Nippondenso Co., Ltd.

Denso Corporation

Japan Storage Battery

Hirohide Sato

Atsushi Umeda

Shin Kusase

Makoto Taniguchi

Norihito Tokura

Toshio Tsutsui

Toshinori Maruyama

Hidetoshi Kato

Takeshi Sada

Nobuo Mayumi

Kenzo Mitani

Masatoshi Togawa

Fuyuki Maehara

Keiichiro Banzai

Kazumasa Mori

Yoshio Akita

Toshiaki Matsuhashi

Wakako Kanazawa

Hiroshi Shibata

Shigeru Tanaka

Junji Kawai

Yoshiya Hatakeyama

A generation-stop detection system of an alternator is provided. A unit provides a generation-stop condition signal when an output voltage of the alternator is lower than a reference voltage. A rotation speed detection unit detects a rotation speed. A reference voltage changing unit changes the reference voltage proportionally to the rotation speed of the alternator. A warning signal unit provides a warning signal if the generation-stop condition signal is provided at a rotation speed lower than a predetermined speed. The warning signal is maintained even when the rotation speed of the alternator becomes higher than the predetermined speed. The warning signal is interrupted when the output voltage of the alternator is higher than the voltage of the battery.

Generation-stop detection system of alternator

Battery voltage is compared by a comparator so that when the voltage of a normally-charged battery becomes higher than a normal reference voltage, it is regulated to be as high as a normal reference voltage. When an average value of the battery voltages in a period encompassing a typical operating speed of the engine becomes higher than an upper level, the reference voltage is lowered. On the other hand, when the average of the battery voltages in such period becomes lower than a lower level, the reference voltage is increased.

Voltage regulating system for vehicle including alternator

In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic pole cores that are polarized by a rotor coil to alternately different polarities are circumferentially disposed on the outer periphery thereof at prescribed equi-angular intervals. A permanent magnet which is embedded within a resin-made retainer body is provided between the magnetic pole cores and has side faces, as viewed circumferentially, which are polarized respectively to the same polarities as those of adjacent respective magnetic pole cores to thereby vary the magnetic flux quantity directed toward stator coils so as to exhibit a circumferential gentle curve. A rectifier is constructed using SiC-MOS transistors so that it is conductive and operative to thereby charge a battery with the current developed in the stator coils only when the alternating current voltages generated in the stator coils have become higher than the battery voltage.

Alternator

A generating apparatus for a vehicle is composed of an AC generator, a battery and a rectifying bridge circuit. The bridge circuit is composed of high-side elements and low-side elements. One of the low-side rectifying elements which is connected to an armature coil generating the giant-pulse-voltage is turned on to circulate the giant-pulse-voltage in the armature coils, thereby suppressing the giant-pulse-voltage.

Generating apparatus for vehicle

In a power generating system having an AC power generator, a quantity which is related to the state of power generation of the power generator and varies according to the supply of a leading phase current to the power generator, is detected. When the passage of the leading phase current through each armature winding is determined as necessary based on the detected status quantity, the leading phase current is supplied to each armature winding (an increase in the amount of supply of the leading phase current is included). If passage is determined as unnecessary, then the supply of the leading phase current to each armature winding is stopped (a decrease in the leading phase current is included). If so, then a change (improvement) in the state of power generation such as an increase in output or the like due to the above supply can be achieved by supplying the leading phase current thereto when its change is required. When the above change is unnecessary, the supply of the leading phase current thereto can be stopped to suppress a defective condition incident to the supply of the leading phase current thereto, particularly, the rate of change in output current, i.e., an increase in ripple. Owing to the above construction, the supply of the leading phase current to the power generator can be achieved by a simple circuit configuration and the state of power generation can be improved.

Vehicle power generating system

An exciting current controlling transistor or a high-side switch or low-side switch of a three-phase full-wave rectifier for an on-vehicle a.c. generator is formed of a MOS power transistor made of a monocrystalline SiC semiconductor. Further, at high output condition time, for example, a state wherein the generator is in a condition of low temperature and a battery capacity is decreased, a controller suppresses the duty ratio of the exciting current controlling transistor to thereby limit a field coil exciting current. As a result, an increase in cross-sectional area of the electric wire or a temporary rapid increase in torque of the engine load is avoided. Also, by limiting the rate of increase in the duty ratio, the controller prevents a fall in the engine speed.

Control system for A.C. generator

Reverse current is supplied from a battery to armature coils of a three-phase synchronous power generator, via semiconductor switching devices of a three-phase full-wave rectifier, by controlling the switches. By this control, the reverse current will reduce waveform distortion of armature current of each phase so as to reduce the electromagnetic force pulsation and, therefore, reduce vibration or noise.

AC power generating apparatus and method

In order to restrain increase in rotor temperature and reduction in field magnetic flux in an AC power generator, advanced-phase currents are supplied to stator windings of a stator via semiconductor switching devices by controlling the semiconductor switching devices during the power generating operation of the power generator. By this control, the advanced-phase currents will increase the field magnetic flux and, accordingly, increases in generated voltage. By reducing a field current to a field winding of a rotor by an amount corresponding to the increase in the power generation output, the temperature increase in the field winding can be reduced.

