JP2014165983A - Rotary electric machine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine for vehicle capable of improving reliability by promptly completing high voltage generation during load dump.SOLUTION: A load dump protection determination section 111 monitors an output voltage from a vehicle generator, instructs a driver 182 to turn on a MOS transistor forming a lower arm when the output voltage exceeds a first threshold voltage, and instructs the driver 182 to turn off the MOS transistor after OFF for a predetermined time when the output voltage becomes lower than a second threshold voltage which is lower than the first threshold voltage, after exceeding the first threshold voltage. A length of the predetermined time is set variable on the basis of a state of an excitation current determined by an excitation ON/OFF determination section 124.

Description

  The present invention relates to a vehicular rotating electrical machine mounted on a passenger car, a truck, or the like.

  The vehicular generator supplies charging power and operating power to a battery and various electric loads via a charging line connected to an output terminal. If the output terminal or the battery terminal is disconnected during the power generation operation of this vehicle generator, a transient high voltage called a load dump is generated. The voltage generated at this time may reach 100 V or more depending on the output current or the like. Since the high voltage generated in this way causes damage to various elements in the electric load and the vehicular generator, some measures (load dump protection) are required. As a conventional technique for taking such measures, for example, a low-side element of a bridge circuit of a vehicular generator is configured by a MOS transistor, and when the output voltage of the vehicular generator exceeds a reference voltage when a load dump occurs, these technologies are used. 2. Description of the Related Art A vehicular power generation device is known that performs a protective operation for suppressing generation of a high voltage by turning on a MOS transistor (see, for example, Patent Document 1). In this vehicular power generation device, when each MOS transistor as the low side element of the bridge circuit is turned on and the output voltage becomes lower than the reference voltage again, each MOS transistor is turned off again, and normal rectification operation by the bridge circuit is resumed. It has become so.

Japanese Patent Laid-Open No. 9-219938

  By the way, in the vehicle power generator disclosed in Patent Document 1, this load dump protection and release are repeated until the energy accumulated in the stator disappears, but the capacitance of the noise removing capacitor connected to the output terminal If the value is small, the number of repetitions increases, loss is accumulated, and the MOS transistor or the like may break down. In particular, when an excitation current is supplied to the field coil by the power generation control circuit unit, the excitation current is supplied from a capacitor having a small capacity, so that the output voltage decreases rapidly. As a result, the power generation control circuit unit determines that the output voltage is equal to or lower than the adjustment voltage, so the supply of excitation current does not stop, and it takes time to converge the load dump.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicular rotating electrical machine that can quickly terminate generation of a high voltage during load dumping and improve reliability. There is.

  In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a field winding, a stator, a power generation control device, an excitation determination unit, a switching unit, a switching control unit, and a load dump protection determination unit. The field winding magnetizes the field pole of the rotor. The stator has an armature winding as a multiphase winding that generates an AC voltage by a rotating magnetic field generated by a field pole. The power generation control device controls the output voltage by adjusting the excitation current supplied to the field winding. The excitation determination unit determines the state of the excitation current supplied to the field winding under the control of the power generation control device. In the switching unit, a bridge circuit having a plurality of upper arms and lower arms is configured by the switching elements, and rectifies the induced voltage of the armature winding. The switching control unit controls on / off of the switching element. The load dump protection determination unit monitors the output voltage of the switching unit, and instructs the switching control unit to turn on the switching element constituting the lower arm when the output voltage exceeds the first threshold voltage. Do. In addition, the load dump protection determination unit determines that the lower arm when the output voltage becomes lower than the second threshold voltage lower than the first threshold voltage after exceeding the first threshold voltage. The switching control unit is instructed to turn on the switching elements constituting the circuit after being turned off for a predetermined time. Furthermore, the load dump protection determination unit variably sets the length of the predetermined time based on the state of the excitation current determined by the excitation determination unit.

  If a large amount of excitation current is applied when a load dump occurs, the time during which the output voltage is higher than the second threshold voltage is lengthened so that the excitation current does not flow through the field winding as much as possible. Therefore, the high voltage generation at the time of load dump can be quickly terminated and the reliability can be improved.

It is a figure which shows the structure of the generator for vehicles of 1st Embodiment. It is a figure which shows the detailed structure of a power generation control apparatus. It is a figure which shows the structure of a rectifier module. It is a figure which shows the detailed structure of a control circuit. It is a figure which shows the specific example of the voltage comparison by an upper MOS _VDS detection part. It is a figure which shows the specific example of the voltage comparison by a lower MOS _VDS detection part. It is a figure which shows the specific example of the temperature detection result by a temperature detection part. It is a figure which shows the detailed structure of a control part. It is an operation | movement timing diagram of the synchronous rectification control (synchronous control) performed by a control part. It is a figure which shows a structure required in order to perform synchronous control start determination. It is a figure which shows the phase voltage in the normal time when the load dump does not generate | occur | produce. It is a figure which shows the phase voltage at the time of the load dump protection operation | movement after load dump generate | occur | produces. It is a figure which shows the voltage waveform after amplifying the drain-source voltage of the MOS transistor of the low side at the time of load dump protection operation. It is a figure which shows the operation timing of synchronous control start determination. It is a figure which shows the specific example of a phase voltage waveform when the off timing set by the lower MOS off timing calculating part is overdue. It is a figure which shows the relationship between an output voltage fluctuation | variation, an upper arm ON period, and a lower arm ON period. It is a figure which shows a structure required in order to perform synchronous control stop determination. It is a flowchart which shows the operation | movement procedure at the time of load dump generation | occurrence | production. It is a figure which shows the operation timing at the time of load dump generation. It is a figure which shows the detailed structure of the control part contained in the rectifier module of 2nd Embodiment. It is a flowchart which shows the operation | movement procedure at the time of load dump generation in 2nd Embodiment. It is a figure which shows the operation | movement timing at the time of load dump generation in 2nd Embodiment. It is a figure which shows the modification of a rectifier module.

  Hereinafter, a vehicle generator according to an embodiment to which a vehicular rotating electrical machine of the present invention is applied will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the vehicle generator 1 according to the first embodiment includes two stator windings (armature windings) 2 and 3, a field winding 4, and two rectifier module groups 5 and 6. The power generation control device 7 and the Zener diode 30 are included. Two rectifier module groups 5 and 6 correspond to a switching unit.

  One stator winding 2 is a multiphase winding (for example, a three-phase winding composed of an X-phase winding, a Y-phase winding, and a Z-phase winding), and is wound around a stator core (not shown). It is disguised. Similarly, the other stator winding 3 is a multi-phase winding (for example, a three-phase winding composed of a U-phase winding, a V-phase winding, and a W-phase winding). The stator winding 2 is wound at a position shifted by 30 degrees in terms of electrical angle. In the present embodiment, a stator is constituted by these two stator windings 2 and 3 and the stator core.

  The field winding 4 is wound around a field pole (not shown) disposed opposite to the inner peripheral side of the stator core to constitute a rotor. The field pole is magnetized by passing an exciting current. The stator windings 2 and 3 generate an alternating voltage by a rotating magnetic field generated when the field pole is magnetized.

  One rectifier module group 5 is connected to one stator winding 2 to form a three-phase full-wave rectifier circuit (bridge circuit) as a whole, and the alternating current induced in the stator winding 2 is converted into direct current. Convert to current. The rectifier module group 5 includes rectifier modules 5X, 5Y, and 5Z corresponding to the number of phases of the stator winding 2 (three in the case of a three-phase winding). The rectifier module 5 </ b> X is connected to the X-phase winding included in the stator winding 2. The rectifier module 5 </ b> Y is connected to a Y-phase winding included in the stator winding 2. The rectifier module 5Z is connected to the Z-phase winding included in the stator winding 2.

