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Distribution networks are increasingly hosting embedded generators, most of them converting renewable energy primary sources. These units are usually interfaced with the main network by means of static power converters. Grid codes have recently introduced stabilizing functions to engage distributed plants in supporting the main system stability during network events and consequent voltage/frequency...
Vast increase of renewable energy resources' (RER) share in total electricity production have led to evolving studies regarding different aspects of renewables integration. Other than their effects on network, the electricity markets are also affected by uncertain behavior of RERs in the market place. Hence, new approaches for market clearing are investigated. One of the possible solutions is the...
The paper presents a model based analysis of different network charging schemes with respect to their ability to provide good incentives for prosumers with or without storage as well as to achieve a fair distribution of network cost between different network levels with varying shares of distributed generation. It finds charging schemes based on net energy or net peak to reflect the effects of generation...
This paper presents the implementation of the Nordic test system in DIgSILENT PowerFactory. The implemented system is a variant of the Nordic32 network and is based on the technical report “Test Systems for Voltage Stability Analysis and Security Assessment” prepared by the IEEE Power System Dynamic Performance Committee, the Power System Stability Subcommittee, and the Test Systems for Voltage Stability...
Nodal pricing or LMP is one option to deal with congestion in the distribution grids that are expected due to the emergence of electric vehicles. When optimal power flow (OPF) with losses is used to determine optimal dispatch and locational marginal prices (LMP) of a power systems, the prices include marginal losses. Marginal losses are double the amount of the real physical losses. This leads to...
This paper presents some considerations on the use of a Maximum Power Point Tracking circuit for a thermoelectric generator. The authors present experimental results obtained with a thermoelectric generator that comprises an array of thermoelectric generation modules used then to model and simulate a circuit that extracts the maximum output electric power for a low temperature difference range. The...
This paper proposes a frequency regulation strategy applied to wind turbine generators (WTGs) in an isolated grid. In order to complement active power shortage caused by sudden load or wind speed change, an improved deloading method is proposed to solve inconsistent regulation capabilities in different speed regions and provide WTGs a certain capacity of power reserves. Considering the torque compensation...
Study on use of UFLS scheme in the prevention of voltage collapse on Nigerian 330 kV network. The network was modelled using PSS/E. Three simulation cases were considered: case one determined the network convergence status, case two considered AC contingency study to see the network weak points and case three dealt with the situation of voltage collapse as occurred on the grid on 27th May, 2013 and...
Diesel Engine Generators (DEGs) are used to generate power but in the process produce emissions of toxic air pollutants (taps). These ‘taps’ include Particulate Matter (PM) and Oxides of Nitrogen (NOx) which are harmful to humans and the environment. This paper has investigated the effect of retrofitting a 15kVA DEG using Retrofitted Diesel Fuel (RDF) and Pure Diesel Fuel (PDF). The data obtained...
Interactions between electricity market models and network models are more and more investigated due to higher international market integration and operation security concerns. In this paper, a procedure for flow-based analysis according to market results is proposed, in order to inspect the effects of new connections under varying operating conditions over a whole year. In particular, aggregated...
In countries with Capacity Mechanisms in place, where Explicit Interconnector Participation model is to be used, one of the key market design questions to be answered is how the amount of interconnector capacity that is allowed to participate in the auctions should be determined. This paper argues for an interconnector capacity de-rating approach. In order for the de-rating factor to be representative...
The occurrence of wide-area cascading events suggests that the power system is operating at reduced safety margins. The generation dispatches provided by current energy markets may influence the risk of cascading outages. This paper aims at estimating the risk of cascading outages associated with diverse dispatch solutions by integrating market-based power dispatch models and a cascading failure analysis...
As the German Energiewende policy enters the latter stages of its goal to dismantle the country's nuclear power plant fleet, the southern state of Bavaria must decide how it will replace its nuclear generation capacity. This study extends a renewable capacity expansion model that was initially developed to find optimal extensions of wind and solar generation and transmission for Texas, United States...
Most of the distance relays base their operation on the measured apparent fault impedance. These relays are bound to have an error inflicted by the unknown remote end parameters and fault resistance. This paper presents a method, which diminishes such errors using optimization techniques. The proposed method executes a system model unknown parameter estimation by adjusting model output to measurements...
Autonomous microgrid planning is a Mixed-Integer Non Convex decision problem that requires to consider investments in both distribution and generation capacity and represents significant computation challenges. We proposed in a previous publication a deterministic Second-Order Cone (SOC) relaxation of this problem that made it computationally tractable for real-size cases. However, this problem is...
This paper joins the developing trend of modeling distributed generators based on dq0 quantities, and proposes an open-source software for modeling and analysis of large-scale power networks based on dq0 signals. The dynamic models describing the network are provided as state-space objects that are sparse and of minimal order. The software supports integration of various models of synchronous machines,...
A demand and supply simulator is developed to evaluate the effectiveness of various countermeasures against the balancing problems caused by the large integration of variable renewable energy sources (VRES). In our study, photovoltaic and wind power generation output pattern is modeled based on the actual data obtained at physical sites and forecast data from Japanese Meteorological Agency (JMA),...
Current models of capacity market designs in the U.S. and elsewhere ignore the important issue of carbon emission produced by power generators. While the current designs may produce optimal and efficient capacity market prices, these designs contribute little or nothing to reduce such emission. In this paper, we present a novel alternative to the current capacity market design which can realistically...
This paper proposes a smoothing method of frequency fluctuations of power system due to the varying output of wind farms (WFs) by using High Voltage Direct Current (HVDC) transmission system. The proposed control method is designed to minimize the fluctuations of the power system frequency without any additional installation of energy storage systems such as batteries. Simulation analysis is performed...
As penetration of variable renewable generation increases, many conventional thermal power plants need to operate long hours at their minimum stable levels (MSL) due to operational constraints. In these conditions, they may be generating at times when the price of the system is below their marginal costs, incurring in economic losses and hurting their profitability. This paper discusses how operational...
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