JP5966980B2 - Rotating electric machine for vehicles - Google Patents

Description

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

  Conventionally, the MOS transistor (switching element) is turned on in accordance with the diode rectification period, and the diode rectification period is secured after the MOS transistor is turned off so as not to continue the ON state of the MOS transistor beyond the diode rectification period. A vehicular rotating electrical machine is known (for example, see Patent Document 1). In this vehicular rotating electrical machine, the difference between the diode rectification period after turning off the MOS transistor and the target electrical angle is calculated for the MOS transistor, and feedback control is performed by adding a value obtained by multiplying the difference by a correction coefficient. The off timing of the focused MOS transistor is determined.

JP 2012-70559 A

  By the way, in the vehicular rotating electrical machine disclosed in Patent Document 1, when a predetermined synchronous control start condition is satisfied during the diode rectification operation, the operation shifts to a synchronous rectification operation in which the MOS transistor is turned on / off and rectified. However, since the voltage drop between the diode and the MOS transistor is different, the period in which the output can be extracted from the stator winding by synchronous rectification is longer than the period in which the output can be extracted from the stator winding by diode rectification. Becomes longer. For this reason, the influence of mutual inductance is exerted between the stator winding and the magnetic circuit, or between the stator windings of the other phase sharing the magnetic circuit, and the electromotive force in the stator winding of the other phase is reduced. Occurs and the commutation possible period is shortened. In addition, when the affected stator winding of the other phase is in synchronous rectification, if the rectification possible period is shortened, an off-synchronization occurs in which the off timing of the MOS transistor is later than the end of the rectification possible period, A phenomenon occurs in which the current flowing backward through the MOS transistor is cut off. For this reason, the occurrence of surge and the accompanying damage of the MOS transistor may occur, which may lead to loss of the rectification function.

  In addition, even if a loss of synchronization occurs so that current does not reversely flow through the MOS transistor, if the diode rectification period secured after the MOS transistor is turned off becomes extremely short, the synchronous rectification is terminated and a transition is made to diode rectification. Will reduce efficiency.

  Further, in a six-phase vehicle generator using two sets of three-phase windings, two sets of stator windings share a magnetic circuit. Since each phase of a pair of stator windings has almost the same voltage waveform, when shifting from diode rectification to synchronous rectification, each phase tends to shift almost simultaneously, and the above-described influence of mutual inductance is even more pronounced. Therefore, loss of synchronization is likely to occur.

  The present invention has been created in view of the above points, and its purpose is to prevent loss of synchronization when shifting from diode rectification to synchronous rectification, generation of a surge voltage associated with loss of synchronization, and the switching element. An object of the present invention is to provide a vehicular rotating electrical machine capable of preventing breakage and maintaining a highly efficient rectifying operation.

In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes an armature winding, a switching unit, and a control circuit. The armature winding has two or more phase windings. In the switching unit, a plurality of upper arms and lower arms of the bridge circuit are configured by switching elements having diodes connected in parallel, and rectify the induced voltage of the armature winding. The control circuit includes a diode rectification operation in which the switching element is turned off to perform rectification by the diode, and a synchronous rectification operation in which the switching element is turned on for a predetermined period and then energized through the diode. And a control circuit that performs a transition rectification operation for gradually increasing a predetermined period during which the switching element is turned on by performing on / off control of the switching element.
The control circuit further includes a rotation speed detection unit that detects the rotation speed, and the control circuit performs a transition rectification operation at a low rotation time when the rotation speed detected by the rotation speed detection unit is a predetermined value or less. Alternatively, the control circuit further includes an output current detection unit that detects the output current, and the control circuit performs the transition rectification operation when the current value detected by the output current detection unit is low or lower than a predetermined value. Alternatively, the control circuit further includes a rotation speed detection unit that detects the rotation speed and an output current detection unit that detects the output current, and the control circuit has a low rotation speed detected by the rotation speed detection unit of a predetermined value or less. In addition, the transition rectification operation is performed at the time of low output when the current value detected by the output current detector is a predetermined value or less.

  When transitioning from diode rectification to synchronous rectification, transition rectification is performed to gradually increase the period during which the switching element is turned on. Therefore, the change in the rectifiable period due to the voltage drop between the diode and the switching element is moderate. Therefore, loss of synchronization when synchronous rectification is started after transition rectification is completed can be prevented. In addition, since there is no loss of synchronization, it is possible to prevent the occurrence of surge voltage and damage to the switching element due to loss of synchronization, and the highly efficient rectification operation by reducing the frequency of occurrence of loss of synchronization and shifting to diode rectification Can be maintained.

