Panasonic Intellectual Property Management Co., Ltd.

Panasonic Intellectual Property Corporation of America

Panasonic Corporation

Kenichi Asanuma

Tsutomu Sakata

Hiroshi Kanno

Atsushi Yamamoto

Hiroshi Yamamoto

Akio Hidaka

Toshiaki Kikui

Makoto Ozone

A power conversion system according to the present disclosure includes a plurality of power converters for performing power conversion on AC power and is connected to a power grid of multi-phase power that is a combination of multiple alternating current sources with mutually different phases. Each of the plurality of power converters includes a power converter circuit, a setting unit, and a control circuit. The power converter circuit performs power conversion between either DC power or AC power and AC power supplied from any of the multiple alternating current sources. The setting unit selects one of the multiple alternating current sources as a target of the power conversion to be performed by the power converter circuit. The control circuit controls operation of the power converter circuit in accordance with selection made by the setting unit.

Power converter and power conversion system

A power transmission device includes an inverter, an oscillator, a foreign substance detector, and power transmission control circuitry. The foreign substance detector performs a series of multiple processes to determine whether or not a foreign substance is present between two resonators. The power transmission control circuitry repeats a foreign substance detection period and a power transmission period alternately. The foreign substance detection period is a period in which the foreign substance detector performs one of the series of multiple processes. The power transmission period is a period in which the inverter transmits AC power. The power transmission control circuitry also causes the foreign substance detector to divide the series of multiple processes and determine whether or not the foreign substance is present as a result of performing all of the divided series of multiple processes.

Power transmission device and wireless power transmission system

A power transmission apparatus oscillates alternating current power at a first frequency (f1) which is lower than a resonant frequency (fr) of the second resonator and at a second frequency (f2) which is higher than the resonant frequency (fr). The power transmission apparatus measures an inductance value Lin (f1) and an inductance value Lin (f2). The inductance value Lin (f1) is measured when the oscillation circuit oscillates alternating current power at the first frequency (f1), and the inductance value Lin (f2) is measured when the oscillation circuit oscillates alternating current power at the second frequency (f2). The power transmission apparatus calculates a coupling coefficient k by using an expression represented by k=1&#x2212;Lin(f2)/Lin(f1), to detect relative position of the second resonator to the first resonator on the basis of the coupling coefficient k.

Power transmission apparatus for detecting relative position of a power reception apparatus

An object detecting device includes a coil array including coils, short-circuit switches connected in parallel with the coils, an oscillator circuit that outputs, to the coils, a voltage including an alternating current component, selection switches connected between the coils and the oscillator circuit, a detecting circuit that detects an object based on a change in a physical value such as voltage, and a control circuit that opens and closes the short-circuit switches and the selection switches. When a first selection switch is closed, a first short-circuit switch, which is connected to the first selection switch, is opened. The other selection switches are opened, and the other short-circuit switches are closed.

Foreign object detecting device, wireless power transmitting device, and wireless power transmission system

A power transmission device includes an inverter, an oscillator, a foreign substance detector, and a power transmission control circuitry. The power transmission control circuitry causes the foreign substance detector to perform a series of multiple processes and determine whether a foreign substance is present before a transmission of first AC power starts, and then causes the inverter to start the transmission of the first AC power. After the transmission starts, a detection period in which foreign substance detecting is performed and a power transmission period in which transmission of the first AC power is performed are repeated. The series of multiple processes is divided and performed in the multiple repeated detecting periods. The foreign substance detector is caused to divide and perform the series of multiple processes using the detecting periods and determine whether a foreign substance is present.

A power transmitting antenna includes a first resonant circuit including a power transmitting coil, a power receiving antenna includes a second resonant circuit including a power receiving coil. When the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency. A wireless power transmitting apparatus is provided with a power transmitting circuit configured to generate high-frequency power at a variable frequency, and supply the high-frequency power to the power transmitting antenna. A control circuit sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency.

Wireless power transmission system capable of continuing power transmission while suppressing heatup of foreign objects

A foreign object detector detects a metallic foreign object between a first resonator and a second resonator which is composed of a parallel resonant circuit including a coil and a capacitor. The foreign object detector includes the first resonator; an oscillator circuit capable of oscillating at a first frequency (f1) which is lower than a resonant frequency (fr) of the second resonator and at a second frequency (f2) which is higher than the resonant frequency (fr); and a measurement circuit to measure changes in input impedance of the first resonator. The measurement circuit detects a metallic foreign object between the first resonator and the second resonator based on: changes in input impedance of the first resonator as measured by the measurement circuit while the oscillator circuit is oscillating at the first frequency f1; and changes in input impedance of the first resonator as measured by the measurement circuit while the oscillator circuit is oscillating at the second frequency f2.

