Toshiba Mitsubishi-electric Industrial Systems Corporation

Mitsubishi Electric Corporation

Tmeic Corporation

Jumpei Isozaki

Taichiro Tsuchiya

Akito Nakayama

Yuki Ishii

Takayuki Yachida

Shohei Harada

Yuhei Wada

First to third capacitors each have an identical shape of a rectangular parallelepiped. The rectangular parallelepiped has a first surface with a first side and a second side, a second surface with the second side and a third side, and a third surface with the third side and the first side. The first side has a length not less than twice and less than three times a length of the third side. The first and second capacitors are arranged such that the first surfaces thereof are perpendicular to an installation surface, the first surfaces face each other, and the second surfaces are horizontal to the installation surface. The third capacitor is arranged such that the first surface thereof faces the second surfaces of the first and second capacitors and the third surface thereof is flush with the third surfaces of the first and second capacitors.

Power conversion apparatus

A main circuit power supply device includes: a plurality of voltage-division power storage elements connected in series; voltage adjustment circuits for adjusting each of voltages of the plurality of voltage-division power storage elements through mutual transfer of power between the plurality of voltage-division power storage elements; and at least one DC/DC converter which is connected to at least one of the voltage-division power storage elements and supplies a control power source to a main circuit control circuitry to control a main circuit.

Power conversion device

Each of a plurality of unit converters includes: a main circuit; a control circuit that controls the plurality of switching elements according to a control signal received from the controller; a power supply that lowers a voltage of a first capacitor to generate a power supply voltage and supplies the power supply voltage to the control circuit; and a current-limiting resistance circuit having a variable resistance value and disposed between the main circuit and the power supply. The power supply includes a second capacitor, an overcharge suppression circuit, a power supply circuit, and a controller. The controller includes: an overcharge suppression control circuit that controls the overcharge suppression circuit in accordance with a magnitude of a voltage of the second capacitor; and a resistance switching circuit that changes a resistance value of the current-limiting resistance circuit in accordance with a magnitude of a voltage of the first capacitor.

Current limiting circuit for multilevel power converter cell

A power supply includes a second capacitor, an overcharge suppression circuit, a power supply circuit, and a controller. The controller includes: an overcharge suppression control circuit that controls the overcharge suppression circuit in accordance with a magnitude of a voltage of the second capacitor; and a resistance switching circuit that changes a resistance value of the current-limiting resistance circuit depending on whether a gate block state occurs or not and in accordance with a magnitude of the voltage of the first capacitor. In the gate block state, each of the switching elements is fixed in a non-conductive state.

A master converter and a plurality of slave converters each have an input connected to an associated one of a plurality of power storage elements, respectively, and an output connected to an output terminal in parallel. The master converter converts the voltage of the associated capacitor based on a duty ratio for matching an output voltage to a voltage command value, outputs the converted voltage to the output terminal, and transmits a control signal indicative of the duty ratio to the plurality of slave converters via a signal insulation unit. Each of the plurality of slave converters converts the voltage of the associated capacitor in response to the control signal transmitted via the signal insulation unit and outputs the converted voltage to the output terminal. A correction means is configured to correct at least the duty ratio in the master converter such that the duty ratio in the master converter matches the duty ratio in each of the plurality of slave converters.

Self-power feed circuit and power conversion device

A power supply circuit is configured to convert a voltage of a second electricity storage element into a power supply voltage for a driving circuit, and a voltage detector is configured to detect the voltage of the second electricity storage element. A unit converter includes a first resistor connected to the second electricity storage element electrically in series between the terminals of a first electricity storage element, and a second resistor and a first switch connected electrically in series between the terminals of the second electricity storage element. The power supply circuit is configured to generate a control signal for controlling the first switch on and off based on the detection value from the voltage detector. The power supply circuit is further configured to sense an overloaded state of the second resistor based on the control signal.

A control unit activates a power supply circuit when an input voltage becomes equal to or greater than a first threshold value. The control unit brings a switch into a conductive state when the input voltage becomes equal to or greater than a second threshold value and brings the switch into a non-conductive state when the input voltage becomes equal to or less than a third threshold value. The control unit deactivates the power supply circuit when the input voltage becomes equal to or less than a fourth threshold value. Based on the number of times that the input voltage becomes equal to or greater than the second threshold value after the power supply circuit is activated, the control unit further enables a latch function for holding the power supply circuit in a deactivated state.

Growing community of inventors

Chuo-ku, Japan

Jumpei Isozaki