Abstract
In active distribution grids (ADNs), a distribution corporation (Disco) can trade electricity with micro-grids (MGs) besides trading electricity with wholesale markets. Therefore, the operational flexibility of the Disco is increased so that it can play as a price-maker agent in electricity markets. To model the actions of Disco, a bi-level optimization method is developed where Disco problem is modeled at the upper-level problem, whereas the MGs problem together with the day-ahead market clearing procedure are modeled as the lower-level problems. To take the stochastic performance of green energy integration and loads into account, the Disco analysis is shown as two-stage stochastic problem, in which the Disco risk aversion is programmed considering the conditional value-at-risk tool. The subsequent non-linear bi-level approach is converted into a linear single-level approach through Karush-Kuhn-Tucker (KKT) conditions and dual theory. To validate the success of the proposed method, a 24-bus power system is used. Conclusions are duly drawn.

Abstract
Electric vehicles (EVs) promote many advantages for distribution systems such as increasing efficiency and reliability, decreasing dependence on non-endogenous resources, and reducing pollutant emissions. Due to increased proliferation of EVs and their integration in power systems, management and operation of distribution systems (ODS) is becoming more important. Recent studies have shown that EV can increase power grid flexibility since EV owners do not use them for 93-96% of the daytime. Therefore, it is important to exploit parking time, during which EVs can act either as a load or distributed storage device, to maximize the benefit for the power system. Following a survey of the current state-of-the-art, this work studies the impact of EV charging on the load profile. Since renewable energy resources (RES) play a critical role in future distribution systems the current case study considered the presence of RES and their stochastic nature has been modeled. The study proceeds with analyzing EV owners' driving habits, enabling prediction of the network load profile. The impact of: EV charging modes (i.e., controlled and uncontrolled charging), magnitude of wind and photovoltaic (PV) generation, number of EVs (penetration), and driving patterns on the ODS is analyzed.

Abstract
Electrical distribution system operators (DSOs) are facing an increasing number of challenges, largely as a result of the growing integration of distributed energy resources (DERs), such as photovoltaic (PV) and wind power. Amid global climate change and other energy-related concerns, the transformation of electrical distribution systems (EDSs) will most likely go ahead by modernizing distribution grids so that more DERs can be accommodated. Therefore, new operational strategies that aim to increase the flexibility of EDSs must be thought of and developed. This action is indispensable so that EDSs can seamlessly accommodate large amounts of intermittent renewable power. One plausible strategy that is worth considering is operating distribution systems in a meshed topology. The aim of this work is, therefore, related to the prospects of gradually adopting such a strategy. The analysis includes the additional level of flexibility that can be provided by operating distribution grids in a meshed manner, and the utilization level of variable renewable power. The distribution operational problem is formulated as a mixed integer linear programming approach in a stochastic framework. Numerical results reveal the multi-faceted benefits of operating distribution grids in a meshed manner. Such an operation scheme adds considerable flexibility to the system and leads to a more efficient utilization of variable renewable energy source (RES)-based distributed generation.

Abstract
In this study, an optimization problem is proposed for improving the flexibility of a distribution system including shared energy storage systems (ESSs) and residential consumers with elastic heating, ventilation and air conditioning (HVAC) units. To this end, a direct compressor control mechanism (DCCM) is used for meeting the load reduction target of load serving entities (LSEs) by controlling the HVACs, and an optimal management strategy is presented for exploiting the benefits of shared ESSs during critical peak periods. Furthermore, an additional objective is included in the problem structure, which leads to a bi-level optimization problem, in order to reduce the possible consumers' discomfort caused by frequent HVAC interruptions. The effectiveness of the proposed bi-level optimization problem is demonstrated by comparing various performance metrics with those of two benchmark methods.

Abstract

Abstract
With the deepening of the reform of the power system, the sale companies need to constantly explore new business models and marketing programs. At the same time, the power quality should meet the requirements of the user, in which the harmonic problem is a very important aspect. Based on the service level of the harmonic losses of the application of the evaluation value of governance, the harmonic characteristics of the user put forward the harmonic control scheme of passive and active service, and simulated under PSCAD verification. Based on the analyses of the effectiveness and cost of the above schemes, combined with the profit analysis of the selling companies, a value-added service package containing the harmonic treatment is designed for the users to choose. © 2018 IEEE