A phase-shifting control for variable frequency multi-cells interleaved boost pre-regulator based on FPGA device

In this paper were investigated phase-shift control strategies applied to a four cells interleaved high input-power-factor pre-regulator boost rectifier, operating in critical conduction mode, using a non-dissipative commutation cells and frequency modulation. The digital control has been developed using a hardware description language (VHDL) and implemented using the XC2S200E-SpartanII-E/Xilinx FPGA, performing a true critical conduction operation mode for a generic number of interleaved cells. Experimental results are presented, in order to verify the feasibility and performance of the proposed digital control, through the use of a Xilinx FPGA device.

Bridgeless interleaved boost PFC converter with variable duty cycle control

This paper proposes a bridgeless boost interleaved PFC (power factor correction) converter with variable duty cycle control. The application of bridgeless technique causes reduction of conduction losses, while the interleaving technique of converters cells allows division of efforts in semiconductor devices and reduction of weight and volume of the input EMI filter. The use of variable duty cycle control has the functions of regulating the output voltage and eliminating the low order harmonic components that appears in the input current of the common interleaved power factor converters working in Discontinuous Conduction Mode (DCM). The simulation results of the proposed converter presented high power factor and a good transient response in relation to the output voltage regulation in presence of high load variations and supply voltage variations. © 2011 IEEE.

Experimental evaluation of the bridgeless interleaved boost PFC converter

This paper presents theoretical evaluation and experimental results to the proposed bridgeless interleaved boost PFC (power factor correction) converter. The application of bridgeless technique causes reduction of conduction losses, while the interleaving technique of the converter cells allows division of the current stress in semiconductor devices and reduction of weight and volume of the input EMI filter. In each cell of the converter, the inductor current operates in discontinuous conduction mode (DCM), which eliminates turn-on switching losses and the effects of reverse recovery in semiconductors, increasing the efficiency of the converter. The experimental results show the power factor of 0.96 for employed voltage ratio and an efficiency of 95.2 % for nominal load conditions. © 2012 IEEE.

Design and implementation of a synchronous interleaved boost converter for fuel cell-powered catamaran

The present work describes the different stages of design, implementation, and validation procedures for an interleaved DC-DC boost converter intended for the 2022 Futura, a fuel cell-powered racing catamaran developed by the UniBoAT team. The main goal of the entire design has been the significant reduction of the weight of the converter by removing heat sinks and reducing component size while increasing its efficiency by adopting high-end power switches and the interleaved architecture operated with a synchronous control strategy. The obtained converter has been integrated into the structure containing the fuel cell stack obtaining a fully integrated system. The realized device has been based on an interleaved architecture with six phases controlled digitally through the average current mode control. The design has been validated through simulations carried out using the software LT-Spice, whereas experimental validations have been performed by means of laboratory bench tests and on-field tests. Detailed thermal and efficiency analyses are provided with the bench tests under the two synchronous and non-synchronous operating modes and with the adoption of the phase shedding technique. The prototype implementation and its performance in real operating conditions are also discussed. Eventually, it is underlined as the designed converter can be used in other applications requiring a voltage-controlled boost converter.

Retificador entrelaçado boost, no modo de condução descontínua, com técnica de correção da corrente de entrada e elevado fator de potência, para aplicação em sistema trólebus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Trolleybus power system for operation with AC or DC distribution networks

This paper presents the development and experimental analysis of a special input stage converter for a Trolleybus type vehicle allowing its operation in AC (two wires, single-phase) or DC distribution networks. The architecture of proposed input stage converter is composed by five interleaved boost rectifiers operating in discontinuous conduction mode. Furthermore, due to the power lines characteristics, the proposed input power structure can act as AC to DC or as DC to DC converter providing a proper DC output voltage range required to the DC bus. When operation is AC to DC, the converter is capable to provide high power factor with reduced harmonic distortion for the input current, complying with the restrictions imposed by IEC 61000-3-4 standard. Finally, the main experimental results are presented in order to verify the feasibility of the proposed converter, demonstrating the benefits and the possibility for AC feeding system for trolleybus type vehicle. © 2010 IEEE.

