K. Soshin

Tapped-inductor filter assisted soft-switching PWM DC-DC power converter

A novel high-frequency transformer linked full-bridge type soft-switching phase-shift pulsewidth modulated (PWM) controlled dc-dc power converter is presented, which can be used as a power conditioner for small-scale photovoltaic and fuel cell power generation systems as well as isolated boost dc-dc power converter for automotive ac power supply. In these applications with low-voltage large-current sources, the full-bridge circuit is the most attractive topology due to the possibility of using low-voltage high-performance metal-oxide-semiconductor field-effect transistor (MOSFET) and achieving high efficiency of the dc-dc power converter. A tapped-inductor filter including the freewheeling diode is newly implemented in the output stage of the full-bridge phase-shift PWM dc-dc converter to achieve soft-switching operation for the wide load variation range. Moreover, in the proposed converter circuit, the circulating current is effectively minimized without using additional resonant circuit and auxiliary power switching devices. The practical effectiveness of the proposed soft-switching dc-dc power converter was verified in laboratory level experiment with 1 kW 100 kHz breadboard setup using power MOSFETs. Actual efficiency of 94-97% was obtained for the wide duty cycle and load variation ranges.

Small-scale wind turbine coupled single-phase self-excited induction generator with SVC for isolated renewable energy utilization

In this paper, the static VAR compensator (SVC) composed of the fixed excitation capacitor(FC) in parallel with the thyristor switched capacitor (TSC) and the thyristor controlled reactor (TCR) is applied to regulate and stabilize the generated terminal voltage of the single-phase self-excited induction generator (SEIG) for the passive load variations and the prime mover speed changes. The conventional fixed gain PI controller is employed to adjust the equivalent capacitance of the single-phase SVC in the output of the single-phase SEIG. The closed-loop terminal voltage responses due to different inductive passive load disturbances in the single-phase SEIG using the single-phase SVC with the PI controller are considered and discussed herein. A prototype setup for the single-phase SEIG with SVC voltage regulation feedback control scheme is implemented. The experimental results of this power conditioner are illustrated and give good agreements with the digital simulation results.

Boost transformer linked full bridge soft-commutation DC-DC power converter with secondary-side phase-shifted PWM rectifier switches

This paper presents a novel circuit topology of a voltage source type zero voltage soft-switching full bridge inverter DC-DC power converter with an isolated high-frequency transformer link this power converter incorporates zero-current soft-switching (ZCS) mode phase-shifted PWM active power switches in series with diode into two diode arms of full-bridge rectifier or center-tapped rectifier in transformer secondary-side. This isolated DC-DC power converter circuit can achieve ZVS/ZVT transition commutation for non-controlled active power switches in the primary side of transformer and ZCS/ZCT transition commutation for phase-shifted PWM active power switches in the secondary side of transformer, which can operate under wide load variations from a light load to a heavy load as well as a condition of PWM voltage regulation strategy.

Transformer parasitic parameters and lossless inductive snubber assisted zero current soft switching DC-DC converter for high power magnetron drive

This paper presents a novel prototype of a high-frequency transformer parasitic parameter and a lossless inductive snubber assisted series-resonant ZCS-PFM DC-DC power converter, which is designed for high power magnetron. When a conventional series-resonant PFM DC-DC converter is designed for magnetron drive, it is very difficult to implement zero current soft switching commutation due to the influence of the magnetizing current through a high-frequency transformer. In order to implement soft switching commutation, the new topology that can actively utilize the magnetizing current is proposed and discussed on the basis of simulation and experimental results.

Tapped inductor filter-assisted soft-switching PWM DC-DC power converter with high frequency transformer link for automotive AC power supply

This paper presents a novel voltage source full-bridge type soft-switching phase-shift PWM controlled DC-DC power converter with a high frequency transformer link, which can operate under ZVS transition of leading bridge leg and ZCS transition of lagging bridge leg. This power converter can be used as power conditioner for small-scale solar photovoltaic cell and fuel cell power generation systems and isolated step-up DC-DC power converter for automotive AC power supply. The full-bridge circuit topology with a high frequency step-up transformer makes possible to apply low voltage high performance MOSFETs in order to achieve high efficiency processing of the DC-DC power conversion. The tapped inductor filter including a freewheeling diode is implemented in the output stage of the proposed soft-switching DC-DC power converter to perform soft-switching phase-shift PWM high frequency operation for wide load variation ranges. Moreover, in the proposed DC-DC power converter circuit, the circulating currents are effectively minimized without adding active auxiliary quasi-resonant snubber circuit with power switching devices. The practical effectiveness of the proposed soft-switching DC-DC power converter is verified on the basis of experimental setup.

High performance sensorless induction motor drive incorporating vector controlled scheme PWM inverter-fed with auto-tuning machine parameter estimation

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation for general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with automatic tuning machine parameter estimation schemes. The dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.

Sensorless induction motor drive incorporating vector controlled scheme PWM inverter-fed with autotuning machine parameter estimation strategy

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation for general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sinewave PWM inverter with an automatic tuning machine parameter estimation schemes. The dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.

Sensor-less speed control strategy for induction motor drive incorporating vector controlled scheme PWM inverter-fed with auto-tuning machine parameter estimation

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation for general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with automatic tuning machine parameter estimation schemes. The dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.