Toshiba Mitsubishi-electric Industrial Systems Corporation

Fuji Jukogyo Kabushiki Kaisha

Omron Corporation

Tmeic Corporation

Mitsubishi Electric Corporation

Kobe Electric Industry Inc.

Masahiro Kinoshita

Yushin Yamamoto

Tatsuaki Amboh

Eduardo Kazuhide Sato

Issei Fukasawa

Atsushi Ikeda

Kimiyuki Koyanagi

Kazumasa Arai

Hiroyuki Iwasaka

Keisuke Ohnishi

Yoshihiro Tawada

Tsuguhiro Tanaka

Masaru Toyoda

Tatsuaki Ambo

Toshimitsu Fujiwara

Naoya Shibata

Hiroshi Masunaga

Tomoya Katsukura

Kazuki Nishimura

Shoichi Abe

Katsumi Ikeda

Yoshihiro Tanabe

Hideyuki Bingo

Wataru Nakamura

Hideshi Tsugui

Jun Sasaki

Makoto Nakamura

Morito Akiyama

Takashi Kondo

Hiroyuki Fujita

Ayaka Miyake

Kazuhiro Tsutsui

Ruben Alexis Inzunza Figueroa

Hiroyoshi Komatsu

Kazunori Sanada

Noriyoshi Matsuo

Kenta Yamabe

Toshiya Arakawa

Hideyuki Urata

Kazuhiro Fukamachi

Yasunari Kitajima

Tingan Lee

Tomonori Ujiie

Kazuhide Eduardo Sato

Yasuhiro Yabunishi

Takeshi Horiuchi

Teppei Sumino

Seiichi Kurosawa

Shinichi Satomi

Keisuke Tsuji

Masakazu Okayasu

Katsuya Umeda

Nobuyuki Nagai

Toshiki Tatsuta

A controller for a power conversion system includes a determination unit configured to determine whether a current time is in nighttime in an environment of a power converter that is connected to one or both of a direct-current power supply and an alternating-current power supply, and a control unit configured, in a case that the determination unit determines that the current time is in the nighttime, to maintain a switch in a closed state, the switch being provided between the power converter and one of the alternating-current power supply and the direct-current power supply, and to maintain power consumption by a resistor provided in a main circuit inside a housing of the power converter. The power conversion system can suppress lowering of temperature inside a housing without separately including a space heater.

Controller for power conversion system

A control device includes a modulation rate calculator configured to calculate a modulation rate based on a DC voltage on a DC side an, a limiter configured to update a DC voltage command lower bound limiter based on the lower bound limiter operation value; a maximum power point tracking controller configured to calculate a first DC voltage command value and determine a second DC voltage command value based on the calculated first DC voltage command value and the DC voltage command lower bound limiter set to the limiter, and an inverter controller configured to control an inverter of the power conversion system based on the second DC voltage command value.

Control device and power conversion system

A multiple power conversion system includes a plurality of first to n-th unit power converters. DC positive sides of the plurality of unit power converters are connected to one another, DC negative sides of the plurality of unit power converters are connected to one another, and n is an integer of two or more. The multiple power conversion system further includes a detector to detect a current flowing through the DC positive side or the DC negative side of a corresponding one of (n−1) or more of the plurality of unit power converters. The multiple power conversion system that can detect a circulating current with a smaller number of current sensors.

Multiple power conversion system

An electric power conversion apparatus includes: an electric power conversion circuit that allows a DC terminal to be connected to a DC power source via a DC bus line, and performs at least one of converting DC power of the DC power source into AC power to output, or converting AC power into DC power to output; a DC switch turned on when the electric power conversion circuit performs electric power conversion; an AC switch provided on a side of the AC terminal, and turned on when the electric power conversion circuit performs the electric power conversion; a DC voltmeter that measures a potential at a predetermined portion, on a side of the DC terminal; a ground connection portion that connects the DC bus line and ground potential; and a control circuit connected to the electric power conversion circuit, the DC switch, the AC switch, and the DC voltmeter.

Electric power conversion apparatus and electric power conversion system

A power conversion system including a plurality of power conversion devices connected in parallel. Each of the plurality of power conversion devices includes: a power conversion circuit configured to convert DC to AC; and an AC filter circuit connected to an output side of the power conversion circuit. The AC filter circuit is an LC low-pass filter including a first filter reactor and an AC filter capacitor connected in an L shape. The AC filter circuit further includes a second filter reactor connected in series to the AC filter capacitor, and a resistance constructing a series circuit together with the AC filter capacitor and the second filter reactor.

Power conversion system having a plurality of power conversion devices connected in parallel

A multiplex power conversion system enabling preventing a failure from spreading, with a simple configuration. The multiplex power conversion system includes a plurality of unit power converters. In the plurality of unit power converters, respective direct-current positive sides are connected. Respective direct-current negative sides are connected. Respective direct-current neutral points are not short-circuited. For example, the respective direct-current neutral points are not connected. Therefore, a failure in a power converter can be prevented from spreading.

Multiplex power conversion system having means to prevent failure spread

A power conversion device includes a power conversion module, a phase change material, a heat dissipation member, a cooling mechanism, and a controller. A semiconductor switching element and a freewheeling diode configure a power conversion circuit. The phase change material is provided on a principal plane of a casing. The heat dissipation member includes a heat dissipation surface. The heat dissipation surface is overlapped with the principal plane to sandwich the phase change material. The cooling mechanism cools the heat dissipation member. The controller generates a driving signal for driving the power conversion circuit and controls the cooling mechanism. The controller includes a predetermined heating operation. The heating operation may drive the power conversion circuit, in a state that the cooling mechanism is stopped or intermittently operated, such that heat generation occurs in both the semiconductor switching element and the freewheeling diode.

