A power transmission device for a noncontact power supply device includes a resonant circuit that outputs an alternating magnetic flux by power from a power source circuit, and switching elements for making the resonant circuit generate an alternating magnetic flux, and transmits power to a power receiving coil of a power reception device by the alternating magnetic flux. A power transmission controller of the power transmission device includes a transmission mode of supplying alternating power to the resonant circuit by repeating ON and OFF of switching elements by controlling switching elements. ON time in one cycle of operation of each of switching elements used in the transmission mode is a first fixed value. Accordingly, the power transmission device in a simplified configuration can be provided.

A power transmission device for a noncontact power supply device includes a resonant circuit that outputs an alternating magnetic flux by power from a power source circuit, and switching elements for making the resonant circuit generate an alternating magnetic flux, and transmits power to a power receiving coil of a power reception device by the alternating magnetic flux. A power transmission controller of the power transmission device includes a transmission mode of supplying alternating power to the resonant circuit by repeating ON and OFF of switching elements by controlling switching elements. ON time in one cycle of operation of each of switching elements used in the transmission mode is a first fixed value. Accordingly, the power transmission device in a simplified configuration can be provided.

In an embodiment, an off-grid phase splitter includes: a first input port and a second input port that are separately connected to a power supply; a first output port and a second output port that provide a second voltage, and the second output port and a third output port provide a third voltage; a first capacitor connected between the first output port and the second output port; a second capacitor connected between the second output port and the third output port; a first switch circuit and a second switch circuit connected in series to form a first node between the first input port and the second input port, where the first switch circuit and the second switch circuit are unidirectionally switched on in opposite directions,; and an inductor connected between the first node and the second output port.

According to an embodiment, a capacitor diagnosis device includes a sensor, a frequency spectrum analysis unit, a frequency component extraction unit, and a diagnosis processing unit. The sensor detects a physical quantity that changes with an current flowing through a capacitor in a power conversion unit (PCU) for converting DC power smoothed by the capacitor connected in parallel to DC link(s) into AC power according to a power running operation. The frequency spectrum analysis unit generates a frequency spectrum based on a detection result of the sensor detected during the power running operation of the PCU. The frequency component extraction unit extracts a component of a specific frequency band related to a frequency depending on a configuration of the PCU based on the frequency spectrum. The diagnosis processing unit diagnoses a state of the capacitor based on at least a magnitude of the extracted component of the specific frequency band.

According to an embodiment, a capacitor diagnosis device includes a sensor, a frequency spectrum analysis unit, a frequency component extraction unit, and a diagnosis processing unit. The sensor detects a physical quantity that changes with an current flowing through a capacitor in a power conversion unit (PCU) for converting DC power smoothed by the capacitor connected in parallel to DC link(s) into AC power according to a power running operation. The frequency spectrum analysis unit generates a frequency spectrum based on a detection result of the sensor detected during the power running operation of the PCU. The frequency component extraction unit extracts a component of a specific frequency band related to a frequency depending on a configuration of the PCU based on the frequency spectrum. The diagnosis processing unit diagnoses a state of the capacitor based on at least a magnitude of the extracted component of the specific frequency band.

An inverter device includes a converter circuit and a filter. The converter circuit converts a DC input voltage into an AC intermediate voltage based on six control signals, and includes first and second converters. Each of the first and second converters includes three switches, two diodes and a coupled inductor circuit. The switches of the first converter operate respectively based on three of the control signals. The switches of the second converter operate respectively based on the other three of the control signals. The filter filters the AC intermediate voltage to generate an AC output voltage.

A semiconductor module includes a semiconductor device and bus bar. The device includes an insulating substrate, conductive member, switching elements, and first/second input terminals. The substrate has main/back surfaces opposite in a thickness direction, with the conductive member disposed on the main surface. The switching elements are connected to the conductive member. The first input terminal, including a first terminal portion, is connected to the conductive member. The second input terminal, including a second terminal portion overlapping with the first terminal portion in the thickness direction, is connected to the switching elements. The second input terminal is separate from the first input terminal and conductive member in the thickness direction. The bus bar includes first/second terminals. The second terminal, separate from the first terminal in the thickness direction, partially overlaps with the first terminal in the thickness direction. The first/second terminals are connected to the first/second terminal portions, respectively.

A self-contained, all-in-one MPPT controller and micro-inverter that can be connected directly to the load (that can be on or off grid) using a standard power socket or to the load center, feeding energy to the grid generated by different kind of sources, including wind turbines, solar panels, hydro generators or gas generators, and that also controls a storage device to be used to reduce peak consumptions or as a back up solution.

Provided is a power conversion device that does not require adaptation work and can suppress a current beat regardless of an operation state of a motor. The power conversion device includes an inverter 1 that converts a DC voltage into an AC voltage and drives an AC motor 2, and beat compensation units 46 and 49 that suppress a current beat component of an output current of the inverter 1. The beat compensation units 46 and 49 include beat extraction units 50, 51, and 52 that calculate beat components of the output current of the inverter 1, and beat compensation voltage calculation units 53 and 54 that estimate beat compensation voltages from the beat components calculated by the beat extraction units 50, 51, and 52. The current beat component of the output current of the inverter 1 is suppressed based on the beat compensation voltages estimated by the beat compensation voltage calculation units 53 and 54.

A threshold detection system can be configured to monitor a location (e.g., a DC link) for overcurrent. The threshold detection system can be configured to generate a pulse width modulated signal with a duty cycle that is proportional to current through the DC link. The threshold detection system can be configured to determine whether the duty cycle exceeds a selected threshold.