Regulacija aktivnega trifaznega omrežno priključenega usmernika

VUJINOVIĆ, SLAVKO (author), Nemec, Mitja (mentor)

V diplomi je predstavljena regulacija trifaznega omrežno priključenega tranzistorskega usmernika z možnostjo vračanja energije v omrežje. Regulacija je izvedena v stacionarnem in rotirajočem koordinatnem sistemu. Poleg tega je možno delovanje v sinhronizmu in izven sinhronizma z omrežjem ter možnost uporabe sinusne oblike tokovne reference in tokovne reference z obliko omrežne napetosti. Med vsemi možnosti je možno preklapljati med delovanjem naprave. Cilj je bil ugotoviti, kakšna je razlika v delovanju naprave, ko je le-ta sinhronizirana z omrežjem in ko ni sinhronizirana, vendar deluje dovolj blizu sinhronizma. V tem primeru je bila osnovna frekvenca 50 Hz, tokovna referenca pa je bila generirana s pomočjo diskretne fourierjeve transformacije in inverzne diskretne fourierjeve transformacije. S tem je tokovna referenca še vedno sinhronizirana z omrežno napetostjo. Nadalje je bil cilj ugotoviti razliko v delovanju, ko je tokovona referenca čiste sinusne oblike ali pa sledi obliki trenutne omrežne napetosti. Opravljenih je bilo več meritev. Najprej brez priključenega bremena, ko je tekel med napravo in omrežjem jalov tok, nato pa še s 510 Ω bremenom. V prvem primeru je bilo vidno le rahlo povečanje izgub, ko naprava ni sinhronizirana z omrežjem in višje harmonsko popačenje toka, ko naprava deluje v stacionarnem koordinatnem sistemu s tokovno referenco z obliko omrežne napetosti. Meritve z bremenom so pokazale višje harmonsko popačenje toka, ko naprava ni sinhronizirana z omrežjem.

• Language: Slovenian
• Keywords: Regulacija napetosti trifaznega usmernika, sinhronizacija z omrežjem, stacionarni koordinatni sistem, rotirajoči se koordinatni sistem
• Work type: Undergraduate thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2016
• PID: 20.500.12556/RUL-84177
• Publication date in RUL: 14.07.2016

Secondary language

• Language: English
• Title: Control of active three phase grid connected rectifier

Abstract

This diploma thesis presents the control of three phase grid connected transistor rectifier with the ability to transfer energy both from and into the grid. Control can be done both in stationary and rotating reference frame. Additionaly, the rectifier can work both in synchronism with the grid in out of synchronism. The current reference can have either the sine wave and grid voltage form. All modes of operation can be changed during operation of the rectifier. The goal of the thesis was to measure the difference between the synchronised and unsychronised operation of the rectifier as well as the difference when the current reference has sine wave form and the form of the grid voltage. When the device operated in unsychronised mode, the base frequency was set to 50 Hz and the current reference was generated with help of discrete Fourier transform and inverse discrete Fourier transform. That ensures the synchronization of the reference frame to the grid voltage. The measurements were done first without load with reactive current and then with 510 Ω load. In the first case, there was a slight increase in losses when the rectifier operated out of synchronism with the grid and higher total harmonic distortion of current when the current reference had grid voltage form and the control was done in stationary reference frame. Measurements with the load showed higher total harmonic distortion of current when the rectifier operated out of synchronism with the grid.

• Keywords: Three phase rectifier voltage control, grid synchronization, stationary reference frame, rotary reference frame