A non-linear model based feed forward flatness control approach to speed governor systems of hydropower plants

Ovo istraživanje je dio projekta sanacije kojim se hidro-mehanički regulator brzine hidroelektrane (HEPP) zamjenjuje s novim, digitalnim. Na temelju ranijeg istraživanja procjene HEPP modela, simulacijska istraživanja u Matlab/Simulink okruženju provedena su u svrhu razvijanja najbolje filozofije za proizvodnju digitalnog regulatora brzine. Kako bi se moglo ponuditi odgovarajuće rješenje za reguliranje učestalosti punjenja energetskog sustava, regulator brzine bi u okviru dopuštenih granica trebao što brže reagirati na zadane promjene. U svrhu kompenzacije pokazatelja nezadovoljavajuće performanse uobičajenog proporcionalno-integralnog (PI) regulatora, konstruiran je novi regulator zasnovan na teoriji diferencijalne ravnomjernosti. Novi je regulator konstruiran dodavanjem postojećem PI regulatoru povratne sprege na ravnomjernosti zasnovan dio unaprijedne sprege. Rezultat je bolji rad nego s konvencionalnim PI regulatorom.This study is a part of a refurbishment project, which renews the hydro-mechanical speed governor of a hydroelectric power plant (HEPP) with a new digital one. Based on the previous study of the project, which covers the validation of the HEPP model, the simulation studies implemented in Matlab/Simulink environment are conducted to design the best controller philosophy for the digital speed governor controller. In order to be able to give satisfactory response to the load frequency control of the power system, the speed governor should respond to the set point changes as quickly as possible within the safe margins. In order to compensate unsatisfactory performance indices of conventional proportional-integral (PI) controller, a new controller based on the differential flatness theory is designed. The new controller is constructed by adding on a flatness-based feed forward part to the existing PI feedback controller, which results in improved performance compared to the conventional PI controller

A Simple Short Circuit Analysis for Power Networks

This study investigates the transient behavior of short circuits in power circuits. The circuit consists of two part; input part and load part. These two parts are connected with a circuit breaker switch. The circuit works in two modes; first mode is when the switch is open and second mode is when the switch is closed. This study analyses the circuit when the switch is closed. The analysis is done with different types of closing angle. The analysis is done by forming state equations and those equations are solved numerically by using Matlab. The analysis and conclusion is performed by observing the behaviors of the graphs

Elektromanyetik Alanlar ve Bioenerji Olgusu

Elektromanyetik enerji geniş bir frekans aralığında tanımlanmakta ve her frekans aralığında varlığını farklı şekilde hissettirmektedir. İnsanlık tarihi düşünüldüğünde, elektriğin keşfi ve elektrik-elektronik tabanlı cihazların varlığı çok eski değildir. İnsanoğlu kendi meydana getirdiği cihazlar nedeniyle asırlardır daha önce alışık olmadığı frekansta elektromanyetik alan ve dalgalara maruz kalmaktadır. Buna bağlı olarak, bu alanların insanlara zararlı etkileri olabileceği tezi üzerine birçok çalışma yapılmış ve yapılmaktadır. Yapılan çalışmaların kayda değer sonuçları bulunmakla birlikte, genel anlamda henüz fazla sayıda çıktı ve yargı ortaya koymak mümkün olmamıştır. Bu çalışma, süregelen birçok çalışmadan farklı olarak, elektromanyetik enerjinin zararlı etkileri olabileceği yanında bazı frekanslarda faydalı etkilerinin de olabileceği tezini destekleyen bulguların ortaya konması amacıyla meydana getirilmiştir

A Simple Short Circuit Analysis for Power Networks

This study investigates the transient behavior of short circuits in power circuits. The circuit consists of two part; input part and load part. These two parts are connected with a circuit breaker switch. The circuit works in two modes; first mode is when the switch is open and second mode is when the switch is closed. This study analyses the circuit when the switch is closed. The analysis is done with different types of closing angle. The analysis is done by forming state equations and those equations are solved numerically by using Matlab. The analysis and conclusion is performed by observing the behaviors of the graphs

AN APPLICATION EXAMPLE ; FAULT DIAGNOSIS IN POWER SYSTEM

There are a lot of protective devices in electrical transmission and distribution systems which are monitored and data are collected from these devices via Supervisory Control and Data Acquisition System (SCADA). distribution systems are more complicated when compared with transmission systems. However, SCADA is not available in most distribution systems where phones from the customers are used as alarms. In the cases where SCADA is not available experiences of the dispatchers and the information from customers becomes important. In this work a user friendly software is developed for even unexperienced dispatchers