  The other rectifier module group 6 is connected to one stator winding 3 to form a three-phase full-wave rectifier circuit (bridge circuit) as a whole, and the alternating current induced in the stator winding 3 is converted into direct current. Convert to current. The rectifier module group 6 includes a number of rectifier modules 6U, 6V, and 6W corresponding to the number of phases of the stator winding 3 (three in the case of a three-phase winding). The rectifier module 6U is connected to a U-phase winding included in the stator winding 3. The rectifier module 6V is connected to a V-phase winding included in the stator winding 3. The rectifier module 6 </ b> W is connected to the W-phase winding included in the stator winding 3.

The power generation control device 7 is an excitation control circuit that controls the excitation current that flows through the field winding 4 connected via the F terminal (excitation drive terminal). The generator 1 for the vehicle is adjusted by adjusting the excitation current. The output voltage (power generation voltage, output voltage of each rectifier module) V _B is controlled to become the regulated voltage Vreg. For example, the power generation controller 7 stops the supply of the exciting current to the field winding 4 when the output voltage V _B is higher than the regulated voltage Vreg, it is lower than the regulated voltage Vreg output voltage V _B When the exciting current is supplied to the field winding 4 at this time, the output voltage V _B is controlled to become the adjustment voltage Vreg. Further, the power generation control device 7 detects the rotation speed of the rotor based on any phase voltage (for example, X phase) of the stator winding applied to the P terminal, and when the rotation stop is detected, the field generator The supply of exciting current to the winding 4 is stopped or reduced. Furthermore, the power generation control device 7 is connected to the ECU 8 (external control device) via the communication terminal L and the communication line, and performs bidirectional serial communication (for example, a LIN (Local Interconnect Network) protocol) with the ECU 8. LIN communication used) and a communication message is transmitted or received.

  The Zener diode 30 is connected in parallel to the outputs of the two rectifier module groups 5 and 6. Specifically, the Zener diode 30 is arranged so that the output terminal side of the vehicle generator 1 is a cathode and the ground side is an anode.

  As shown in FIG. 2, the power generation control device 7 includes a MOS transistor 71, a freewheeling diode 72, resistors 73 and 74, a voltage comparison circuit 75, an excitation current control circuit 76, a rotation detection circuit 77, a communication circuit 78, a power supply circuit 79, A capacitor 80 is provided. The communication circuit 78 performs serial communication with the ECU 8. Thereby, data such as the adjustment voltage Vreg sent from the ECU 8 can be received.

  The resistors 73 and 74 constitute a voltage dividing circuit, and a voltage obtained by dividing the generated voltage (output voltage) of the vehicle generator 1 is input to the voltage comparison circuit 75. The voltage comparison circuit 75 compares the generated voltage divided by the resistors 73 and 74 with the reference voltage corresponding to the adjustment voltage Vreg received by the communication circuit 78. For example, as a comparison result, when the reference voltage is higher than the generated voltage, a high level signal is output. Conversely, when the generated voltage is higher than the reference voltage, a low level signal is output. .

  The exciting current control circuit 76 supplies and stops the exciting current to the field winding 4 by performing on / off control of the MOS transistor 71 based on the output of the voltage comparing circuit 75 (voltage comparison result). “Supplying” the field current means not only the case where the MOS transistor 71 is turned on and the exciting current is continuously supplied to the field winding 4, but also during normal operation (a state where no abnormality has occurred). This includes a case in which the MOS transistor 71 is intermittently turned on with a high on-duty to increase the output current and a current is passed through the field winding 4. On the other hand, “stopping” the field current (supply) means that the MOS transistor 71 is intermittently turned off with a low on-duty in order to reduce the output current during normal operation, in addition to the case where the MOS transistor 71 is continuously turned off. And the case where the current is passed through the field winding 4 is included. Further, in order to suppress a rapid fluctuation of the output current, the excitation current control circuit 76 may perform a slow excitation control for gradually changing the field current.

The rotation detection circuit 77 is connected to the X-phase winding of one stator winding 2 via a P terminal and a high-impedance resistor 20 (FIGS. 1 and 2), and is connected to the end of the X-phase winding. Based on the phase voltage V _P that appears, specifically, rotation detection is performed by detecting that the magnitude relationship between the phase voltage and the reference voltage for rotation detection changes periodically. Rectifier short-circuit failure or the like module 5X and stator winding 2 is not generated in the normal state, to appear the phase voltage V _P having a predetermined amplitude to the terminal P at the time of power generation, the rotation detection based on the phase voltage V _P It becomes possible.

  The excitation current control circuit 76 receives the rotation detection result from the rotation detection circuit 77 and outputs a signal necessary for supplying the field winding 4 with an excitation current necessary for the power generation operation during the rotation detection. When rotation stop (rotation cannot be detected) is detected, a signal necessary for initial excitation is output.

  The power supply circuit 79 supplies an operating voltage to each circuit included in the power generation control device 7. The capacitor 80 is for removing noise entering from the output terminals of the rectifier module groups 5 and 6, and has a capacity of about 1 μF, for example.

  The vehicular generator 1 of the present embodiment has such a configuration. Next, details of the rectifier module 5X will be described. The other rectifier modules 5Y, 5Z, 6U, 6V, and 6W have the same configuration. As shown in FIG. 3, the rectifier module 5 </ b> X includes two MOS transistors 50 and 51 and a control circuit 54.

  The MOS transistor 50 has a source connected to the X-phase winding of the stator winding 2 and a drain connected to the electrical load 10 and the positive terminal of the battery 9 via the charging line 12. It is a switching element. The MOS transistor 51 is a switching element on the lower arm (low side) whose drain is connected to the X-phase winding and whose source is connected to the negative terminal (earth) of the battery 9. A series circuit composed of these two MOS transistors 50 and 51 is disposed between the positive terminal and the negative terminal of the battery 9, and a connection point between these two MOS transistors 50 and 51 is connected via a P terminal (phase voltage detection terminal). An X-phase winding is connected.

  A diode is connected in parallel between the source and drain of each of the MOS transistors 50 and 51. This diode is realized by a parasitic diode (body diode) of the MOS transistors 50 and 51, but a diode as another component may be further connected in parallel. Note that at least one of the upper arm and the lower arm may be configured using a switching element other than a MOS transistor.

As shown in FIG. 4, the control circuit 54 includes a control unit 100, an output voltage detection unit 110, an upper MOS V _DS detection unit 120, a lower MOS V _DS detection unit 130, an upper MOS short-circuit fault confirmation unit 140, and a lower MOS V _DS. The amplifying unit 142, the energization direction determining unit 144, the temperature detecting unit 150, the rotation detection signal transmitting unit 160, the power source 170, and the drivers 180 and 182 are provided.

  The power supply 170 supplies an operating voltage to each element included in the control circuit 54. The power supply 170 is started and stopped in response to an instruction from the control unit 100.

  The driver 180 has an output terminal (G1) connected to the gate of the high-side MOS transistor 50, and generates a drive signal for turning on and off the MOS transistor 50. Similarly, the driver 182 has an output terminal (G2) connected to the gate of the low-side MOS transistor 51, and generates a drive signal for turning the MOS transistor 51 on and off.

The output voltage detection unit 110 includes, for example, a differential amplifier and an analog-digital converter that converts the output into digital data. The output voltage detection unit 110 includes an output terminal (B terminal) of the vehicle generator 1 (or the rectifier module 5X). Data corresponding to the voltage V _B is output. The analog-digital converter may be provided on the control unit 100 side.

