It is an exciting time for power systems as there are many ground-breaking changes happening simultaneously. There is a global concensus in increasing the share of renewable energy-based generation in the overall mix, transitioning to a more environmental-friendly transportation with electric vehicles as well as liberalizing the electricity markets, much to the distaste of traditional utility companies. All of these changes are against the status quo and introduce new paradigms in the way the power systems operate. The generation penetrates distribution networks, renewables introduce intermittency, and liberalized markets need more competitive operation with the existing assets. All of these challenges require using some sort of storage device to develop viable power system operation solutions. There are different types of storage systems with different costs, operation characteristics, and potential applications. Understanding these is vital for the future design of power systems whether it be for short-term transient operation or long-term generation planning. In this paper, the state-of-the-art storage systems and their characteristics are thoroughly reviewed along with the cutting edge research prototypes. Based on their architectures, capacities, and operation characteristics, the potential application fields are identified. Finally, the research fields that are related to energy storage systems are studied with their impacts on the future of power systems.INDEX TERMS Storage systems, electric vehicles, power system optimization, market liberalization, renewable energy, new operation schemes, power system planning.

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Due to environmental concerns, power system generation is shifting from traditional fossil-fuel resources to renewable energy such as wind, solar and geothermal. Some of these technologies are very location specific while others require high upfront costs. Photovoltaic (PV) generation has become the rising star of this pack, thanks to its versatility. It can be implemented with very little upfront costs, e.g., small solar home systems, or large solar power plants can be developed to generate MWs of power. In contrast with wind or tidal generation, PV can be deployed all around the globe, albeit with varying potentials. These merits have made PV the renewable energy technology with highest installed capacity around the globe. However, PV penetration into the grid comes with its drawbacks. The inverter-interfaced nature of the PV systems significantly impacts the power system operation from protection, power flow and stability perspectives. There must be strategies to mitigate these negative impacts so that PV penetration into the grid can continue. This paper gives a thorough overview of such strategies from different research fields: such as communication, artificial intelligence, power electronics and electric vehicle charging coordination. In addition, possible research directions are given for future work.

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Clocks are perhaps the most important circuits in high-speed digital systems. The design of clock circuitry and the quality of clock signals directly impact the performance of a very large scale integrated chip. Clock skew verification requires high accuracy and is typically performed using circuit simulators. However, in high-performance deep-submicrometer digital circuits, clocks are running at higher frequencies and are driving more gates than ever, thus presenting a higher current load on the power distribution network with the potential for substantial power grid voltage (IR)-drop. This IR-drop affects the clock timing and must be taken into account in the verification process. Since IR-drop is a full-chip phenomenon, the use of standard circuit simulation on both the clock circuitry and the power-grid is not practical. In this paper, we present a new methodology for the verification of clock delay and skew. An iterative technique is presented for clock simulation in the presence of full-chip dynamic IR-drop. The effect of IR-drop on the timing of clock signals is quantified on a small example, and demonstrated on a large chip.

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Smart grid is the nexus of advanced Information and Communication Technologies (ICT) and legacy power systems. With increasing awareness on vulnerabilities of smart grids to cyber-attacks, cybersecurity is becoming a prime concern. Earlier, it was assumed that power system communication protocols are very specialized and different, so the "security by obscurity" approach would be sufficient. However, with the standardization of communication protocols for power utilities and emergence of power market, this approach is no longer valid. IEC 62351 standard has been published to provide security recommendations for different power system communication protocols including IEC 61850. IEC 61850 is emerging as the most promising and popular power system communication standard. Therefore, in this paper, a detail analysis of security threats, possible attacks and security requirements for IEC 61850 communication is presented. Building on this, the security considerations presented in IEC 62351 for securing different IEC 61850 messages such as Generic Object-Oriented Substation Events (GOOSE), Sampled Values (SV), Routable-GOOSE (R-GOOSE), Routable-SV (R-SV) and Manufacturing Message Specification (MMS) messages have been presented in great detail.