Foreign object detector, power transmitting device and power receiving device for wireless power transmission, and wireless power transmission system

A contactless connector apparatus is provided with a first coil closely opposed to a second coil so as to be electromagnetically coupled thereto. The first coil includes: an inner transmitter coil wound around an axis passing through its center; and an outer transmitter coil wound around the axis and outside the inner coil. One end of the outer transmitter coil is connected to one end of the inner transmitter coil such that, when a current flows through the transmitter coils, a direction of a loop current generated around the axis by a current flowing through the inner transmitter coil is opposite to that of a loop current generated around the axis by a current flowing through the outer transmitter coil. A self-inductance of the outer transmitter coil is larger than that of the inner transmitter coil.

Contactless connector system tolerant of position displacement between transmitter coil and receiver coil and having high transmission efficiency

A power transmitting device determines transmitting power P(t) at a beginning of a first unit time, and transmitting power P(t) at an end of the first unit time, stores a control parameter Q(t) that determines a voltage of the transmitting power at a beginning of a second unit time, and a control parameter Q(t) that determines a voltage of the transmitting power at an end of the second unit time, determines a power difference &#x394;P=P(t)&#x2212;P(t) and a difference &#x394;Q=Q(t)&#x2212;Q(t) in the control parameter Q, and, if the &#x394;P is equal to or larger than a first threshold and an absolute value of the &#x394;Q is equal to or larger than a second threshold, determines that there is a foreign object between a receiver resonator and a transmitter resonator and decreases the transmitting power output from an inverter circuit.

Power transmitting device and wireless power transmission system

A power transmission device includes an inverter using a frequency f11 lower than a frequency f0 between a first resonator and a second resonator or a frequency f12 higher than the frequency f0 to generate a first power; an oscillator using a frequency f10 lower than a frequency fr between the first resonator and the second resonator or a frequency f20 higher than the frequency fr to generate a second power; and a power transmission control circuitry setting a foreign object detection period between first and second transmission periods, using the frequency f11 or frequency f12 in the first transmission period, using the frequency f10 or frequency f20 in the foreign object detection period, and if it is determined that a substance is present in the foreign object detection period, transmitting power in the second transmission period at a frequency different from the frequency used in the first transmission period.

Wireless power transmission system and power transmission device of wireless power transmission system

A foreign object detector includes: an oscillator circuithaving a coiland resonant capacitors Cx, Cy, the oscillator circuitbeing configured to output a voltage which includes an AC component and a DC component, the AC component having a positive cycle and a negative cycle; and an electric circuit for sensing a variation of the AC component and a variation of the DC component in the voltage output from the oscillator circuitwhen a foreign object approaches the coil

Foreign object detector, power transmitter, power receiver, and wireless power transmission system

A power transmitting antenna includes a first resonant circuit including a power transmitting coil. A power receiving antenna includes a second resonant circuit including a power receiving coil. When the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency. A wireless power transmitting apparatus is provided with a power transmitting circuit configured to generate high-frequency power at a variable frequency, and supply the high-frequency power to the power transmitting antenna. A control circuit sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency.

A power transmission apparatus oscillates alternating current power at a first frequency (f) which is lower than a resonant frequency (fr) of the second resonator and at a second frequency (f) which is higher than the resonant frequency (fr). The power transmission apparatus measures an inductance value Lin (f) and an inductance value Lin (f). The inductance value Lin (f) is measured when the oscillation circuit oscillates alternating current power at the first frequency (f), and the inductance value Lin (f) is measured when the oscillation circuit oscillates alternating current power at the second frequency (f). The power transmission apparatus calculates a coupling coefficient k by using an expression represented by k=1&#x2212;Lin(f)/Lin(f), to detect relative position of the second resonator to the first resonator on the basis of the coupling coefficient k.

Power transmission apparatus for detecting relative position of resonators based on a coupling coefficient

A wireless power transmitting device includes a self-oscillator circuit, a detection circuit that detects at least one of an oscillation frequency of the self-oscillator circuit and an output voltage of the self-oscillator circuit, a detection resonator that outputs, to detect a position of the power receiving device, power output by the self-oscillator circuit, and a control circuit that detects a degree to which the power receiving device approaches the detection resonator, based on a result of a detection performed by the detection circuit.

Growing community of inventors

Kyoto, Japan

Kenichi Asanuma