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EPE Journal Volume 18-2 - Papers
- A New Method to Obtain I-V Characteristics Curves of Photovoltaic Modules Based on SEPIC and Cuk Converters
- Novel Carrier-Based PWM Methods for Multi-level Inverters
- Active-Clamping Single-Stage AC-DC Converter with the Input Current Shaper Charged in the Duty-Off Time
- Input-Output Feedback Linearization Control of Induction Motor with Adaptive Backstepping Observer
- A Neuro-Based Classification Algorithm for Implementation of Space Vector Modulation for Multi-Level Converters
EPE Journal Volume 18-2 - Editorial
By Joan Peracaula, Enrique Dede
On behalf of the Executive Council of EPE, the European Power Electronics and Drives Association, and the Conference Organising Committee, it is our honour to invite the whole power electronics community to the 13th Power Electronics and Applications Conference, EPE 2009, to be held in Barcelona, Spain, from September 8 to September 10, 2009.
EPE Journal Volume 18-2 - Papers
By E. Durán, J. Galán, J.M. Andújar, M. Sidrach-de-Cardona
The basic operation of a solar cell, module or photovoltaic generator under different irradiation and temperature conditions is characterized by its I-V characteristic curve. Only the experimental measurement of the I-V curve allows us to know with precision the electrical parameters of a photovoltaic cell, module or array. This measure provides very relevant information for the design, installation and maintenance of photovoltaic systems. Currently, the I-V characteristic curve is obtained by connecting a variable charge to the panel terminals in order to achieve that the current of the terminals ranges from zero to the short circuit current. In this paper we propose a new experimental way to measure this characteristic curve by using Buck-Boost-Derived DC-DC converters. It has been proved that the optimal topologies for this purpose are the SEPIC (Single-Ended Primary Inductance Converter) and Cuk converters. The theoretical analysis performed has been validated by means of simulation and experimentally. Additionally, a comparison between three known conventional methods and the proposed one is provided.
By A. Radan, A. H. Shahirinia
Carrier-based methods have been used widely for the switching of multilevel inverters due to their simplicity, flexibility and reduced computational requirements compared to Space Vector Modulation (SVM). Several multi-carrier modulation methods with miscellaneous properties have been already known. The paper proposes three novel multi-carrier techniques being more efficient for high-power inverter applications. While evaluating and comparing these new with all classical methods through measures like THD,WTHD, WTHD0, switching losses and DC bus utilization, the paper shows their advantges for applications of Diode-clamped and Cascade multi-level topologies by simulation results. The validity of obtained results is approved by experimental results.
By Lon-Kou Chang, Yen-Ming Liu
Single-stage a.c.-d.c. converters employing boost-type input current shapers (ICS) usually suffer from relatively high switch current stress and line current waveform distortion caused by the voltage-follower control. To remedy these drawbacks, this paper presents a novel single-stage soft-switching a.c.-d.c. converter. Unlike the conventional single-stage designs, the proposed ICS scheme is intentionally arranged to be charged in the duty-off time. With this design, the switch current stress in the duty-on time is greatly reduced. Moreover, this design produces a.c. modulation effect on the charging time of the ICS so that the waveforms of the average charging current and discharging current of the boost inductor can compensate each other automatically. Consequently, the input i-v curve has nearly linear relationship. In the proposed topology, an auxiliary transformer winding is employed to achieve the above functions. By programming the turns ratio between the auxiliary and secondary windings, the proposed converter can be guaranteed to comply with the IEC 1000-3-2 Class D specifications at as high efficiency as possible. Experimental results, obtained from a prototype circuit with universal line input and 48 V/100 W output, are given to confirm the predicted performance.
By G. R. Arab Markadeh, R. Yazdanpanah, J. Soltani
This paper presents a direct-torque control and stator flux control scheme for a three-phase Induction motor which is supplied by a Field Programmable Gate Array (FPGA)-based two level Space Vector Modulation (SVM) voltage-source inverter. Using the three-phase Induction Motor (IM) model in a stationary (a, b) axis reference frame with stator currents and stator flux as state variables, an Ideal Feedback Linearization Control (IFLC) is first adopted to decouple the motor generated torque and the norm of stator flux. Then in order to increase the robustness of the drive system control against the motor resistance variations and uncertainties, an adaptive backstepping observer is designed that provides the simultaneous estimation of the above parameters and stator flux. Using the Lyapunov theory, a full proof for convergence of states is presented together with stability proof for the parameter estimates. Finally, the effectiveness and validity of the proposed control approach is demonstrated by both the simulated and experimental results.
By Maryam Saeedifard, Hamidreza Saligheh Rad, Alireza Bakhshai, Reza Iravani
This paper proposes a novel, simple and fast classification algorithm for implementation of Space Vector Modulation (SVM) method for a multi-level Diode Clamped Converter (DCC) with any number of levels. The proposed algorithm is based on a classifier neural network. The proposed algorithm provides a straightforward and computationally efficient approach without the use of trigonometric calculations or look-up tables to identify the location of reference voltage vector, its adjacent switching voltage vectors, and their corresponding on-duration time intervals. The feasibility of the proposed SVM algorithm is validated based on theoretical analysis, simulation studies and experimental tests on a DSP-controlled, 5 kVA, three-level DCC system.