R. Pawelek

Application of STATCOM controllers for power quality improvement - modeling and simulation

The paper deals with compensation of frequently time-varying loads by means of STATCOM controllers. As a varying load an arc furnace is considered. The 12-pulse STATCOM system was used for compensation to ensure good power quality in the point of common coupling. For analysis of the system performance the PSCAD/EMTPDC programme was applied. Models of the load and STATCOM controller useful for simulation are discussed. A PSCAD model of measurement blocks is also proposed for power quality assessment. Some results of simulation are presented in the paper, which show the effectiveness of compensation.

A simulation method for estimating supply voltage dips in electrical power networks

This paper describes the probabilistic approach for estimating voltage dips in electrical power networks. A method has been worked out which can estimate the typical magnitude and frequency of voltage dips, as well as momentary interruptions that may be expected at a given site. Evaluating such characteristics of voltage dips allows assessing compatibility between loads and the supply network. This methodology has been used to draw up a simulation tool by means of the LABVIEW program. The paper presents the results of simulation performed for a given electrical transmission and distribution network and discusses them.

Control algorithm for the 12-pulse SVC

A method is presented which became a basis for designing a control algorithm for the 12-pulse SVC system. The algorithm enables balancing of currents and powers drawn from the supplying network by unbalanced and time-varying load devices and at the same time effects in reduction supplying voltage fluctuations. The results of simulation are shown which illustrate the compensation effect and verifies correctness of the proposed algorithm.

Comparative measurements of voltage harmonics in transmission grid of 400 kV

In the paper the comparative analysis of voltage harmonics measurements performed in the transmission network of 400 kV is presented. The voltage was measured using three measuring instruments: resistive voltage divider, inductive voltage transformer and capacitive voltage transformer. Measurement errors were estimated for transformers with reference to the harmonic values obtained with the use of the voltage divider.

Simulation method for designing compensation equipment applied for power quality improvement

This paper proposes a simulation method which can be applied when designing compensation equipment in electrical power networks. In the form of a block diagram the way of proceedings is presented for selection of compensator units and their parameters. The aim of the method is obtaining supply voltage characteristics which can meet requirements of power quality standards.

Monitoring disturbances in electrical power systems

This paper describes a measuring system for monitoring electromagnetic disturbances in power systems. The system was designed and constructed at the Institute of Electrical Power Engineering of the Technical University of Lodz. The basic characteristics of it as well as the range of possible measurements are discussed. The paper presents the results of measurements performed in one industrial plant and discusses them.

Examination of power quality in industry

This paper provides the results of tests of power quality for an industrial power network. Several parameters were identified including: voltage variation; harmonics and total distortion factor; and voltage unbalance. The measurement aimed at assessing the influence of some loads which are operated in the plant on power quality and evaluating the quality of supply from the public distribution network. Some results of the tests and analyses are presented in the paper.

Experimental analysis of DC electric vehicles charging station operation and its impact on the supplying grid

This paper present the results of measurements of EV fast charging process in ABB Terra 52 charging station installed in Aleksandrow Lodzki (Poland) and it is impact on the power quality of supplying network. For the reference purposes, the results of AC slow charging measurements were evaluated.