Omron Corporation

Hironori Nakada

Satoshi Iwai

Noriyuki Nosaka

Wataru Okada

Yuhki Kamatani

Takeo Nishikawa

Takuro Hashimoto

Hiroki Kawano

Kuniyuki Hirai

A power converter includes a capacitor for smoothing a voltage entering therein, first and second switching units, a reactor, an isolated transformer, a second capacitor, and a controller for controlling the switching of the first and second switching units. The controller converts direct-current power to alternating-current power via the reactor and the isolated transformer and converts the alternating-current power to direct-current power via the second capacitor. The controller includes a phase-shift operation unit for taking at least any of first switching control signals as a reference signal and for calculating a phase shift that shifts the phase of the reference signal, as well as a logic operation unit for performing a logic operation that takes the signal resulting from shifting the phase of the reference signal by exactly the phase shift as input and for outputting a second switching control signal.

Power conversion device that performs synchronous control of switching elements to achieve synchronous rectification

A driving circuit for a switching element that drives a switching element of a current-driven type. The driving circuit includes a controller including a first terminal and a second terminal and that outputs a control signal to a gate terminal of the switching element. A first resistor, which regulates a current serving as the control signal, is connected to the first terminal, and a first capacitor is connected in parallel to the first resistor. A second resistor and a second capacitor are connected in parallel, and a current path extends from the first resistor and the first capacitor to the gate terminal and from a source terminal of the switching element to the second terminal of the controller. The second resistor and the second capacitor are in the current path.

Driving circuit for switching element and switching circuit

An overcurrent protection circuit is provided for a switching element turned on/off based on a control voltage. The overcurrent protection circuit includes a first transistor and a second transistor. The first transistor is a PNP bipolar transistor and has an emitter connected to the control voltage. The second transistor is an NPN bipolar transistor and has a base connected to a collector of the first transistor, a collector connected to a base of the first transistor and pulled up to a predetermined pull-up voltage, and a grounded emitter. When the control voltage exceeds a predetermined first threshold voltage, the first and second transistors are turned on, the control voltage is dropped by drop of the pull-up voltage, and thus the overcurrent protection circuit starts a protection operation of turning off the switching element.

Overcurrent protection circuit for switching element turned on and off based on control voltage

A switching elementhas a gate terminal connected to an output end Vout of a driving circuitvia a capacitorand a resistorconnected in parallel. The switching elementhas a source terminal connected to the driving circuitvia a capacitorand a Zener diodeconnected in parallel. The Zener diodehas an anode terminal connected to the source terminal of the switching elementand a cathode terminal connected to the driving circuit

Driving circuit for switching element, and switching circuit

A switching elementhas a gate terminal connected to an output endof a driving circuitvia a capacitorand a resistorconnected in parallel. The switching elementhas a source terminal connected to the driving circuitvia a capacitor. A diodeconnected in series with a resistorhas a cathode terminal connected to a section between the capacitorand the resistor, and the gate terminal and an anode terminal connected, via the resistor, to a section between the source terminal and the capacitor

A power converter is provided with an inverter unit for converting DC power from a DC power supply into AC power, and a control unit that generates a control signal for controlling the inverter unit. The control unit includes an impedance estimation unit that injects a disturbance signal into a load and derives an estimated value of an impedance of the load based on a voltage signal from the load into which the disturbance signal is injected, the impedance compensator unit whose control parameters are set based on the estimated value of the impedance, and that corrects an output current signal in accordance with the control parameters, a command value unit that outputs a command value indicating a control target value, and a control compensator unit that generates a control signal, based on the command value from the command value unit and the current signal from the impedance compensator unit.

Power converter for converting DC power to AC power with adaptive control on characteristics of load

An inverter has a plurality of switching elements, the states of which are each switched by a pulse signal supplied in accordance with a power grid voltage. The inverter is provided with: a switching circuit that converts an input DC voltage to an AC voltage and outputs the AC voltage to a pair of output lines; a filter circuit having output coils inserted in the output lines; a current detection sensor that detects the current flowing through the output coils; and a high-speed pulse control circuit that, when an absolute value of the detected current is a threshold value or more, stops the supply of the pulse signal to the switching circuit.

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Nara, Japan

Hironori Nakada