Diego Urrutia

Optimizing the Surge Arresters Location for Improving Lightning Induced Voltage Performance of Distribution Network

This paper will deal with improvement of lightning induced voltage performance of distribution network by optimizing the surge arrester location on the distribution network. The optimization of the location is made by using a novel formulation based on genetic algorithms. Here is described the implementation of this methodology by using sophisticate software which has been used for lightning induced voltage analysis. It is also described the capabilities and the limitations of this novel formulation. The performance of the network is evaluated by means of a probability distribution curve obtained from a statistical evaluation of the lightning induced voltages on the distribution line.

A methodological proposal for monitoring, analyzing and Estimating Power Quality indices: the case of Bogotá-Colombia

The estimation of power quality (PQ) indices has a vital importance on the development of national PQ standards not only because provides truthful information about PQ conditions in our facilities, but also because permits to establish, with an own criterion, the values for the limits of the most common PQ disturbances. This paper proposes a methodology for the estimation of PQ indices based on statistical sampling and weighting factors techniques which are applied for commercial and industrial customers in the city of Bogota. In addition, some strategies for the classification of the type of customer as well as some final obtained values of PQ indices in Bogota are presented.

Impact Assessment of Power Quality Limits in Colombia: a Regulatory Approach

In order to improve present regulations about power quality (PQ) in Colombia, an impact assessment of PQ limits among utility companies and customers is presented in this paper. This evaluation takes into account results obtained from a previous project of PQ measurements in Bogota-Colombia (PQB) over a representative sample of end users. This paper evaluates the percentage of users that would be surpassing some proposed limits for PQ disturbances such as: THD, TDD, individual harmonics, unbalance voltage, flicker and unbalance current. This analysis was carried out for industrial and commercial facilities taking into account that these users require higher levels of power quality and therefore may inquire in bigger costs in case of poor power quality conditions compared to other type of users such as residential customers. The results achieved in this work show that for some disturbances is possible to apply a regulation based on international standards as IEC and IEEE but in other parameters their application could become very expensive for utilities and end users

A Methodological Proposal for the Estimation of Optimal Power Quality Levels

In order to improve present regulations about power quality (PQ) in Colombia, an impact assessment of PQ limits among utility companies and customers is presented in this paper. This evaluation takes into account results obtained from a previous project of PQ measurements in Bogota-Colombia (PQB) over a representative sample of end users. This paper evaluates the percentage of users that would be surpassing some proposed limits for PQ disturbances such as: THD, TDD, individual harmonics, unbalance voltage, flicker and unbalance current. This analysis was carried out for industrial and commercial facilities taking into account that these users require higher levels of power quality and therefore may inquire in bigger costs under a poor power quality conditions compared to other type of users such as residential customers. The results achieved in this work show that for some disturbances is possible to apply in Colombia a regulation based on international standards as IEC and IEEE but in other parameters their application could become very expensive for utilities companies and end users

A Novel Approach to the Simulation of Power Quality Disturbances in Electric Power Systems

According to international standards, power quality disturbances (PQD) is classified in agreement with amplitude or proportion, bandwidth and duration. In this paper an additional PQD classification is proposed, consisting in classifying PQD according to their occurrence in random or permanent disturbances. Random disturbances are those whose times of occurrence cannot be determined in advance (surges, sags, swells, etc.) and permanent disturbances are those present in electric distribution systems continuously (harmonics, inter-harmonics, voltage fluctuations, flicker, etc). This paper shows a method for calculation of permanent disturbances indices based on measurements, distribution system modeling and Monte Carlo perfect simulation, a method to simulate PQD with random behavior is proposed

Method for the calculation of power quality indices

According to international standards, power quality disturbances (PQD) are classified in agreement with amplitude or proportion, bandwidth and duration. In this paper an additional PQD classification is proposed, consisting in classifying PQD according to their occurrence in random or permanent disturbances. Random disturbances are those whose times of occurrence can not be determined in advance (surges, sags, swells, etc.) and permanent disturbances are those present in electric distribution systems continuously (harmonics, interharmonics, voltage fluctuations, flicker, etc). This paper shows a method for calculation of permanent disturbances indices based on measurements, distribution system modelling and Monte Carlo perfect simulation. Power definitions under non sinusoidal conditions are used to evaluate the effect of modelled disturbances

The usage of neural networks and time series in pattern recognition and forecasting of power consumption profiles

Most of the power quality disturbances such as unbalances, sags, swells and harmonic distortion are ultimately related to power consumption variations. In this manner, with the aim of identifying electrical problems causing PQ disturbances, a suitable knowledge of these power consumption profiles is required. These profiles can be obtained by either a continuous monitoring or by using some tools capable of representing the behavior of the power demand. This paper presents a comparison between two analytical tools, one is an artificial intelligence approach by means of neural networks, and the other one uses statistical techniques such as time series analysis. These techniques not only can represent power consumption profiles, but also may predict them allowing the customer to make a suitable planning of the electrical facilities.

Impact of the interruptions of long and short duration in the value of the Pst indicator

This paper presents a comparative analysis between the voltage interruption effects (higher and shorter than one minute) in the value of Pst indicator given by the flicker meter instrument. The Colombian regulator has proposed a modification in the flicker meter to disregard the interruption effects, in this paper an analysis related to this topic is presented. In order to simulate the effect of voltage interruptions, a model of the flicker meter has been developed in Matlab according to the IEC 61000-4-15 standard. Random quantities of interruptions with random duration have been simulated in fixed time intervals to study their impact in Pst value