Abstract: A power conversion apparatus includes a power conversion circuit, a choke coil, an auxiliary coil, and a rectifier element. The choke coil is disposed between the power conversion circuit and an input side direct current power source. The auxiliary coil is magnetically coupled to the choke coil and is connected in parallel with an output side circuit. The auxiliary coil is wound in a direction so that an excitation current flows from a negative electrode to a positive electrode of the output side circuit when an excitation current flows from a positive electrode to a negative electrode of the direct current power source through the choke coil. The rectifier element is series connection with the auxiliary coil, and cuts off power supply from the direct current power source to the output side circuit through the auxiliary coil and power supply from the output side circuit to the input side.

Abstract: In a power converter, a driver that drives, according to a control signal, a switching element of a switch circuit for converting input power to output power. The control signal represents how to drive the switching element. A controller outputs the control signal to the driver for controlling the driver. A measuring unit measures a value of input power input to the switch circuit. A protection determining unit determines, based on the measured value of the input power, whether there is a need to protect the power converter. The protection determining unit outputs a stop control signal to at least one of the driver and the controller based on a result of the determination of whether there is a need to protect the power converter. The stop control signal represents whether to forcibly stop drive of the switching element.

Abstract: A power conversion apparatus includes a switch circuit which activates switching elements on the basis of a control signal, a feedback means which performs feedback control, a signal output means which outputs the control signal on the basis of a control variable of the feedback control, and a mode switching means which controls switching operation of the switch circuit by switching an operation mode between a normal mode and an intermittent mode in which the number of operations is less than that in the normal mode. The mode switching means changes timing of switching from the normal mode to the intermittent mode, on the basis of either or both of a first detection value which is an input value inputted to the switch circuit and a second detection value which is an output value outputted from the switch circuit.

Abstract: Power conversion apparatus converts input voltage and supplies output voltage to the electric load. The apparatus includes a semiconductor switch switches between open and closed states to regulate voltage control current for controlling output voltage, a first voltage detection section detects remote voltage being applied to the electric load as output voltage, a second voltage detection section detects a local voltage being applied to the output terminal as output voltage, a target current calculation section calculates target current which is the voltage control current target value, based on voltage deviation between target voltage which is the output voltage target value and either remote voltage or local voltage, and a switch control section controls the semiconductor switch so voltage control current becomes target current, to regulate output voltage to target voltage.

Abstract: In a power converter, a feedback controller feedback controls a manipulated variable based on a first electrical parameter depending on input power and a feedback controlled variable determined for output power. A dead-time determiner determines a value of the dead time as a function of a boundary condition variable depending on at least one of the input power and the output power. The boundary condition represents a reference for determining whether the power converter is operating in a continuous conduction mode or a discontinuous conduction mode. The continuous conduction mode is designed for a current to be continuously flowing through an inductor included in the power converter or a load as an inductor current. The discontinuous conduction mode is designed for the inductor current to be discontinuously flowing through the inductor.

Abstract: A current mode controlled power converter controllable in a digitally processing current mode even during an on time. In the power converter, each control period based on a reference signal includes a slope calculation period in which a slope compensation signal for the control period is calculated by a slope compensation unit. During each slope calculation period, the slope compensation unit negates the slope compensation signal calculated previous to the control period including the slope calculation period, and a reset signal generation unit compares a current detection signal detected by a current detection unit with a current instruction set to an error signal generated by an error signal generation unit to generate a reset signal.

Abstract: A power conversion apparatus for converting AC power supplied from an AC power source to DC power includes an AC-DC conversion circuit connected with the AC power source at an input end thereof for converting the AC power to DC power, a DC-DC conversion circuit connected with an output end of the AC-DC conversion circuit at an input end thereof for converting DC voltage level of the DC power generated by the AC-DC conversion circuit, a smoothing capacitor parallel connected to the output end of the AC-DC conversion circuit and the input end of the DC-DC conversion circuit, a DC link voltage detector for detecting a voltage of the smoothing capacitor as a DC link voltage, and a control unit for controlling operation of the DC-DC conversion circuit.

