Khairul Safuan Muhammad

ZCS Bridgeless Boost PFC Rectifier Using Only Two Active Switches

Existing bridgeless boost (BLB) converter with soft switching utilize more than two active switches and extra resonant networks. In this paper, a new zero-current-switching BLB rectifier with high power factor (PF) using only two active switches is proposed. The proposed BLB converter is based on a totem-pole BLB (TPBLB) configuration, which allows the current to flow from high side to low side and vice versa during resonance. Hence, no auxiliary active switch is needed to provide soft switching for all semiconductor devices. The soft switching also reduces the body diode reverse recovery problem, hence allowing the TPBLB to operate in continuous conduction mode. Standard components are used to prove that the proposed converter is working with an acceptable performance compared with other BLB converters with soft switching. In order to achieve smooth input current waveform, high PF, and wide soft-switching operations, a pulsewidth modulation controller is proposed and developed, which combines a conventional PF correction average current mode controller with several logic gates and a phase detector. A detailed analysis of the converter operation and control is presented. Design considerations and parameter values calculations are given. An experimental prototype is developed and tested to verify the converter performance.

Magnetically Isolated Gate Driver With Leakage Inductance Immunity

This letter presents the design of a magnetically isolated gate driver with high immunity to leakage inductance. The proposed gate driver (PGD) is developed based on a bipolar totem-pole gate driver (noninverting) located on the secondary side of the coupling transformer. It is able to drive a MOSFET/IGBT from standard CMOS to TTL output and down to LSTTL level. It also achieves large duty cycle ratio and small input to output delay and provides reliable isolation. In this letter, the PGD is analyzed and verified experimentally. The design guidelines are also provided including design considerations.

Digital Control of High DC Voltage Converter Based on Cockcroft Walton Voltage Multiplier Circuit

A new method of controlling high DC voltage based on Cockcroft Walton voltage multiplier circuit by using digital controller is presented. The digital controller is developed using complex programmable logic devices (CPLD). The proposed system utilizes a single-phase AC as an input supply. The power switching devices in the controlled bridge are controlled by the multiple-pulse pulse width modulation (PWM) switching technique so as to minimize the low order harmonic present on the AC side of the converter system. A low pass filter is incorporated in the circuit to filter out unwanted harmonics and to give a sinusoidal AC current. A high frequency transformer with 1:1 ratio is incorporated in the design to provide galvanic isolation for better circuit performance and protection. The optimum operation of transformer core in four quadrant of B-H curve is also considered in the proposed converter topology. The laboratory model of the converter is developed and tested. The experimental result is compared with the simulation result.

An improved topology of digitally-controlled single-phase single-stage high DC voltage converter

This paper presents An improved topology of digitally-controlled single-phase single-stage high dc voltage converter where CPLD is used to develop the PWM switching pattern which will be discussed in detail. The proposed system utilizes a single-phase AC input supply. The power switching devices in the controlled bridge are controlled by the multiple-pulse Pulse Width Modulation (PWM) switching technique to minimize the low order harmonics present on the AC side of the converter. A low pass filter is incorporated in the circuit to filter out unwanted harmonics and provide a sinusoidal AC supply current. A high frequency transformer with 1:1 ratio is used in the design to provide galvanic isolation for better circuit performance and protection. The optimum operation of transformer core in four quadrant of B-H curve is also considered in the proposed converter topology. A laboratory prototype of the converter is developed and tested. Experimental results are compared with the simulation results to illustrate the effectiveness of the proposed technique.

