1,721,183 research outputs found
Nondiscriminatory system losses dispatching policy in a bilateral transaction-based market
No full textIn this paper, a new method to allocate transmission
losses for simultaneous bilateral transactions is proposed. The
methodology uses a circuit approach of the system in conjunction
with a classical power flow. For a given operating point, it is
possible to derive system loss expression as a sum of partial terms
due to each transaction. These transaction loss components,
supplied by slack buses, can turn into costs associated with the
respective transactions. Alternatively, in this paper it is proposed
that each transaction provides for its own loss, thus eliminating
the need for a balancing mechanism. In this case, the developed
methodology evaluates the increase of active power at each
transaction generator through loss contributions not arbitrarily
assumed but calculated from a developed loss allocation formula.
The main advantage of the developed method lies in its simplicity
and capability of treating multiple transactions simultaneously
Evaluation of transmission system usage contributions
No full textThe impact of generators and loads on transmission line flows is of much interest in competitive electricity markets. Equitable methods to set transmission usage charges in system operated in normal as well as in congested states are needed. In this paper, a method for determining the impact of generation and load values on transmission line flows has been developed to derive useful factors for allocating transmission charges. By using these factors, allocation can be attributed to generators, loads, or transaction-related net power injections. The developed procedure adopts circuit theory to evaluate individual power contributions of each generator and load on total power flowing in system lines. Derived relationships highlight dominant and opposite flows. Tested using the simple Ward-Hale six-bus test system and the IEEE 118-bus test system under a variety of operating conditions, the suggested procedure confirms the effectiveness of the proposed method to selectively assign line flow burden to generators and loads
Real and reactive power allocation in bilateral transaction markets
No full textIn deregulated power systems, transmission networks are available for third-party access to allow power
wheeling. In such a deregulated environment, the ancillary services are no longer treated as integral to the electricity
supply. They are unbundled and priced separately, and system operators have to purchase ancillary services from
ancillary service providers.
Issues pertaining to costing of ancillary services, and hence appropriate pricing mechanisms for all market
participants to recover the costs, become an important issue for proper functioning of the system. This paper presents a
method able to allocate real power losses and reactive power support to each transaction in a multi-transaction
environment. The approach utilizes a static power system representation in terms of nodal admittance matrix in
conjunction with a classical power flow. With this formulation, it is possible to derive system losses as well as reactive
supply expression as a sum of partial terms due to each transaction
A pipelined-in-time parallel algorithm for transient stability analysis
No full textA new parallel algorithm for transient stability analysis is presented. An implicit trapezoidal rule is used to discretize the set of algebraic-differential equations which describe the transient stability problem. A parallel-in-time formulation has been adopted. A Newton procedure is used to solve the equations which describe the system at each time step, whereas a Gauss-Seidel algorithm relaxes the solution across the time steps. A Gauss-Seidel-like procedure can be usefully exploited in the parallel processing mode by pipelining the computation through time steps. The parallelism in space of the problem is also exploited. Furthermore, the parallel-in-time formulation is used to change the time steps between iterations by a nested iteration multigrid technique in order to enhance the convergence of the algorithm. The method has the same reliability and model-handling characteristics of typical dishonest Newton-like procedures. Test results on realistic power systems are presented to show the capability and usefulness of the suggested technique
Probabilistic method for the stability analysis of an induction motor with a variable-frequency supply
No full textDiscussion to the paper "Computationally Efficient Optimal Control Methods Applied to Power Systems"
No full textThe Meterglob Project
No full textMeterglob Project is focused on practical tools to assess Global Earthing Systems (GES) in urbanized or industrial areas. Declaring the existence of a GES in a set area leads to significant benefits with regards to safety issues. Advantages for final users, both in relation to the reduction of installations construction costs and in terms of periodical verifications (earth resistance and touch voltages measurement, etc.), are considerable too. Present standards do not include any suggestion on how to asses reliably the presence of a GES and if or how to take into account the influence of extraneous conductive parts.
The paper presents a brief report of activities carried out by the Polytechnic of Bari research unit within the Meterglob Project
Parallel algorithms for transient stability simulations in very large scale power systems
No full textState space representation of interconnected power systems for dynamic interaction studies
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