Upper MOS V _DS detector 120 is connected to the B terminal and the P terminal, to detect the drain-source voltage V _DS of the MOS transistor 50 of the high-side, predetermined the detected drain-source voltage V _DS Compared with the threshold value, a signal corresponding to the magnitude is output. In FIG. 5, the horizontal axis indicates the drain-source voltage V _DS with reference to the drain side output voltage V _B. The vertical axis indicates the voltage level of the signal output from the upper MOS V _DS detector 120. As shown in FIG. 5, when the phase voltage V _P becomes higher and becomes higher than the output voltage V _B by 0.3 V or more, V _DS becomes 0.3 V or higher, so that the output signal of the upper MOS V _DS detection unit 120 is low. It changes from level (0V) to high level (5V). Thereafter, when the phase voltage V _P becomes 1.0 V or more lower than the output voltage V _B , V _DS becomes −1.0 V or less, so that the output signal of the upper MOS V _DS detection unit 120 changes from the high level to the low level. .

A value higher by 0.3V than the output voltage V _B described above corresponds to the threshold value V10 in FIG. This threshold value V10 is for reliably detecting the start point of the diode energization period, and is higher than the value obtained by adding the drain-source voltage V _DS of the MOS transistor 50 at the ON time to the output voltage V _B. The output voltage V _B is set to a value lower than the value obtained by adding the forward voltage VF of the diode connected in parallel with the MOS transistor 50. Further, a value 1.0V lower than the output voltage V _B described above corresponds to the threshold value V20 in FIG. The threshold V20 is used to reliably detect the end of diode conduction period is set to a value lower than the output voltage V _B. The period from when the phase voltage V _P reaches the threshold value V10 to when the phase voltage V _P reaches the threshold value V20 is defined as the “on period” of the upper arm. The ON period is different from the “diode energization period” in which the diode is actually energized when the MOS transistor 50 is in the OFF state. It is done based on the period.

The lower MOS V _DS detector 130 is connected to the P terminal and the ground terminal (E terminal), detects the drain-source voltage V _DS of the low-side MOS transistor 51, and detects the detected drain-source voltage V. _DS is compared with a predetermined threshold value and a signal corresponding to the magnitude is output. In FIG. 6, the horizontal axis represents the drain-source voltage V _{DS based} on the ground terminal voltage V _GND that is the battery negative terminal voltage on the drain side. The vertical axis indicates the voltage level of the signal output from the lower MOS V _DS detection unit 130. As shown in FIG. 6, when the phase voltage V _P becomes low and becomes 0.3 V or more lower than the ground voltage V _GND , V _DS becomes −0.3 V or less. Therefore, the output signal of the lower MOS V _DS detection unit 130 is It changes from a low level (0V) to a high level (5V). Thereafter, when the phase voltage V _P becomes 1.0 V or more higher than the ground voltage V _GND , V _DS becomes 1.0 V or more, so that the output signal of the lower MOS V _DS detection unit 130 changes from high level to low level.

A value lower by 0.3 V than the above-described ground voltage V _GND corresponds to the threshold value V11 in FIG. The threshold V11 is used to reliably detect the beginning of the diode conduction period, less than the value obtained by subtracting the drain-source voltage V _DS of the MOS transistor 51 when on the ground voltage V _GND The value is set higher than the value obtained by subtracting the forward voltage VF of the diode connected in parallel with the MOS transistor 51 from the ground voltage V _GND . Further, a value 1.0V higher than the output voltage V _GND described above corresponds to the threshold value V21 in FIG. This threshold value 21 is used to reliably detect the end point of the diode energization period, and is set to a value higher than the ground voltage _VGND . The period from when the phase voltage V _P reaches the threshold value V11 until it reaches the threshold value V21 is referred to as the “on period” of the lower arm. Note that this on period is different from the “diode energization period” in which the diode is actually energized when the MOS transistor 51 is in the off state. It is done based on the period.

  The temperature detector 150 detects the temperature of the MOS transistors 50 and 51 based on, for example, the forward voltage of a temperature-sensitive diode disposed adjacent to the MOS transistors 50 and 51, and is high when the temperature is high and low when the temperature is low. A level signal is output. The temperature detection unit 150 may be included in the control unit 100. In FIG. 7, the horizontal axis indicates the temperature (° C.). The vertical axis indicates the voltage level of the signal output from the temperature detection unit 150. As shown in FIG. 7, when the temperature rises to 200 ° C. or higher, the output signal of the temperature detection unit 150 changes from the low level (0 V) to the high level (5 V). Thereafter, when the temperature decreases and becomes lower than 170 ° C., the output signal of the temperature detection unit 150 changes from the high level to the low level.

The upper MOS short-circuit fault confirmation unit 140 confirms that a short-circuit fault between the drain and source of the high-side MOS transistor 50 has not occurred. This short-circuit failure includes not only the case where the MOS transistor 50 itself fails, but also the case where the driver 180 driving the MOS transistor 50 fails and the MOS transistor 50 is always turned on. When no failure has occurred in the MOS transistor 50 or the driver 180, the phase voltage V _P periodically changes between the output voltage V _B and the ground voltage V _GND . On the other hand, when the drain and source of the MOS transistor 50 are always short-circuited, the phase voltage V _P is fixed in the vicinity of the output voltage V _B. The upper MOS short-circuit fault confirmation unit 140 detects that the short-circuit fault between the drain and source of the MOS transistor 50 has not occurred by detecting that the phase voltage V _P is periodically changing, and outputs the output. Set to low level. On the other hand, when a short circuit failure between the drain and source of the MOS transistor 50 has occurred, the upper MOS short circuit failure confirmation unit 140 sets the output to a high level.

The lower MOS V _DS amplification unit 142 amplifies the drain-source voltage V _DS of the low-side MOS transistor 51 at the time of ON, for example, by 5 times (−0.5 V to +0.5 V) (FIG. 11C). The energization direction determination unit 144 determines the direction of the current flowing through the MOS transistor 51 based on the drain-source voltage V _DS after being amplified by the lower MOS V _DS amplification unit 142. Specifically, the energization direction determination unit 144 compares, for example, the threshold voltage set to +0.35 V and the drain-source voltage V _DS after amplification, and the threshold voltage is higher. A high level signal is output (range W in FIG. 11C), and a low level signal is output at other times.

  The rotation detection signal transmission unit 160 generates a pseudo rotation detection signal during the load dump protection operation, and outputs it via the RP terminal. The rotation detection signal output from the RP terminal in this manner is input to the P terminal of the power generation control device 7 (FIG. 2).

  The control unit 100 determines the timing for starting and ending the synchronous rectification operation, sets the on / off timing of the MOS transistors 50 and 51 for performing synchronous rectification, and the driver 180 corresponding to the setting of the on / off timing. 182 driving, load dump protection operation transition and overheat protection operation transition timing and protection operation execution, whether or not normal rectification operation is being performed, whether or not an abnormal condition has occurred, etc. Do.

As shown in FIG. 8, the control unit 100 includes a rotation speed calculation unit 101, a synchronization control start determination unit 102, an upper MOS on timing determination unit 103, a lower MOS on timing determination unit 104, a target electrical angle setting unit 105, and an upper MOS. _TFB time calculation unit 106, upper MOS off timing calculation unit 107, lower MOS · _TFB time calculation unit 108, lower MOS off timing calculation unit 109, load dump protection determination unit 111, power supply start / stop determination unit 112, off A timing abnormality determination unit 121, a synchronous control stop determination unit 122, an overheat protection unit 123, and an excitation ON / OFF determination unit 124 are provided. Each of these components is realized by, for example, a predetermined operation program stored in a memory or the like being executed by the CPU, but each component may be realized by using hardware. Specific operation contents of each component will be described later.

