Kouichi Ishizaka

Model for a Three-Phase Contactless Power Transfer System

This paper studies the model for the three-phase contactless power transfer system. A phase winding in the three-phase contactless power transformer has the magnetic couplings with all of the other phase windings. Moreover, the magnetic couplings depend on the displacement of the secondary armature with respect to the primary armature. The equivalent model of the three-phase system with the complicated mutual inductances due to such magnetic couplings is presented. The model is transformed into the single-phase model that is similar to the model for the conventional system. The simplified model allows the easy consideration of the operation of the three-phase system. By using the model, the resonant capacitances for the three-phase system are available. The model is confirmed to successfully simulate the performance of the actual system. In addition, the experimental and theoretical results confirm that the three-phase system has the stable performance of the power transfer independently of the displacement of the secondary.

Comparison of Characteristics on Planar Contactless Power Transfer Systems

This paper reports the characteristics of planar contactless power transfer systems, which are classified into the following types: single-phase primary and single-phase secondary system (SS system), three-phase primary and single-phase secondary system (TS system), and three-phase primary and three-phase secondary system (TT system). The SS system is used in conventional contactless power transfer. On the other hand, in the last few years, the TS system has been studied more. As a novel system, the TT system is here proposed. The characteristics of all three systems are measured by using a common experimental prototype made of printed circuit board. The comparison confirms that the TT system has higher efficiency and can output uniform power independent of the secondary position, as compared to the other systems.

Trifoliate Three-Phase Contactless Power Transformer in Case of Winding-Alignment

This paper proposes a trifoliate three-phase contactless power transformer. This transformer can achieve balanced electrical behavior between three phases at winding alignment. For this transformer, models are presented with accompanying detailed explanations. The models reproduce the electrical behavior more precisely than conventional models. A contactless power transfer system using a prototype of the proposed transformer and the resonant capacitances estimated by the models works effectively and attains good performance levels. In addition, in winding misalignments with slight displacements, the system is able to maintain these high-performance levels.

Single-Phase Voltage-Quadrupler Rectifier With Sinusoidal Input Current

A single-phase voltage-quadrupler rectifier with sinusoidal input current is presented. This has the circuit configuration that is based on the combination of a half-bridge rectifier and pump circuits. The circuit can be operated in the switching states for pumping action to pump twice the peak supply voltage onto each of 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 prototype tested, using the insulated gate bipolar transistors and a controller for the output voltage regulation, is implemented to investigate the operation. The experimental and the simulated results confirm that the input current can be waveshaped sinusoidally with a near-unity power factor.

Single-phase soft-switched current-source inverter for utility interactive photovoltaic power generation system

A novel single-phase soft-switched current-source inverter, which connects the photovoltaic arrays with the utility grid, is studied. To provide the soft-switching capability under the pulse width modulation for a line-commutated thyristor inverter, an auxiliary resonant switch to bypass the current on the DC side is connected across the DC input of a thyristor inverter. The arrangement tested, using two insulated-gate bipolar transistors and a single-phase thyristor bridge, is implemented to investigate the operation under the sinusoidal pulse width modulation. The operation is also simulated using PSpice. The experimental and simulated results confirm that the utility current can be sinusoidally waveshaped with a near unity power factor.

Single-Phase Half-Controlled Buck Rectifier Capable of Recovering Snubber Energy

Single-phase half-controlled buck rectifier using a simple snubber energy recovery bridge leg is studied. When the active power devices assembled into this bridge leg are simultaneously turned on, the snubber capacitor is discharged and its stored energy is transferred to the load circuit. The experimental results confirm that the input current can be waveshaped sinusoidally with the higher efficiency than that of the conventional one.

Improvement in Input Current Distortion of Single-Phase Two-Stage Boost Rectifier

An improvement in the input current distortion of single-phase two-stage boost rectifier is studied. To cause the input current to follow its sinusoidal reference by means of current-mode control, a capacitor voltage is superimposed upon that of the supply when the switches are turned on. The experimental prototype, employing two insulated-gate bipolar transistors as active power switching devices and PI 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 independent of the working conditions.

Voltage-Doubler Rectifier with Sinusoidal Input Current Using Pump Circuits

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.