A Review of Architectures and Concepts for Intelligence in Future Electric Energy Systems <s> A. Autonomous Control With Central Configuration Ability <s> In this paper, a coordinated voltage control scheme utilizing electrical energy storage (EES) is presented, for future distribution networks with large, clustered distributions of low carbon technologies (LCTs) in terms of both feeder and phase location. The benefits of the EES integrated scheme over conventional voltage control schemes are demonstrated by realizing a set of network scenarios on a case study network both in simulation and in network in the loop (NIL) emulation at a smart grid laboratory facility. The case study uses a rigorously validated model of an actual GB distribution network with multiple EES installations. It was found that the EES integrated voltage control scheme is able to provide increased capability over conventional voltage control schemes and increase the value of EES to network operation. <s> BIB001 </s> A Review of Architectures and Concepts for Intelligence in Future Electric Energy Systems <s> A. Autonomous Control With Central Configuration Ability <s> Increasing penetration of photovoltaic (PV), as well as increasing peak load demand, has resulted in poor voltage profile for some residential distribution networks. This paper proposes coordinated use of PV and battery energy storage (BES) to address voltage rise and/or dip problems. The reactive capability of PV inverter combined with droop-based BES system is evaluated for rural and urban scenarios (having different \mbi R/X ratios). Results show that reactive compensation from PV inverters alone is sufficient to maintain acceptable voltage profile in an urban scenario (low-resistance feeder), whereas coordinated PV and BES support is required for the rural scenario (high-resistance feeder). Constant, as well as variable, droop-based BES schemes are analyzed. The required BES sizing and associated cost to maintain the acceptable voltage profile under both schemes are presented. Uncertainties in PV generation and load are considered, with probabilistic estimation of PV generation and randomness in load modeled to characterize the effective utilization of BES. Actual PV generation data and distribution system network data are used to verify the efficacy of the proposed method. <s> BIB002 </s> A Review of Architectures and Concepts for Intelligence in Future Electric Energy Systems <s> A. Autonomous Control With Central Configuration Ability <s> This paper proposes a decentralized storage strategy to support voltage control in low-voltage (LV) residential feeders with high photovoltaic (PV) capacity installed. The proposed strategy is capable of preventing overvoltage situations during high PV generation periods, by the use of locally controlled battery energy storage systems (ESS) at the PV system grid interface. The traditional way of operating a domestic ESS is based on charging the battery as soon as the PV generation exceeds the consumption, without taking into account overvoltage events during high PV generation hours; the proposed storage concept improves the traditional approach, thanks to the provision of voltage support. A novel method, based on voltage sensitivity analysis, identifies a common power threshold that triggers the ESSs activation in the feeder. A Belgian residential LV feeder is used as a case study. Time-series simulations based on 1-year load and generation profiles verify the method findings and quantify the ESS size in terms of storage power and energy level. <s> BIB003
This approach describes autonomous control of single components based on predefined function characteristics with the opportunity to reconfigure functions from a central unit. The control algorithm can also be based on rules in combination with threshold levels. The configuration of the single components is often based on offline or online load flow calculations of the local power grid BIB001 . A control architecture based on predefined droop characteristics is discussed in BIB002 . It is shown that the simple adoption of the droop characteristics for single systems decreases the investment costs for the ESS by reducing the required capacity significantly. One approach to achieve this functionality is the implementation of a droop control function according to IEC 61850 [17] or SunSpec  . Both the standard frameworks not only provide a definition of standardized input and output registers of inverter-based distributed generators and storage systems but also define standardized functions and services. Each function defined in IEC 61850 or SunSpec can be configured based on a predefined set of parameters. Marra et al. BIB003 discussed a threshold-based control algorithm for increasing local consumption and simultaneously providing voltage control. The defined threshold is based on the nominal power of each PV array. When the PV penetration in a feeder changes, the threshold for each storage system changes as well. Once the threshold is set for each storage system, they operate autonomously. While the strategy provides consistent voltage control, the impact on local consumption is not discussed. The authors of the work showed that, with an increasing PV penetration, the requirements for the storage system increase significantly. Only simple algorithms from the AI point of view are being applied in the current solutions, but there is space for more intelligent concepts and algorithms in future developments.