  The control unit 100 and the drivers 180 and 182 described above correspond to the switching control unit, and the excitation ON / OFF determination unit 124 corresponds to the excitation determination unit. The rectifier module 5X and the like of this embodiment have such a configuration, and the operation will be described next.

(1) Power supply start / stop determination The power supply start / stop determination unit 112 is connected to the P terminal, and the phase voltage (peak voltage) of the X phase of the stator winding 2 to which the rectifier module 5X is connected is a predetermined value. When it is detected that the voltage exceeds (for example, 5 V), the power supply 170 is instructed to start. In addition, the power supply start / stop determination unit 112 instructs the power supply 170 to stop when the state where the phase voltage has become equal to or lower than a predetermined value (5 V) continues for a predetermined time (for example, 1 second). In this way, the rectifier module 5X or the like is operated only during power generation of the vehicle generator 1, and when it is stopped without generating power, only a necessary minimum circuit is operated, so that dark current is reduced, The battery can be prevented from running out.

(2) Synchronous control operation In FIG. 9, the “upper arm ON period” indicates the output signal of the upper MOS V _DS detector 120, and the “upper MOS ON period” indicates the ON / OFF timing of the high-side MOS transistor 50. Each is shown. The “lower arm on period” indicates the output signal of the lower MOS V _DS detector 130, and the “lower MOS on period” indicates the on / off timing of the low-side MOS transistor 51, respectively. T _FB1 , T _FB2 , target electrical angle, and ΔT will be described later.

The upper MOS on-timing determination unit 103 monitors the output signal (upper arm ON period) of the upper MOS V _DS detection unit 120, and the rise of the output signal from the low level to the high level is detected on the high side MOS. It is determined that the transistor 50 is on, and an instruction is sent to the driver 180. The driver 180 turns on the MOS transistor 50 in response to this instruction.

  The upper MOS off timing calculation unit 107 determines that a predetermined time has elapsed after the MOS transistor 50 is turned on as the off timing of the MOS transistor 50, and sends an instruction to the driver 180. The driver 180 turns off the MOS transistor 50 in response to this instruction.

The predetermined time for determining the OFF timing is earlier than the end point of the upper arm ON period (the time point when the output signal of the upper MOS _VDS detection unit 120 falls from the high level to the low level) by “target electrical angle”. As described above, the variable setting is made each time.

  This target electrical angle is set so that the OFF timing of the MOS transistor 50 is not delayed from the end of the energization period in this diode rectification when considering the case where the MOS transistor 50 is always turned off and rectified through a diode. And is set by the target electrical angle setting unit 105. The target electrical angle setting unit 105 sets the target electrical angle based on the rotation speed calculated by the rotation speed calculation unit 101. The target electrical angle may be constant regardless of the rotational speed, but more desirably, the target electrical angle may be set large in the low rotation region and the high rotation region, and the target electrical angle may be set small in the intermediate region. .

The rotation speed calculation unit 101 calculates the rotation speed based on the rising cycle or the falling cycle of the output signal of the lower MOS V _DS detection unit 130. By using the output signal of the lower MOS V _DS detection unit 130, stable rotation speed detection can be performed regardless of fluctuations in the output voltage V _B of the vehicular generator 1.

Similarly, the lower MOS ON timing determination unit 104 monitors the output signal (lower arm ON period) of the lower MOS V _DS detection unit 130, and the rising of the output signal from the low level to the high level is detected on the low side. This is determined as the ON timing of the MOS transistor 51 and an instruction is sent to the driver 182. The driver 182 turns on the MOS transistor 51 in response to this instruction.

  The lower MOS off timing calculation unit 109 determines that a predetermined time has elapsed after the MOS transistor 51 is turned on as the off timing of the MOS transistor 51 and sends an instruction to the driver 182. The driver 182 turns off the MOS transistor 51 in response to this instruction.

The predetermined time for determining the OFF timing is earlier than the end point of the lower arm ON period (the time point when the output signal of the lower MOS _VDS detection unit 130 falls from the high level to the low level) by “target electrical angle”. As described above, the variable setting is made each time.

  The target electrical angle is set so that the off timing of the MOS transistor 51 is not delayed from the end of the energization period in the diode rectification when considering the case where the MOS transistor 51 is always turned off and rectification is performed through the diode. And is set by the target electrical angle setting unit 105.

  Actually, the end time of the upper arm on period and the lower arm on period is not known at the time when the MOS transistors 50 and 51 are turned off. Therefore, the upper MOS off timing calculation unit 107 and the lower MOS off timing calculation are performed. The unit 109 raises the setting accuracy of the off timing of the MOS transistor 50 and the MOS transistor 51 by feeding back the information before the half cycle.

For example, the off timing of the high-side MOS transistor 50 is set as follows. The lower MOS · T _FB time calculation unit 108 calculates a time (electrical angle) T _FB2 (FIG. 9) from turning off the low-side MOS transistor 51 half a cycle ago to the end of the lower arm ON period. The upper MOS off timing calculation unit 107 obtains ΔT obtained by subtracting the target electrical angle from _TFB2 . If the rotation or the like is stable, T _FB2 and the target electrical angle should be equal and ΔT = 0, but (1) rotational fluctuation accompanying acceleration / deceleration of the vehicle, (2) pulsation of engine rotation, ( 3) Variation of electric load, (4) Variation of operation clock cycle when realizing the control unit 100 by executing a predetermined program, (5) Instructing the drivers 180 and 182 to turn off the MOS transistors 50 and 51 In many cases, ΔT does not become zero with a delay in turn-off until the actual turn-off.

  Therefore, the upper MOS off timing calculation unit 107 sets the upper MOS on period by correcting the lower MOS on period used by the lower MOS off timing calculation unit 109 half a cycle before based on ΔT. The off timing is determined. Specifically, when the correction coefficient is α, the upper MOS on period is set by the following equation.

(Upper MOS on period) = (Lower MOS on period before half cycle) + ΔT × α
Similarly, the off timing of the low-side MOS transistor 51 is set as follows. The upper MOS · T _FB time calculation unit 106 calculates a time (electrical angle) T _FB1 (FIG. 9) from turning off the high-side MOS transistor 50 half a cycle before to the end of the upper arm ON period. Then, the lower MOS off timing calculation unit 109 obtains ΔT obtained by subtracting the target electrical angle from _TFB1 . The lower MOS off timing calculation unit 109 sets the lower MOS on period by correcting the upper MOS on period used by the upper MOS off timing calculation unit 107 half a cycle before based on ΔT, and the off timing of the MOS transistor 51 Is determined. Specifically, when the correction coefficient is α, the lower MOS on period is set by the following equation.

(Lower MOS on period) = (Upper MOS on period before half cycle) + ΔT × α
In this way, the high-side MOS transistor 50 and the low-side MOS transistor 51 are alternately turned on in the same cycle as when diode rectification is performed, and a low-loss synchronous rectification operation using the MOS transistors 50 and 51 is performed. Done.

(3) Determination of start of synchronous control Next, the operation of determining whether or not to shift to the above-described synchronous control will be described. Immediately after the rectifier module 5X or the like is activated, or after a certain abnormality occurs and the synchronous control is temporarily stopped, the process shifts to the synchronous control when a predetermined synchronous control start condition is satisfied. The synchronization control start determination unit 102 determines whether or not the synchronization control start condition is satisfied. If it is determined that the condition is satisfied, a notification to that effect is sent to the upper MOS on timing determination unit 103 and the lower MOS on timing determination unit 104. It is done. Thereafter, the above-described synchronization control is performed, and the MOS transistors 50 and 51 are alternately turned on.

