20.500.12556/RUL-183356 Modeliranje regulacije pretvorniških virov električne energije za stabilnostne študije Modelling of converter-interfaced generation control for stability studies Magistrsko delo raziskuje modeliranje in analizira odzive regulacije sledenja omrežni napetosti ali pretvornika RSON (ang. Grid-following – GFL), ki je vse pomembnejši gradnik sodobnih elektroenergetskih sistemov pri uveljavljanju obnovljivih virov energije. Kot je znano, so pretvorniki tega tipa ključni za vključevanje obnovljivih virov energije, kot sta sončna in vetrna energija, v omrežje. Cilj raziskave je bil razviti in preučiti simulacijski model pretvornika v programskem okolju Matlab/Simulink ter primerjati odzive sistema v dveh različnih pristopih simulacije: EMT (Electromagnetic Transients) in RMS (Root Mean Square). Ta dva pristopa omogočata različne natančnosti in časovne obremenitve simulacij, kar je ključno za analizo dinamičnih pojavov in dolgoročnih trendov v omrežju. V začetni fazi raziskave so bile določene ključne predpostavke za izdelavo modela. Predpostavili smo, da pretvornik deluje v omrežju s togo mrežo, kar pomeni, da napetost in frekvenca ostajata konstantni ne glede na obremenitev. Poleg tega smo predpostavili, da je pretvornik tipa RSON, kar pomeni, da sledi frekvenčnemu in napetostnemu profilu omrežja, namesto da bi jih aktivno uravnaval, kot to počnejo regulacije oblikovanja omrežne napetosti ali pretvorniki ROON (ang. Grid-forming – GFM). Torej lahko rečemo, da pretvornik RSON določa injiciranje ali absorpcijo moči v ali iz omrežja glede na trenutne potrebe. Osnova za izdelavo modela je bil matematični opis delovanja pretvornika v dvoosnem (dq) sistemu, kjer so se elementi, kot so sinhronizacijski mehanizem (PLL) in regulacijske zanke, modelirali z diferencialnimi enačbami. Model je bil izdelan v okolju Matlab/Simulink, kjer je bil vsak del zgrajen od začetka, brez uporabe vnaprej pripravljenih knjižnic. Implementacija EMT-modela je vključevala podrobno časovno simulacijo prehodnih pojavov, po drugi strani pa je RMS-model poenostavljen, saj opisuje efektivne vrednosti napetosti, tokov in moči ter zanemarja hitre prehodne pojave. Ta poenostavitev omogoča bistveno hitrejšo simulacijo, vendar na račun natančnosti. V okviru raziskave so bili implementirani ključni elementi pretvornika, eden od teh je sinhronizacijski mehanizem (PLL), ki omogoča sledenje omrežni frekvenci in napetosti. PLL je lahko modeliran z uporabo PI-regulatorja in matematičnih transformacij (Parkova in Clarkina transformacija), kar omogoča prehod iz trifaznega sistema v dvoosni dq referenčni sistem. Seveda ga v EMT-modelu ali kar sistemu ni bilo treba modelirati, saj v Simulinku že obstaja predpripravljen model. Tega smo uporabili v našem primeru. Regulacijske zanke za tok smo implementirali z uporabo PI-regulatorjev, ki omogočajo uravnavanje toka v obeh oseh (d in q), s čimer pretvornik zagotavlja pravilno injiciranje ali absorpcijo delovne in jalove moči glede na zahteve odjemalcev in razpoložljivost obnovljivega vira energije. Močnostni del pretvornika je vključeval model LCL-filtra, ki zmanjšuje harmonike in preprečuje popačenja, kar izboljša kakovost pri regulaciji. EMT-model je pokazal visoko stopnjo natančnosti pri nenadnem spreminjanju potrebe po moči. RMS-model je bil uspešno izdelan, celo do te mere, da je natančnost primerljiva z natančnostjo v EMT. Celo več, trajanje simulacije se nam v primeru RMS zmanjša za približno desetkrat, medtem ko se natančnost ne poslabša veliko. Primerjava rezultatov obeh pristopov je pokazala, da vsak od njiju prednjači na svojem področju. EMT-simulacije so podrobnejše, vendar zahtevajo daljše trajanje simulacije, medtem ko je izvedba RMS-simulacij hitrejša, vendar manj natančna pri analizi prehodnih pojavov. Ta raziskava omogoča možnost uporabe pridobljenih modelov pri načrtovanju in optimiziranju delovanja pretvornika RSON v različnih scenarijih, ki se dogajajo v omrežju. Delo tudi omogoča priložnost za nadaljnjo analizo kompleksnejših omrežij, kjer se vključujejo dinamični pojavi in stabilnostne študije ali celo interakcije med več pretvorniki. This thesis focuses on the modelling and analyses the responses of a grid-following converter, which is a key component in modern power systems and in the integration of renewable energy sources. Grid-following converters play a crucial role in integrating