AUTOMATYCZNA REGULACJA MOCY BIERNEJ PRZEZ URZĄDZENIA FACTS W WARUNKACH NIESTABILNOŚCI NAPIĘCIA W SIECI ELEKTRYCZNEJ

This article describes the problem of automatic regulation of reactive power using electronic devices FACTS (Flexible AC Transmission Systems): static synchronous compensator (STATCOM) and unified power flow controller (UPFC). With the help of a complex writing form, the following are determined: voltages at the installation nodes of the FACTS device and loads, currents of loads, power sources and electronic compensators in case of voltage instability at the load node of the electrical network. Voltages and currents are determined using the node-voltage method. The task of STATCOM is partial or full compensation of reactive power. During the reduction of the voltage at the load node, the reactive power generated by the power source decreases. The STATCOM should partially or fully compensate for the reactive power imbalance as quickly as possible. However, at the same time, it is not possible to fully compensate for the voltage reduction. A series-parallel or parallel-series UPFC can be used to solve this problem. As a result of using the UPFC, it is possible to automatically raise the voltage level to acceptable values with the help of the UPFC series compensator. The analysis shows that the parallel-serial UPFC is characterized by the stability of operation. In the case of using a series-parallel UPFC, there are restrictions on the ability to adjust the imaginary voltage component of the series compensator, since the angle of the voltage vector changes, which causes a failure in the operation of the regulator of the parallel compensator UPFC.W artykule opisano problematykę automatycznej regulacji mocy biernej za pomocą urządzeń elektronicznych FACTS (Flexible AC Transmission Systems): statycznego kompensatora synchronicznego (STATCOM) oraz regulatora przepływu mocy (UPFC). Za pomocą złożonego formularza rejestracyjnego określane są: napięcia w węzłach instalacji urządzenia FACTS i obciążenia, prądy obciążenia, źródeł zasilania i kompensatorów elektronicznych w przypadku niestabilności napięcia w węźle obciążenia sieci elektrycznej. Napięcia i prądy są wyznaczane metodą napięć węzłowych. Zadaniem STATCOM jest częściowa lub pełna kompensacja mocy biernej. Podczas spadku napięcia w węźle obciążenia, moc bierna generowana przez źródło zasilania maleje. STATCOM powinien częściowo lub w pełni skompensować nierównowagę mocy biernej tak szybko, jak to możliwe. Jednocześnie jednak nie jest możliwe pełne skompensowanie spadku napięcia. W celu rozwiązania tego problemu można zastosować szeregowo-równoległy lub równoległo-szeregowy układ UPFC. W wyniku zastosowania UPFC możliwe jest automatyczne podniesienie poziomu napięcia do akceptowalnych wartości za pomocą kompensatora szeregowego UPFC. Analiza pokazuje, że równoległo-szeregowy UPFC charakteryzuje się stabilnością działania. W przypadku zastosowania szeregowo-równoległego UPFC istnieją ograniczenia w zakresie możliwości regulacji składowej urojonej napięcia kompensatora szeregowego, ponieważ zmienia się kąt wektora napięcia, co powoduje awarię działania regulatora kompensatora równoległego UPFC

Optimization of Fiber Optic Sensors Parameters for Temperature Measurement

Nowadays, there are many devices the failure of which could not only lead to huge financial losses but also wreak havoc in the natural environment. Such circumstances require us to analyze the electrical components before something dangerous happens. Early reaction gives an opportunity to implement prevention measures and avoid serious consequences. Optical fiber sensors have a number of advantages, the most important of which include immunity to electromagnetic interference, low weight and the ability to incorporate them within the measured structure. Fiber Bragg gratings have other special advantages; for instance, they enable the creation of distributed sensing arrays, which contain multiple sensors. They are also insensitive to optical power source fluctuations. The multitude of FBG sensors applications extorted fabrication of gratings with different spectral shapes. Uniform gratings have spectra with strong side lobes which could affect the processing characteristics of temperature sensor. Apodization is one of ways for affecting the gratings spectral shape. This article concerns simulations based on an original computer application, which is numerical model implementation of Transfer Matrix Method. It allows to determine the spectral characteristic of optical components on the basis of the theory of coupled modes and matrix description of electromagnetic wave that passes through optical fiber. Different fiber gratings lengths were analyzed according to their reflection and transmission spectra. In the beginning, the impact of various parameters on the Bragg grating spectral characteristics was checked. Results of those simulations have been attached. The article covers measurement of real optic elements put in climatic chamber and Bragg gratings, produced under very strict conditions. The profile of the laser beam was approximated by Gaussian function using MatLab software and additional tools from package. Function matching has been defined as statistical parameters and evaluated later. The comparison of mathematical model and physical optical system, based on previously designated function apodization, has been covered. The results of these two visualizations have been summarized to better exemplify the differences and similarities. The previously measured fiber Bragg grating has been proposed as temperature sensor and parameters which may be used to construct an optical fiber temperature sensor were established. Temperature sensitivity was determined in the end