It is a figure which shows the structure of the generator for vehicles of one Embodiment. 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 the mode of the fluctuation | variation of the electrical angle supposing the case where a vehicle accelerates rapidly. It is a figure which shows the mode of the fluctuation | variation of the electrical angle supposing the case where engine rotation fluctuates. It is a figure which shows the mode of a fluctuation | variation of the electrical angle supposing the case where an electric load fluctuates rapidly. It is a figure which shows the mode of a fluctuation | variation of the electrical angle supposing the turn-off delay in a driver. It is a figure which shows the mode of the fluctuation | variation of the electrical angle supposing the combination of various factors. 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 state transition diagram of the whole rectification operation including a transition rectification operation. It is explanatory drawing of transition rectification. It is a figure which shows the modification of a rectifier module. It is a figure which shows the modification of a control circuit.

  Hereinafter, a vehicular 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. As shown in FIG. 1, the vehicle generator 1 of this embodiment includes two stator windings (armature windings) 2, 3, a field winding 4, two rectifier module groups 5, 6, and power generation. A control device 7 is 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 the other 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 in the field winding 4 connected via the F terminal, and adjusts the excitation current to adjust the output voltage of the vehicle generator 1 (each output voltage) V _B of the rectifier module is controlled to be a 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. The power generation control device 7 is connected to an ECU 8 (external control device) via a communication terminal L and a 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 vehicle generator 1 of the present embodiment has such a configuration, and details of the rectifier module 5X and the like will be described next. Each rectifier module 5X has the same configuration as the other rectifier modules 5Y, 5Z, 6U, 6V, 6W.

  As shown in FIG. 2, the rectifier module 5X 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 arranged between the positive terminal and the negative terminal of the battery 9, and the X-phase winding is connected to the connection point (P terminal) of these two MOS transistors 50 and 51. ing. 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. 3, 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 power source 160, and the drivers 170 and 172 are provided.

  The power supply 160 starts operating at the timing when the excitation current is supplied from the power generation control device 7 to the field winding 4, supplies the operating voltage to each element included in the control circuit 54, and stops supplying the excitation current. When it is done, supply of operating voltage is stopped. The power supply 160 is started and stopped in response to an instruction from the control unit 100.

  The driver 170 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 172 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. 4, the horizontal axis represents 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. 4, 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 more, 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. 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. 5, the horizontal axis represents the drain-source voltage V _DS with respect to 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. 5, when the phase voltage V _P becomes low and becomes lower than the ground voltage V _GND by 0.3 V or more, 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 0.3V lower than the ground voltage V _GND described above 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 V21 is for reliably detecting 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. 6, 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. 6, 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 170 that drives the MOS transistor 50 fails and the MOS transistor 50 is always turned on. When no failure occurs in the MOS transistor 50 or the driver 170, 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 when turned on, for example, by a factor of 5 (−0.5 V to +0.5 V) (FIG. 15C). 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. 15C), and a low level signal is output at other times.

  The control unit 100 determines the timing to start and end the synchronous rectification operation, sets the on / off timing of the MOS transistors 50 and 51 for performing the synchronous rectification, and the driver 170 corresponding to the setting of the on / off timing. 172 driving, determination of transition timing of load dump protection operation, execution of protection operation, and the like are performed.

As shown in FIG. 7, the control unit 100 includes a rotation speed calculation unit 101, a synchronization control start processing 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, and an overheat protection unit 123 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 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 160 is instructed to start. The power supply start / stop determination unit 112 instructs the power supply 160 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. 8 showing the operation timing of synchronous rectification control (synchronous control), the “upper arm on period” is the output signal of the upper MOS V _DS detector 120, and the “upper MOS on period” is high. The ON / OFF timing of the side-side MOS transistor 50, the output signal of the lower MOS _VDS detector 130 in the “lower arm ON period”, and the ON / OFF state of the low-side MOS transistor 51 in the “lower MOS on period” Each timing is shown. 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 170. The driver 170 turns on the MOS transistor 50 in response to this instruction.

  The upper MOS off timing calculation unit 107 determines that the 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 170. The driver 170 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. . A specific example of the method for setting the target electrical angle will be described later.

