The compensation of the sharp jumping in the input voltage of the DC-DC converters; buck and boost has been investigated in this paper. A combined averaging and linearization techniques have been utilized to generate a mathematical model for each type of DC-DC converters. Two control schemes, Feedback and Feedforward controllers, have been applied in the developed model. The MATLAB/SIMULINK 2015a software has been used in order to demonstrate more realistic model which include some parasitic parameters. The simulation results show that using two degree of freedom controllers is better than the one with only feedback controller. The Disturbance rejection and input tracking were improved for all DC-DC converter types under several conditions.
Słowa kluczowe: Buck Converter. Boost Converter, Feedforward Controller, Feedback Controller.
Zbadano możliwości kompensacji skoków napięcia na wejściu przekształtnika DC-DC typu buck and boost. Wyniki symulacji wykazały że użycie kontrolerów o dwóch stopniach swobody dało najlepsze rezultaty we wszystkich typach badanych przejkształtników.
Keywords: przekształtniki typu boost I buck, sterowniki sprzężenia zwrotnego.
Many factors affect considering the applications in the market such as; cost, efficiency, size and complexity. DCDC converters such as; buck, boost and buck-boost are widely used in industry. Transferring energy from source to the load and vice versa can be improved using DC-DC converters. The source can be a battery, AC grid, photovoltaic system (PV) or different types of AC generators and the load can be AC/DC machines. DC-DC converters are used in many power system applications such as; DC-micro grid, hybrid vehicles, and photovoltaic system. The efficiency of the system can be improved by adding a controller [1, 2]. The DC micro-grid power system is one of the systems that uses all types of converters. The sources of DC power in such grid are either PV cells or battery modules. For high power application two or more sources can be used to supply grid. Sudden jumps in the input of DC-DC choppers can occur during the process of switching between sources. Shutting down of whole system is not an option, and one failing unit is enough to create a sudden jump in the input of the DC chopper . Very well-designed feedback controller can handle the smooth disturbance in the input but not the fast one. The feedforward controller sounds promising to compensate the sharp deviation in the input voltage for the DC-DC converter. In , the small signal mathematical model has been used to design the input voltage feed-forward controller, which was applied on a two-switch Buck-Boost (TSBB). The authors concluded that, by using this technique the switching process became easier and the unstable response in the output voltage due to the disturbance in the input voltage has been reduced. In , the author presented a method that can estimate the input voltage and the load without measuring the actual quantities. In his work, the small signal model for the single phase boost rectifier has been developed, assuming that there is no var [...]
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