Abstract: The objective is to provide a function of detecting loss of a current detection function, at a time when a switching device has an open failure, in an arm that has the current detection function and a temperature detection function and in which two or more switching devices are connected in parallel with one another. A switching apparatus includes a current detector and a temperature detector provided in at least one of the two or more switching devices that are connected in parallel with one another and a controller that determines an overcurrent in the switching device in which the current detector is provided, that determines an overheating state and a temperature-rising failure in the switching device in which the temperature detector is provided, based on an output of the temperature detector, and that controls the switching devices.

Abstract: To provide a controller for power conversion circuit which can maintain the detection value of second voltage at the target value of second voltage without depending on feedback control, when the first voltage is varied. A controller for power conversion circuit changes a control value by feedback control so that the detection value of second voltage approaches a target value of second voltage; calculates a control value for control, by correcting the control value based on the detection value of first voltage so as to correct, in feedforward manner, a change of the control value due to a change of the first voltage if correction of the control value is not performed; and controls on/off the switching device based on the control value for control.

Abstract: The objective is to provide a function of detecting loss of a current detection function, at a time when a switching device has an open failure, in an arm that has the current detection function and a temperature detection function and in which two or more switching devices are connected in parallel with one another. A switching apparatus includes a current detector and a temperature detector provided in at least one of the two or more switching devices that are connected in parallel with one another and a controller that determines an overcurrent in the switching device in which the current detector is provided, that determines an overheating state and a temperature-rising failure in the switching device in which the temperature detector is provided, based on an output of the temperature detector, and that controls the switching devices.

Abstract: To provide a power converter which can maintain the stability and the response of the feedback control system, even if the frequency characteristic of the chopper circuit changes according to change of driving condition. A power converter is provided with a chopper circuit which has reactor and switching device; and a control circuit which changes a feedback value of duty ratio of the switching device so that a deviation between a target value of output voltage and a detection value of output voltage approaches to 0, wherein the control circuit changes a frequency characteristic of the feedback control, based on at least any two or more of information on the output voltage, information on an input voltage, and information on duty ratio.

Abstract: With respect to a failure in voltage sensors each for detecting a high-voltage-side voltage in a DC/DC converter, it is so arranged that a circuit failure of the DC/DC converter is prevented, and that the DC/DC converter is continuingly controlled. Two voltage sensors are included therein each for detecting a high-voltage-side voltage, so that, even when a first voltage sensor for detecting a high-voltage-side voltage on one side fails to work properly, a control device turns on a second switching device, and detects a voltage by a second voltage sensor for detecting the high-voltage-side voltage on the other side, whereby a failure of the voltage sensor for detecting the high-voltage-side voltage is detected.

Abstract: A power conversion device including an intermediate capacitor that carries out a charging and discharging operation and a voltage sensor that detects a voltage of the intermediate capacitor, and including a current sensor that detects a current flowing in a reactor, and an abnormality determining unit that determines that there is an abnormality of the voltage sensor using a current value calculated based on a detected value from the current sensor, wherein a gain error, an offset error, and a sticking error of the voltage sensor can be detected.

Abstract: A power conversion device including an intermediate capacitor that carries out a charging and discharging operation and a voltage sensor that detects a voltage of the intermediate capacitor, and including a current sensor that detects a current flowing in a reactor, and an abnormality determining unit that determines that there is an abnormality of the voltage sensor using a current value calculated based on a detected value from the current sensor, wherein a gain error, an offset error, and a sticking error of the voltage sensor can be detected.

Abstract: To provide a power converter which can maintain the stability and the response of the feedback control system, even if the frequency characteristic of the chopper circuit changes according to change of driving condition. A power converter is provided with a chopper circuit which has reactor and switching device; and a control circuit which changes a feedback value of duty ratio of the switching device so that a deviation between a target value of output voltage and a detection value of output voltage approaches to 0, wherein the control circuit changes a frequency characteristic of the feedback control, based on at least any two or more of information on the output voltage, information on an input voltage, and information on duty ratio.

Abstract: With respect to a failure in voltage sensors each for detecting a high-voltage-side voltage in a DC/DC converter, it is so arranged that a circuit failure of the DC/DC converter is prevented, and that the DC/DC converter is continuingly controlled. Two voltage sensors are included therein each for detecting a high-voltage-side voltage, so that, even when a first voltage sensor for detecting a high-voltage-side voltage on one side fails to work properly, a control device turns on a second switching device, and detects a voltage by a second voltage sensor for detecting the high-voltage-side voltage on the other side, whereby a failure of the voltage sensor for detecting the high-voltage-side voltage is detected.

Abstract: An inverter circuit is connected in series to an AC power supply, and at the subsequent stage, a smoothing capacitor is connected via a converter circuit including semiconductor switching devices. A control circuit controls the converter circuit by providing a short-circuit period for bypassing the smoothing capacitor in each cycle, and controls the inverter circuit to improve the power factor of the AC power supply by using a current instruction such that the voltage of the smoothing capacitor becomes a target voltage. When the voltage of a DC voltage source of the inverter circuit has exceeded a predetermined upper limit, the control circuit increases the current instruction to control the inverter circuit, thereby increasing the discharge amount of the DC voltage source. Thus, even if the voltage variation of the DC voltage source of the inverter circuit increases, it is possible to stably continue the control.

