In this study, a simple auxiliary circuit is proposed and investigated to provide soft-switching operation in the boost converter. The proposed auxiliary circuit includes only a small auxiliary inductor and two auxiliary capacitors. In... more
In this study, a simple auxiliary circuit is proposed and investigated to provide soft-switching operation in the boost converter. The proposed auxiliary circuit includes only a small auxiliary inductor and two auxiliary capacitors. In this structure, by implementing the auxiliary inductor, a negative current flows through the power switch before its turn-on moment. Therefore, the power switch turns on under zero voltage switching condition. In addition, by properly designing the parallel capacitor of the power switch, a soft-switching condition can be achieved for its turn-off. Furthermore, implementing this simple auxiliary circuit can be helpful to decrease the reverse recovery losses of the diode since the diode turns off under zero current switching condition. Another advantage of the proposed structure is its zero input current ripple. In this study, the performance of the proposed auxiliary circuit with conventional boost converter has been analysed, and designing the methodo...
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In this article, a soft-switched structure for the synchronous buck converters is proposed and analyzed. In this structure, by adding an LC circuit to the synchronous buck converter, soft-switching condition performance is obtained. Both... more
In this article, a soft-switched structure for the synchronous buck converters is proposed and analyzed. In this structure, by adding an LC circuit to the synchronous buck converter, soft-switching condition performance is obtained. Both the main and synchronous power switches turn on and turn off under ZVS condition. Therefore, the switching losses are eliminated completely and high power efficiencies can be obtained by implementing the proposed converter. In this article, the proposed structure and its operational modes are investigated in details. The proposed converter is compared with other soft-switched synchronous converters and the results are investigated comprehensively. The efficiency of the proposed converter is obtained and compared to the hard-switched converter. In addition, in order to validate the desired operation of the proposed structure, a 200W sample of this converter is simulated in the PSCAD software and the achieved results are analyzed in details.
In this paper, an interleaved high voltage-gain DC-DC converter is proposed and analyzed. Low voltage-stress on semiconductors and low input current-ripple are the main features of this converter. Due to the mentioned features, this... more
In this paper, an interleaved high voltage-gain DC-DC converter is proposed and analyzed. Low voltage-stress on semiconductors and low input current-ripple are the main features of this converter. Due to the mentioned features, this converter can be a suitable choice for renewable energy applications. In this structure, a voltage multiplier cell and two output capacitors are implemented to increase the voltage gain. Furthermore, in order to decrease the input current-ripple, two inductors are paralleled in the input side. In this paper, in the steady state analysis, the voltage gain and the voltage stresses across the power semiconductors have been calculated. In addition, the input current-ripple analysis has been presented. Also, the proposed converter has been compared with some related structures. Finally, to prove the theoretical calculations, this converter is simulated in PSCAD/EMTDC software and the results have been investigated.
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Partial shading condition is an unavoidable issue for photovoltaic systems. This condition affects the performance of the photovoltaic systems. An important effect of the partial shading condition is causing power losses and reducing the... more
Partial shading condition is an unavoidable issue for photovoltaic systems. This condition affects the performance of the photovoltaic systems. An important effect of the partial shading condition is causing power losses and reducing the power efficiency. In this paper, different array structures with different types of connections between the photovoltaic modules have been investigated. Series-Parallel (SP), Total-Cross-Tied (TCT), Bridged-Linked (BL), and Honey-Comb (HC) and hybrid connection such as BL-TCT, HC-TCT, and SP-TCT have been presented and investigated. In order to analyze the mentioned structures, a 4*4 photovoltaic array including 16 photovoltaic modules under partial shading condition has been tested in MATLAB / Simulink environment. In these analysis, the performance of different structures has been investigated to reach the maximum power. The simulation results show the excellent performance of the TCT structure in extracting the maximum power from the photovoltaic...
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In this paper a high voltage-gain interleaved structure for DC-DC converters is proposed. This structure provides high voltage-gain with reasonable number of elements and low voltage-stress range. Also continuous input current and low... more
In this paper a high voltage-gain interleaved structure for DC-DC converters is proposed. This structure provides high voltage-gain with reasonable number of elements and low voltage-stress range. Also continuous input current and low current ripple are other advantages of this structure. These features make this converter suitable to use in renewable energy sources. In this paper, proposed converter is analyzed completely and all relations in different modes will be achieved. In order to realize improvement in this converter, proposed converter will be compared with related structures.
