Hitachi, Ltd.

Renesas Technology Corp.

Hitachi Industrial Equipment Systems Co., Ltd.

Renesas Electronics Corporation

Hitachi Automotive Systems, Ltd.

Takuya Ishigaki

Akihiko Kanouda

Takae Shimada

Koji Tateno

Yasuaki Norimatsu

Yuuichi Mabuchi

Ryotaro Kudo

Takashi Sase

Tadahiko Chida

Yusuke Uei

Yutaka Matsumoto

Noboru Akiyama

Takayuki Hashimoto

Hiroyuki Shoji

Takashi Hirao

Fumihiro Sato

Masaki Sugiura

Tetsuo Yanada

Eigo Kishimoto

Naoya Takahashi

Hideto Takada

Takayuki Ouchi

A power conversion system includes a power conversion device supplying electric power to a motor and a power supply device supplying electric power to the power conversion device. The power conversion device includes a reverse converter that converts the electric power, a control circuit that controls the reverse converter, and a current detector that detects current flowing through the reverse converter. The power supply device includes a storage device that stores electric power in accordance with a voltage, a step-up/down power supply circuit that changes the voltage of the storage device based on a voltage command, and a voltage command computing circuit that computes the energy stored in the storage device and output it as the voltage command to the step-up/down power supply circuit. When the characteristics of the motor are restricted, the voltage command computing circuit temporarily changes the voltage command to improve the motor characteristics.

Power conversion system and motor control method based on same

A resonance type power supply device includes: a power supply main circuit having a transformer, a resonance element connected on a primary side of the transformer, and a plurality of switching elements connected to the resonance element; and a power supply control circuit switching the plurality of switching elements in the power supply main circuit with a predetermined switching frequency, in which the power supply control circuit includes: a voltage controller outputting a current command value from a reference voltage, an output voltage of the power supply main circuit, and a voltage control gain; a current controller calculating a reference current, a current flowing on a secondary side of the transformer, and a current control gain; a gain calculator outputting the voltage control gain and the current control gain; and a control signal generator controlling the plurality of switching elements based on the switching frequency outputted by the current controller, and the gain calculator outputs the voltage control gain or current control gain that is proportional to the switching frequency outputted by the current controller.

Resonance type power supply device

An object of the present invention is to provide a charging apparatus having high efficiency of charging a battery by inputting an alternating current voltage. A charging apparatus that charges a direct current battery includes a step-down converter unit to which a direct current voltage from a power supply is input and that converts the direct current voltage, and when a voltage of the direct current battery is between a predetermined first voltage smaller than a charge completion voltage of the direct current battery and the charge completion voltage, a variable voltage that increases from the first voltage to the charge completion voltage in accordance with charging of the direct current battery is input to the step-down converter unit.

Power supply apparatus

If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.

Power conversion apparatus with frequency operation change based on input voltage

Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.

Power conversion device and power conversion control method for the same

Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs. An insulation cooling structure is provided by a wind-tunnel structure in which two input and output substrates are opposed and are connected by insulation members, and another wind-tunnel structure arranged in the downstream of the wind-tunnel structure and including the LLC resonant structure therein. The wind-tunnel structures are integrated with each other.

A semiconductor device for control applied to a constant-voltage power supply device includes a digital-analog converter circuit which outputs a reference voltage corresponding to a value of a first register with taking an output voltage of a reference voltage source as a criterial reference voltage, and generates a control signal for driving a power semiconductor device based on an output voltage of an error amplifier which differentially amplifies a feedback voltage obtained by resistive-dividing on an output voltage of the constant-voltage power supply device and the reference voltage. An analog-digital converter circuit which converts the feedback voltage to a digital value with taking the output voltage of the constant-voltage power supply device as a reference voltage is provided, and based on the output, a value of a first register is corrected so as to offset an effect of an error in voltage dividing ratio of a voltage dividing resistor circuit.

Semiconductor device and power supply using the same

In a switching power supply apparatus for performing a switching control of a power MOS transistor that flows current to a coil and converting input voltage into output voltage, even if there occurs offset voltage in a current sensing operational amplifier, source potential of a current sensing MOS transistor is precisely kept at source potential of a low side power MOS transistor. For example, an offset cancel capacitor is arranged at an inverting input terminal of the current sensing operational amplifier, and voltage in the direction to offset the offset voltage occurring in the operational amplifier is charged to this capacitor.

Switching power supply

A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.

Growing community of inventors

Tokyo, Japan

Takuya Ishigaki