Abstract: A DC-DC converter generates PWM signals PWM1H, PWM1L on the basis of a reference signal CLK1 to drive switching elements connected in series. When generating a reset signal RST, the converter generates PWM signals PWM2H, PWM2L on the basis of the reset signal RST. When generating no reset signal, the converter generates the PWM signals PWM2H, PWM2L on the basis of a reference signal CLK2 in order to drive other switching elements connected in series. The converter generates the reset signal RST at an optional timing to the reference signal CLK1. The reference signal CLK2 is brought forward from the reference signal CLK1 by ?T1. The PWM signals PWM1H, PWM1L are different in timing from the PWM signals PWM2H, PWM2L. This makes it possible to avoid the switching elements diagonally arranged from being simultaneously turned on and off, and suppress a switching loss, and to increase an efficiency of the converter.

Abstract: In a power converter, a driver that drives, according to a control signal, a switching element of a switch circuit for converting input power to output power. The control signal represents how to drive the switching element. A controller outputs the control signal to the driver for controlling the driver. A measuring unit measures a value of input power input to the switch circuit. A protection determining unit determines, based on the measured value of the input power, whether there is a need to protect the power converter. The protection determining unit outputs a stop control signal to at least one of the driver and the controller based on a result of the determination of whether there is a need to protect the power converter. The stop control signal represents whether to forcibly stop drive of the switching element.

Abstract: An electric power conversion device has a transformer, a DC-AC conversion circuit, an AC-DC conversion circuit and a control circuit. The control circuit calculates an input current instruction value Iref based on a difference value ?V between an output voltage Vout of the AC-DC conversion circuit and an output voltage instruction value Vref. A comparator compares an input current Iin of the DC-AC conversion circuit with the value Iref. The DC-AC conversion circuit is controlled by the comparison result of the comparator. The control circuit correctly determines an occurrence of an abnormality state of the electric power conversion device based on the operation state of the comparator, the difference value ?V between the output voltage Vout of the AC-DC conversion circuit and the output voltage instruction value Vref, and the input voltage Vin of the DC-AC conversion circuit without using any output current of the AC-DC conversion circuit.

Abstract: A power conversion apparatus includes a switch circuit which drives switching elements based on a control signal, a feedback section which performs feedback control, a signal output section which outputs the control signal based on a controlled variable of the feedback control, an output value detecting section which detects an output value outputted from the switch circuit, and an operation determining unit which has an operation stop determination section which determines whether to stop operation of the switching elements based on a rate of change of the output value, and an operation start determination section which determines whether to start operation of the switching elements based on the controlled variable.

Abstract: In a power converter, a feedback controller feedback controls a manipulated variable based on a first electrical parameter depending on input power and a feedback controlled variable determined for output power. A dead-time determiner determines a value of the dead time as a function of a boundary condition variable depending on at least one of the input power and the output power. The boundary condition represents a reference for determining whether the power converter is operating in a continuous conduction mode or a discontinuous conduction mode. The continuous conduction mode is designed for a current to be continuously flowing through an inductor included in the power converter or a load as an inductor current. The discontinuous conduction mode is designed for the inductor current to be discontinuously flowing through the inductor.

Abstract: A power conversion apparatus includes a switch circuit which activates switching elements on the basis of a control signal, a feedback means which performs feedback control, a signal output means which outputs the control signal on the basis of a control variable of the feedback control, and a mode switching means which controls switching operation of the switch circuit by switching an operation mode between a normal mode and an intermittent mode in which the number of operations is less than that in the normal mode. The mode switching means changes timing of switching from the normal mode to the intermittent mode, on the basis of either or both of a first detection value which is an input value inputted to the switch circuit and a second detection value which is an output value outputted from the switch circuit.

Abstract: A current mode controlled power converter controllable in a digitally processing current mode even during an on time. In the power converter, each control period based on a reference signal includes a slope calculation period in which a slope compensation signal for the control period is calculated by a slope compensation unit. During each slope calculation period, the slope compensation unit negates the slope compensation signal calculated previous to the control period including the slope calculation period, and a reset signal generation unit compares a current detection signal detected by a current detection unit with a current instruction set to an error signal generated by an error signal generation unit to generate a reset signal.

