The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB’s ability to act as a fault current limiter and a circuit breaker.

The treatment of water and wastewater provides numerous benefits to human health and the environment. Along with these benefits, however, come negative consequences associated with greenhouse gas (GHG) emissions, which until recently have been largely overlooked. Energy is required to produce water for consumptive uses as well as to collect and treat wastewater. Recent studies have begun to explore the total environmental impact of the water sector's energy use and GHG emissions. This research investigated a method for determining the impact of GHG resulting from municipal water consumption and wastewater disposal by customers in a specific geographic region. WATER AND ENERGYWater is indispensable to human health and well-being and crucial for sustainable development. The sustainability of water systems, however, is not limited to the quality of service provided. Approximately 4% of the electricity in the United States is used to move and treat water and wastewater (Appelbaum, 2002). The energy consumed in the municipal water cycle carries significant environmental consequences, most notably GHG emissions. Potable water is typically produced with nonrenewable energy resources; thus, the greater the embodied energy of the water, the greater the GHG emissions (The Brendle Group, 2007). Reduced consumption of electricity at treatment and pumping facilities equates to reduced operating costs and GHG emissions (Tripathi, 2007).Embodied energy refers to the quantity of energy required to manufacture and supply a product, material, or service to the point of use. In the water utility sector, embodied energy is the total amount of energy associated with the use of a given amount of water in a specific location (Wilkinson, 2000). It is the amount of energy consumed by all the processes associated with the production, delivery, consumption, and disposal of water.The US Department of Energy (DOE) and the US Environmental Protection Agency (USEPA) recently initiated programs aimed at assessing the nexus between water and energy (Sandia National Laboratories, 2006). Through the Energy-Water Nexus program, DOE is responsible for the development of technological products that will improve the nation's energy and water security. Eleven of DOE's national laboratories and the Electric Power Research Institute are investigating energy use by water-related systems and processes (Klein, 2005). USEPA is also investigating the relationship between water and energy consumption. In a 2008 memorandum to USEPA regional administrators, Benjamin H. Grumbles, assistant administrator in USEPA's Office of Water, promoted energy efficiency for the water sector (Grumbles, 2008). Some of the agency's efforts include adoption of environmental management systems, ENERGY STAR program additions such as water utility energy-tracking tools and a carbon footprint calculator, and use of Clean Water and Drinking Water State Revolving Funds to advance energy efficiency. USEPA has also developed a step-by-step workbook to help utilities ensure a sustainabl...

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Several types of high voltage direct current (HVDC) breakers have been introduced and commercialized. Each of them has advantages and disadvantages. Among them, the hybrid HVDC breaker is highly successful. One of the most important concerns that the hybrid HVDC breaker has faced is high power loss throughout its fault current breaking process. The hybrid HVDC breaker comprises a high voltage bidirectional main HVDC breaker. A significant number of electronic switches need to be connected in a series where anti-parallel diodes are essentially embraced. During fault inception, a number of series solid-state switches and a number of series diodes dramatically increase the power loss of the main breaker. This study, firstly, studies the power loss of the hybrid HVDC breaker and later develops a structure of a full-bridge hybrid breaker (FBHB) to reduce the losses of the current structure both in the normal and fault protection states. In this paper simulations are done based on PSCAD. In addition to the analytical study and simulations, we show that the developed structure substantially decreases the amount of power lost during the normal operation and fault current breaking stage.

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