Abstract: In a rotary electric machine, a load-dump protector turns on a switching element as a low-side rectifying element for at least one of plural-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. The load dump protector determines a turnoff timing of the switching element as the low-side rectifying element for the at least one of the plural-phase stator windings after the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage. The second threshold voltage is set to be lower than the first threshold voltage. The load dump protector turns off, at the determined turnoff timing, the switching element as the low-side rectifying element for the at least one of the at least two-phase stator windings.

Abstract: A rectifying unit rectifies an alternating current voltage induced across each of at least two-phase stator windings. A turn-on unit monitors an output voltage of the rectifying unit, and turns on a switching element as a low-side rectifying element for at least one of the at least two-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. After the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage, a turnoff unit waits for turnoff of the switching element until a turnoff time suited for preventing occurrence of a surge across the at least one of the at least two-phase stator windings appears. The second threshold voltage is set to be lower than the first threshold voltage. The turnoff unit turns off, at the appearance of the turnoff time, the switching element.

Abstract: A power converter for an electric rotating machine is provided which is designed to ensure a desired length of a current flywheel duration in which current is permitted to freewheel from the electric rotating machine even if the power converter is in a transient state or subjected to an unexpected change. The power converter is equipped with a controller and a switching circuit which is disposed between a power supply and windings of the electric rotating machine. The switching circuit has switches grouped into an upper and a lower arm. The controller works to control an off-operation of one of the switches of one of the upper and lower arm so as to produce a desired length of the current flywheel duration following turning off of the one of the switches, thereby minimizing a loss of rectification and avoiding the backflow of current from the power supply to the windings.

Abstract: The vehicle generator includes an armature winding including a plurality of phase windings, a switching section formed as a bridge circuit constituted of a plurality of pairs of an upper arm and a lower arm connected in series to rectify voltages induced in the phase windings, each of the upper and lower arms being constituted of a switching element parallel-connected with a diode, a control section for controlling on/off timings of the switching elements, and a voltage zero-cross detecting section for performing voltage zero-cross detection to detect, as voltage zero-cross points, time points at which at least one of line-to-line voltages among the phase windings of the armature winding changes in polarity. The control section is configured to start on-off control of the switching elements based on the voltage zero-cross points detected by the voltage zero-cross detecting section.

Abstract: A generator has a field coil of a rotor, an armature coil of a stator, a control device supplying an exciting current to the field coil when detecting rotation of the rotor, and a control circuit alternately setting an upper arm transistor and a lower arm transistor in on state in a rectifier module to generate a phase voltage. The control device detects the rotation from a periodic change in a sign of the difference between the phase voltage and a reference voltage. When the rectifier module is overheated, the control circuit sets the upper arm transistor in the off state and sets the lower arm transistor in the on state to almost fix the phase voltage, the control device detects no rotation and stops supplying the exciting current, and the rectifier module generates no phase voltage to decrease temperature of the rectifier module.

Abstract: A vehicle generator includes armature windings, rectifier module groups, an upper MOS on-timing determining section, a lower MOS on-timing determining section, a rotational speed calculating section, a target electrical angle setting section for setting a value of a target electrical angle, an upper MOS off-timing determining section, a lower MOS off-timing determining section, and drivers for driving high-side and low-side MOS transistors constituting upper and lower arms. The target electrical angle represents a margin period between when the low-side MOS transistor was turned off a half cycle ago and the moment when the lower arm on-period has ended. The upper MOS off-timing determining section and the lower MOS off-timing determining section set off timings of the MOS transistors such that the margin period is equivalent to the set value of the target electrical angle.

Abstract: In a vehicular rotary electric machine, a switching section includes a bridge circuit having plurality of upper arms and plurality of lower arms. The arms include switching elements. A diode is connected in parallel to each switching element. One end of the switching element of each of the upper arms is connected to a positive terminal of a battery and one end of the switching element of each of the lower arms is connected to a negative terminal of the battery via a vehicle body. The switching section rectifies induced phase voltage of an armature winding. A section sets ON-timing of the switching elements. A section sets OFF-timing of the switching elements. When the switching element of each lower arm is OFF, a detector detects an energization period in which current flows to the diode. A calculator calculates a rotation frequency based on the detected energization period.

Abstract: In a rotary electric machine, an on-timing setter sets on-timings of each of a high-side switching element and a low-side switching element for each of at least two-phase stator windings. An off-timing setter sets off-timings of each of the high-side switching element and the low-side switching element. An off-timing fault determiner determines a fault of an off-timing of a target switching element as one of the high-side switching element and the low-side switching element set by the off-timing setter when a time interval from the off-timing of the target switching element set by the off-timing setter to time when a phase voltage corresponding to the target switching element reaches a threshold after the off-timing thereof is shorter than a preset value.

