Eksperimentalni model virtualnega električnega pogona za preizkušanje močnostnih pretvornikov

Selan, Žiga (author), Nemec, Mitja (mentor)

Magistrsko delo obravnava izdelavo t. i. virtualnega električnega pogona, s katerim nadomestimo klasični sistem za preizkus močnostnih pretvornikov (frekvenčnih pretvornikov oz. inverterjev), namenjenih za vodenje PMSM. Klasični preizkusni sistem sestoji iz preizkušanega pretvornika, testnega stroja, ki ga ta pretvornik napaja oz. vodi, ter bremenskega stroja in pretvornika, ki ta stroj napaja. Testni in bremenski stroj sta sklopljena preko gredi. Prednost uporabe virtualnega pogona je v tem, da se navzven obnaša kot pravi pogon, čeprav ne vsebuje nikakršnih premičnih mehanskih se delov, kar sam preizkusni sistem zmanjša in poenostavi ter izboljša izkoristek glede na klasični sistem. Virtualni pogon je sestavljen iz bremenskega pretvornika in sklopnega LCL vezja, ki služi za sklopitev bremenskega in preizkušanega pretvornika. Z bremenskim pretvornikom na kondenzatorjih sklopnega vezja generiramo napetost, ki je ekvivalentna inducirani napetosti, ki bi jo generiral realni testni stroj v določenem obratovalnem stanju (pri neki vrtilni hitrosti in navoru). Na podlagi te napetosti testni pretvornik vidi sklopno vezje kot realni testni stroj. Magistrsko delo obsega načrtovanje in izdelavo virtualnega pogona na primeru sinhronskega stroja s trajnimi magneti (PMSM). To je obsegalo izdelavo simulacijskega modela sistema in kasnejšo izdelavo ustreznega sklopnega vezja, izdelavo tiskanega vezja bremenskega pretvornika ter pripravo programske kode za mikrokrmilnik, v katerem se izvaja regulacijski algoritem bremenskega pretvornika. Po izdelavi prototipa strojne in programske opreme smo delovanje virtualnega pogona preizkusili v različnih obratovalnih stanjih. Rezultati meritev so pokazali, da sistem deluje ustrezno in v skladu s pričakovanji.

• Language: Slovenian
• Keywords: virtualni električni pogon, močnostna strojna oprema v zanki, sinhronski stroj s trajnimi magneti, preizkušanje močnostne elektronike
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2020
• PID: 20.500.12556/RUL-120634
• Publication date in RUL: 23.09.2020

Secondary language

• Language: English
• Title: Experimental model of virtual electric drive for frequency inverter testing

Abstract

This master’s thesis deals with the design of a so called virtual electric drive which can replace the conventional test bench used to test inverters used in variable speed drives. The conventional test bench consists of a inverter to be tested, a test machine which the tested inverter supplies and of a load machine and a inverter to drive the load machine. The test and load machines are coupled through a shaft. The advantage of a virtual drive is that while it behaves as an actual drive it does not contain any moving mechanical parts, which simplifies the test setup and increases efficiency in comparison to the conventional system. Virtual drive consists of a load power converter and a LCL coupling circuit which is used to couple the test and load converters. Load power converter generates such current through the LCL circuit that the voltage on the capacitors is equal to the induced voltage (back EMF voltage) of the actual test machine. Through this voltage the test converter sees the coupling circuit as an actual test machine. The thesis covers the design and construction of a virtual drive based on a model of a permanent magnet synchronous machine (PMSM). Firstly a simulation model of the proposed system has been built. Once the basic functionality was confirmed we proceeded with construction of the experimental system. Lastly a control program for the load converter has been developed. After completion of hardware and software of the prototype virtual drive, we have tested its operation in various working states. The measurements showed that the system operation is correct and in order with our expectations.

• Keywords: virtual electric drive, Power-Hardware-in-the-Loop, permanent magnet synchronous machine, power electronics testing