Masoud Davoudi

Distribution systems have traditionally received the least attention in the bulk picture of power systems; they are yet the most "critical component" as they directly impact customers’ perception and utilities’ reputation. While transmission systems have seen abundant literature, innovations, and applications of power electronic-based devices to optimize their performance, distribution systems still require more attention toward a flexible and dynamic scheme to cope with volatile energy consumption and production. As a replacement or enhancement of the traditional ones, Solid-State Transformers can play a central role in the energy management of distribution systems towards this goal, in addition to the mere voltage conversion. This manuscript, developed within the IEEE Task Force on Solid-State Transformer integration in distribution grids, offers a critical review of the Solid-State Transformer potential, services, and technical challenges for its integration in distribution systems. Particular attention is given to scientific trends and open points in the current research that must be addressed before utilities extensively integrate the Solid-State Transformer in distribution systems.

The risk of catastrophic wildfire has challenged our societies and impacted various industries with imminent danger to people's lives, financial burden, and irreparable damages to the environment, among other consequences. While progressive wildfires can impact power system operation and customer reliability and resilience, the relationship between power systems and wildfires is mutual: power systems can also contribute to wildfires. Wildfire risk of power systems is related to, in particular, fault-induced ignition events that can quickly turn into wildfires. While some electric utilities are working on approaches to mitigate such risk, the need for further research, development and demonstration of novel methodologies still exists. This paper identifies, analyzes, and compares the practices that can be further employed by utilities to manage the risk and mitigate the impact of power-system generated wildfires.

US power system is faced with proliferation of renewable generation in its transmission and distribution networks. Renewable energy integration in power systems have caused specific concerns for system planners and operators because of its intermittent and variable nature. This paper focuses on the benefits of using battery energy storage systems for the integration of wind energy. Several scenarios for using the battery are examined in this paper and their benefits discussed in order to justify the investment in a BESS. Results are provided using a combination of simulations and real-life data for each scenario to demonstrate the quantifiable benefits that result from using battery storage to integrate wind energy resources.

In this paper, fault location on three-terminal and tapped transmission lines without requiring line parameters is presented, which mitigates the effect of line parameters variations due to weather and loading conditions on fault location accuracy. For three-terminal lines, a fault location method is presented which utilizes post-fault measurements of all three terminals. For tapped lines, two methods are presented. The first one uses post-fault measurements of the main two terminals. The second one needs one cycle of pre-fault measurements at main terminals as well. Synchronized transient-based measurements are used in methods proposed in this paper. In all presented methods, the fault location problem is converted to an optimization problem and then solved to find the line parameters and the accurate location of fault. The simulations are carried out by ATP/EMTP software and the presented algorithms are executed by MATLAB. Simulation results assess the effects of fault resistance, type and inception angle on the accuracy of presented methods. Further discussion is also provided on the impacts of synchronization errors, noisy measurements, and nonresistive faults.

Electrical distribution systems are experiencing higher amount of distributed generation (DG), which originates from societal and environmental concerns, economical benefits of local generation, and more deregulated energy systems. While having numerous advantages, the presence of DG in the system is limited by several constraining factors. In this paper, in order to allow for higher hosting capacity of the distribution system, a network reconfiguration scheme is presented to select the best network topology to maximize allowable DG penetration while satisfying steady state voltage and current limits. The network reconfiguration technique relaxes the radiality constraint of the system to search for possible radial and meshed optimal configurations. A modified genetic algorithm has been used to solve the reconfiguration problem. The results of the reconfiguration problem are then presented for a 69 bus test system showing higher hosting capacity for distribution system meshed configurations. Moreover, the results of the proposed network reconfiguration approach are compared with the time-consuming method of repetitive power flow, verifying selection of the optimum configuration by the presented method. As side benefits, voltage profile and real power losses have been shown to improve in such optimum configurations.

Electrical distribution systems are experiencing increased penetration levels of distributed generation thanks to economic incentives and technology cost reductions. Analyzing the effects of distributed generation on planning and operation of distribution system is typically done based on steady-state simulations; output variability of renewable dispersed generation units implies the need for more dynamic evaluation of their effects on the system and for the introduction of mitigating measures. The authors previous work has shown the advantages of select meshed configuration of distribution systems for accommodating higher levels of distributed generation considering steady-state voltage and current limitations. In this paper, after introducing stiffness factor and its relation to Thevenin equivalent impedance, the effects of intermittent photovoltaic systems on bus voltages are investigated. The IEEE 34-node test feeder in its radial and in different meshed configurations is used as test case. Results of the study verify the superior performance of select meshed configuration for accommodating intermittent renewable resources in distribution systems.

In this paper, a mathematical optimization approach for green energy portfolio is presented to strike a right balance between risk and profit associated with retailing in power market. This approach emphasizes on the increasing use of renewable resources to overcome conservation concerns to some degrees. Three different uncertainties are considered for electricity price and energy output of wind and solar distributed generation units. In order to model the uncertainties properly, scenario construction schemes, namely Monte Carlo and time series with ARIMA (Auto regressive integrated moving average) are implemented in this paper. Moreover, risk and elasticity analysis are considered simultaneously to enable consumers and retailers to manage their risk and incomes. Two-stage stochastic programming with fixed recourse is used to model the probabilistic space of decision making process in this paper. At the end, numerical results and simulations are presented which demonstrate the applicability of the proposed approach in a retail electricity market.

An accurate algorithm for locating faults on two‐terminal transmission lines is presented in this study. The presented method does not require values of line parameters to locate the fault; therefore variation of line parameter values does not affect its accuracy. The method utilises synchronous post‐fault measurements of currents and voltages in both terminals and is based on the distributed time‐domain representation of transmission lines. Unlike conventional methods, fault location is converted to an optimisation problem. Then, this problem is solved by genetic algorithm to find the accurate location of fault. Furthermore, modifying the problem to be solved by the Newton optimisation method is discussed in this study. Simulation results performed by ATP/EMTP verify high accuracy of the presented method, and reveal that it is not significantly affected by fault resistance, fault type, fault inception angle and source impedance. Moreover, effect of measurement errors and synchronisation errors on the accuracy of presented method have been analysed which verify the efficiency of the algorithm in these conditions.