Abstract: Ringing is securely reduced in a case where a Schottky barrier diode of a wide-gap semiconductor is applied to a power conversion circuit. A gate voltage increasing circuit 11a is included. In a period since a gate voltage of a semiconductor switching element in one of upper and lower arms starts being increased from a value in an off-state until the gate voltage reaches a value in an on-state, the gate voltage increasing circuit 11a is configured to make a gate voltage of the semiconductor switching element in the other one of the upper and lower arms change from a value in an off-state into a value larger than the value in the off-state and is configured to control the value larger than the value in the off-state for a predetermined period of time.

Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.

Abstract: In a switching circuit in which a power semiconductor switching element and a unipolar type diode are connected in parallel, the noise due to ringing is reduced. When the main circuit current flowing is equal to or less than a predetermined value, an Si-IGBT is switched and driven by a gate resistance. In this case, when the main circuit current detected is equal to or more than a threshold value, a main circuit current detection circuit changes a gate resistance switching pMOS from ON state to OFF state. Accordingly, the Si-IGBT operates with a summation of a gate resistance and a gate resistor. More specifically, a gate resistance value of a gate drive circuit of the Si-IGBT increases. Therefore, dv/dt of the collector-emitter voltage of the Si-IGBT, i.e., the recovery dv/dt of the unipolar type diode, is small, and therefore, the noise due to ringing can be reduced.

Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.

Abstract: A power converter including: a plurality of semiconductor devices forming a power conversion circuit; a base section to which the plurality of semiconductor devices are attached; and radiating fins dissipating heat generated from the semiconductor devices into outside air, in the power converter in which the direction of the flow of a refrigerant flowing into the radiating fins changes depending on the operation status of the power conversion circuit, the shape of each radiating fin changes in such a way that the cross-sectional area of a channel of the refrigerant on the outflow side becomes smaller than the cross-sectional area of the channel of the refrigerant on the inflow side in the radiating fins depending on the direction of the flow of the refrigerant.

Abstract: The present invention provides a power converter which, while ensuring safety, implements control for the flow of a constant current in a specified switching element, more accurately determines the lifetime of a switching element, and reduces the number of temperature detectors. The power converter is provided with a mechanism which causes a brake device to operate or which confirms that a brake mechanism is operating. The power converter supplies current to the d-axis and the q-axis of a rotational coordinate system, within the range of the braking torque of the brake mechanism, and passes the desired current to the desired element. Furthermore, temperature detectors are attached only in chips in sections where a crack readily develops in the upper solder layer or peeling is readily generated in the wire bonding, and in chips where a crack readily develops in the lower solder layer.

Abstract: The dead time is secured stably in a semiconductor drive circuit for switching devices using a wide band gap semiconductor. The drain terminal of the switching device of an upper arm is connected to the positive terminal of a first power supply, the source terminal of the switching device of a lower arm is connected to the negative terminal of the first power supply, and the source terminal of the switching device of the upper arm is connected with the drain terminal of the switching device of the lower arm. A gate drive circuit provided for each switching device includes an FET circuit and a parallel circuit made of a parallel connection of a first resistor and a first capacitor and having a first terminal connected to the gate terminal of the switching device.

Abstract: A power converter including: a plurality of semiconductor devices forming a power conversion circuit; a base section to which the plurality of semiconductor devices are attached; and radiating fins dissipating heat generated from the semiconductor devices into outside air, in the power converter in which the direction of the flow of a refrigerant flowing into the radiating fins changes depending on the operation status of the power conversion circuit, the shape of each radiating fin changes in such a way that the cross-sectional area of a channel of the refrigerant on the outflow side becomes smaller than the cross-sectional area of the channel of the refrigerant on the inflow side in the radiating fins depending on the direction of the flow of the refrigerant.

Abstract: In order to reduce the average power of the ringing noise, the present invention provides a power converter comprising: an arm circuit including a high-voltage side switching device to which a first diode is connected in parallel and a low-voltage side switching device to which a second diode is connected in parallel; and a main power supply connected to a series circuit of the high-voltage side switching device and the low-voltage side switching device, wherein a connecting point between the high-voltage side switching device and the low-voltage side switching device is connected to a load, and a resonant frequency calculated from inductances of wirings of a closed circuit including the first diode, the second diode, and the main power supply and a capacitance across the first diode is different form that calculated from the inductances of the wirings and a capacitance across the second diode.

Abstract: A driver circuit that lowers the dependence of the loss in the wide gap semiconductor device upon the temperature is provided. A gate driver circuit for voltage driven power semiconductor switching device includes a power semiconductor switching device, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a unit for detecting a temperature of the switching device. The temperature of the power semiconductor switching device is detected, and a gate drive voltage or a gate drive resistance value is changed based on the detected temperature.

Abstract: The invention provides a switching circuit of a power semiconductor device having connected in parallel SiC diodes with a small recovery current, capable of significantly reducing turn-on loss and recovery loss without increasing the noise in the MHz band, and contributing to reducing the loss and noise of inverters. The present invention provides a switching circuit and an inverter circuit of a power semiconductor device comprising a module combining Si-IGBT and SiC diodes, wherein an on-gate resistance is set smaller than an off-gate resistance.

