2016
7
th
Power Electronics, Drive Systems & Technologies Conference
16-18 February 2016, Iran University of Science and Technology
Single Stage DC-AC Boost Converter
Ali Nahavandi
Faculty of Engineering
Malayer University
Malayer, Iran
E-mail:
Ali.nahavandi@malayeru.ac.ir
Mehdi Roostaee
Faculty of Engineering
Malayer University
Malayer, Iran
E-mail:
Mehdi.roostaee@stu.malayeru.ac.ir
Abstract—This paper presents a new DC-AC converter which
not only acts as inverter but also boosts the output voltage with
respect to input. This topology is cost-effective due to reduced
switch number and it is suitable for compact design. Switching
strategy in this topology is similar to conventional inverter and in
each half cycle, boost operation is done by one of the two boost
converter. Variable duty cycle is applied for generating
sinusoidal output voltage. Theoretical analysis and operation
principle are presented together with simulated results to
validate the proposed concepts.
Keywords—Photovoltaic system; single-stage
converter; full bridge Inverter; boost converter.
I.
Mohammad Reza Azizi
Faculty of Engineering
Malayer University
Malayer, Iran
E-mail:
Azizi.malayeru@gmail.com
As a consequence, when a higher output voltage level is
needed, a DC-DC boost converter must be used between the
DC source and inverter as shown in figure 1. Depending on
the power and voltage levels involved, this solution can result
in high volume, weight, cost and reduced efficiency.
The proposed structure in this paper as shown in figure 2
uses one circuit for DC-DC boost converter and DC-AC
conversion. This structure introduces a new single stage
topology based on a full-bridge DC-AC inverter together with
two additional diodes and one input inductor to implement two
boost converters that share the same input inductor. By such a
topology in recluse places that there is no achievement to AC
grid, AC voltage in different level and frequency can be
generated. Similar circuit is analyzed in [1]. Other DC-AC
boost converter achieves DC-AC conversion, by connecting
the load differentially across two DC-DC boost converters and
modulating the DC-DC converter output voltages sinusoidally.
This concept has been discussed in [2-5]. Several authors have
worked on expanded circuit with transformer [6-8].In [9] and
[10] the DC source is first boosted and then inverted to AC.
DC-AC
INTRODUCTION
The growing use of renewable energy sources brings new
challenges to the energy conversion technology. One of this
challenges is related to the fact that some devices that store or
produce electric energy (e.g. batteries, solar panels,... ) are
built using low-voltage cells, Usually connected in series in
order to attain a reasonable voltage. The connection of large
number of cells in series will increase the complexity of the
system and may reduce its performance because of differences
between cells and different working conditions. So, the output
voltage of source (PV cells) need to be boosted with high
conversion ratio and then must be inverted to AC for practical
applications.
In this structure the duty cycle is variable and alternative
[11].One advantage of this topology is using the minimum
number of switches and consequently less power loss and
other advantage is the ability of producing AC voltage in
different level with different desired frequency.
In the next part, proposed structure is analyzed and
different modes (operation principle) are illustrated and then
the simulation results verify converter analyzes and at last the
conclusion is added.
Fig.1. Traditional DC-AC boost converter (consisted of a DC-DC boost
converter and an inverter)
Fig. 2. Proposed structure (DC-AC boost converter)
Proceeding of 7th Power Electronics, Drive Systems & Technologies Conference (PEDSTC 2016)
16-18 February 2016, Iran University of Science and Technology, Tehran, Iran
378