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With a view to the integration in national power system of new power plants based on renewable energy sources, such as wind energy, this paper presents the technical requirements related to the connection of the wind power plants to the main grid. Grid connected wind turbines may cause power quality problems, such as voltage variation and flicker, and therefore, the connection of wind farms requires...
The electrical power system restoration after an incident is a complex process involving decision-making problems of combinatory nature. In this case, the operator support systems play an important role in a performance of this process. This paper introduces a decision support tool based on particle swarm optimization technique (PSO). The technique is based on the change of system functional configuration...
This paper presents a procedure for sizing a Battery Energy Storage System (BESS) for the purposed of shaving the peak demand of a residential distribution feeder. The BESS power and energy storage rating are determined from actual load demand data and desired level of peak reduction using the load following method. The impact of distributed photovoltaic (PV) power generation (to be installed by residential...
In a research project a fault data collection device for substations with a communication interface according to IEC 61850 was developed. The IEC 61850 standard is the future of substation automation networking. This standard has no models for signaling faults included up to date. Therefore, specific logical nodes were defined by using attribute types of the standard. These additional nodes were implemented...
The paper proposes an autonomous integrated system performing remote monitoring activities for strategic objectives surveillance and risk prediction, focusing on monitoring of turbogenerator mechanical vibrations through communication channels. This system was designed to efficiently collect data regarding the turbogenerator mechanical vibrations and those induced in the turbogenerator support structure...
In the planning of the electrical transmission system it is of greatest concern to quantify the security margin for unwanted conditions in the system. This paper proposes an approach based on quantifying the risk of insufficient transmission capacity in bottlenecks in the system. Stresses in these critical transfer sections (CTS) provide a potential risk to corrective actions, or worst, load curtailments...
This paper presents a novel method to determine a minimum number of representative load flow cases with load and generation data in a meshed transmission grid, which cover all critical power line loading situations in a given time frame. Measured active and reactive line loading data obtained from SCADA are the basic data input for this method. In order to find the optimum number of load flow cases...
Operation of future power systems will be shared between central and distributed generators. Control of distributed generators will need to be aggregated to form microgrids or dasiavirtual' power plants to facilitate their integration both in the physical system and in the market. Even customers will be part of the ldquonetwork looprdquo, both producer and consumer of electricity = ldquoprosumerrdquo...
Since a superconducting magnetic energy storage (SMES) unit with a self-commutated converter is capable of controlling both the active and reactive power simultaneously and quickly, increasing attention has been focused recently on power system stabilization by SMES control. In this study, a self-tuning control scheme for SMES is proposed and applied to automatic generation control (AGC) in power...
When amending the Renewable Energy Sources Act (EEG) in June 2008 the German government acknowledged the importance of enhanced technical requirements. From now on, for wind power plants, full grid code-compliance will become a necessary precondition for privileged network access, receipt of feed-in tariff, and extra payments (system services bonus). Thus, the amended EEG ensures further development...
In this paper we present a hybrid methodology built on a combination of clustering and forecasting techniques used to solve the short-term bus load forecasting problem. The proposed method was made in two phases: In the first phase a clustering algorithm is used to identify buses clusters with similar daily load profile and in the second phase is proposed an aggregate structure for to foresee each...
This paper proposes a new heuristic approach to deal with discrete variables in an optimal power flow (OPF). This approach relies on the first order sensitivity of the objective and inequality constraints with respect to the discrete variables. The impact of a discrete variable change on the objective and inequality constraints is aggregated into a merit function. The proposed approach searches iteratively...
In this paper it is presented a formulation for the DC optimal power flow problem considering load and generation cost uncertainties and the corresponding solution algorithms. The paper also details the algorithms implemented to allow the integration of losses on the results as well the algorithm developed to compute the nodal marginal price in the presence of such uncertainties. Since loads and generation...
Oil filled transformer explosions and their prevention are a complex industrial issue. Experimental tests showed that when an electrical fault occurs in a transformer, it generates dynamic pressure waves that propagate in the oil. Reflections of these waves on the walls build up high static pressure which transformer tanks can not withstand. Besides, a numerical tool was developed to simulate the...
State estimation in the modern power systems of large dimensionality is a sophisticated problem which is accompanied by the difficulties related to inhomogeneity of the calculated schemes, a large volume of information to be processed and the requirement for high-speed software. Distributed data processing in decomposition of the state estimation problem is an efficient method of tackling the difficulties...
Conventional tools to provide steady-state power network solutions rely on bus-branch models, in which a ldquobusrdquo is actually the result of merging internal electrical nodes pertaining to given substation. The corresponding network solutions are thus unable to readily provide information about variables internal to the substations, such as power flows through circuit breakers and bus-section...
The safe operation of electrical power systems is an ongoing problem. Despite the existing defense lines in the different electrical systems, they are not immune to widespread incidents leading to tripping of most consumers. In the defense plans against these major incidents, selective load shedding (LS) even optimized (but brutal), is the last resort before total blackout. This paper proposes a new...
Fault location (FL) is one of the most important diagnostics tasks in transmission and distribution networks. Due to long distances of the power lines, the search and repair can take a long time, while modern microprocessor technology can help automate the FL process and give a precise (up to a span) location of the fault. The fault extinction time is reduced dramatically. In this report, the basic...
The size and complexity of primary distribution networks make it impossible to carry out an exhaustive analysis of each individual feeder, so a sampling approach may be adopted to evaluate the energy losses for whole distribution networks. Clustering techniques were applied to several databases, obtaining particular characteristics of the feeders groups. For every group (cluster), the feeder that...
Paper presents the difficulties of existing anti-emergency automation when operating in islanded power system. The operation of existing anti-emergency automation is apprized from the point of view of elimination of active power deficiency or surplus. Shortages of existing anti-emergency automation as well as necessary areas for improvements are shown. New method for estimation of active power deficiency...
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