Abstract: A DC-DC converter generates PWM signals PWM1H, PWM1L on the basis of a reference signal CLK1 to drive switching elements connected in series. When generating a reset signal RST, the converter generates PWM signals PWM2H, PWM2L on the basis of the reset signal RST. When generating no reset signal, the converter generates the PWM signals PWM2H, PWM2L on the basis of a reference signal CLK2 in order to drive other switching elements connected in series. The converter generates the reset signal RST at an optional timing to the reference signal CLK1. The reference signal CLK2 is brought forward from the reference signal CLK1 by ?T1. The PWM signals PWM1H, PWM1L are different in timing from the PWM signals PWM2H, PWM2L. This makes it possible to avoid the switching elements diagonally arranged from being simultaneously turned on and off, and suppress a switching loss, and to increase an efficiency of the converter.

Abstract: In a power converter, a reference signal generator generates a reference signal with a predetermined period. A current detector detects a current flowing in the converter. When a value of the detected current is larger than a value of a predetermined current command, a reset signal generator generates a reset signal. A driving unit drives a switch. The switch is turned on, and subsequently is turned off: (i) in synchronization with the reference signal when the reset signal is not outputted before the reference signal is outputted; and (ii) in synchronization with the reset signal when the reset signal is outputted before the reference signal is outputted. However, the switch is turned off in synchronization with the reset signal during a predetermined time including a first predetermined time before an output timing of the reference signal and a second predetermined time after the output timing of the reference signal.

Abstract: A power converter is preferably mounted in a vehicle. The converter has a power converting unit including an electrical switching element electrically switched on and off selectively in response to a duty ratio of PWM (pulse-width modulation) signal given to the switching element. The converter further has a controller including a drive unit that generates the PWM signal, in addition to a controlling unit and a limiting unit. The controlling unit controls the duty ratio of the PWM signal such that a voltage inputted to the power converter is converted to a voltage to be outputted depending on the duty ratio. The limiting unit limits at least one of a time change amount of the duty ratio of the PWM signal and a maximum duty ratio of the PWM signal.

Abstract: A power converter is preferably mounted in a vehicle. The converter has a power converting unit including an electrical switching element electrically switched on and off selectively in response to a duty ratio of PWM (pulse-width modulation) signal given to the switching element. The converter further has a controller including a drive unit that generates the PWM signal, in addition to a controlling unit and a limiting unit. The controlling unit controls the duty ratio of the PWM signal such that a voltage inputted to the power converter is converted to a voltage to be outputted depending on the duty ratio. The limiting unit limits at least one of a time change amount of the duty ratio of the PWM signal and a maximum duty ratio of the PWM signal.

Abstract: The control apparatus for controlling a voltage transforming apparatus having a transformer, power switching elements disposed in a primary side, and synchronous-rectifying switching elements disposed in a secondary side includes a judging circuit making a judgment as to whether or not an output current of the voltage transforming apparatus is smaller than a specified current on the basis of a primary-side current of the transformer and an inhibition circuit inhibiting the synchronous-rectifying switching elements from performing their synchronous-rectifying control operation when the judging circuit judges that the output current is smaller than the specified current. The judging circuit makes the judgment on the basis of the primary-side current flowing through the primary coil of the transformer immediately before the power switching elements are turned off.

Abstract: The control apparatus for controlling a voltage transforming apparatus having a transformer, power switching elements disposed in a primary side, and synchronous-rectifying switching elements disposed in a secondary side includes a judging circuit making a judgment as to whether or not an output current of the voltage transforming apparatus is smaller than a specified current on the basis of a primary-side current of the transformer and an inhibition circuit inhibiting the synchronous-rectifying switching elements from performing their synchronous-rectifying control operation when the judging circuit judges that the output current is smaller than the specified current. The judging circuit makes the judgment with compensating for a variation of a relationship between the primary side-current and the output current due to variation of duty ratio of the power switching elements, and variation of at least one of the DC output voltage and the DC input voltage of the voltage transforming apparatus.