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. Is determined as the ON timing of the MOS transistor 51, and an instruction is sent to the driver 172. The driver 172 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 172. The driver 172 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 the time (electrical angle) T _FB2 (FIG. 8) 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 in electrical load, (4) Variation in operation clock cycle when realizing the control unit 100 by executing a predetermined program, (5) Instructing the drivers 170 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 the time (electrical angle) T _FB1 (FIG. 8) from turning off the high-side MOS transistor 50 half a cycle before 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) Target Electric Angle Setting Method Next, a target electric angle setting method will be described. The target electrical angle is set to a value corresponding to the rotational speed. This is because the value (minimum value) of the target electrical angle necessary for performing synchronous control so that the timing for turning off the MOS transistors 50 and 51 does not become later than the end point of the upper arm on period or the lower arm on period. This is because it depends on the rotational speed. Specifically, as described for the off-timing setting operation in the upper MOS off-timing computing unit 107 and the lower MOS off-timing computing unit 109 described above, (A) rotational fluctuation accompanying acceleration / deceleration of the vehicle, (B) engine Pulsation of rotation, (C) fluctuation of electrical load, (D) fluctuation of operation clock cycle when the control unit 100 is realized by executing a predetermined program by the CPU, (E) MOS transistor 50 in the drivers 170 and 172, For the same reason that ΔT does not become 0 due to a turn-off delay from when an instruction to turn off 51 is issued until it is actually turned off, the required target electrical angle value is changed according to the rotational speed. Yes.

  In FIG. 9 corresponding to the above case A, the horizontal axis represents the rotational speed of the vehicle generator 1, and the vertical axis represents the rotational fluctuation in which the rotational speed of the vehicle generator 1 increases from 2000 rpm to 16000 rpm in 1 second. The electrical angles representing how much the lengths of the upper arm on period and the lower arm on period fluctuated at the same time are shown. In FIG. 9, the characteristic indicated by the solid line corresponds to the case where the rotor has 8 poles, and the characteristic indicated by the dotted line corresponds to the case where the rotor has 6 poles.

  As shown in FIG. 9, the lower the number of rotations, the greater the degree of on-period variation expressed in electrical angle, and the higher the number of rotations, the smaller the degree of on-period variation expressed in electrical angle. If this characteristic is reflected, it can be said that the target electrical angle needs to be set to a larger value as the speed becomes lower, and the target electrical angle needs to be set to a smaller value as the speed becomes higher.

  In FIG. 10 corresponding to the case B above, the horizontal axis is the rotational speed of the vehicle generator 1 and the vertical axis is the pulley ratio is 2.5. The electrical angle representing how much the length of the period and the lower arm on period fluctuated is shown. In FIG. 10, the characteristic indicated by the solid line corresponds to the case where the rotor has 8 poles, and the characteristic indicated by the dotted line corresponds to the case where the rotor has 6 poles.

  As shown in FIG. 10, the lower the number of rotations, the greater the degree of on-period variation expressed in electrical angle, and the higher the number of rotations, the smaller the degree of on-period variation expressed in electrical angle. If this characteristic is reflected, it can be said that the target electrical angle needs to be set to a larger value as the speed becomes lower, and the target electrical angle needs to be set to a smaller value as the speed becomes higher.

In FIG. 11 corresponding to the above case C, the horizontal axis represents the rotational speed of the vehicular generator 1, and the vertical axis represents the output voltage V _B of 13.5V to 14.0V with the 50A electric load 10 cut off. Electric angles representing how much the lengths of the upper arm on period and the lower arm on period fluctuate when changed are shown. In FIG. 11, the characteristic indicated by the solid line corresponds to the case where the rotor has eight poles, and the characteristic indicated by the dotted line corresponds to the case where the rotor has six poles.

  As shown in FIG. 11, the lower the number of rotations, the greater the degree of on-period variation expressed in electrical angle, and the higher the number of rotations, the smaller the degree of on-period variation expressed in electrical angle. If this characteristic is reflected, it can be said that the target electrical angle needs to be set to a larger value as the speed becomes lower, and the target electrical angle needs to be set to a smaller value as the speed becomes higher.

  In FIG. 12 corresponding to the above case E, the horizontal axis represents the rotational speed of the vehicle generator 1, and the vertical axis represents the turn-off from when the drivers 170 and 172 are instructed to turn off to when they are actually turned off. Electric angles representing how much the lengths of the upper arm on period and the lower arm on period fluctuate when the delay is 15 μs are shown. In FIG. 12, the characteristic indicated by the solid line corresponds to the case where the rotor has 8 poles, and the characteristic indicated by the dotted line corresponds to the case where the rotor has 6 poles.