Power conversion device and method for manufacturing the same

A control system of a power converter includes a plurality of carrier wave generating units which are respectively provided for a plurality of power converters connected between a plurality of DC power supplies and a common AC power supply and which are configured to respectively generate carrier waves on the basis of an AC voltage of the AC power supply. The control system of the power converter can thereby synchronize carrier phases of a plurality of power converters.

Control system of power converter

A control device for a power converter that can suppress oscillation of an output voltage of the power converter. The control device for the power converter includes an overvoltage detector configured to detect an overvoltage on an output side of the power converter and a controller configured to, when the overvoltage on the output side of the power converter is detected by the overvoltage detector, perform gate block after reducing a current command value given to the power converter. With the configuration, when the overvoltage on the output side of the power converter is detected, the control device performs the gate block after reducing the current command value given to the power converter. Accordingly, it is possible to suppress oscillation of an output voltage of the power converter.

Control device for power converter

A power conversion device includes: a power conversion circuit for converting DC power into AC power; and a controller to generate a control signal for the power conversion circuit based on a control command value and an output voltage of the power conversion circuit. The controller is configured to generate the control signal based on a corrected voltage command value calculated by subtraction correction to decrease a voltage command value when the output voltage of the power conversion circuit is equal to or higher than a predetermined threshold value, and to generate the control signal based on a voltage command value not subjected to the subtraction correction when the output voltage of the power conversion circuit is lower than the threshold value.

Power conversion device and power conversion system

A power system includes an AC power supply, an AC filter circuit, an AC circuit breaker, and a first switch. The AC filter circuit includes an inductor having one end connected in series to an output end of the AC power supply, and a capacitor having one end receiving a voltage at another end of the inductor. The AC circuit breaker exists between the other end of the inductor and an electric power grid. The first switch switches a state between the one end of the capacitor and a wire connecting the other end of the inductor to the AC circuit breaker, between a connected state and a disconnected state. The AC power supply may be a generator and include a generator control unit controlling the generator. The generator control unit may turn off the first switch when the AC power supply operates in a predetermined standby mode.

Power conversion device, power system and method of suppressing reactive power in power system

A power conditioner includes an inverter circuit that converts a DC voltage into an AC voltage, a voltage dividing circuit having one end connected to the positive electrode input terminal and the other end connected to the negative electrode input terminal, and a ground fault detector configured to receive a voltage divided by the voltage dividing circuit as an input voltage signal and to detect an occurrence of a ground fault based on the magnitude of the voltage of the input voltage signal. the ground fault detector emits an AC ground fault detection signal when the input voltage signal includes a first voltage signal having a frequency equal to or higher than a predetermined first frequency and a deviation of the first voltage signal with respect to an AC ground reference potential is equal to or larger than an AC ground fault detection voltage.

Ground fault detector and power conditioner with input-side ground fault detection

A control device for an electric power conversion apparatus, the control device detecting occurrence of an earth fault in a direct-current path in a system in which the direct-current path between a solar cell module and an electric power conversion apparatus is grounded, is provided. The control device for the electric power conversion apparatus includes: a grounding control unit configured to, in a system in which a direct-current path between a solar cell module and an electric power conversion apparatus is grounded via a switch, control a switch; and an earth fault determination unit configured to, when the switch is open under the controlled of the grounding control unit, detect whether or not an earth fault has occurred in the direct-current path.

Control device for electric power conversion apparatus

According to an embodiment of the invention, a power conversion device that includes a power converter, a direct current capacitor, a voltage sensor, a rectifying element, an electromagnetic contactor, and a control circuit is provided. The power converter includes a pair of direct current terminals connected to a direct current power supply, includes multiple alternating current terminals connected to an electric power system of alternating current, converts direct current power input from the direct current power supply into alternating current power, and supplies the alternating current power to the electric power system. The direct current capacitor is connected between the pair of direct current terminals. The voltage sensor detects a voltage value of the direct current capacitor. The rectifying element is provided between the direct current capacitor and the direct current power supply and suppresses a reverse flow of electrical power from the power converter and the direct current capacitor into the direct current power supply. The electromagnetic contactor is connected in parallel with the rectifying element. The control circuit controls operations of the power converter and the electromagnetic contactor. In the case where the voltage value of the direct current capacitor detected by the voltage sensor is a prescribed value or more, the control circuit engages the electromagnetic contactor and supplies active power from the power converter to the electric power system; and in the case where the voltage value of the direct current capacitor detected by the voltage sensor is less than the prescribed value, the control circuit opens the electromagnetic contactor and supplies a reactive power from the power converter to the electric power system.

Power conversion device and method for operating same with reactive power compensation

A control device for a power conversion device that is capable of detecting current abnormality of the power conversion device with no delay is provided. The control device for the power conversion device includes a current detection unit for outputting an error signal when a detection value of a current sensor for detecting current flowing through the power conversion device is larger than a preset overcurrent determination value, and outputting a state detection value larger than a value corresponding to the error signal based on the error signal, and an abnormality detection unit for accepting an input of the state detection value of the current detection unit via the wiring, and an abnormality detection unit for outputting an error signal when the state detection value of the current detection unit is larger than a preset overcurrent abnormality determination value, and detecting abnormality based on the error signal.

Power conversion device including overcurrent detection with reduced delay

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Tokyo, Japan

Masahiro Kinoshita