The following (A) to (F) are used as the synchronous control start conditions.
(A) The upper arm on period and the lower arm on period (FIG. 9) occur 32 times in succession. Note that 32 times is a value corresponding to two mechanical angles, assuming an 8-pole rotor. This value may be changed to a value other than 16 corresponding to one rotation, a value corresponding to three or more rotations, or a value corresponding to an integral multiple of one mechanical angle rotation.
(B) The output voltage V _B is included in a range that is higher than the normal range of 7V and lower than 18V. Although the lower limit value of the normal range is 7V and the upper limit value is 18V assuming a 12V system, the lower limit value and the upper limit value may be changed as appropriate. Further, in a vehicle system such as a 24V system, it is necessary to change the lower limit value and the upper limit value according to the generated voltage.
(C) The overheat state of the MOS transistors 50 and 51 is not determined.
(D) The load dump protection operation is not in progress.
(E) The fluctuation of the output voltage V _B is smaller than 0.5 V / 200 μsec. It should be noted that the degree to which this variation is allowed when synchronous control is started varies depending on the elements and programs used, so the allowable value of this variation should be changed as appropriate according to the elements used. Also good.
(F) Both T _FB1 and T _FB2 are longer than 15 μs. It should be noted that the extent to which these periods fall below what is considered abnormal depends on the cause of the abnormality, etc., so this allowable value (15 μs) may be changed as appropriate according to the cause of the abnormality. Good. Also, T _FB1 and T _FB2 have been described as being calculated during the synchronous control operation by the upper MOS · T _FB time calculation unit 106 and the lower MOS · T _FB time calculation unit 108, but before the start of the synchronous control, These calculations are also performed and are used to determine the start of synchronous control.

In FIG. 10, when the output voltage V _B exceeds 20 V, the load dump protection determination unit 111 detects a load dump in which the output terminal and the battery terminal of the vehicle generator 1 are disconnected and a surge voltage is generated, and the driver An instruction is sent to 180 and 182 to turn off the high-side MOS transistor 50 and to start a load dump protection operation to turn on the low-side MOS transistor 51. Further, the load dump protection determination unit 111 decreases the output voltage V _B once higher than 20 V (first threshold voltage V1) and lower than 17 V (second threshold voltage V2). Sometimes, the low-side MOS transistor 51 is turned on again after being turned off for a predetermined period. Ends the load dump protection operation. The load dump protection determination unit 111 outputs a signal that is at a high level during the load dump protection operation and at a low level at other times to the synchronization control start determination unit 102.

  In order to avoid the occurrence of a new surge voltage due to the on / off of the MOS transistors 50 and 51 at the start or end of the load dump protection operation, the load dump protection determination unit 111 performs the lower arm on-period shown in FIG. During this period, the load dump protection operation is started or ended.

At the normal time when synchronous control is performed, as shown in FIG. 11A, the phase voltage V _P is between the lower limit value near the output voltage V _B (the positive terminal voltage of the battery 9) and the upper limit value near the ground terminal voltage V _GND. It changes periodically. On the other hand, when a load dump occurs, the high-side MOS transistor 50 is turned off and the low-side MOS transistor 51 is turned on, and this state is maintained. Therefore, as shown in FIG. 11B, the phase voltage V _P periodically changes around the ground terminal voltage V _GND in the range of the drain-source voltage V _DS when the MOS transistor 51 is on. In the example shown in FIG. 11B, the drain-source voltage V _DS when the MOS transistor 51 is on is shown as 0.1 V, for example. However, the drain-source voltage V _DS differs depending on the specifications of the MOS transistor 51 used, the gate voltage, and the like.

The lower MOS V _DS amplifier 142 shown in FIG. 4 amplifies the drain-source voltage V _DS of the MOS transistor 51 when turned on, for example, by a factor of 5 (−0.5 V to +0.5 V) (FIG. 11C). . The energization direction determination unit 144 compares, for example, the threshold voltage set to +0.35 V with the drain-source voltage V _DS after amplification, and the threshold voltage is higher (range W ) Outputs a high level signal, and outputs a low level signal at other times.

  In FIG. 11C, the range indicated by W substantially corresponds to the timing when the low-side MOS transistor 51 is turned on during normal operation. In this embodiment, the range of W is set as a timing for starting or ending the load dump protection operation. That is, if included in the range of W, when the low-side MOS transistor 51 is turned on to start the load dump protection operation, the same direction as the forward direction of the diode connected in parallel to the MOS transistor 51 Since current flows through the MOS transistor 51, generation of surge voltage can be suppressed. In addition, if included in the range of W, before turning off the low-side MOS transistor 51 in order to end the load dump protection operation, the direction of the current flowing through the MOS transistor 51 and after turning off the MOS transistor 51 are turned off. Since the direction of the current flowing through the diode connected in parallel to the MOS transistor 51 is the same, the generation of a surge voltage can be suppressed.

Note that the threshold voltage described above may have hysteresis characteristics. For example, the threshold voltage when the drain-source voltage V _DS is lower is +0.35 V, and the threshold voltage after the drain-source voltage V _DS is higher is +0.3 V. There are cases. Thereby, when the drain-source voltage V _DS is changed in the vicinity of the threshold voltage, it is possible to prevent the level of the output signal of the energization direction determination unit 144 from being frequently switched.

The V _B range determination unit 113 determines whether or not the output voltage V _B detected by the output voltage detection unit 110 is included in the range of 7 to 18 V. If included, the low level is included. If not (higher than 7V or higher than 18V), a high level signal is output. The V _B fluctuation determination unit 114 determines whether or not the fluctuation of the output voltage V _B detected by the output voltage detection unit 110 is smaller than 0.5 V / 200 μsec. Outputs a high level signal. The T _FB time determination unit 115 determines whether T _FB1 detected by the upper MOS · T _FB time calculation unit 106 and T _FB2 detected by the lower MOS · T _FB time calculation unit 108 are longer than 15 μs. A low level signal is output if it is long, and a high level signal is output in the following cases.

  The overheat protection unit 123 determines whether or not an overheat state has occurred based on the output signal of the temperature detection unit 150, and performs an overheat protection operation when an overheat state occurs. When the overheat state is reached, the overheat protection unit 123 sets an overheat flag indicating that and sets the output signal corresponding to the overheat flag to a high level.

In FIG. 10, the V _B range determination unit 113, the V _B fluctuation determination unit 114, and the T _FB time determination unit 115 are provided outside the synchronization control start determination unit 102, but are included in the synchronization control start determination unit 102. It may be. In the above-described example, it is assumed that synchronous control is started when all the conditions (A) to (F) are satisfied, but at least one of (B) to (F) and (A) are combined. Thus, the synchronous control start condition may be used.

In FIG. 12, “count value” is a count value synchronized with the rise (start timing) of each of the upper arm on period and the lower arm on period, and “T _FB time flag” is an output of the T _FB time determination unit 115. “Voltage range flag” indicates the output of the V _B range determination unit 113, “LD flag” indicates the output of the load dump protection determination unit 111, “Overheat flag” indicates the output of the overheat protection unit 123, and “Voltage variation flag” "Indicates the output of the V _B fluctuation determination unit 114, respectively.

