Omejevanje toka ob vklopu električnih naprav

OSTROUŠKA, TOMAŽ (author), Vončina, Danijel (mentor)

Diplomska naloga opisuje razvoj elektronske enote za mehki zagon različnih naprav, pri katerih steče ob vklopu velik tok. V prvem delu so predstavljene naprave, kot so: transformator, univerzalni motor, omrežni usmernik s kapacitivnim bremenom ipd., ki pri neposrednem vklopu v omrežje povzročijo, da steče kratkotrajno velik tok. V nadaljevanju so opisane nekatere znane rešitve za omejevanje vklopnih tokov. V osrednjem delu pa je predstavljen razvoj elektronske enote za mehki zagon, ki temelji na faznem krmiljenju triaka oziroma dveh protiparalelno vezanih tiristorjev s pomočjo mikrokrmilnika PIC18F4520. Podane so nekatere programske rešitve za izvedbo mehkega zagona pri različnih tipih bremen. Z dodatnim vezjem za detekcijo vklopa in izklopa stikala na bremenski strani, lahko izvedemo mehki zagon tudi pri napravah, pri katerih je sicer značilen velik vklopni tok. To lahko dosežemo brez kakršnekoli spremembe oz. posega v samo napravo. Enoto za mehki zagon preprosto vstavimo med napravo in omrežje. Pomembna prednost elektronske enote za mehki zagon je možnost prilagoditve vklopnega postopka specifičnim zahtevam naprave. Na koncu so prikazani tudi praktični primeru uporabe enote za mehki zagon in njena učinkovitost.

• Language: Slovenian
• Keywords: Ključne besede: vklopni tok, fazno krmiljenje, mikrokrmilnik, mehki zagon
• Work type: Undergraduate thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2015
• PID: 20.500.12556/RUL-30579
• Publication date in RUL: 19.02.2015

Secondary language

• Language: English
• Title: Limiting of inrush current in electrical devices

Abstract

The thesis investigates the development of a soft-start electronic unit suitable for different devices, which are known by significant inrush currents. Different devices, such as a transformer, a universal motor, AC rectifier with a capacitive load, etc., which in the case of direct switching on the network cause a short-term high current flow, are presented in the first part. Further, some of the known solutions for limiting the inrush current are examined. In the central part, a development of soft-start electronic unit, which is based on the phase control of triac or two anti-parallel coupled thyristors by means of PIC18F4520 microcontroller is highlighted. Some software solutions for the implementation of a soft-start electronic unit for different types of loads are explained. Due to additional circuit for detecting the switch-on and switch-off on the load side, a soft-start of devices, which are otherwise characterised by high inrush current, can be carried out. This can be achieved without any changes or modification of the device itself. Soft-start unit can be without any difficulties inserted between the device and the network. An important advantage of a proposed soft-start electronic units is the possibility of adjusting the activation procedure with respect to the specific requirements of the device. At the end, practical examples of use of a soft-start electronic unit and its effectiveness are presented.

• Keywords: Keywords: inrush current, phase control, microcontroller, soft start