Search

A single-phase voltage-doubler rectifier, which has two auxiliary bidirectional switches, is studied. The proposed rectifier has the advantages that the imbalance of the voltages across the capacitors, connected in series, is minimized independent of the working conditions and the discharge of capacitors is adjusted by arranging two auxiliary bidirectional switches. Therefore, the total capacitance of the rectifier can be reduced. The tested setup, using four insulated-gate bipolar transistors (IGBTs) and a microcomputer as a PI control-ler, is implemented and IGBTs are switched with 20kHz, which is out of audible band. Moreover, a rigorous state-space analysis is introduced to predict the operation of the rectifier. From the results, the well-balanced capacitor voltages can be achieved and the input current can be sinusoidally waveshaped with a near-unity power factor under the steady state and transient conditions even if the rectifier is operated with small series-connected capacitors. Consequently, the single-phase voltage-doubler rectifier studied is suitable for AC-DC conversion equipment with output voltage higher than twice that of the supply and with reduced total capacitance.

Single-phase buck-boost rectifier with minimized input current distortion is studied in the paper. To sinusoidally waveshape the input current with a near-unity power factor over a wide variety of operating conditions, the output capacitor is operated with voltage reversibility for the supply by arranging the auxiliary diode and power switching device. Then the output voltage is superposed on the input voltage during on-time duration of power switching devices in order to minimize the input current distortion caused by the small input voltage when changing the polarity. The tested setup, using two insulated-gate bipolar transistors (IGBTs) and a microcomputer, is implemented and IGBTs are switched with 20kHz, which is out of the audible band. Moreover, a rigorous state-space analysis is introduced to predict the operation of the rectifier. The experimental and simulated results confirm that the input current can be sinusoidally waveshaped with a near-unity power factor and a satisfactory output voltage regulation can be achieved.

To reduce the supply current distortions and low power factor operations with a conventional diode bridge rectifier connected to the utility system, a novel three-phase single-way rectifier is presented in the paper. The circuit configuration is based on the buck-boost DC-DC converter, in which AC flyback inductors play a role of the energy storage/transfer. If the simple pulsewidth modulation with uniform duty factor is introduced and if the rectifier operates in discontinuous current conduction mode, the supply currents can be sinusoidally waveshaped with a near unity power factor. Moreover, the step-up/step-down characteristics of the output voltage can easily be obtained by appropriately adjusting the duty factor of the switches. The experimental setup, employing insulated-gate bipolar transistors as the power switching devices, is implemented and the state-space method is introduced to predict the voltage and current waveforms and steady-state characteristics. The experimental and simulated results confirm the relevance of the presented circuit configuration as an useful rectifier with sinusoidal supply currents and step-up/down output voltage regulation.

A single-phase voltage-doubler rectifier using pump circuits is presented. This can be operated in the switching states for pumping action to pump twice the peak supply voltage onto the output capacitor and for forcing the input current to follow its sinusoidal reference in the vicinity of a zero crossing of the supply. The arrangement tested, using two dual-switch power modules with IGBTs and a controller for output voltage regulation, is implemented to investigate the operation. The experimental results confirm that the input current can be waveshaped sinusoidally with a near-unity power factor under the output voltage duplication.

A novel switch-mode voltage-doubler rectifier derived from the half-bridge configuration using diodes is studied. This has an advantage that an only power switching device can provide the necessary control over the current. The arrangement tested, using an insulated-gate bipolar transistor and a controller for output voltage, is implemented to investigate the input current waveshaping. The experimental results confirm that the input current can be waveshaped sinusoidally with a near-unity power factor under the output voltage duplication.

To provide a thyristor rectifier with pulsewidth modulated operations and zero-voltage and/or zero-current switchings, two resonant switches, which consist of LC resonant circuit plus other switching devices and diodes, are connected with a thyristor bridge in series and in parallel. The arrangement tested, using four insulated-gate bipolar transistors, is implemented to investigate the operations under the sinusoidal pulsewidth modulation. The experimental results confirm that AC current can be sinusoidally waveshaped with reduced harmonic distortion.

A novel switch-mode single-phase voltage-doubler rectifier, which is not based on the half-bridge topologies, is presented. The boost capacitors are symmetrically arranged to obtain the good current regulation and the voltage across the boost capacitor adds to the supply to pump twice the peak supply voltage onto the output capacitor. The arrangement tested, using three insulated-gate bipolar transistors (IGBTs) and a microcomputer as a PID controller, is implemented and IGBTs are switched at 20kHz, which is out of the audible band. The experimental results confirm that the input current can be sinusoidally waveshaped with near-unity power factor.

The paper presents a novel single-phase rectifier with step-up/down characteristics. This is fundamentally based on the cascade combination of a diode bridge and a single-ended primary inductor convertor. To sinusoidally waveshape the supply current with a near-unity power factor independent of the working conditions, buffer capacitor is operated with voltage reversibility for the supply by arranging the auxiliary power switching device and diode. The circuit operation is macroscopically analysed by state-space averaging method based on a DC equivalent circuit and such an operation is also simulated by rigorous state-space method. Moreover, the tested setup, using two insulated-gate bipolar transistors and a 16-bit microcomputer, is implemented to experimentally investigate the steady-state and transient characteristics. The experimental and simulated results confirm the usefulness of the rectifier presented.