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The number of electric vehicle (EV) users is strongly increasing so that today roughly every second registered vehicle in Norway is an EV. To increase the EV utilization, politics, industry and the EV users strongly promote the integration of fast charging infrastructure. While the future demand of fast charging sites is a well‐studied topic, not much is known about the utilization of the existing charging sites and daily load curves. To fill this knowledge gap, usage data of a charging site in Oslo is analysed. Further on, the impact of a battery energy storage (BES) as well as a photovoltaic generator on peak load reduction is studied. The analysis shows variations and trends in the daily and weekly charging behaviour depending on the degree of utilization of the charging station. On average, a single EV user charges around 10 kWh in 19 min. Furthermore, the evidence indicates that EV users may have adapted fast charging as a part of their daily travels and it is not used only during long distance journeys. The results suggest that a BES can reduce the peak load by up to 55%. By adding a photovoltaic generator, a minor additional reduction of peak load is seen.

Tn this paper power quality measurement results of electric vehicle (EV) battery charging are presented. The power quality issues of EV charging are a rising concern among power utilities, as a rapid penetration of EVs on automotive markets is expected to happen in a few years to come. For evaluating the impact of EV charging a series of field measurements are conducted and harmonic current profiles based on the measurements were created. Paper also discusses the calculation methodology of harmonic current flow in distribution networks using the harmonic profiles. For this purpose an OpenDSS based calculation tool is developed and preliminary simulation results are presented.

The smart grid includes wide-area applications in which inter-substation communication is required to realize innovative monitoring, protection, and control solutions. Internet-based data exchange, i.e., communication over Internet Protocol (IP), is regarded as the latest trend for inter-substation communication. Interoperability can be achieved via the use of standardized IEC 61850-90-5 messages communicating over IP. Wide-area applications can obtain benefits from IP-multicast technologies and use a one-to-many communication model among substations communicating across a communication network. Cellular Internet is being considered as a potential cost-efficient solution which can be used for the IP-multicast communication. However, it requires knowledge of communicating uncommon IP-multicast traffic over the Internet. Moreover, it presents challenges in terms of cybersecurity and real-time requirements. These challenges must be overcome to realize authentic and correct operation of the wide-area applications. There is thus a need to examine communication security and to evaluate if the communication network characteristics satisfy the application real-time requirement. This paper investigates the secure communication of IEC61850-90-5 multicast messages over the public communication network and proposes two network architectures using the Generic Routing Encapsulation (GRE) tunnel and multipoint GRE (mGRE) within Dynamic Multipoint VPN (DMVPN). Additionally, this paper evaluates the feasibility of cellular (5G and 4G) Internet for the communication of multicast Routable Generic Object Oriented Substation Events (R-GOOSE) messages in wide-area protection applications. For this purpose, we introduce a lab setup to experiment the transmission of R-GOOSE messages within the proposed network architectures. The lab setup contains both software and hardware components. A software application is developed to publish multicast R-GOOSE with a fresh timestamp acquired from time synchronization equipment. These messages are transmitted over the Internet by computer networking devices that support cellular communication. The communication latency of the transmitted messages is measured and analyzed statistically. The statistical analysis results are discussed to evaluate performance of R-GOOSE over cellular Internet for two communication-based protection applications: Logic Selectivity and Loss-of-Main protection schemes.

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