Conventional Half-bridge Converter Research Articles

Extending the Speed Range of a Switched Reluctance Motor Using a Fast Demagnetizing Technique

In this paper, a switched reluctance motor (SRM) with phase windings similar to an autotransformer is presented. The new winding structure allows for fast demagnetization. This enhances the machine performance at high speeds. During demagnetization, the dc bus voltage is applied to a portion of the phase winding, and accordingly a higher negative demagnetization voltage/turn is applied. This results in the faster discharge of the phase excitation currents. The power electronic converter configuration is modified to facilitate the new winding topology. However, the number of switches is the same as a conventional half-bridge converter used in SRMs. The proposed SRM drive with the modified winding configuration is verified through finite element analysis based circuit simulations and experimental results.

A new topology for Z-source half-bridge inverter with low voltage stress on capacitors

In this paper, a new topology for Z-source half-bridge inverter is proposed. This topology is achieved by using LC networks in conventional half-bridge converter. The proposed inverter can produce symmetric and asymmetric voltages with different amplitudes during positive and negative half-cycles. By appropriate value of duty cycle it is possible to achieve the conventional half-bridge characteristics. Other advantage of this inverter is producing zero voltage level at output. It is noticeable that the conventional half-bridge inverter cannot generate zero voltage at the output. This inverter can be used in different applications in industry such as electrochemical, electroplating and residential applications. In this paper, the steady state analysis of the proposed inverter in different operating modes is presented. Moreover, the calculations of voltage stress of capacitors, current ripple of inductors, voltage ripple of capacitors, and power loss of the proposed inverter are presented. Then, design of proper values of inductors and capacitors is given. To show the advantages and disadvantages of the proposed topology, it is compared with some conventional topologies. The correct operation of the proposed topology is reconfirmed by simulation and experimental results.

Integrated Asymmetrical Half-Bridge Zeta (AHBZ) Converter for DC/DC Stage of LED Driver With Wide Output Voltage Range and Low Output Current

The conventional half-bridge converter for a dc/dc stage in wide-output-voltage and constant-output-current applications such as LED drivers is limited in achieving high efficiency because it is difficult to be designed optimally. To overcome this limitation, an integrated asymmetrical half-bridge zeta converter is proposed for high efficiency in the overall output voltage range. The proposed converter can be simply implemented by replacing a snubber diode with a switch. The proposed converter operates similar to the asymmetrical half-bridge converter by turning off the switch in the low-output-voltage region, which enables it to have a small dc-offset current in the transformer. In the high-output-voltage region, the proposed converter operates similar to the half-bridge zeta converter by turning on the switch, which has small transformer core loss. Therefore, the proposed converter can achieve high efficiency over the entire output voltage range compared with the conventional converters. The validity of the proposed converter is confirmed by experimental results from a prototype with 400-V input and 90–180-W/3-A output.

A novel ZVS-PWM half-bridge converter with secondary switches

This paper proposes a ZVS-PWM half-bridge converter of a novel control system with secondary switches. The present converter has two switches added in series with the rectifying diodes on the secondary side of the conventional half-bridge converter. A new type of PWM control is carried out at a fixed frequency. The main switches are turned on at zero voltage while the secondary switches are turned on and off at zero voltage and zero current. Various characteristics of this converter are clarified by the dynamic analysis and the circuit operation is verified by experiment. The fabricated converter has a high efficiency with a maximum of about 95% at a switching frequency of 100 kHz and an output voltage of 25 V. © 2000 Scripta Technica, Electron Comm Jpn Pt 1, 83(5): 90–96, 2000