the protection systems may be compromised. To address these challenges, it calls for new adaptive techniques, transformative mindsets, and advanced technologies for the secure, resilient, affordable, and dependable protection systems in the electric grids of the future. This chapter overviews and discusses the protection challenges of the massively RES-integrated transmission systems, distribution systems, and microgrids and also offers the possible solutions that can help realize a robust, adaptive, and yet affordable protection schemes in smart grids.

This paper investigates the challenges of conventional transmission protection system dependability and security when meeting the operating complexities affecting power system resilience. Effective Hierarchically Coordinated Protection (HCP) scheme is proposed to illustrate various approaches to corrective, adaptive and predictive protection actions aimed at improving power system resilience. The results obtained using IEEE test cases are used to illustrate the benefits.

One of the important points in optimal operation of a micro-CHP based microgrids (e.g., a residential building) is to coordinate its thermal and electrical loads. Therefore, in this study, thermal load is analyzed more precisely in terms of the required hot water and desired building temperature. The microgrid is assumed to be equipped with smart meters and controllable electrical loads. The information provided by smart meters is utilized in implementing smart control of micro-CHP, storages, and demand response programs. This study is aimed at presenting an optimal scheduling model for a microgrid considering technical and economical constraints based on temperature dependent thermal load modeling. A sensitivity analysis is conducted to identify and rank the impact of several uncertainties such as variations in temperature, electrical and thermal demand.

One big challenge raised by frequent topology change in today's power system is assessing the system protection security and dependability afterwards. This paper reviews the setting algorithm for the distance relays and proposes an automated setting calculation module. The calculation procedure is broken down into blocks which could be processed in parallel in order to improve the computation speed. The module could be used to assess the system protection vulnerabilities following a topology change in instances when multiple switching actions are done in response to occurrence of cascading faults or as a result of intentional control action. The module performance is tested on New England 39-bus and IEEE 118-bus systems. A sensitivity analysis in the form of N-2 contingency impact on the network relay settings is conducted on both test systems.

The topology (transmission line) switching to achieve economic and reliability gains in the power grid has been proposed some time ago. This approach did not gain much attention until recently when large penetration of renewable generation created incentives to use transmission line switching to control sudden changes in power flows and mitigate contingencies caused by the generation variability. This paper explores implementation issues related to circuit breaker (CB) monitoring, relay setting coordination and detection of relay misoperations in the context of the topology switching sequence implementation. The paper covers risk-based assessment of CB status needed for determination of reliable switching sequences; it indicates how relay settings may be changed due to switching actions; it also provides an on-line algorithm for detection of relay misoperations, which identifies the lines that may be switched back to service after being trip erroneously by a relay.

Fault current magnitude and transient recovery voltage (TRV) are two important factors effecting circuit breaker (CB) operation during short-line faults. In this paper an inductive fault current limiter (FCL), which is a traditional kind of FCL, is modeled and simulated using electromagnetic transient program (EMTP) to study its effects on these two factors. It is assumed that the FCL is placed following the circuit breaker at the beginning of the line. Mathematical formulas are obtained for describing the relationship between the current limit factor and the recovery voltage of a CB as well as the rate of rise of recovery voltage (RRRV) based on theoretical analysis. The mathematical analysis is compared and verified with simulation results.

According to the recent research significant amount of building energy consumption can be saved through optimized operation and management and it is not necessary to change the building structure and the hardware configuration of the energy supply system. Therefore, there is a huge potential for building energy savings through efficient operation. In this paper a smart building (microgrid) is assumed to be supplied by different power sources such as CHP, PV, battery, and main grid. The microgrid is connected to the main grid and it can buy/sell power from/to the grid. Furthermore, day-ahead electricity pricing is assumed for the grid power. The goal is to find optimized solution for scheduling problem of the building energy sources. Furthermore the effect of the battery on operation cost is investigated.

Any sudden change in the configuration or the loading of an electrical network causes power swing between the load concentrations of the network. In order to prevent the distance protection from tripping during such conditions, a power swing blocking is utilized. This paper compares and evaluates the performance of several power swing detection algorithms in the presence of series compensation and without it. The decreasing impedance, the Vcosφ and the power derivation methods are ordinary algorithms for power swing detection. A precise model for power swing conditions has been generated by EMTDC/PSCAD software. In this paper this model is used to simulate the algorithms behavior under different operational conditions.