Abstract: A temperature rise of a semiconductor switching element, which is part of a power conversion device such as an inverter, is estimated by an extremely simple method to assess the degradation and remaining lifetime of the semiconductor switching element. In a heat generation amount calculation unit 12 in a calculation processor 3, current command values Id* and Iq* and voltage command values vu*, vv* and vw* are used to calculate a chip loss. First, current values iu*, iv* and iw* of all output phases are estimated from the current command values. The ON/OFF loss of the chip is represented by a function of an estimated value for a current flowing in each output phase, and the loss can be derived by integration with a PWM carrier frequency f. In addition, with respect to a conduction loss, it is necessary to integrate a conduction time with the estimated current value and a saturation voltage, which is a function of the estimated current value.

Abstract: A power semiconductor apparatus which is provided with a first power semiconductor device using Si as a base substance and a second power semiconductor device using a semiconductor having an energy bandgap wider than the energy bandgap of Si as a base substance, and includes a first insulated metal substrate on which the first power semiconductor device is mounted, a first heat dissipation metal base on which the first insulated metal substrate is mounted, a second insulated metal substrate on which the second power semiconductor device is mounted, and a second heat dissipation metal base on which the second insulated metal substrate is mounted.

Abstract: The threshold value for a normally-off junction FET is a low value. Accordingly, in a semiconductor driver circuit using the normally-off junction FET, there have existed such problems as high-accuracy voltage control, high-speed charging into an input capacitor, and misoperations. A semiconductor driver circuit which is the most suitable for the normally-off junction FET is proposed by applying the high-accuracy gate-voltage generation scheme based on a Zener diode, a reduction in the turn-on loss based on a speed-up capacitor, the connection of an inter-gate-source capacitor, and a misoperation-preventing circuit based on the source-terminal optimum implementation scheme.

Abstract: The present invention provides a power converter which, while ensuring safety, implements control for the flow of a constant current in a specified switching element, more accurately determines the lifetime of a switching element, and reduces the number of temperature detectors. The power converter is provided with a mechanism which causes a brake device to operate or which confirms that a brake mechanism is operating. The power converter supplies current to the d-axis and the q-axis of a rotational coordinate system, within the range of the braking torque of the brake mechanism, and passes the desired current to the desired element. Furthermore, temperature detectors are attached only in chips in sections where a crack readily develops in the upper solder layer or peeling is readily generated in the wire bonding, and in chips where a crack readily develops in the lower solder layer.

Abstract: The invention provides a switching circuit and a power converter having a built-in power source for a conduction control terminal even if they have a single-arm structure. In the switching circuit having a switching device and a conduction control terminal power source capacitor, a negative terminal of the capacitor is connected to a reference voltage terminal of a main power source and to the gate terminal selectively through a half-bridge circuit and a positive terminal of the capacitor is selectively connected to a positive terminal of the main power source and to a source terminal of the switching device through a half-bridge circuit. The capacitor is charged when the positive terminal is connected to the main power source and discharges when the negative terminal is connected to the gate terminal and the positive terminal is connected to the source terminal and applies voltage to the gate terminal of the switching device.

Abstract: In order to reduce the average power of the ringing noise, the present invention provides a power converter comprising: an arm circuit including a high-voltage side switching device to which a first diode is connected in parallel and a low-voltage side switching device to which a second diode is connected in parallel; and a main power supply connected to a series circuit of the high-voltage side switching device and the low-voltage side switching device, wherein a connecting point between the high-voltage side switching device and the low-voltage side switching device is connected to a load, and a resonant frequency calculated from inductances of wirings of a closed circuit including the first diode, the second diode, and the main power supply and a capacitance across the first diode is different form that calculated from the inductances of the wirings and a capacitance across the second diode.

Abstract: A gate driving circuit for a voltage-driven power semiconductor switching device has (a) the voltage-driven power semiconductor switching device, (b) a driving circuit for supplying a drive signal to the gate electrode of the switching device, and (c) an inductance between the emitter control terminal or source control terminal of the switching device and the emitter main terminal or source main terminal of a semiconductor module. A voltage produced across the inductance is detected. The gate-driving voltage or gate drive resistance is made variable based on the detected value.

Abstract: An inverter system having a semiconductor device, and a railway vehicle using this inverter, provide a more accurate determination of whether an abnormal heat generation from the inverter is associated with an error of the inverter system or is due to other causes, by use of a plurality of temperature detecting elements at a plurality of sites associated with the semiconductor device. An error detection section applies inputs from the temperature detecting elements, captures a trend of the differential value based on the plurality of temperature inputs using period sampling wherein an error associated with the semiconductor device, and not from some other condition such as outside environment temperature, is determined based on differences from, or a change in, the initial trend.

Abstract: The threshold value for a normally-off junction FET is a low value. Accordingly, in a semiconductor driver circuit using the normally-off junction FET, there have existed such problems as high-accuracy voltage control, high-speed charging into an input capacitor, and misoperations. A semiconductor driver circuit which is the most suitable for the normally-off junction FET is proposed by applying the high-accuracy gate-voltage generation scheme based on a Zener diode, a reduction in the turn-on loss based on a speed-up capacitor, the connection of an inter-gate-source capacitor, and a misoperation-preventing circuit based on the source-terminal optimum implementation scheme.