Synchronous electric power generating apparatus and magnetization

Leading current or lagging current of an alternator is supplied by a simple structure including short-circuit switch elements. The short-circuit switch elements are connected across output terminals of the alternator three-phase armature windings, and are turned on and off at fixed timings to supply a suitable amount of the leading current to armature windings regardless of the rotational speed. Thus, the leading current can be supplied without phase-leading-capacitors so that the apparatus can be made compact, lightweight and powerful. Even if any of the short-circuit switch elements can not turn off, the battery discharge can be prevented.

Generating apparatus

An output controlling apparatus for a vehicle generator includes MOSFETs for full-wave rectification of a voltage output by the generator, a MOSFET for turning the flow of a field current on and off and a voltage controller for controlling the MOSFETs to sustain the voltage of a battery at a fixed value. In this configuration, the thermal resistance between the MOSFETs is set at a value smaller than the thermal resistance between the voltage controller and the MOSFETs. In addition, the MOSFETs are fixed on a common good heat conductive substrate to reduce the thermal resistance between the MOSFETs. In this way, the accuracy of the voltage controller is prevented from deteriorating and, at the same time, the maximum temperature of the MOSFETs can be reduced.

Output controlling apparatus for vehicle generator

A power-generating voltage outputted from a vehicle synchronous power generator is adjusted to a first voltage for charging a battery under the control of a field current. Further, a leading phase current that leads a phase voltage is supplied to each of multiple armature windings and the field current is supplied to the field winding, whereby the power-generating voltage can be adjusted to a second voltage higher than the first power-generating voltage. Owing to the above construction, a voltage higher than the normal voltage can be generated by supplying each leading phase current from the vehicle synchronous power generator; hence power can be supplied to a high-voltage load based on the generated high voltage.

Vehicle power generating system and method for controlling the same

An alternating current generator for motor vehicles having an extremely small power loss and which can be simply cooled includes a power converter having at least either high side semiconductor power elements or low side semiconductor elements. The high side power elements connect an output terminal of the armature coil to a high potential terminal of the battery; the low side semiconductor power elements connect an output terminal of the armature coil to a low potential terminal of the battery. The power converter converts the alternating current generated voltage of the armature coil into a direct current voltage to supply electricity to the battery. An exciting current controller includes a switching transistor for controlling an exciting current to a field coil. The semiconductor power elements in the power converter and/or the switching transistor in the exciting current controller are/is formed of SiC material, which is a compound of Si and C, having a resistivity smaller than that of pure Si.

A.C. Generator for vehicles

A power converter for an AC generator for motor vehicles for converting a generated voltage of the AC generator driven by an engine into a DC voltage to feed to a battery includes at least either high-side MOS power transistors for connecting an output end of an armature coil which generates the generated voltage of the AC generator with a high potential end of a battery or low-side MOS power transistors for connecting the output end of the armature coil with a low potential end of the battery. The MOS power transistors each has a source region, a well region and a drain region. A high resistance connected with either a parasitic diode on the side connected with the source generated between the source region and well region or a parasitic diode on the side connected with the drain generated between the drain region and well region in parallel is formed in the MOS power transistors. Thereby, it allows blocking a reverse current produced by the parasitic diode and giving a necessary potential to the well region. Further, SiC is used in the MOS power transistors rather than Si.

Power converter

An electric power generating device including an induction type electric rotating machine rotating in interlock with an engine comprises an inverter connected at the AC side to and end of an armature winding and at the DC side to an electric power storing device, a detecting means for detecting the quantity of state related to the electric power generating voltage of the induction type electric rotating machine excluding the measured RPM of the induction type electric rotating machine but including the electric power storing voltage of the electric power storing device, and an electric power generation controlling means for maintaining the electric power storing voltage within the preset range by controlling the frequency of the controlling voltage of the inverter based on the quantity of state related to the electric power generating voltage. This electric power generating device can control the electric power generation without using any RPM detecting device for the induction electric machine, and as a result, the composition of the device can be simplified. The frequency can be controlled so that the frequency can be changed in the direction in which the difference between the electric power storing voltage and the preset reference voltage is reduced.

Electric power generating device for vehicles

A vehicular generator motor performing generator operation and motor operation is disclosed. The generator motor comprises an AC-DC converter means and a switching means. The converter means is composed of a plurality of MOSFETs and connected between each armature coil and a vehicular storage battery. Alternating current produced across the coils is converted into a direct current for charging the battery by the AC-DC converter means in generator operation mode. In motor operation mode, the DC output from the battery is converted into an alternating current for setting up a rotating magnetic field by the converter means, and the battery output is fed to the armature coils. The mode of operation of the MOSFETs is switched between these two modes by the switching means. The rotating field produces a certain phase difference with the magnetic field developed by the rotating magnetic poles. The MOSFETs are made of SiC having a smaller resistivity than that of Si. This ensures a high withstand voltage necessary during power generation. Loss caused by large current flowing in the motor operation mode is reduced. Good driving torque can be obtained.

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Toyokawa, Japan

Hirohide Sato