Mini-inversores para aproveitamento de energia fotovoltaica, com técnicas de MPPT, sincronismo e conexão com a rede de CA em BT, proteção de ilhamento, gerenciamento da energia e da operação

Pós-graduação em Engenharia Elétrica - FEIS

Retificador entrelaçado com elevado fator de potência para operação de um veículo trólebus alimentado por redes em CA Ou CC

This paper presents the development and the main results for an interleaved boost rectifier operating as a special input power stage for a trolleybus type vehicle, allowing its feeding by alternate current (AC) or direct current (DC) distribution power systems. When feeding with two wires (single phase) alternate current distribution system, the converter accomplish active power factor correction, providing a relatively sinusoidal current with low total harmonic distortion (THD) and fully complying with IEC 61000-3-4 standards. In addition, a management control system promotes the required automatic operation changes for the proposed rectifier when the vehicle is changing from the DC distribution power system to the AC distribution power system and vice-versa, keeping its original electrical DC system characteristics for the adjustable speed driver sub-system. The main experimental results for a prototype rated at 150kW are presented, considering its application for a trolleybus with DC adjustable speed driver, demonstrating the proposed converter benefits and the possibility of AC feeding system for trolleybus type vehicle.

A 2kW interleaved ZCS-FM boost rectifier digitally controlled by FPGA device

This paper presents a 2kW single-phase high power factor boost rectifier with four cells in interleave connection, operating in critical conduction mode, and employing a soft-switching technique, controlled by Field Programmable Gate Array (FPGA). The soft-switching technique Is based on zero-current-switching (ZCS) cells, providing ZC (zero-current) turn-on and ZCZV (zero-current-zero-voltage) turn-off for the active switches, and ZV (zero-voltage) turn-on and ZC (zero-current) turn-off for the boost diodes. The disadvantages related 'to reverse recovery effects of boost diodes operated in continuous conduction mode (additional losses, and electromagnetic interference (EMI) problems) are minimized, due to the operation in critical conduction mode. In addition, due to the Interleaving technique, the rectifer's features include the reduction in the input current ripple, the reduction in the output voltage ripple, the use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) In the input current, in compliance with the TEC61000-3-2 standards. The digital controller has been developed using a hardware description language (VHDL) and implemented using a XC2S200E-SpartanII-E/Xilinx FPGA device, performing a true critical conduction operation mode for four interleaved cells, and a closed-loop to provide the output voltage regulation, like as a pre-regulator rectifier. Experimental results are presented for a 2kW implemented prototype with four interleaved cells, 400V nominal output voltage and 220V(rms) nominal input voltage, in order to verify the feasibility and performance of the proposed digital control through the use of a FPGA device.

DCM Boost interleaved converter for operation in AC and DC to trolleybus application

This paper is based on the development and experimental analysis of a DCM Boost interleaved converter suitable for application in traction systems of electrical vehicles pulled by electrical motors (Trolleybus), which are powered by urban DC or AC distribution networks. This front-end structure is capable of providing significant improvements in trolleybuses systems and in the urban distribution network costs, and efficiency. The architecture of proposed converter is composed by five boost power cells in interleaving connection, operating in discontinuous conduction mode. Furthermore, the converter can operate as AC-DC converter, or as DC-DC converter providing the proper DC output voltage range required by DC or AC adjustable speed drivers. Therefore, when supplied by single-phase AC distribution networks, and operating as AC-DC converter, it is capable to provide high power factor, reduced harmonic distortion in the input current, complying with the restrictions imposed by the IEC 61000-3-4 standards. The digital controller has been implemented using a low cost FPGA and developed totally using a hardware description language VHDL and fixed point arithmetic. Thus, two control strategies are evaluated considering the compliance with input current restrictions imposed by IEC 61000-3-4 standards, the regular PWM modulation and a current correction PWM modulation. In order to verify the feasibility and performance of the proposed system, experimental results from a 15 kW low power scale prototype are presented, operating in DC and AC conditions.