Abstract: A vehicle-use electric rotating machine includes a switching section having upper and lower arms each constituted of a switching element parallel-connected with a diode to rectify an AC voltage induced in each phase winding of the electric rotating machine, an on-timing setting section for setting an on timing of each of the switching elements, an off-timing setting section for setting an off timing of each of the switching elements such that, when a time period from when a phase voltage of the phase winding reaches a first threshold value to when the phase voltage reaches a second threshold value different from the first threshold value is referred to as a conduction period, a time period in electrical angle from when the switching element is turned off to when the conduction period ends is equal to a target electrical angle set depending on the rotational speed of the electric rotating machine.

Abstract: A rotary electric machine for a vehicle that is capable of starting synchronous rectification through switching elements after having ensured absence of a short circuit fault. The rotary electric machine includes a multi-phase armature winding, a switching element set that includes a plurality of pairs of upper-arm and lower-arm switching elements to form a bridge rectification circuit together with the armature winding, an on/off-timing setter that sets on/off-timing of each switching element, a switching element driver that drives each switching element at the on/off-timing set by the on/off-timing setter; and a synchronous control start determiner that determines timing when an energization period for the upper-arm switching element and an energization period for the lower-arm switching element occur alternately as start timing of the synchronous rectification.

Abstract: A rectifying unit rectifies an alternating current voltage induced across each of at least two-phase stator windings. A turn-on unit monitors an output voltage of the rectifying unit, and turns on a switching element as a low-side rectifying element for at least one of the at least two-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. After the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage, a turnoff unit waits for turnoff of the switching element until a turnoff time suited for preventing occurrence of a surge across the at least one of the at least two-phase stator windings appears. The second threshold voltage is set to be lower than the first threshold voltage. The turnoff unit turns off, at the appearance of the turnoff time, the switching element.

Abstract: In a rotary electric machine, a load-dump protector turns on a switching element as a low-side rectifying element for at least one of plural-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. The load dump protector determines a turnoff timing of the switching element as the low-side rectifying element for the at least one of the plural-phase stator windings after the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage. The second threshold voltage is set to be lower than the first threshold voltage. The load dump protector turns off, at the determined turnoff timing, the switching element as the low-side rectifying element for the at least one of the at least two-phase stator windings.

Abstract: The vehicle generator includes an armature winding including a plurality of phase windings, a switching section formed as a bridge circuit constituted of a plurality of pairs of an upper arm and a lower arm connected in series to rectify voltages induced in the phase windings, each of the upper and lower arms being constituted of a switching element parallel-connected with a diode, a control section for controlling on/off timings of the switching elements, and a voltage zero-cross detecting section for performing voltage zero-cross detection to detect, as voltage zero-cross points, time points at which at least one of line-to-line voltages among the phase windings of the armature winding changes in polarity. The control section is configured to start on-off control of the switching elements based on the voltage zero-cross points detected by the voltage zero-cross detecting section.

Abstract: The vehicle generator includes a rotor wound with a field winding, a stator wound with a stator winding, rectifier modules respectively connected to corresponding output terminals of the stator winding, and a power generation control device to control a power generation voltage of the vehicle generator formed from outputs of the rectifier modules by controlling an excitation current flowing through the field winding. Each of the rectifier modules includes a pair of a first MOS transistor and a second MOS transistor series-connected between positive and negative terminals of a battery. The rectifier modules are connected with one another through a communication line. The rectifier modules exchange data regarding control of the first and second MOS transistors of the rectifier modules by a pulse train signal transmitted on the communication line.

Abstract: In a power generator, three-phase armature windings and a switching unit are provided for each phase armature winding. The switching unit includes a pair of a high-side switching element with a first diode and a second low-side switching element with a second diode. The switching unit rectifies, through at least one of the high-side switching element, the first diode, the second low-side switching element, and the second diode, a voltage induced in each phase armature winding. A zero-cross detector detects a point of time when a phase current based on the voltage induced in each phase armature winding is reversed in direction as a zero-cross point of the phase current. A deter miner determines an off timing of the high-side switching element or the low-side switching element for each phase armature winding relative to the zero-cross point detected by the zero-cross detector.

Abstract: A power converter for an electric rotating machine is provided which is designed to ensure a desired length of a current flywheel duration in which current is permitted to freewheel from the electric rotating machine even if the power converter is in a transient state or subjected to an unexpected change. The power converter is equipped with a controller and a switching circuit which is disposed between a power supply and windings of the electric rotating machine. The switching circuit has switches grouped into an upper and a lower arm. The controller works to control an off-operation of one of the switches of one of the upper and lower arm so as to produce a desired length of the current flywheel duration following turning off of the one of the switches, thereby minimizing a loss of rectification and avoiding the backflow of current from the power supply to the windings.

Abstract: An AC generator is provided with a rotor including a rotating shaft having a pair of collector rings, a pair of brushes, and a brush device having a brush holder that housing portions are formed where the pair of brushes is contained. The brush device is provided with a pair of field terminals that ends are connected to each of the brushes and other ends are connected to the control apparatus, fixing terminals, which is electrically insulated with the field terminals, that fix the brush holder, and a wall part that is formed integrally with the brush holder and is arranged between the pair of field terminals.