Abstract: The inverter includes: a main body case accommodating main circuit terminal block and a control terminal block, high-voltage wire and low-voltage wire being respectively connected to the main circuit terminal block and the control terminal block; a wire cover detachably attached to the main body case to cover the main circuit terminal block; and a front cover detachably attached to the wire cover to cover the control terminal block, the front cover being fixed to the main body case with a fastening member requiring a tool for removal. The front cover includes a stopper, and, in a state where the front cover is attached to the wire cover, the stopper is located on a path through which the wire cover moves when removing the wire cover from the main body case.

Abstract: A power conversion device including a switching element includes: a temperature change estimation unit estimating temperature change in a semiconductor chip containing the switching element; a number calculator calculating the number of power cycles to fracture of the semiconductor chip due to power cycles; and a degradation degree calculator computing a degree of degradation of the semiconductor chip caused by the power cycles. The temperature change estimation unit calculates a maximum value and a minimum value of temperature of the semiconductor chip in one power cycle based on a first threshold of temperature fall allowed when it is determined that the temperature of the semiconductor chip is rising, and a second threshold of temperature rise allowed when it is determined that the temperature of the semiconductor chip is falling. The number calculator calculates the number of power cycles to fracture based on the maximum value and the minimum value.

Abstract: A heat sink includes a first surface including an attachment area to which a semiconductor module is attached and is installed such that a first side of the first surface extends in a vertical direction. Thermal grease containing oil is applied to the attachment area. A first groove extending in a horizontal direction is formed below the attachment area in the first surface. An inner wall of the first groove includes a groove top surface and a groove bottom surface spaced below the groove top surface. The length of the first groove in the horizontal direction is shorter than the length of the first surface in the horizontal direction. A wall includes a first wall extending in the horizontal direction and second walls respectively connected to both end portions of the first wall in the horizontal direction and inclined upward as the second walls extend away from the first wall.

Abstract: The inverter includes: a main body case accommodating main circuit terminal block and a control terminal block, high-voltage wire and low-voltage wire being respectively connected to the main circuit terminal block and the control terminal block; a wire cover detachably attached to the main body case to cover the main circuit terminal block; and a front cover detachably attached to the wire cover to cover the control terminal block, the front cover being fixed to the main body case with a fastening member requiring a tool for removal. The front cover includes a stopper, and, in a state where the front cover is attached to the wire cover, the stopper is located on a path through which the wire cover moves when removing the wire cover from the main body case.

Abstract: A heat sink includes a first surface including an attachment area to which a semiconductor module is attached and is installed such that a first side of the first surface extends in a vertical direction. Thermal grease containing oil is applied to the attachment area. A first groove extending in a horizontal direction is formed below the attachment area in the first surface. An inner wall of the first groove includes a groove top surface and a groove bottom surface spaced below the groove top surface. The length of the first groove in the horizontal direction is shorter than the length of the first surface in the horizontal direction. A wall includes a first wall extending in the horizontal direction and second walls respectively connected to both end portions of the first wall in the horizontal direction and inclined upward as the second walls extend away from the first wall.

Abstract: The power conversion device includes a multilevel boosting circuit and a smoothing capacitor for smoothing output voltage of the multilevel boosting circuit. The multilevel boosting circuit includes: a leg portion in which four semiconductor elements, i.e., a first diode, a second diode, a first switching element, and a second switching element are connected in series; and an intermediate capacitor connected between a connection point of the first diode and the second diode, and a connection point of the first switching element and the second switching element. When voltage of the smoothing capacitor becomes a reference voltage value or more, the control unit executes a protection mode to fix the first switching element and the second switching element in OFF states.

Abstract: The power conversion device includes: a boosting unit for boosting DC voltage, the boosting unit including a second switching element, a third switching element, a second reverse-current blocking element, and a third reverse-current blocking element which are connected in series, the boosting unit including an intermediate capacitor connected between a connection point between the second reverse-current blocking element and the third reverse-current blocking element, and a connection point between the third switching element and the second switching element; a smoothing capacitor which is connected in parallel to the boosting unit and smooths the DC voltage boosted by the boosting unit; and a control unit for turning on the third switching element so that the intermediate capacitor is charged to charge completion voltage of the intermediate capacitor.

Abstract: The power conversion device includes a multilevel boosting circuit and a smoothing capacitor for smoothing output voltage of the multilevel boosting circuit. The multilevel boosting circuit includes: a leg portion in which four semiconductor elements, i.e., a first diode, a second diode, a first switching element, and a second switching element are connected in series; and an intermediate capacitor connected between a connection point of the first diode and the second diode, and a connection point of the first switching element and the second switching element. When voltage of the smoothing capacitor becomes a reference voltage value or more, the control unit executes a protection mode to fix the first switching element and the second switching element in OFF states.

Abstract: The power conversion device includes: a boosting unit for boosting DC voltage, the boosting unit including a second switching element, a third switching element, a second reverse-current blocking element, and a third reverse-current blocking element which are connected in series, the boosting unit including an intermediate capacitor connected between a connection point between the second reverse-current blocking element and the third reverse-current blocking element, and a connection point between the third switching element and the second switching element; a smoothing capacitor which is connected in parallel to the boosting unit and smooths the DC voltage boosted by the boosting unit; and a control unit for turning on the third switching element so that the intermediate capacitor is charged to charge completion voltage of the intermediate capacitor.

Abstract: A converter supplies an output voltage, generated by stepping down or up an input voltage from a DC power supply, to an inverter for driving an AC motor. In the converter in a boost mode, a buck circuit is stopped, a boost circuit is operated, and a first bypass switch is turned on to form a path from the DC power supply to the boost circuit. In a buck mode, the boost circuit (30) is stopped, the buck circuit is operated, and a second bypass switch is turned on to form a path from the buck circuit to the inverter.

Abstract: A series connection body wherein a first backflow prevention elements, a second backflow prevention element, a first switching element and a second switching element are connected in series in this order; a reactor; a first output capacitor connected between a first end of the series connection body and a second end of the series connection body; and a second output capacitor connected between a connection point between the first switching element and the second switching element and a connection point between the first backflow prevention element and the second backflow prevention element are provided, a DC is inputted between an end of the reactor and the second end section of the series connection body, and power is supplied to a first load connected to both ends of the first output capacitor and a second load connected to both ends of the second output capacitor.

Abstract: A converter supplies an output voltage, generated by stepping down or up an input voltage from a DC power supply, to an inverter for driving an AC motor. In the converter in a boost mode, a buck circuit is stopped, a boost circuit is operated, and a first bypass switch is turned on to form a path from the DC power supply to the boost circuit. In a buck mode, the boost circuit (30) is stopped, the buck circuit is operated, and a second bypass switch is turned on to form a path from the buck circuit to the inverter.

Abstract: A series connection body wherein a first backflow prevention elements, a second backflow prevention element, a first switching element and a second switching element are connected in series in this order; a reactor; a first output capacitor connected between a first end of the series connection body and a second end of the series connection body; and a second output capacitor connected between a connection point between the first switching element and the second switching element and a connection point between the first backflow prevention element and the second backflow prevention element are provided, a DC is inputted between an end of the reactor and the second end section of the series connection body, and power is supplied to a first load connected to both ends of the first output capacitor and a second load connected to both ends of the second output capacitor.