  The synchronization control start determination unit 102 performs a count operation synchronized with the rising of each of the upper arm on period and the lower arm on period, and starts the synchronization control when the count value of the count operation reaches “32”. A signal (low level indicates start of synchronous control and high level indicates stop of synchronous control) is input to the upper MOS on timing determination unit 103 and the lower MOS on timing determination unit 104. When the upper MOS on timing determination unit 103 and the lower MOS on timing determination unit 104 receive a signal indicating the start of synchronous control, the synchronous control for alternately turning on the MOS transistors 50 and 51 is started.

By the way, the synchronization control start determination unit 102 determines that the rising interval between the upper arm on period and the lower arm on period is one cycle or less in electrical angle, a T _FB time determination unit 115, a V _B range determination unit 113, load dump protection determination unit 111, the output of the overheat protection unit 123, V _B variation determining section 114 (T _FB time flag, voltage range flag, LD flag, overheating flag, voltage fluctuation flag) that are all at the low level, the The count operation described above is continued under the condition. On the contrary, the synchronization control start determination unit 102 determines that the rising interval between the upper arm on period and the lower arm on period exceeds one cycle in terms of electrical angle or the _TFB time determination unit until the count value reaches 32. 115, when the output of any one of the V _B range determination unit 113, the load dump protection determination unit 111, the overheat protection unit 123, and the V _B fluctuation determination unit 114 becomes high level, the count value is reset to 0, The count operation is restarted after the condition for continuing the count operation is satisfied.

(4) Determination of stop of synchronous control Next, an operation of determining whether to stop synchronous control during the above-described synchronous control will be described. The synchronization control stop determination unit 122 determines whether or not a predetermined synchronization control stop condition is satisfied during the synchronization control. When it is determined that the condition is satisfied, a notification to that effect is sent to the synchronization control start determination unit 102 and the upper MOS on timing. The data is sent to the determination unit 103, the lower MOS on timing determination unit 104, the upper MOS off timing calculation unit 107, and the lower MOS off timing calculation unit 109. Thereafter, the synchronization control is stopped until the synchronization control start determination unit 102 starts the synchronization control.

The following (a) to (e) are used as the synchronous control stop condition.
(A) From the off timing of the MOS transistor 51 set by the lower MOS off timing calculation unit 109, the phase voltage V _P is increased, and the first used for determining the on timing of the MOS transistor 50 next. The time until the threshold value is reached is shorter than the predetermined time.

  This predetermined time is the time from when the lower timing is instructed by the lower MOS off timing calculation unit 109 until the MOS transistor 51 is actually turned off by the driver 182. Specifically, the MOS transistor 51 is turned off by the driver 182. It is set according to the driving capability of the MOS transistor 51 at that time. The off-timing abnormality determination unit 121 outputs a signal that is at a high level when this condition is satisfied (when it is shorter than a predetermined time) and at a low level otherwise.

As shown in FIG. 13, when the timing for turning off the MOS transistor 51 becomes later than the end timing of the lower arm on period, the current that has been flowing through the MOS transistor 51 at that time is cut off. Occur. In FIG. 13, the surge voltage is indicated by S. This surge voltage is generated immediately after the MOS transistor 51 is turned off. When the time required from when the lower MOS off-timing calculation unit 109 is actually instructed to turn off the MOS transistor 51 to t0 (FIG. 13) is to detect the occurrence of a surge voltage associated with the off-timing delay. In addition, the predetermined time described above is set longer by β than the time t0 after the lower MOS off timing calculation unit 109 instructs the off timing. This β is a value including a surge voltage generated after the elapse of time t0, and the phase voltage V _P is increased when the synchronization control is normally performed (when no off-timing abnormality occurs). Therefore, it is necessary to be shorter than the time until the threshold value V10 is reached.
(B) The threshold used to determine the on-timing of the MOS transistor 51 after the phase voltage V _P has dropped from the off-timing of the MOS transistor 50 set by the upper MOS off-timing computing unit 107. The time until the value V11 is reached is shorter than the predetermined time.

  This predetermined time is the time from when the upper MOS off timing computing unit 107 instructs the off timing to when the MOS transistor 50 is actually turned off by the driver 180. Specifically, the driver 180 turns off the MOS transistor 50. It is set according to the driving capability of the MOS transistor 50 at that time. The off-timing abnormality determination unit 121 outputs a signal that is at a high level when this condition is satisfied (when it is shorter than a predetermined time) and at a low level otherwise.

The predetermined times indicated by (a) and (b) described above may be the same value, but different values may be used. In addition, these predetermined times are mainly set according to the driving capabilities of the drivers 180 and 182, and therefore it is desirable to use a constant value regardless of the rotational speed.
(C) The fluctuation of the output voltage V _B became larger than 0.5 V / 200 μsec.

  Note that the degree to which this fluctuation is allowed when synchronization control is continued varies depending on the elements and programs used, so the allowable value used for determining whether to stop synchronization depends on the elements used, etc. You may make it change suitably.

For example, when the output current suddenly decreases from 150 A to 15 A, the output voltage V _B increases as shown in FIG. As the output voltage rises, the upper arm ON period changes from the value T10 when there is no output fluctuation to T11 and T12 (<T10). The same applies to the lower arm on period. Thus, when the upper arm on period or the lower arm on period itself is shortened, the off timing of the MOS transistors 50 and 51 is set to the upper arm on period or the lower arm even if the off timing is set in the same procedure as before. Since the situation occurs later than the arm-on period, the above-described tolerance is used to avoid this. In the synchronous control start determination, the same allowable value is used for the same purpose, but different values may be used for the synchronous control start determination and the synchronous control stop determination.
(D) Shifted to load dump protection operation.
(E) The MOS transistors 50 and 51 are overheated.

The configuration shown in FIG. 15 is obtained by extracting the configuration necessary for the synchronous control stop determination from the configuration shown in FIG. As for the V _B variation determination unit 114, V _B change determination unit 114 of the synchronization control start determination shown in FIG. 10 is also used as such in the synchronization control stop determination.

As shown in FIG. 15, the synchronization control stop determination unit 122, the off timing error determination unit 121, V _B variation determining section 114, load dump protection determination unit 111, the output of the overheat protection portion 123 is input.

The off-timing abnormality determination unit 121 outputs a high level signal when the above-described synchronous control stop condition (a) or (b) is satisfied. Further, from the V _B fluctuation determining unit 114, the fluctuation of the output voltage V _B detected by the output voltage detecting unit 110 is larger than 0.5 V / 200 μsec, and satisfies the above-described synchronous control stop condition (c). Sometimes a high level signal is output. Further, the load dump protection determination unit 111 outputs a high level signal when the load dump operation is being performed and the synchronous control stop condition (d) described above is satisfied. The overheat protection unit 123 outputs a high level signal when the synchronous control stop condition (e) described above is satisfied, specifically, when an overheat state occurs and the overheat flag is set. The

Synchronization control stop determination unit 122, the off timing error determination unit 121, V _B variation determining section 114, load dump protection determination unit 111, also include the high level in one among the output signals of the overheat protection portion 123 If it is determined that the synchronous control stop condition is satisfied, an instruction to stop the synchronous control is sent to the synchronous control start determination unit 102, the upper MOS on timing determination unit 103, the lower MOS on timing determination unit 104, The data is sent to the upper MOS off timing calculation unit 107 and the lower MOS off timing calculation unit 109.
(5) Load dump protection operation Next, FIG. 16 shows the load dump protection operation when the charging line 12 is disconnected from the output terminal, or when the battery 9 or the large electric load 10 is suddenly disconnected and the load dump occurs. It demonstrates according to a flowchart. In the operation timing chart shown in FIG. 17, V _B is the output voltage of the vehicle generator 1, V1 is the first threshold voltage, V2 is the second threshold voltage, and Vf is the field winding. 4 represents the voltage of the F terminal applied to 4, and RP represents the voltage of the RP terminal of the rectifier module 5X. Further, v1 represents the result of comparing the output voltage V _B and the first threshold value V1 (when V _B > V1 corresponds to H (high level)), v2 represents the output voltage V _B and the first threshold value V1. 2 shows a result of comparison with a threshold value V2 of 2 (when V _B > V2 corresponds to H). Further, G2 indicates a signal inputted from the output terminal G2 of the control circuit 54 in the rectifier module 5X to the gate of the MOS transistor 51 of the lower arm, and when it is H, the MOS transistor 51 is turned on and L (low level) ) Is turned off.

