C.Y. Inaba

High frequency PWM boost chopper-fed DC-DC converters with coupled-inductors

In this paper, an advanced two quadrant PWM chopper type DC-DC converter with high boost voltage ratio using coupled inductors and low switch peak voltage stress is proposed for new type parallel processing UPS applications in addition to new energy interface systems. Moreover, a soft switching boost chopper-fed DC-DC converter with high step-up voltage conversion ratio is also proposed. These two boost chopper circuit topologies are evaluated and compared on the basis of simulation and experimental results.

Three phase soft switching inverter with pulse current transformer-assisted resonant snubbers

In this paper, a high frequency pulse current transformer-assisted auxiliary active resonant commutation snubber (HFTA-ARCS) for voltage source power conversion is proposed. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce the current rating of the auxiliary active power switches and simplified sensorless control scheme without the specified boost current management required for soft switching. Its operating principle and digital control scheme are described and a practical design method of circuit parameters on this HFTA-ARCS circuit is also introduced on the basis of computer simulation results. Moreover, this space vector modulated soft switching inverter system with DSP-based digital control scheme is discussed on the basis of performance evaluations. The effectiveness of this inverter is proved by simulation results and this inverter system is also compared with the conventional three-phase hard switching inverter under the conditions of specified parameters.

Soft switching PWM DC-DC flyback converter with transformer - assisted pulse current regenerative passive resonant snubbers

In this paper, a two-switch high frequency fly back transformer linked zero voltage soft switching PWM DC-DC power converter implemented in distributed power conditioning supplies is proposed. This DC-DC power converter circuit is mainly composed of two active power switches and a fly back high-frequency transformer. In addition to this, two passive loss less resonant snubbers with pulse current regeneration loops for energy recovery, consisting of a three winding auxiliary high-frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this DC-DC power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and discussed here into. To determine circuit parameters, some practical design considerations are discussed. Moreover, the effectiveness of the proposed soft switching PWM DC-DC power converter is evaluated and compared with its equivalent hard switching PWM power DC-DC converter from an experimental point of view.

Practical design procedure of resonant snubber with current transformer and performance evaluations of a digitally controlled three phase soft switching inverter

In this paper, a high frequency transformer-assisted auxiliary active resonant commutation snubber (HFTA-ARCS) for voltage source soft switching pulse width modulated power conversion and inversion circuits using IGBTs is presented. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce current rating of auxiliary active power switches and has simplified sensorless control scheme for which specified boost current management for soft switching is not required. Its operation principle and digital control scheme are described and a practical design method of circuit parameters on this HFTA-ARCS circuit is also introduced on the basis of computer simulation. Moreover, this space vector modulated soft switching inverter system with DSP-based digital control scheme is discussed on the basis of performance evaluations. The effectiveness of this inverter is proved by simulation results. The operating performances of this inverter system are compared with those of conventional three-phase hard switching inverter under practical conditions of specified parameters.

High frequency transformer-assisted passive soft switching PWM DC-DC converter with energy recovery for compact auxiliary power supply in rolling stock transportation

In this paper, a two-switch high frequency flyback type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition to these, two passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC-DC converter from an experimental point of view.

Passive resonant snubber-assisted two-switch flyback converter with auxiliary pulse transformer for energy recovery

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented in distributed power conditioning supplies is proposed. This DC-DC power converter circuit is mainly composed of two active power switches and a flyback high frequency transformer. In addition to this, two passive lossless resonant snubbers with pulse current regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this DC-DC power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and discussed here. To determine circuit parameters, some practical design considerations are discussed. Moreover, the effectiveness of the proposed soft switching PWM DC-DC power converter is evaluated and compared with its equivalent hard switching PWM power DC-DC converter from an experimental point of view.

Three-phase voltage source soft-switching active power filter

This paper presents the proposal of voltage clamped auxiliary resonant DC link (ARDCL) snubber for three phase power conversion circuits and a next generation voltage source three-phase soft-switching active power filter (APF) incorporating the ARDCL snubber. In addition, the power loss analysis of this resonant snubber is performed from theoretical and experimental points of view. The effective correction processing of quasi resonant commutation time corresponding to dead time is described in order to improve the instantaneous harmonic compensation current output waveforms obtained from the voltage source three-phase zero voltage soft switching APF operating under a high frequency switching modulation scheme. Its effectiveness due to resonant commutation time correction technique is proved as compared with that of hard switching APF.

Performance evaluations of coupled inductor-assisted high frequency PWM chopper type DC-DC converters

In this paper, an advanced two quadrant PWM chopper type DC-DC power converter with low switch peak voltage stress for parallel processing type small scale UPS applications and utility interactive new energy interface distributed power supplies is presented. In addition, a coupled inductor-assisted soft switching PWM boost chopper type DC-DC converter is also proposed. These two circuit topologies are evaluated and compared on the basis of simulation and experimental results by a 1 kW, 50 kHz breadboard setup. Moreover, some modified circuit topologies of the soft switching boost chopper with coupled inductors are also discussed in this paper.

Space voltage vector modulated three phase inverter using auxiliary pulse current transformer-assisted resonant snubbers

In this paper, a high frequency transformer-assisted auxiliary active resonant commutated snubber (HFTA-ARCS) for voltage source power conversion is presented. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce current rating of auxiliary active power switches and simplified sensorless control scheme without specified boost current management required for soft switching. Its operating principle and digital control scheme are described and a practical design procedure of circuit parameters on this HFTA-ARCS circuit is also introduced on the basis of computer simulation results. The effectiveness of this inverter is proved on the basis of performance evaluations and is also compared with the conventional three-phase hard switching inverter under the conditions of specified parameters.

Three-phase voltage source soft-switching inverter for battery and super capacitor energy storage plants

In this paper, a prototype of a multifunctional bidirectional three-phase voltage-source zero voltage soft-switching converter with a single resonant DC busline linked snubber (RDCS) or three bridge arm linked auxiliary active resonant commutation snubbers (ARCS) is presented for battery and/or electric double layer capacitor energy storage systems (BESS). The operating principle of the active resonant snubber-assisted soft-switching converter circuit and digitally controlled multifunctional converter system including active rectifier and inverter operation modes are described and evaluated herein for BESS. The effectiveness of the soft-switching bidirectional converter system is proved on the basis of simulation analysis.