renewable energy sources, such as solar and wind, into the grid. The primary goal of the research was to develop and investigate a simulation model of the converter in Matlab/Simulink and to compare the responses using two different simulation approaches: EMT (Electromagnetic Transients) and RMS (Root Mean Square). These two approaches allow different level of accuracy and computational time, which is crucial for the analysis of dynamic phenomena and long-term trends in the grid. The initial phase of the research, the key assumptions and parameters for the model were determined. The converter was assumed to operate in a stiff grid, meaning voltage and frequency remain constant regardless of load changes. In addition, we assumed the converter operates in grid-following mode, tracking the grid’s voltage and frequency rather than actively regulating them, as grid-forming converters do. Thus, it can be said that a grid-following converter determines the injection or absorption of power into the grid or from the grid. The basis for developing the model was a mathematical description of a converter’s operation in the two axis (dq) frame, where elements such as the synchronization mechanism (PLL) and control loops were modelled using differential equations. The model was built in Matlab/Simulink environment, with most of the parts built from scratch, without relying on pre-built libraries. The EMT model employed detailed time-domain simulations of transient phenomena, using microsecond-level time steps, while the RMS model was simplified, capturing RMS values of voltages, currents, and power while neglecting fast transients. This simplification enabled significantly faster simulations, albeit at the cost of precision. As part of the research, the key elements of the inverter were implemented, one of which is Phase-Locked Loop (PLL), which ensures synchronization with grid voltage and frequency. The PLL can be modelled using a PI controller and mathematical transformations (Park and Clarke transformations) to switch from a three-phase system to the dq reference frame. Of course, it was not necessary to model it in the EMT system as a pre-prepared model already exists in Simulink. Current control loops were implemented using PI controllers to regulate current in the d and q axes, ensuring the converter injects or absorbs active and reactive power as required by the consumers and the availability of a renewable energy source. The power stage of the converter included an LCL filter model to reduce harmonics and prevents distortion, which improves the regulation quality. The EMT model demonstrated a high degree of accuracy during sudden changes in power demand. The RMS model was successfully developed, to the point where its accuracy is comparable to that of the EMT model. Moreover, the simulation duration in the case of RMS approach is reduced by approximately ten times, while the accuracy does not degrade significantly. A comparison of the results from both approaches has shown that each excels in its own domain. EMT simulations are more detailed but require longer simulation duration, whereas RMS simulations are faster to execute but less accurate in analysis of transient phenomena. This research enables the application of the obtained models in the design and optimization of the operation of a grid-following converter in various scenarios occurring in the power grid. Also, it provides an opportunity for further analysis of more complex networks, where dynamic phenomena and stability studies are included, or even interactions between multiple converters. regulacija pretvornik omrežna napetost sledenje napetosti oblikovanje napetosti RSON ROON modeliranje stabilnost regulation converter grid-following grid-forming GFL GFM EMT RMS modelling stability true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-06-11 14:45:02 2026-06-11 14:45:30 2026-06-12 04:18:44 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 63352 Kekec_Rok_-_Modeliranje_regulacije_pretvorniskih_virov_elektricne_energije_za_stabilnostne_studi.pdf Kekec_Rok_-_Modeliranje_regulacije_pretvorniskih_virov_elektricne_energije_za_stabilnostne_studi.pdf 1 B5D376E3B18FAEDAD2A3CA5A84E4DCB7 f73c91696a77673086e118197a3e58818e98046451bcedeb87249cd4efc7023a 6a252a17-6593-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235372 Fakulteta za elektrotehniko 0 0 0