Synchronous rectification (FIG. 9) is normally performed when no load dump occurs (step 100), and the load dump protection determination unit determines that the output voltage V _B is the first threshold value in parallel with the rectification operation. It is determined whether or not the voltage V1 has been exceeded (step 102). If not, a negative determination is made, and the flow returns to step 100 to continue the rectification operation.

Further, when the output voltage V _B exceeds the first threshold voltage V1, an affirmative determination is made in the determination of step 102, and the load dump protection determination unit 111 sends an instruction to the driver 180 to transmit the upper arm MOS transistor 50. Is turned off and an instruction is sent to the driver 182 to turn on the lower arm MOS transistor 51 (step 104).

Next, the load dump protection determination unit 111 determines whether or not the output voltage V _B exceeds both the first threshold voltage V1 and the second threshold V2 (step 106). If not, a negative determination is made. In this case, the process returns to step 100 and the rectification operation is performed.

Further, when the output voltage V _B exceeds both the first threshold voltage V1 and the second threshold voltage V2, an affirmative determination is made in the determination of step 106. Next, the excitation ON / OFF determination unit 124 determines whether or not the output voltage V _B has become lower than the first threshold voltage V1 (step 108). If the output voltage V _B is maintained at the first threshold voltage V1 or higher, a negative determination is made and this determination is repeated.

Further, when the output voltage V _B becomes lower than the first threshold voltage V1, an affirmative determination is made in the determination of step 108. Next, the excitation ON / OFF determination unit 124 determines whether or not the output voltage V _B has become lower than the second threshold voltage V2 (step 110). If the output voltage V _B maintains the second threshold voltage V2 or higher, a negative determination is made, and the determination in step 108 is repeated.

Further, when the output voltage V _B becomes lower than the second threshold voltage V2, an affirmative determination is made in the determination of step 110. Next, the excitation ON / OFF determination unit 124 calculates a time (voltage decrease time) T required for the output voltage V _B to decrease from the first threshold voltage V1 to the second threshold voltage V2. (Step 112), it is determined whether or not the voltage drop time T is shorter than a predetermined time (Step 114). If the output voltage V _B is short (when the degree of decrease in the output voltage V _B is severe), an affirmative determination is made, and the excitation ON / OFF determination unit 124 sets a predetermined time Toff for temporarily turning off the lower arm MOS transistor 51 to T1. (Step 116). On the other hand, when the voltage drop time T is longer than the predetermined time (when the output voltage V _B is gradually reduced), a negative determination is made in the determination of step 114, and the excitation ON / OFF determination unit 124 A predetermined time Toff for temporarily turning off the MOS transistor 51 of the arm is set to T2 (<T1) (step 118).

Next, the load dump protection determination unit 111 sends an instruction to the driver 182 to turn off the lower arm MOS transistor 51 for the predetermined time Toff set in step 116 or 118 (step 120). Thereafter (after the predetermined time Toff has elapsed), the process returns to step 104 and the MOS transistor 51 is turned on. The determination in step 106 subsequent to step 104 is for determining the end timing of the load dump protection operation, and when the MOS transistor 51 is turned on for a predetermined time, the output voltage V _B is the first. If the threshold voltage V1 is not exceeded, a negative determination is made in the determination of step 106, and the load dump protection operation ends.

If a large amount of excitation current is applied during the load dump protection operation in which the load dump occurs and the lower-arm MOS transistor 51 is turned on, the voltage across the capacitor 80 in the power generation control device 7 having a small capacity is quickly increased. The power generation control device 7 tries to continue the supply of the excitation current by turning on the MOS transistor 71 because the voltage falls below the adjustment voltage Vreg. However, in the vehicular generator 1 of the present embodiment, when such an excitation current is large and the degree of decrease in the output voltage V _B is severe, the output voltage V _B falls below the second threshold voltage V2. After that, the predetermined time for turning off the lower arm MOS transistor 51 is lengthened. For this reason, it is possible to lengthen the time during which the output voltage V _B is higher than the second threshold voltage V2, and to prevent the exciting current from flowing through the field winding 4 as much as possible. The generation of high voltage at the time of dumping can be quickly terminated to improve the reliability. On the contrary, when the energization amount of the exciting current is small, the predetermined time for turning off the lower-arm MOS transistor 51 once is shortened after the output voltage V _B falls below the second threshold voltage V2. For this reason, the time during which the output voltage V _B is maintained at the adjustment voltage Vreg or longer can be lengthened, and the exciting current can be prevented from flowing through the field winding 4 more than necessary. The generation can be finished quickly and the reliability can be improved.

The exciting ON / OFF determination unit 124, based on the rate of decrease in the output voltage V _B (the voltage drop time T), is to determine the extent of energization of the exciting current. By determining the state of the excitation current based on the output voltage V _B , it is not necessary to provide a dedicated terminal, so that the structure and wiring can be simplified, and the cost can be reduced.

  In the load dump protection operation, the rectifier module 5X generates a rotation detection signal by the rotation detection signal transmission unit 160 and outputs the rotation detection signal from the RP terminal, and this signal is input to the P terminal of the power generation control device 7. . As a result, it is possible to avoid the state in which the rotation cannot be detected by the power generation control device 7 and to prevent the transition to the initial excitation state when the rotation is stopped. It is possible to quickly terminate the generation of a high voltage during load dump.

(Second Embodiment)
In the first embodiment described above, the excitation ON / OFF determination unit 124 determines the degree of the energization amount of the excitation current based on the decrease rate of the output voltage V _B. You may make it determine based on the signal output from F terminal to which the coil | winding 4 is connected.

  In the control unit 100A of the second embodiment shown in FIG. 18, the excitation ON / OFF determination unit 124 is replaced with an excitation ON / OFF determination unit 124A compared to the control unit 100 of the first embodiment shown in FIG. It has been. This excitation ON / OFF determination unit 124A is connected to the F terminal (this F terminal is connected to the F terminal of the power generation control device 7), and the signal output from the F terminal of the power generation control device 7 Based on this, the degree of energization of the excitation current is determined. The overall configuration of the vehicle generator 1 is basically the same as that of the first embodiment except for the excitation ON / OFF determination unit 124A, and detailed description thereof is omitted.

Next, the load dump protection operation in the second embodiment will be described with reference to the flowchart shown in FIG. In the operation timing chart shown in FIG. 20, V _B , V 1, V 2, Vf, RP, v 1, v 2, G 2 indicate the same contents as those shown in FIG. In FIG. 20, F indicates a signal output from the F terminal of the power generation control device 7 and input to the F terminal of the rectifier module 5X. Further, the operation procedure shown in FIG. 19 is different in that steps 108 to 114 of the operation procedure shown in FIG. 16 are replaced with steps 200 and 202. In the following, the description will be given focusing on these replaced steps.