A multi-cell variable frequency interleaved ZCS boost rectifier digitally controlled by FPGA

This paper presents a multi-cell single-phase high power factor boost rectifier in interleave connection, operating in critical conduction mode, employing a soft-switching technique, and controlled by Field Programmable Gate Array (FPGA). The soft-switching technique is based on zero-current-switching (ZCS) cells, providing ZC (zero-current) turn-on and ZCZV (zero-current-zero-voltage) turn-off for the active switches, and ZV (zero-vohage) turn-on and ZC (zero-current) turn-off for the boost diodes. The disadvantages related to reverse recovery effects of boost diodes operated in continuous conduction mode (additional losses, and electromagnetic interference (EMI) problems) are minimized, due to the operation in critical conduction mode. In addition, due to the interleaving technique, the rectifier's features include the reduction in the input current ripple, the reduction in the output voltage ripple, the use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) in the input current, in compliance with the IEC61000-3-2 standards. The digital controller has been developed using a hardware description language (VHDL) and implemented using a XC2S200E-SpartanII-E/Xilinx FPGA device, performing a true critical conduction operation mode for all interleaved cells, and a closed-loop to provide the output voltage regulation, like as a preregulator rectifier. Experimental results are presented for a implemented prototype with two and with four interleaved cells, 400V nominal output voltage and 220V(rms) nominal input voltage, in order to verify the feasibility and performance of the proposed digital control through the use of a FPGA device.

Modeling of pre-regulator boost ZCS interleaved operating in critical conduction mode and with high power factor

This paper presents a new pre-regulator boost operating in the boundary area between the continuous and discontinuous conduction modes of the boost inductor current, where the switches and boost diode performing zero-current commutations during its turn-off, eliminating the disadvantages related to the reverse recovery losses and electromagnetic interference problems of the boost diode when operating in the continuous conduction mode. Additionally, the interleaving technique is applied in the power cell, providing a significant input current ripple reduction. It should be noticed that the main objective of this paper is to present a complete modeling for the converter operating in the critical conduction mode, allowing an improved design procedure for interleaved techniques with high input power factor, a complete dynamic analysis of the structure, and the possibility of implementing digital control techniques in closed loop.

HPF boost interleaved operating in discontinuous conduction mode for trolleybus application

This paper deals with results of a research and development (R&D) project in cooperation with Electric Power Distribution Company in São Paulo (Brazil) regarding the development and experimental analysis of a new concept of power drive system suitable for application in traction systems of electrical vehicles pulled by electrical motors, which can be powered by urban DC or AC distribution networks. The proposed front-end structure is composed by five boost power cells in interleaving connection, operating in discontinuous conduction mode as AC-DC converter, or as DC-DC converter, in order to provide the proper DC output voltage range required by DC or AC adjustable speed drivers. Therefore, when supplied by single-phase AC distribution networks, and operating as AC-DC converter, it is capable to provide high power factor, reduced harmonic distortion in the input current, complying with the restrictions imposed by the IEC 61000-3-4 standards resulting in significant improvements for the trolleybuses systems efficiency and for the urban distribution network costs. Considering the compliance with input current restrictions imposed by IEC 61000-3-4 standards, two digital control strategies were evaluated. The digital controller has been implemented using a low cost FPGA (XC3S200) and developed totally using a hardware description language VHDL and fixed point arithmetic. Experimental results from a 15 kW low power scale prototype operating in DC and AC conditions are presented, in order to verify the feasibility and performance of the proposed system. © 2009 IEEE.

Pré-regulador retificador entrelaçado (Interleaved) ZCS-FM boost, com controle digital através de dispositivo FPGA e linguagem VHDL

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A novel architecture of a bidirectional bridgeless interleaved converter for EV battery chargers

This paper presents a novel architecture of a bidirectional bridgeless interleaved converter for battery chargers of electric vehicles (EVs). The proposed converter is composed by two power stages: an ac-dc converter that is used to interface the power grid and the dc-link, and a dc-dc converter that is used to interface the dc-link and the batteries. The ac-dc converter is an interleaved bridgeless bidirectional boost-type converter and the dc-dc converter is a bidirectional buck-boost-type converter. The proposed converter works with sinusoidal grid current and with high power factor for all operating power levels, and in both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operation modes. In the paper is described in detail the proposed converter for EV battery chargers: the circuit topology, the principle of operation, the power control theory, and the current control strategy. Several simulation results for both G2V and V2G operation modes are presented.