Fuji Electric Co., Ltd.

Qichen Wang

Satoru Fujita

Ryuji Yamada

Nobuyuki Tawada

Yoshinari Ikeda

Takaaki Tanaka

Motohito Hori

Takashi Kuwabara

Kazuyuki Yoda

A semiconductor device includes a first input conductive plate on which a plurality of first semiconductor chips arranged in a first direction, a first output conductive plate extending in the first direction and being provided adjacent to the first input conductive plate, a case having first to fourth side walls for accommodating the first input conductive plate and the first output conductive plate, first main current wiring members, each of which connects one of the first output electrodes to a front surface of the first output conductive plate, a first detection terminal disposed in the first side wall, and a first detection wiring member connecting the front surface of the first output conductive plate to the first detection terminal. The first output conductive plate is disposed closer to the first side wall than is the first input conductive plate.

Semiconductor device and method for determining deterioration of semiconductor device

A snubber apparatus includes N parallel charge paths, each of which has a positive-side capacitor, a first diode, and a negative-side capacitor sequentially connected in series between a positive-side terminal and a negative-side terminal, and that allows current to flow from the positive-side terminal's side to the negative-side terminal's side. The snubber apparatus includes N+1 parallel discharge paths, each of which has a second diode connected between the negative-side terminal or the negative-side capacitor in the k-th charge path of the N charge paths, and the positive-side capacitor in the (k+1)-th charge path of the N charge paths or the positive-side terminal, and that allows current to flow from the negative-side terminal's side to the positive-side terminal's side via at least one of the negative-side capacitor and the positive-side capacitor. At least one of the charge paths has a plurality of sections that are turned and adjacent to each other.

Snubber apparatus and power conversion apparatus

A conventional technique makes a configuration complicated. Provided is an apparatus including: a voltage measuring unit configured to measure each of instantaneous voltages of three-phase AC voltage; and a determination unit configured to determine a state of a power supply source of the three-phase AC voltage based on a result of comparison between a comparison target value corresponding to a sum of n-th powers (n is a positive even number) of the instantaneous voltages of the three-phase AC voltage and a reference value.

Apparatus, power supply, method and recording medium to determine a state of a three-phase AC power supply using instantaneous voltages of three phases of the AC voltage

A snubber module is provided, which constitutes a snubber apparatus attachable to a terminal of a semiconductor module. The snubber module includes: a positive-side capacitor, a first diode and a negative-side capacitor sequentially connected between a positive-side snubber terminal and a negative-side snubber terminal, the positive-side snubber terminal connectable to a positive-side terminal of the semiconductor module, and the negative-side snubber terminal connectable to a negative-side terminal of the semiconductor module; a first coupling terminal directly or indirectly connected to one node of either a first node between the positive-side capacitor and the first diode or a second node between the negative-side capacitor and the first diode; and a housing accommodating the positive-side capacitor, the negative-side capacitor and the first diode, and having provided therein the positive-side snubber terminal, the negative-side snubber terminal and the first coupling terminal in a manner enabling external connection.

Snubber module, snubber apparatus and power conversion apparatus

A snubber device to be mounted to a terminal of a semiconductor module is provided. The snubber device includes n (n: integer of 1 or greater) parallel charge paths each having a positive-side capacitor, a first diode, and a negative-side capacitor sequentially connected in series between positive-side and negative-side terminals of the semiconductor module, and configured to enable current to flow from the positive-side terminal toward the negative-side terminal; and (n+1) parallel discharge paths each of which having a second diode connected between the negative-side terminal or the negative-side capacitor of an Ncharge path (N: integer within a range of 0&#x2264;N&#x2264;n) of then charge paths and the positive-side capacitor of a (N+1)charge path of the n charge paths or the positive-side terminal, and configured to enable current to flow from the negative-side terminal toward the positive-side terminal via at least one of the negative-side and positive-side capacitors.

Snubber device and power conversion apparatus

A transformer includes: a core having a shaft; primary windings; and secondary windings around the shaft alternately with the primary windings. A first number of turns of a first secondary winding, closest to a first end of the shaft, is less than a second number of turns of a second secondary winding, second closest to the first end. A third number of turns of a third secondary winding, closest to a second end of the shaft, is less than a fourth number of turns of a fourth secondary winding, second closest to the second end. The first and second windings are connected in series. The third and fourth windings are connected in series. The first and second windings are connected in parallel to the third and fourth windings. A total of the first and second numbers is equal to that of the third and fourth numbers.

Transformer

A transformer is configured to include a pair of cores and that each have an inner leg, wherein a primary winding that is wound around a bobbin having a hollow into which the inner legs of the cores and are inserted, and a secondary winding that has a hollow into which the inner legs of the cores and are inserted and that is constituted of a conductor formed by die-cutting a metal plate into a ring, are dispersedly arranged over the inner legs of the cores and. The bobbin has bobbin support portions that come into contact with a surface of a printed circuit board on which the transformer is implemented.

High-frequency transformer

A power conversion device includes a potential variation suppression portion having first and second ground capacitors and a reactor, for suppressing a potential variations at an A point at which switching elements and are connected together and at a B point in a bidirectional switch. The potential variation suppression portion suppresses potential variation at the A point by cancelling a first leakage current, which flows due to the potential variation at the A point at the positive and negative polarities of an alternating current voltage, with a first compensating current flowing via the reactor and ground capacitor, and suppresses the potential variation at the B point by cancelling a second leakage current, which flows due to the potential variation at the B point at the negative polarity of the alternating current voltage, with a second compensating current flowing via the reactor, a switch, and the second ground capacitor.

Power conversion device for cancelling leakage current

A power conversion device includes an AC power source configured to output an AC voltage, a DC power source configured to output a plurality of DC voltages having different levels, an inverter configured to receive the AC voltage and the plurality of DC voltages and output an output voltage by boosting the AC voltage in a booster mode in accordance with first and second control signals, the booster mode being a mode in which a level of the AC voltage is smaller than a predetermined value, a reactor configured to smooth the output voltage of the inverter, and a control circuit configured to generate the first and second control signals using a first and second carrier signals having different frequencies, respectively, in the booster mode, and selectively output the first or second control signal in accordance with the level of the AC voltage from the AC power source.

Power conversion device

When in an operation mode in which an alternating current voltage Vout is output using a positive voltage Vof a direct current power sourceinput via a switching element Q, a negative voltage Vof the direct current power sourceinput via a switching element Q, and a zero voltage Vz input via a bidirectional switch element BSor an alternating current voltage Vs input via a bidirectional switch element BS, in the period in which the polarity of the output voltage Vout and the polarity of an output current Iout are the same, a control signal of an element to be caused to perform an on/off operation is generated by being pulse-width modulated using a carrier signal S with a first frequency, and in the period in which the polarity of the output voltage Vout and the polarity of the output current Iout are different, a control signal of an element to be caused to perform an on/off operation is generated by being pulse-width modulated using a carrier signal with a second frequency lower than the first frequency.

Inverter device

In a power converter, in a period in which the polarities of output voltage and output current of a power converter differ, a pulse train voltage corresponding to a PWM signal is output by a first switching element and a second switching element being turned off, one element of a first switch element and a second switch element being turned on, and the other element being turned on and off based on an inverted signal of a PWM signal pulse width modulated in accordance with an output voltage command.

Growing community of inventors

Hino, Japan

Qichen Wang