Single-phase single-stage high DC voltage multiple converter

This paper proposed a single-phase single-stage high DC voltage multiplier converter. The conversion of high DC voltage converter without a DC-link is involved. A high frequency transformer using ETD 59 ferrite core with ratio 1:1 is used as energy storage and also providing isolation. Cockcroft-Walton circuit is connected at secondary side of the transformer. AC input is controlled by IGBT switch which the current flow in both directions of the transformer to fully utilize the transformer core. The current flow is controlled by the IGBTs using PWM technique. Experimental and simulation results are provided to show the effectives of the proposed technique

Single-phase single-stage ZCS boost PFC rectifier with reduced switch count

In this paper, a new single-phase single-stage ZCS PFC boost rectifier with reduced switch count is introduced. The efficiency of the proposed converter is improved by eliminating input stage diode-bridge. Moreover, only two active switches are used to permit bi-directional current flow from high-voltage-rail to low-voltage-rail and vice versa. Hence, no auxiliary switch is needed. A resonant inductor and a capacitor are used to make both switches operate at ZCS turn-off and soft turn-on. The proposed converter is developed by using totem-pole bridgeless boost (TPBLB) converter. Standard components are used to prove that the proposed converter is working with acceptable performance compared to other bridgeless boost converters with soft-switching. In addition, a PWM controller is proposed, which combines a conventional average-current-mode power factor correction (PFC) controller, several logic-gates and a phase detector. A detailed analysis of the converter operation and control is supported by simulation results. Finally, a 400 W, 50 kHz experimental prototype is built to verify the theoretical analysis and performance of the proposed converter.

A high power factor three-phase AC-DC current injection hybrid resonant converter

This paper proposes a new circuit topology of threephase AC to DC that is use current injection technique based on the series-parallel (hybrid) circuit configuration of resonant converter. Thus, the features such as shaping the sinusoidal line current waveforms with improving power-factor resulting in low total harmonics distortion (THD) are achieved. This is implemented by employing the resonant conversion technique, involving two active soft switches that generate high frequency currents. The latter are in turn injected into the junction of input three-phase rectifier, leading to frequency modulation of the supply voltages. The principle operation of the hybrid current injection topology is explained in details, complete with its steady state analysis. Such analysis is used to generate the converter characteristics. Design considerations and parameter values calculations are also presented. The feasibility of the converter is verified through a detailed MATLAB/Simulink software and laboratory test-rig results.

Open-circuit fault tolerant bridgeless boost rectifier

In this paper, a bridgeless boost rectifier with open circuit fault tolerant capability is proposed. The proposed converter is based on a H-bridge rectifier configuration. It possesses a redundancy feature such that only two out of four switches require to be functional to ensure the continuity of the converter operation with power factor correction (PFC). A detailed analysis of the converter operation under all open circuit faults of the switches are presented. In order to achieve smooth input current waveform, a PWM controller is proposed and developed which combines a conventional average current mode PFC controller with several logic gates and a phase detector. An experimental prototype is developed and tested to verify the converter performance.

Impact of switching frequency variation to the power transfer efficiency of wireless power transfer converter

This paper presents the impact of the switching frequency variation to the power transfer efficiency of a wireless power transfer converter. An experimental demonstrator is used to as a model for this study. The transmitter use Wurth Elektronik wireless power charging coils, 24μH, 10%, which is installed across the output of high frequency half-bridge inverter. The switching frequency is varied from 10kHz in steps of 10kHz until 100kHz. The distance between the coils is fixed at 10mm. The receiving coil is fed with a high frequency full-bridge rectifier and a DC load. Experimental results show that the power transfer efficiency varies when the switching frequency is increased. The power transfer efficiency reached its peak at 72% when the switching frequency is at 30kHz.

Flexible absolute circuit for advanced power factor correction controller

In this paper, a flexible absolute circuit of advanced power factor correction (PFC) control for a bridgeless boost converter is proposed. The proposed circuit are able to eliminate the diode-bridge short-circuit problem if negative sensing signal is required by the power factor correction (PFC) controller. The polarity of the absolute circuit output could be changed just by reversing the polarity of the diodes. In addition, it is also has high input impedance. The proposed circuit could also be applied to other converters that uses hall effect sensor as the current sensing devices. Detailed analysis and design guidelines based on well-known PFC controller, UC3854AN are given.