In this paper a high step up non isolated DC-DC converter with extendable topology is proposed. This converter is symmetric and by using this structure it can be possible to achieve high voltage gain in low duty cycle range. This... more
In this paper a high step up non isolated DC-DC converter with extendable topology is proposed. This converter is symmetric and by using this structure it can be possible to achieve high voltage gain in low duty cycle range. This converter consists of m + n+ 2 Active Passive Inductor Cell (APIC) and a Voltage Multiplier Cell (VMC). In addition to increasing voltage gain, the VMC decreases voltage stress on the switches and diodes. Operational modes and steady state analysis of proposed converter will be discussed completely, also voltage gain and voltage stress on the switches and diodes will be formulated. Different components will be designed for example output capacitor will be designed in order to decrease output voltage ripple. Voltage gain and voltage stress on the switches will be compared with related structure to illustrate advantages of proposed converter. In order to verify theoretical analysis of proposed converter will be simulated in PSCAD and results of this simulatio...
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In this paper, direct control of predictive power for three-phase rectifier using pulse width modulation is presented. For this purpose, direct power control is based on strategy of predictive control to achieve simultaneous control of... more
In this paper, direct control of predictive power for three-phase rectifier using pulse width modulation is presented. For this purpose, direct power control is based on strategy of predictive control to achieve simultaneous control of active & reactive power of converter. To achieve this goal at the beginning of each period the switching average voltage vector of the rectifier which makes possible to zero the error of active& reactive power tracking. Also, at the end of the switching period voltage vectors are calculated by the predictive control algorithm based on the deadbeat control method. As a result, with usage of PWM, the pulses which are required for the rectifier switches are produced.
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In this paper, a new high step-up three-port structure using one PV panel and a battery as a storage element is proposed. In this proposed structure, three power switches, one single inductor and one coupled inductor are used. The gain of... more
In this paper, a new high step-up three-port structure using one PV panel and a battery as a storage element is proposed. In this proposed structure, three power switches, one single inductor and one coupled inductor are used. The gain of voltage for the presented topology is higher than conventional three-port converters which is referred in this paper. Using one unidirectional and one bidirectional inputs develop the proposed topology as a compatible candidate for hybrid power system. Controlling state of charge (SOC) for battery, and regulating the voltage of output can be achieved by adjusting duty cycles of switches. Also, the capability of supplying the load and either charging or discharging of the storage element is provided by input source. In addition, the capability of supplying the load without PV source is provided by battery. The analysis of steady-state condition in the proposed converter is discussed completely. Finally, the validity of the presented structure is ver...
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In this article, a high step-up DC-DC converter based on DCL (Diode-Capacitor-Inductor) stages is introduced and explored. The first advantage of this topology is that the utilized DCL stages can be extended according to the required... more
In this article, a high step-up DC-DC converter based on DCL (Diode-Capacitor-Inductor) stages is introduced and explored. The first advantage of this topology is that the utilized DCL stages can be extended according to the required voltage gain. In addition, the voltage stress across the power switches and power diodes is low, which is another advantage of this structure. Considering these features, the proposed structure is applicable in renewable energy conversion systems. In this paper, a two-DCL-stage topology is garnered to increase the voltage gain. The voltage gain and voltage stress across the utilized components are calculated. In order to analyze the reliability of the proposed converter, the loss calculation and the effective parameters on the failure rates of the components are investigated. Also, a comparison of the introduced structure and some similar topologies is accomplished in order to prove its advantages. Finally, this converter is modelled in PSCAD/EMTDC simulation environment for 400W output power, to validate the theoretical computations, and the results are mentioned and analyzed in detail.
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In this article, a new boost converter with zero-voltage switching capability has been introduced. In this structure, only by adding an auxiliary inductor to the conventional boost converter and splitting the output capacitor, the desired... more
In this article, a new boost converter with zero-voltage switching capability has been introduced. In this structure, only by adding an auxiliary inductor to the conventional boost converter and splitting the output capacitor, the desired soft-switching condition is provided. The main advantages of this structure are its simplicity and ZVS performance of the semiconductors. The ZVS turn-on of the switch has been achieved within the DCM operation of the applied auxiliary inductor. Meanwhile, the ZVS turn-off of the power switch is obtained by charging process of the switch’s parallel capacitor. In addition, the power diode turns off with zero-current switching condition. In this paper, the voltage gain, voltage stress across the semiconductors, and the efficiency analysis of the converter have been investigated in the steady state analysis. Also, the comparison results of this structure and other similar topologies have been mentioned. Finally, a simulation of this structure has been implemented in PSCAD/EMTDC software, and the simulation waveforms of the semiconductors have been obtained and comprehensively illustrated to prove the theoretical calculations.