The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We developed a constrained state estimation method that clarifies the range of the feeder voltage in an unobservable distribution network in which the number of telemetric sensors is smaller than the number of state variables to be estimated. Instead of using pseudo-measurements, whose reliability is affected by unexpected power flow conditions, the method uses constant nominal boundaries as inequality...
This paper proposes an algorithm for the capacity constrained management of Distributed Energy Resources in unbalanced distribution network. The algorithm is based on linear constraints being generated from a linear approximation of the functional relationship between control variables and constrained operational variables. To eliminate the incurred linearization error, the proposed algorithm is performed...
One of the factors hindering the large scale integration of wind power is the post contingency congestion of a network due to limited availability of network capacity and auxiliary constraints. Under such conditions, the network operators can potentially request a curtailment of wind farm output if the remedial strategies fail. The paper investigates this problem in detail and proposes a mathematical...
An on-line line switching method based on a three-stage strategy to effectively relieve overloads in power systems is proposed. The proposed method is designed for on-line applications in the control center environment. To balance the requirements of solution speed and of effectiveness, the proposed three-stage method is composed of screening stage, ranking stage and detailed analysis stage. One distinguishing...
Wind energy has been playing a critical role in modern electric power system due to the fact that wind is free of cost and environment-friendly. However the inherent intermittency of wind has complicated system operation such as optimal power flow (OPF). In this paper, the authors present a stochastic OPF model integrated with wind power (WOPF). Since WOPF is a highly non-linear and non-convex problem,...
This paper describes a methodology and an automated process to implement node-breaker capabilities for representing major stations within Con Edison's footprint. This process creates a “hybrid” power flow model of Con Edison's system such that the user-defined stations are represented using the node-breaker model and the rest of the system is modeled using bus-branch representation. The process is...
The planning of distribution network is faced with a great challenge when large-scale renewable energy mostly wind power entering into power system. This paper proposes a bi-level programming model considering distributed wind generation (DWG) allocation in the active distribution network environment which introduces active management fee (AMF) concept firstly. The bi-level programming is a complex...
Security-constrained optimal power flow (SCOPF) and security-constrained unit commitment (SCUC) problems are necessary tools to system operators for operational planning and near-to-real-time operation. The solution time of these problems are challenging mainly due to their inherent large size. Previous studies have shown that relatively few of those problems' constraints serve to enclose their feasible...
This paper presents the OPF formulation of a recent power flow STATCOM model [1]. The new model puts forward an alternative, insightful interpretation of the fundamental frequency operation of the PWM-controlled Voltage Source Converter (VSC), in an optimal fashion. The new model makes provisions for the explicit representation of the converter's internal ohmic and switching losses which in the context...
This paper presents a model for a MV/LV bidirectional solid state transformer (SST) for distribution system studies. A multilevel converter configuration is used in the MV side for voltage and current harmonic reduction. The model has been implemented in the ATP version of the EMTP. Several case studies have been carried out in order to evaluate the behavior of the SST model under different operating...
In this paper, the authors discuss a set of software laboratory assignments on power distribution systems that address emerging and smart grid technologies such as the interconnection of solar PV generation and of microgrids, of series compensation and capacitor placement and control, and selective meshed structure. Although these software laboratory modules can be used by any university and user,...
This panel discussion addresses two topics. The first one concerns the functionality of power system restoration tool entitled “System Restoration Navigator (SRN)” supported by EPRI. The SRN is based on the theory of Generic Restoration Milestones (GRMs). The functions of this prototype include: GUIs, strategy generation engine and security checking interface. By interactive GUIs, constraints and...
Coordination of ancillary services provided by decentralized power units has become one of the main grid operation challenges because system service responsibilities are increasingly being shifted to medium- and low-voltage networks. This paper describes an implementation method of considered control algorithms on real power units in German mediumvoltage systems in order to maintain the distribution...
The overall system behavior of a three-terminal DC grid with symmetric monopole configuration is the focus of this paper. The modeling of the DC grid test system which includes converter stations, hybrid DC breakers, cables, etc. is carried out in real-time digital simulator (RTDS) platform. For control and protection, ABB's MACH system is used. Some important system aspects of DC grid, e.g. AC fault-ride-through,...
As more non-dispatchable renewable resources are integrated into the grid, it will become increasingly difficult to predict the transfer capabilities and the network congestion. At the same time, renewable resources require operators to acquire more operating reserves. With today's deterministic reserve requirements unable to ensure optimal reserve locations, improvements to re-serve policies are...
This paper proposes a new concept of loadability for interconnected distribution systems, in which feeders are connected with normally-open tie-switches and the N-1 security principle is applied. Firstly, this paper presents a nonlinear model to formulate the N-1 loadability, in which network topology, thermal rating of lines and substation transformers, voltage limits and losses are considered. Secondly,...
The DC power flow model is in widespread utilization in electricity-market applications and contingency analysis. The presented versions of this model can be classified into two categories: state-dependent, or Hot-Start, models and state-independent, or Cold-Start, models. A reasonable accuracy is reported in the literature regarding Hot-Start models as they take into account branch losses and bus...
This paper analyses the 11 kV Medium Voltage (MV) networks using real network and load data. High penetration Photovoltaic (PV) connected to a MV feeder is modeled using RETScreen to estimate the output power based on meteorological and geographical data. Simulations are run across 24 hour period to see the voltage fluctuations, active and reactive power behavior, load profile, power loss and energy...
This paper presents model for Modular Multilevel Converter (MMC) in phasor format, which is convenient for power flow and parameter studies. The model is derived in rotating dq coordinate frame, and the coordinate frame at double the fundamental frequency, in steady-state. A substantial analytical basis is presented in order to facilitate direct mathematical manipulations of non-linear terms in the...
This paper presents optimized approaches for microgrid design and allocation of energy storage units to enhance self adequacy of microgrids. Microgrids are clusters of distributed energy resources serving clusters of distributed loads either in grid connected or isolated grid modes. The self adequacy of microgrids is maximized by the optimal installment of energy storage units that can store the spilled...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.