Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Kenichiro Nagashita

Kenichi Takagi

Takahide Sugiyama

Masanori Ishigaki

Takahiro Hirano

Jun Muto

Shuntaro Inoue

Masaki Okamura

Takaji Umeno

Yoshitaka Niimi

Yasuharu Terada

Masaru Sugai

Fumiki Tanahashi

An electric power conversion circuit comprises U-phase and V-phase switching circuits, a transformer, and an &#x3b1;-phase switching circuit. A primary winding of a transformer is connected between the U-phase switching circuit and the V-phase switching circuit, and both ends of a secondary winding are connected to the &#x3b1;-phase switching circuit. The &#x3b1;-phase switching circuit comprises positive and negative terminals, a half bridge including and two switching devices, and a voltage divider circuit. The half bridge is provided between the positive terminal and the negative terminal, and a common connection point between the two switching devices is connected to one end of the secondary winding. A voltage divider output point of the voltage divider circuit is connected to the other end of the secondary winding.

Electric power conversion circuit

There is provided a power supply system including a first power supply and a second power supply. The power supply system includes a power conversion circuit capable of bidirectionally sending and receiving power by bidirectional voltage conversion between the first power supply and the second power supply, converting the first voltage from the first power supply to output a third voltage and a fourth voltage, and converting the second voltage from the second power supply to output the third voltage and the fourth voltage.

Power supply system

A power conversion apparatus is configured to supply a power to an auxiliary device provided in a vehicle, and the power conversion apparatus includes: a primary side circuit including a primary side port; a secondary side circuit including a plurality of secondary side ports and magnetically coupled with the primary side circuit via a transformer; a control unit configured to control a transmitted power that is transmitted between the primary side circuit and the secondary side circuit by changing a phase difference between a switching of the primary side circuit and a switching of the secondary side circuit; an inverter connected to a first secondary side port and supplying the power to the auxiliary device via the primary side port; and a charger connected to a second secondary side port and supplying the power to the auxiliary device via the primary side port.

Power conversion apparatus

The present invention provides a power conversion circuit system in which a circulating current can be reduced by accurately detecting the circulating current, to thereby improve efficiency in power conversion. The power conversion circuit system includes a power conversion circuit composed of a primary conversion circuit having left and right arms and a secondary conversion circuit having left and right arms, and a control circuit for controlling switching of switching transistors in the primary and secondary conversion circuits. The control circuit detects the circulating current at at least one of timings lagged by &#x3c0;/2+&#x3c6;/2 from at least either a peak timing or a valley timing in a carrier counter where &#x3c6; represents a difference in phase between the primary and secondary conversion circuits, and performs feedback control for reducing the detected circulating current to zero.

Isolated DC-DC power conversion circuit system with circulating current reduction

An electric power conversion circuit system for reducing core loss in a transformer particularly during light loading and improving conversion efficiency during light loading comprising an electric power conversion circuit composed of a primary side conversion circuit having a left arm and a right arm and a secondary side conversion circuit having a left arm and a right arm, and a control circuit for controlling switching of switching transistors of the first side conversion circuit and the secondary side conversion circuit. When the output voltage is at a relatively light load, the control circuit controls to change the duty of the transmitting side among the primary side conversion circuit and the secondary side conversion circuit and controls to change the half-bridge phase differences of the left arm and the right arm of the primary side conversion circuit and the secondary side conversion circuit, respectively.

Electric power conversion circuit system

A magnetically coupled reactor includes a coupled core member, a first coil, and a second coil. The coupled core member includes a first core and a second core made of a magnetic material and disposed to face each other, a coil channel, and a sheet-like magnetic body by which a coupling portion between cores is put between the first core and the second core at an outer portion of the first and second cores. Each coil is wound around a leg through the coil channel in a lap winding manner such that the coils are overlapped on top of each other in the coil channel when seen in an axial direction. The sheet-like magnetic body extends from the coupling portion between coils into the coil channel and includes a portion arranged between coils located between the coils in the axial direction.

Magnetically coupled reactor and power converter

There is provided an electric power conversion circuit system having a primary side electric power conversion circuit, a secondary side electric power conversion circuit, and a control circuit. The control circuit sets at least one of a half-bridge phase difference between a lower-left-arm transistor and a lower-right-arm transistor of the primary side electric power conversion circuit and a half-bridge phase difference of the secondary side electric power conversion circuit based on OFF periods of the primary side and secondary side electric power conversion circuits, dead-times of the primary side and secondary side electric power conversion circuits, and an amount of change of a power supply voltage so that a current in a non-transmission period of electric power is zero between the primary side and secondary side electric power conversion circuits.

The power conversion apparatus converts power among a plurality of ports, and includes: a first voltage conversion unit that converts a voltage of a first port and outputs power having the converted voltage to a second port; and a second voltage conversion unit that performs a first operation of converting a voltage of one port of the second port and a third port and outputting power having the converted voltage to the other port, or a second operation of converting a voltage of the other port and outputting power having the converted voltage to the one port, and when performing the first operation the second voltage conversion unit switches from the first operation to the second operation when a vehicle condition where power of the one port is insufficient is detected.

Power conversion apparatus and method

An electric power conversion system includes: a primary electric power conversion circuit including a primary coil connected to a connection point between a plurality of transistors; a secondary electric power conversion circuit configured similarly to the primary electric power conversion circuit and including a secondary coil corresponding to the primary coil; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits. The control circuit executes feedforward control for setting one of an on/off ratio of a terminal voltage signal of the primary coil and an on/off ratio of a terminal voltage signal of the secondary coil, in response to at least one of fluctuations in voltage ratio between both waveforms and fluctuations in phase symmetry between both waveforms, when the terminal voltage waveform of the primary coil and the terminal voltage waveform of the secondary coil are different from each other.

Electric power conversion system

An electric power conversion system includes: a primary electric power conversion circuit including primary right and left arms; a secondary electric power conversion circuit including secondary right and left arms; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits by magnetically coupling a primary coil to a secondary coil. The control circuit sets an interphase difference in switching between right and left arm lower transistors in the primary electric power conversion circuit and an interphase difference in switching between right and left arm lower transistors in the secondary electric power conversion circuit on the basis of off times of the primary and secondary electric power conversion circuits such that a phase difference between terminal voltage waveforms of the primary and secondary coils is 0 and duty ratios of the terminal voltage waveforms are equal to each other.

Growing community of inventors

Toyota, Japan

Kenichiro Nagashita