If an affirmative determination is made in the determination in step 106, the excitation ON / OFF determination unit 124A then determines whether or not the output voltage V _B has become lower than the second threshold voltage V2 (step 200). ). If the output voltage V _B is maintained at the second threshold voltage V2 or higher, a negative determination is made and this determination is repeated.

Further, when the output voltage V _B becomes lower than the second threshold voltage V2, an affirmative determination is made in the determination of step 200. Next, the excitation ON / OFF determination unit 124A acquires the low level time Treg off of the signal output from the F terminal of the power generation control device 7, and determines whether or not the time Treg off is shorter than the predetermined time. (Step 200).

When the output voltage V _B becomes higher than the adjustment voltage Vreg, the power generation control device 7 turns off the MOS transistor 71 and stops the excitation current supplied to the field winding 4 from the F terminal. The output signal is fixed at a low level. However, when the output voltage V _B becomes higher than the adjustment voltage Vreg, the power generation control device 7 cannot immediately recognize that fact and a delay of about 1 to 2 ms actually occurs. In the example shown in FIG. 20, when the delay time is used and the output voltage V _B is lower than the second threshold voltage V2, the signal output from the F terminal is changed from the high level to the low level before that. The time from the time of changing to the level to the time of changing to the next high level (when not changing to the high level, the time when step 202 is performed) is measured as time Treg off. Time Treg off is acquired.

When the time Treg off is shorter than the predetermined time (when the supply amount of the excitation current just before the output voltage V _B drops below the second threshold voltage V2 is large), an affirmative determination is made in the determination of step 202. The excitation ON / OFF determination unit 124A sets a predetermined time Toff for temporarily turning off the lower arm MOS transistor 51 to T1 (step 116). On the contrary, when the time Treg off is longer than the predetermined time (when the supply amount of the excitation current just before the output voltage V _B drops below the second threshold voltage V2 is small), the determination at step 202 is negative. The determination is made, and the excitation ON / OFF determination unit 124A sets T2 (<T1) as a predetermined time Toff for temporarily turning off the lower arm MOS transistor 51 (step 118).

As described above, in the vehicle generator according to the second embodiment, the excitation ON / OFF determination unit 124A determines the degree of energization of the excitation current based on the signal output from the F terminal of the power generation control device 7. Therefore, the state of the excitation current can be reliably determined. In particular, as shown in FIG. 20, the load dump protection determination unit 111 instructs to turn on the lower arm MOS transistor 51 once turned off after the supply of the excitation current through the F terminal of the power generation control device 7 is stopped. It is carried out. As a result, since the output voltage V _B does not rapidly decrease by turning on the MOS transistor 51, the exciting current supply operation under the control of the power generation control device 7 can be reliably stopped.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the resistor 20 is connected to the rectifier module 5X in FIG. 1, but may be connected to another rectifier module 5Y or the like. In addition to the case where the resistor 20 is built in a terminal block (not shown) that serves as a wiring and attachment of six or a part of the rectifier module 5X, the resistor 20 is built in the rectifier module 5X. (FIG. 21). In the embodiment described above, both the P terminal and the RP terminal of the rectifier module 5X are connected to the power generation control device 7. However, these P terminal and RP terminal may be provided in separate rectifier modules.

  In the above-described embodiment, the two stator windings 2 and 3 and the two rectifier module groups 5 and 6 are provided. However, the vehicle includes one stator winding 2 and one rectifier module group 5. The present invention can also be applied to power generators.

  Further, in the above-described embodiment, the case where the rectifying operation (power generation operation) is performed using each rectifier module 5X or the like has been described. However, it is applied from the battery 9 by changing the on / off timing of the MOS transistors 50 and 51. The present invention can be applied to a vehicular rotating electrical machine that converts a direct current to be converted into an alternating current and supplies it to the stator windings 2 and 3 to perform an electric operation.

  In the above-described embodiment, each of the two rectifier module groups 5 and 6 includes three rectifier modules. However, the number of rectifier modules may be other than three.

  In the second embodiment described above, the excitation ON / OFF determination unit 124A determines the amount of energization of the excitation current based on the low level time Treg off of the signal output from the F terminal of the power generation control device 7. Although it has been determined, this signal may be smoothed (for example, through a low-pass filter), and the degree of energization of the excitation current may be determined based on the voltage value. The higher the on-duty of the signal output from the F terminal, the higher the voltage value obtained by smoothing this signal. Therefore, the predetermined time Toff may be set longer.

  In the above-described embodiment, the predetermined time Toff is set to two stages. However, the predetermined time Toff may be set to three or more stages, or may be continuously variably set according to the degree of excitation current.

  As described above, according to the present invention, at the time of load dump occurrence, if the energization amount of the excitation current is large, it is possible to increase the time during which the output voltage becomes a higher value than the second threshold voltage. Since it is possible to prevent the exciting current from flowing through the field winding as much as possible, the generation of a high voltage at the time of load dumping can be quickly terminated to improve the reliability.

2, 3 Stator winding 4 Field winding 5, 6 Rectifier module group 7 Power generation control device 50, 51 MOS transistor 100 Control unit 111 Load dump protection determination unit 124 Excitation ON / OFF determination unit 180, 182 Driver

Claims (7)

A field winding (4) for magnetizing the rotor field poles;
A stator having an armature winding (2, 3) as a multiphase winding that generates an alternating voltage by a rotating magnetic field generated by the field pole;
A power generation control device (7) for controlling an output voltage by adjusting an exciting current supplied to the field winding;
An excitation determination unit (124) for determining a state of an excitation current supplied to the field winding under the control of the power generation control device;
A switching circuit (5, 6) configured to form a bridge circuit having a plurality of upper and lower arms by the switching elements (50, 51), and rectifies the induced voltage of the armature winding;
A switching control unit (100, 180, 182) for controlling on / off of the switching element;
Monitoring the output voltage of the switching unit, and when the output voltage exceeds a first threshold voltage, the switching control unit is instructed to turn on the switching element constituting the lower arm, The switching that constitutes the lower arm when the output voltage becomes lower than a second threshold voltage lower than the first threshold voltage after exceeding the first threshold voltage Load dump protection for instructing the switching control unit to turn on the element after turning it off for a predetermined time, and variably setting the length of the predetermined time based on the state of the excitation current determined by the excitation determination unit A determination unit (111);
A vehicular rotating electrical machine comprising: In claim 1,
The vehicular rotating electrical machine is characterized in that the load dump protection determination unit sets the predetermined time longer when the excitation current is large, and conversely sets the predetermined time short when the excitation current is small. In claim 1 or 2,
The rotating electrical machine for a vehicle according to claim 1, wherein the excitation determination unit determines a degree of energization amount of the excitation current based on a decrease rate of the output voltage. In claim 1 or 2,
The power generation control device has an excitation drive terminal to which the field winding is connected,
The rotating electrical machine for a vehicle according to claim 1, wherein the excitation determination unit determines a degree of energization amount of the excitation current based on a signal output from the excitation drive terminal. In claim 4,
The rotating electrical machine for a vehicle according to claim 1, wherein the load dump protection determination unit gives an instruction to turn on the switching element constituting the lower arm after the supply of the excitation current via the excitation drive terminal is stopped. In any one of Claims 1-5,
A vehicle comprising a plurality of rectifier modules provided corresponding to each of a plurality of output terminals of the armature winding, each including the excitation determination unit, the switching unit, and the load dump protection determination unit. Rotating electric machine. In claim 6,
The power generation control device has a phase voltage detection terminal connected to the output terminal of the armature winding,
The rectifier module outputs a rotation detection signal capable of detecting rotation toward the phase voltage detection terminal during a load dump protection operation by the load dump protection determination unit.

Images