Showing 4 results for Z-Source Inverter
S. Thangaprakash, A. Krishnan,
Volume 6, Issue 2 (6-2010)
Abstract
New control circuits and algorithms are frequently proposed to control the
impedance (Z) source inverter in efficient way with added benefits. As a result, several
modified control techniques have been proposed in recent years. Although these techniques
are clearly superior to the simple boost control method which was initially proposed along
with the Z-source inverter (ZSI), little or conflicting data is available about their merits
relating to each other. In this paper, it is shown how the shoot-through periods are inserted
in the switching waveforms of the power switches and the performances of them are
analyzed based on the operation of ZSI. Simple boost control, maximum boost control,
constant boost control and space vector modulation based control methods given in the
literature has been illustrated with their control characteristics. A critical investigation on
ripples of the impedance source elements, output voltage controllability, output harmonic
profile, transient response of the voltage across the impedance source capacitor and voltage
stress ratio etc has been presented with the simulation results. The simulation results are
experimentally verified in the laboratory with digital signal processors (DSP). DSP coding
for the above all control techniques has been generated by interfacing Matlab/Simulink
with DSP C6000 tool box and signal processing block set.
D. Arab Khaburi, H. Rostami,
Volume 7, Issue 1 (3-2011)
Abstract
This paper presents a method to control both the dc boost and the ac output voltage of Z-source inverter using neural network controllers. The capacitor voltage of Z-source network has been controlled linearly in order to improve the transient response of the dc boost control of the Z-source inverter. The peak value of the line to line ac output voltage is used to control and keep the ac output at its desired value. A modified space vector pulse-width-modulation method is also applied to control the shoot-through duty ratio for boosting dc voltage. This modified method lets the dc voltage stress across the inverter switches be minimized. The neural network control technique is verified by simulation results. The results are compared with that of the traditional PI controller.
M. Ghani Varzaneh, A. Rajaei, M. Fakhraei,
Volume 13, Issue 3 (9-2017)
Abstract
This paper presents a new structure to provide the ability for power sharing of two Z-source inverters. According to the operation principles of Z-source inverters, only one input source supplies the circuit, which is a limitation particularly for the stand alone systems feeded by limited output power such as photovoltaics and feul cells. Furthermore; if one source fails to supply, the load can't be supplied. This paper covers those via interconnection of impedance network of two Z-source inverters. The operating principles of the proposed topology for the stand-alone and power sharing conditions are described and the relations are derived. The topology is simulated, which the results verify the theoretical analysis and well performance of the system.
E. Babaei, T. Ahmadzadeh,
Volume 13, Issue 4 (12-2017)
Abstract
First of all, in this paper, the topology and operation of the three-phase three-level Z-source inverter based on neutral-point-clamped (Z-NPC) are studied. Moreover, different combinations of permissible switching states and control signals are explained for this inverter. In this paper, the topology of the three-phase three-level Z-NPC inverter is extended for an n-level state. Also, a combination of allowed switching states with relevant mathematical equations is presented for the proposed n-level Z-NPC inverter. In comparison with multilevel voltage-source inverters (only voltage-boost capability), the proposed multilevel Z-NPC inverter is a single-stage converter and it has a buck-boost capability of voltage. On the other hand, the control of two-stage converters compared to single-stage converters can be more difficult because of existing more active and passive components. In this paper, two new PWM control methods are also proposed for various multilevel Z-NPC inverters. One advantage of the proposed PWM control methods in comparison with conventional PWM control methods is maintaining the charge balance of the dc-link capacitors in neutral point. The correct performance of the proposed multilevel Z-NPC topology and PWM control methods are verified by the obtained results of analysis and simulations performed in the PSCAD software.