Abstract: A power conversion apparatus includes a high-power-factor converter section converting an AC voltage to a DC voltage, a smoothing capacitor, a DC/DC converter section, and a control circuit. The control circuit controls the high-power-factor converter section such that the power factor of AC is controlled and a DC voltage follows a target value, and performs duty control for semiconductor switching devices such that a DC voltage from the DC/DC converter section to a load follows an instruction value. In accordance with the DC voltage, the control circuit adjusts the DC voltage target value of the high-power-factor converter section such that the duty ratio of the semiconductor switching devices approaches a set value, thereby optimizing the duty ratio of the semiconductor switching devices and reducing power loss.

Abstract: A DC-DC converter in which a primary side and a secondary side are insulated by a transformer, includes: two diodes having anodes respectively connected to both ends of a secondary winding of the transformer and cathodes connected to each other; a series circuit composed of a resistor and a capacitor connected in series; and a snubber circuit formed by connecting the cathodes of the diodes to the connection point between the resistor and the capacitor. Surge voltage caused on the secondary side of the transformer is clamped at the voltage of the capacitor, and surge energy stored in the capacitor is regenerated to a load via the resistor. Thus, surge voltage caused on the secondary side of the transformer is suppressed with a simple configuration, and effective use of surge energy is ensured.

Abstract: A DC-DC converter in which a primary side and a secondary side are insulated by a transformer, includes: two diodes having anodes respectively connected to both ends of a secondary winding of the transformer and cathodes connected to each other; a series circuit composed of a resistor and a capacitor connected in series; and a snubber circuit formed by connecting the cathodes of the diodes to the connection point between the resistor and the capacitor. Surge voltage caused on the secondary side of the transformer is clamped at the voltage of the capacitor, and surge energy stored in the capacitor is regenerated to a load via the resistor. Thus, surge voltage caused on the secondary side of the transformer is suppressed with a simple configuration, and effective use of surge energy is ensured.

Abstract: In order to widen an operational input voltage range of a power conversion apparatus and obtain a maximum efficiency value comparable to that in a case where the operational input voltage range is not widened by changing software but not hardware, provided is a power conversion apparatus, in which a control section (5) controls a current input to an inverter circuit (14) to cause a DC output voltage from an AC/DC converter section (10) which is a voltage across a smoothing capacitor (22) to follow a target voltage and to cause an input power factor from an AC power supply (1) to approach one, to thereby maintain a DC voltage from a single-phase inverter (14a), and adjusts the target voltage for the DC output voltage from the AC/DC converter section (10) in accordance with a voltage of the AC power supply (1).

Abstract: An inverter circuit is connected in series to an AC power supply, and at the subsequent stage, a smoothing capacitor is connected via a converter circuit including semiconductor switching devices. A control circuit controls the converter circuit by providing a short-circuit period for bypassing the smoothing capacitor in each cycle, and controls the inverter circuit to improve the power factor of the AC power supply by using a current instruction such that the voltage of the smoothing capacitor becomes a target voltage. When the voltage of a DC voltage source of the inverter circuit has exceeded a predetermined upper limit, the control circuit increases the current instruction to control the inverter circuit, thereby increasing the discharge amount of the DC voltage source. Thus, even if the voltage variation of the DC voltage source of the inverter circuit increases, it is possible to stably continue the control.

Abstract: A power conversion apparatus includes a high-power-factor converter section converting an AC voltage to a DC voltage, a smoothing capacitor, a DC/DC converter section, and a control circuit. The control circuit controls the high-power-factor converter section such that the power factor of AC is controlled and a DC voltage follows a target value, and performs duty control for semiconductor switching devices such that a DC voltage from the DC/DC converter section to a load follows an instruction value. In accordance with the DC voltage, the control circuit adjusts the DC voltage target value of the high-power-factor converter section such that the duty ratio of the semiconductor switching devices approaches a set value, thereby optimizing the duty ratio of the semiconductor switching devices and reducing power loss.

Abstract: In order to widen an operational input voltage range of a power conversion apparatus and obtain a maximum efficiency value comparable to that in a case where the operational input voltage range is not widened by changing software but not hardware, provided is a power conversion apparatus, in which a control section (5) controls a current input to an inverter circuit (14) to cause a DC output voltage from an AC/DC converter section (10) which is a voltage across a smoothing capacitor (22) to follow a target voltage and to cause an input power factor from an AC power supply (1) to approach one, to thereby maintain a DC voltage from a single-phase inverter (14a), and adjusts the target voltage for the DC output voltage from the AC/DC converter section (10) in accordance with a voltage of the AC power supply (1).

Abstract: A transmitter node includes a first data transmission portion that transmits data in a first transmission time slot on a first transmission channel and a second data transmission portion that transmits the same transmission data from the first data transmission portion in a second transmission time slot on a second transmission channel that does not superimpose in time on the first transmission time slot. A receiver node includes a first data reception portion that receives data transmitted from the transmitter node in a first reception time slot superimposing in time on the first transmission time slot on the first transmission channel and a second data reception portion that receives transmission data transmitted from the second data transmission portion in a second reception time slot on the second transmission channel superimposing in time on the second transmission time slot. Data transmission and reception can be thus ensured even at a trouble.

Abstract: A transmitter node includes a first data transmission portion that transmits data in a first transmission time slot on a first transmission channel and a second data transmission portion that transmits the same transmission data from the first data transmission portion in a second transmission time slot on a second transmission channel that does not superimpose in time on the first transmission time slot. A receiver node includes a first data reception portion that receives data transmitted from the transmitter node in a first reception time slot superimposing in time on the first transmission time slot on the first transmission channel and a second data reception portion that receives transmission data transmitted from the second data transmission portion in a second reception time slot on the second transmission channel superimposing in time on the second transmission time slot. Data transmission and reception can be thus ensured even at a trouble.