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In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation
Thesis (MEng) -- Stellenbosch University, 2022.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2022
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| _version_ | 1867613987676356608 |
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| access_status_str | Open Access |
| author | Gerber, Ian |
| author2 | Mwaniki, Fred |
| author_browse | Gerber, Ian Mwaniki, Fred |
| author_facet | Mwaniki, Fred Gerber, Ian |
| author_sort | Gerber, Ian |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng) -- Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/126092 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:52.743Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/126092 In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation Gerber, Ian Mwaniki, Fred Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Electric inverters Renewable energy sources Smart power grids Thesis (MEng) -- Stellenbosch University, 2022. ENGLISH ABSTRACT: DC-AC inverters are important in the shift towards renewable energy as they are used to integrate solar and wind power systems with the electrical grid. Inverters influence the power quality and stability of the grid. Inverter-based generation need to adhere to certain power quality and technical requirements. Accurate inverter models and parameters are, therefore, required for the analysis, design and simulation of inverters in grid studies. In this project, a methodology for estimating inverter model parameters is presented. Various inverter models exist. In this project electromagnetic transient models of inverters are used, as it is allows for the most accurate representation of inverters. Parameter estimation studies are applied to inverters to populate the electromagnetic models with accurate model parameters. This project makes use of excitation signals to perturb inverters to aid inverter modelling and parameter estimation of inverter parameters. A wideband pseudo-random impulse sequence source is applied to an inverter to characterize the output impedance of the inverter. The pseudo-random impulse sequence signal is a wideband excitation signal that is suitable for system identification and can be used in high-power, high-voltage environments, such as inverter systems. The output impedance of the inverter contains information about the inverter’s filter parameters, as well as the control-loop parameters and can subsequently be of great value during parameter estimation studies. The output impedance, as well as the output voltage and current of the inverter are used during parameter estimation to estimate the inverter’s filter and controller parameters. The proposed inverter parameter estimation methodology is first evaluated through two simulation case studies. Parameter estimation is performed on a single-phase, stand-alone inverter with output voltage control to obtain five filter and controller parameters as a first case study. As another case study, seven filter and controller parameters of a single-phase, grid-connected, current-controlled inverter are estimated. An experimental approach is then adopted to estimate five controller parameters for a practical single-phase, stand-alone, current-controlled inverter. The output impedance frequency response of a practical half-bridge inverter is also investigated and non-linearities present in the output impedance are identified. During this project the output impedance of inverters are characterized in a practically implementable way. This project accurately estimated parameters of inverters in situ to aid accurate inverter modelling. AFRIKAANS OPSOMMING: GS-WS wisselrigters is toenemend belangrik in die skuif vanaf nie-hernubare na hernubare energiebronne, omdat dit gebruik word om wind- en sonplase te integreer met die elektriese netwerk. Wisselrigters beïnvloed die kwaliteit en stabiliteit van die netwerk. Wisselrigter gebaseerde generasie moet tot seker drywing kwaliteite en tegniese vereistes voldoen. Analise, ontwerp en simulasie van wisselrigters is belangrik vir netwerk studies. In hierdie projek word ’n metode om wisselrigters se parameters te bekom vir akkurate modellering voorgestel. Verskeie modellering tegnieke bestaan vir wisselrigters, in hierdie projek word elektromagnetiese modelle gebruik, omdat dit die mees akkurate voorstelling van ’n wisselrigter is. Parameter bepalings studies word aangewend to wisselrigters om die elektromagnetiese modelle met akkurate parameters te populeer. Hierdie projek maak gebruik van breëband seine om wisselrigter modellering te verbeter. In hierdie projek word ’n pseudo-lukrake impuls volgorde bron gebruik om ’n wisselrigter se uittree impedansie te karakteriseer. Die pseudo-lukrake impuls volgorde is ’n opwekkingsein wat onlangs voorgestel is. Dit kan in hoë drywing, hoë spanning omgewings gebruik word. Die pseudo-lukrake impuls volgorde is ’n breëband sein wat oor die vermoë beskik om ’n breë frekwensie band op te wek. ’n Wisselrigter se uittree impedansie kan gekarakteriseer word deur ’n pseudo-lukrake impuls volgorde sein aan te wend om die wiselrigter oor ’n wye frekwensie band op te wek. Die uittree impedansie bevat inligting rakende die wisselrigter se filter en beheerder parameters en kan gevolglik doeltreffend gebruik word in parameter bepalings studies. Deur die uittree impedansie, spanning en stroom te gebruik kan die wisselrigter se parameters bepaal word. In hierdie projek word verskeie wisselrigters uitleggings ondersoek. Die uittree impedansie van die wisselrigters word gevind en gebruik in parameter bepaling studies. Parameter bepaling word toegepas op ’n enkelfase wisselrigter wat die uittree spanning oor ’n alleenstaande las reguleer om vyf beheer en filter parameters te bepaal. Vir ’n ander gevalle studie word sewe beheer en filter parameters van ’n enkelfase, netwerk gekoppelde, stroom beheerde wisselrigter bepaal. ’n Simulink model vir ’n praktiese enkelfase, alleenstaande, stroom beheerde wisselrigter word ook afgelei en die vyf beheer parameters van die wisselrigter word bepaal deur gebruik te maak van praktiese metings. Die uittree impedansie van ’n half-brug wisselrigter word ook ondersoek. In hierdie projek word die uittree impedansie van wisselrigters op ’n prakties behaalbare wyse gevind. Die projek kry dit reg om die parameters van wisselrigters wat aangeskakel is te bepaal. Masters 2022-11-21T08:30:26Z 2023-01-16T12:49:41Z 2022-11-21T08:30:26Z 2023-01-16T12:49:41Z 2022-12 Thesis http://hdl.handle.net/10019.1/126092 en_ZA Stellenbosch University xxii, 162 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Electric inverters Renewable energy sources Smart power grids Gerber, Ian In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title | In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title_full | In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title_fullStr | In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title_full_unstemmed | In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title_short | In situ parameter estimation of a single-phase voltage source inverter using pseudo-random impulse sequence perturbation |
| title_sort | in situ parameter estimation of a single phase voltage source inverter using pseudo random impulse sequence perturbation |
| topic | Electric inverters Renewable energy sources Smart power grids |
| url | http://hdl.handle.net/10019.1/126092 |
| work_keys_str_mv | AT gerberian insituparameterestimationofasinglephasevoltagesourceinverterusingpseudorandomimpulsesequenceperturbation |