A NON-LINEAR MODEL BASED FEED FORWARD FLATNESS CONTROL APPROACH TO SPEED GOVERNOR SYSTEMS OF HYDROPOWER PLANTS

This study is a part of a refurbishment project, which renews the hydro-mechanical speed governor of a hydroelectric power plant (HEPP) with a new digital one. Based on the previous study of the project, which covers the validation of the HEPP model, the simulation studies implemented in Matlab/Simulink environment are conducted to design the best controller philosophy for the digital speed governor controller. In order to be able to give satisfactory response to the load frequency control of the power system, the speed governor should respond to the set point changes as quickly as possible within the safe margins. In order to compensate unsatisfactory performance indices of conventional proportional-integral (PI) controller, a new controller based on the differential flatness theory is designed. The new controller is constructed by adding on a flatness-based feed forward part to the existing PI feedback controller, which results in improved performance compared to the conventional PI controller

HARMONİK VE SIÇRAMA İÇEREN ELEKTRİK GÜÇ ŞEBEKESİ GERİLİM İŞARETİNE KİLİTLENMENİN YİNELENEN EN KÜÇÜK KARELER METODUYLA İNCELENMESİ

Bu çalışmada, klasik uyarlanabilir metotlardan Yinelenen En Küçük Kareler Metodu (YEKK) kullanılmıştır. Öncelikle YEKK metoduna unutma faktörü algoritması adapte edilmiştir. Geliştirilen yaklaşım kullanılarak bir elektrik güç şebekesinin harmonik ve sıçrama içeren faz gerilim sinyalinin faz bilgileri elde edilerek; gerilim göçmesi, faz kayması ile ani gerilim sıçramaları'na algoritmanın tepkileri incelenmiştir. Benzetim işlemi MATLAB® yardımıyla gerçekleştirilmiş olup benzetim sonuçları ve metodun etkinliği incelenmiştir

Machine-Learning-Based Modeling of a Hydraulic Speed Governor for Anomaly Detection in Hydropower Plants

Hydroelectric power plants (HEPPs) are renewable energy power plants with the highest installed power in the world. The control systems are responsible for stopping the relevant unit safely in case of any malfunction while ensuring the desired operating point. Conventional control systems detect anomalies at certain limits or predefined threshold values by evaluating analog signals regardless of differences caused by operating conditions. In this study, using real data from a large hydro unit (>150 MW), a normal behavior model of a hydraulic governor’s oil circulation in an operational HEPP is created using several machine learning methods and historical data obtained from the HEPP’s SCADA system. Model outputs resulted in up to 96.45% success of prediction with less than 1% absolute deviation from actual measurements and an R2 score of 0.985 with the random forest regression method. This novel approach makes the model outputs far more appropriate to use as an active threshold value changing for different operating conditions, eliminating insufficiency of the constant threshold, resulting in the detection of anomalies in early stages and taking precautions accordingly. The study fills the gap in the literature on anomaly detection in hydraulic power units, which is a demanding task with state-of-the-art methods

INVESTIGATION OF TRACKING OF VOLTAGE SIGNAL CONTAINING HARMONICS AND SPIKE BY USING RECURSIVE LEAST SQUARES METHOD

In this study, recursive least squares method (RLSM) that is one of the adaptable classical methods was used. Firstly forgetting factor was adapted to RLSM. Phase information of voltage signal belonging to an electric power network that contains harmonics and spike was obtained by developed approach. Then responses of the algorithm were investigated for voltage collapse, phase shift and spike. Simulation was implemented by using MATLAB® code. Results of simulation were examined and efficiency of method was presented

Network Based Building Lighting Design and Fuzzy Logic via Remote Control

Bu çalışmada, bir binanın aydınlatma sistemi ağ tabanlı olarak tasarlanmıştır. Tasarımda Profibus-DP ağ yapısı kullanılmıştır. Bina aydınlatmasının kontrolünde Bulanık Mantık Denetimi (BMD) kullanılmıştır. BMD uygulamasında, bina aydınlatma seviyelerini ölçen algılayıcılardan gelen bilgiler kullanılmıştır. Bu bilgiler Profibus-DP ağı üzerinden sisteme aktarılmıştır. Aydınlatma armatürlerinin Profibus-DP ağı üzerinden denetimi sağlanmıştır. Tasarlanan sistemde, bina içi aydınlatma ihtiyaç duyulan seviyede kalması sağlanmıştır. Tasarım ile, enerji tasarrufu ve sağlıklı aydınlatma imkanı elde edilmiştirIn this paper, a network based building lighting system is implemented. Profibus-DP network structure is used in the design and Fuzzy Logic Controller (FLC) is used on control of the building lighting. Informations received from sensors which measures level of the building illumination is used on FLC and they are transferred to the system by Profibus-DP network. Control of lighting luminaries are made via Profibus-DP network. The illuminance inside the bulding is fitted required level. Energy saving and healthy lighting facilities have been obtained by the desig