  As shown in FIG. 12, the lower the rotational speed, the smaller the degree of on-period variation expressed in electrical angle, and the higher the rotational speed, the greater the degree of on-period variation expressed in electrical angle. If this characteristic is reflected, it can be said that the target electrical angle needs to be set to a smaller value as the rotation speed becomes lower, and the target electrical angle needs to be set to a larger value as the rotation speed becomes higher.

In addition to the above, it is necessary to consider the fluctuation of the clock cycle (corresponding to the above case D). For example, if a 2 MHz system clock is used and its accuracy is ± β%, that is, β% varies, the variation in the length of the upper arm on period and the lower arm on period is The smaller the rotation speed, the smaller the rotation speed. This is because the accuracy of the clock is constant regardless of the number of rotations, but the time for one electrical angle period of the phase voltage V _P becomes shorter as the rotation speed becomes higher. This is because the ratio increases. If this characteristic is reflected, it can be said that the target electrical angle needs to be set to a smaller value as the rotation speed becomes lower, and the target electrical angle needs to be set to a larger value as the rotation speed becomes higher.

  In FIG. 13 showing the state of fluctuation of the electrical angle assuming the combination of various factors corresponding to the cases A to E described above, the horizontal axis represents the rotation speed of the vehicle generator 1 and the vertical axis represents the various factors. The corresponding accumulated values of electrical angle fluctuation are shown. The characteristic S shown in FIG. 13 is a cumulative value of the electrical angle fluctuation when the rotor has 8 poles.

  As shown in FIG. 13, when various factors corresponding to the cases A to E are combined, the degree of electrical angle fluctuation becomes large in the low speed rotation range and the high speed rotation range, and the degree of electrical angle fluctuation in the medium speed rotation range. It turns out that it becomes small. The target electrical angle setting unit 105 reflects this characteristic, that is, sets the target electrical angle value large in the low speed rotation range and the high speed rotation range, and sets the target electrical angle value small in the medium speed rotation range. The two types of characteristics indicated by P and Q in FIG. 13 indicate the target electrical angle set in this way. One of the target electrical angles indicated by P is such that the value changes continuously according to the rotational speed. In this case, the minimum value of the target electrical angle can be set according to the rotation speed. The target electrical angle indicated by Q on the other side has a value that changes stepwise according to the rotational speed. In this case, for example, a plurality of values that change according to the number of rotations may be stored in the form of a table, so that the configuration necessary for variably setting the target electrical angle can be simplified.

  In the vehicle generator 1 of the present embodiment, by setting the target electrical angle value variably in accordance with the rotational speed, a period during which current flows through the diode after the MOS transistors 50 and 51 are turned off is secured and this period is set. Therefore, it is possible to reduce loss caused by diode rectification and improve power generation efficiency. In particular, by setting a large target electrical angle value in the low-speed rotation range and high-speed rotation range, and setting a small target rotation angle value in the medium-speed rotation range, set an appropriate value for the target electrical angle for each rotation speed. Therefore, loss reduction and improvement in power generation efficiency can be realized in each rotation region.

  In addition, by continuously changing the target electrical angle, it is possible to set the minimum value of the target electrical angle according to the rotational speed and the like, and the power generation efficiency can be maximized while minimizing loss. . Further, by changing the target electrical angle in a step shape, the configuration necessary for variably setting the target electrical angle can be simplified.

  In the embodiment described above, the value of the target electrical angle is variably set according to the rotational speed. However, the target electrical angle value may be set by further combining the temperature and the output current with the rotational speed.

  For example, in general, the period of the clock generated by the clock generator varies more as the temperature increases. Considering the case where this clock generator is built in the rectifier module 5X or the like, it can be considered that the temperature detected by the temperature detector 150 matches the temperature of this clock generator. The target electrical angle setting unit 105 sets the target electrical angle to a large value when the temperature detected by the temperature detection unit 150 is high and the target electrical angle is increasing with respect to the rotation speed, and the temperature is low. The target electrical angle is set to a smaller value. By taking into account the influence of temperature, it is possible to further set an appropriate value of the target electrical angle, and to further reduce loss and improve power generation efficiency.

