Denso Corporation

Denso Corpora Tion

Kengo Mochiki

Mitsunori Kimura

Yuu Yamahira

Tetsuya Matsuoka

Kazuma Fukushima

Hiroshi Shimizu

Yasuyuki Ohkouchi

Yoshinori Hayashi

Tomohisa Sano

Yohei Kondo

Tatsuya Murakami

A drive circuit for a switch drives an upper-arm switch and a lower-arm switch that include body diodes. Of the body diodes in upper- and lower-arm switches, the diode through which a feedback current flows during a dead time is a target diode. Of the upper- and lower-arm switches, the switch that includes the target diode is a target switch. The remaining switch is an opposing arm switch. The drive circuit maintains an electric potential of a control terminal relative to a second terminal of the target switch at a negative voltage over a period from a timing subsequent to a start timing of a dead time immediately after the target switch is switched to an off-state until a point within a period over which the opposing arm switch is set to an on-state, and subsequently maintains the electric potential at an off-voltage until a next dead time is ended.

Drive circuit for driving an upper arm switch and a lower arm switch each having a body diode

A power conversion device, mounted on a motor vehicle, has a battery, a power converter, a reactor and a control unit. The power conversion device boosts a battery voltage of the battery, and supplies a boosted voltage to a motor generator mounted on a motor vehicle. The power conversion device transmits electric power generated by the motor generator and supplies the generated electric power to the battery through the power converter. The power converter has an upper arm and a lower arm. The upper arm has upper arm side switching elements. The lower arm has lower arm side switching elements which are directly connected to the respective upper arm side switching elements. At least one of the upper arm side switching elements is composed of a MOS FET and at least one of the lower arm side switching elements is composed of an IGBT.

Power conversion device of motor vehicles

In a drive circuit, one of an upper-arm switch and a lower-arm switch being in an on state by a main driver is referred to as a target arm switch. The other of the upper-arm switch and the lower-arm switch being in an off state by the main driver is referred to as an opposite arm switch. An intrinsic diode connected in antiparallel to the opposite arm switch is referred to as an opposite arm diode. The drive circuit includes a protective driver configured to determine whether a failure has occurred in the target arm switch. The protective driver is configured to change the target arm switch from the on state to the off state, and the opposite arm switch from the off state to the on state upon determining that a failure has occurred in the target arm switch.

Drive circuit

A power conversion apparatus is provided in which an upper arm semiconductor device, a lower arm semiconductor device and a capacitor. At least either upper arm semiconductor device or lower arm semiconductor device constitutes a parallel-connected body. In an opposite arm against the parallel-connected body, a permissible element is provided. In the switching elements that constitute the parallel-connected body, a last off element and a non-last off circuit are identified. Inductance of a last off closed circuit where current flows through the last off element, reflux element in the opposite arm and the capacitor is smaller than inductance of a non-last off closed circuit where current flows through the last off element, reflux element in the opposite arm and the capacitor.

Power conversion apparatus in which an inductance of a last off closed circuit is smaller than an inductance of a non-last off closed circuit

A power conversion apparatus performs power conversion. The power conversion apparatus includes a semiconductor module and a cooler. The semiconductor module includes an insulated-gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a lead frame. The insulated-gate bipolar transistor and the metal-oxide-semiconductor field-effect transistor are connected in parallel to each other and provided on the same lead frame. The cooler has a coolant flow passage. The coolant flow passage extends such that the coolant flow passage and the lead frame of the semiconductor module are opposed to each other. The semiconductor module is configured such that the metal-oxide-semiconductor field-effect transistor is not disposed further downstream than the insulated-gate bipolar transistor in a flow direction of a coolant in the coolant flow passage of the cooler.

Power conversion apparatus

A power conversion apparatus includes a semiconductor module including a semiconductor device and a control circuit unit controlling the semiconductor module. The semiconductor module has main and subsidiary semiconductor devices connected in parallel. The control circuit unit performs control such that the subsidiary semiconductor device is turned on after the main semiconductor device is turned on, and the main semiconductor device is turned off after the subsidiary semiconductor device is turned off. The control circuit unit performs control such that, one of the turn-on and turn-off switching timings has a switching speed faster than that of the other of the switching timings. The semiconductor module is configured such that, at a high-speed switching timing, an induction current directed to turn off the subsidiary semiconductor device is generated in a control terminal of the subsidiary semiconductor device depending on temporal change of a main current flowing to the main semiconductor device.

A power converter is provided with semiconductor devices, a capacitor, a positive bus bar, and a negative bus bar. The negative bus bar includes a negative side body and a plurality of negative side branches. The negative side branches include an interposed negative side branch interposed between two positive side branches connected to the upper arm semiconductor devices that belong to the same semiconductor device group as the lower arm semiconductor devices connected to the negative side branches, and include an end negative side branch that is not interposed between two positive side branches. The self-inductance of the end negative side branch is smaller than the self-inductance of the interposed negative side branch.

Power converter for reducing a difference between reference potentials of semiconductor devices that are simultaneously turned on and off

A semiconductor module includes an IGBT and a MOSFET. The IGBT is made of a silicon semiconductor. The MOSFET is made of a wide-bandgap semiconductor having a wider bandgap than the silicon semiconductor. The IGBT and the MOSFET are connected in parallel to each other to form a semiconductor element pair. The IGBT has a greater surface area than the MOSFET. The semiconductor module is configured to operate in a region that includes a low-current region and a high-current region. Electric current flowing through the semiconductor element pair is higher in the high-current region than in the low-current region. In the low-current region, the on-resistance of the MOSFET is lower than the on-resistance of the IGBT. In contrast, in the high-current region, the on-resistance of the IGBT is lower than the on-resistance of the MOSFET.

Semiconductor module and electric power conversion apparatus

In a driving apparatus for switches connected in parallel to each other, drivers respectively turn on or off the switches. A temperature obtainer obtains a value of a temperature parameter correlating with a temperature of at least one of the first and second switches. A selector selects at least one of the switches as at least one drive target switch. A driver causes at least one of the drivers to turn on the at least one drive target switch during an on duration and thereafter turn off the at least one drive target switch in each target switching cycle. The selector adjusts the number of the selected at least one drive target switch based on the value of the temperature parameter.

Driving apparatus for switches

A power conversion apparatus includes a first semiconductor element pair that includes a MOSFET made of wide bandgap semiconductor material and a wide bandgap diode made of wide bandgap semiconductor material which is reverse parallel-connected to the MOSFET, a second semiconductor element pair that includes an IGBT made of silicon semiconductor material and a silicon diode made of silicon semiconductor material which is reverse parallel-connected to the IGBT, and a control circuit section for controlling switching operation of the MOSFET and the IGBT. The first and second semiconductor element pairs are connected in series to each other.

A semiconductor module of an electric power converter includes an IGBT and a MOSFET which are connected in parallel to each other and provided on the same lead frame, either one of the IGBT and the MOSFET is a first switching element and the remaining one is a second switching element, and the conduction path of the second switching element is disposed at a position that is separated from a conduction path of the first switching element in the same lead frame.

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Kariya, Japan

Kengo Mochiki