In general, the increase and decrease of the phase voltage V _P becomes steeper as the output current increases, and conversely, the increase and decrease of the phase voltage V _P becomes gentler as the output current decreases. As stated above, there are deviated from the timing of current flowing in the actual MOS transistor 50 parallel with the diode and the time the upper arm on period ends stops, the degree of this deviation, gradual change of the phase voltage V _P It becomes more noticeable at small output. The target electrical angle setting unit 105 sets the target electrical angle to a larger value as the output current decreases, and sets the target electrical angle to a smaller value as the output current increases. By taking into account the effect of the change in output current, it is possible to set an appropriate value for the target electrical angle, and to further reduce loss and improve power generation efficiency. Note that the magnitude of the output current can be determined by monitoring the on-duty of the PWM signal supplied from the F terminal of the power generation control device 7 to the field winding 4. Alternatively, the magnitude of the output current is determined based on, for example, a current detection resistor inserted between the source of the MOS transistor 51 shown in FIG. 2 and the negative terminal (ground) of the battery 9, and the voltage across the current detection resistor. You may make it determine.

(4) Determination of start of synchronous control Next, an operation for 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. In the present embodiment, instead of immediately shifting to synchronous rectification, the transition is made to synchronous rectification through a transition rectification operation that gradually lengthens the upper arm on period and the lower arm on period (FIG. 8). The transition rectification operation will be described later.

  The synchronous control start processing unit 102 determines whether or not the synchronous control start condition is satisfied, and if it is determined that the synchronous control start condition is satisfied, a notification that the synchronous control start condition is satisfied is performed after controlling the transition rectification operation. It is sent to the upper MOS on timing determination unit 103 and the lower MOS on timing determination unit 104. 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. 8) 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. 14, 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 170 and 182 are sent to turn off the high-side MOS transistor 50 and start the load dump protection operation to turn on the low-side MOS transistor 51. The load dump protection determination unit 111 turns on the low-side MOS transistor 51 again after a predetermined period of turn-off when the output voltage V _B once higher than 20 V drops and drops below 17 V. 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 processing unit 102.

  In order to avoid the occurrence of a new surge voltage due to turning 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 the synchronization control is performed, as shown in FIG. 15A, 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. 15B, 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. 15B, 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. 3 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. 15C). . 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. 15C, 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. 14, the V _B range determination unit 113, the V _B variation determination unit 114, and the T _FB time determination unit 115 are provided outside the synchronization control start processing unit 102, but are included in the synchronization control start processing 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. 16, “count value” is a count value synchronized with the rising (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 processing 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 processing 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 processing unit 102 has a rising interval between the upper arm on period and the lower arm on period exceeding one cycle in electrical angle until the count value reaches 32, or the _TFB time determination unit 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.

(5) 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 processing unit 102, 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 processing unit 102 starts the synchronization control.

The following (a) to (e) are used as the synchronous control stop condition.
(A) Threshold used to determine the on-timing of the MOS transistor 50 after the phase voltage V _P has risen from the off-timing of the MOS transistor 51 set by the lower MOS off-timing calculator 109. The time until the value V10 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 172. Specifically, the MOS transistor 51 is turned off by the driver 172. 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. 17, when the timing at which the MOS transistor 51 is turned off becomes later than the timing at which the lower arm on period ends, the current flowing through the MOS transistor 51 at that time is cut off. Occur. In FIG. 17, the surge voltage is indicated by S. This surge voltage is generated immediately after the MOS transistor 51 is turned off. If the time required from when the lower MOS off-timing calculation unit 109 is actually instructed to turn off the MOS transistor 51 is t0 (FIG. 17), the occurrence of a surge voltage due to the off-timing delay is detected. 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 timing is instructed by the upper MOS off timing calculation unit 107 to when the MOS transistor 50 is actually turned off by the driver 170, specifically, the driver 170 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 170 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. 19 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 for control start judgment synchronization shown in FIG 14 is also used as such in the synchronization control stop determination.

As shown in FIG. 19, 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 processing unit 102, the upper MOS on timing determining unit 103, the lower MOS on timing determining unit 104, The data is sent to the upper MOS off timing calculation unit 107 and the lower MOS off timing calculation unit 109.

(6) Transition rectification operation Next, the transition rectification operation will be described. As shown in FIG. 20, transition rectification is performed when switching from diode rectification to synchronous rectification. Specifically, diode rectification is performed immediately after the rectifier module 5X and the like start operation. In parallel with this diode rectification, the synchronous control start processing unit 102 determines whether or not the synchronous control start condition is satisfied. If not, diode rectification continues. Further, when the synchronous control start condition is satisfied, the synchronous rectification is not immediately started, but the transition rectification by the synchronous control start processing unit 102 is performed.

  As shown in FIG. 21, the transition rectification is performed by setting the upper MOS on period (may be the lower MOS on period) to a predetermined initial value Ts. The upper MOS on period and the lower MOS on period are predetermined increments for each predetermined cycle of the rectification operation (every half cycle in the example shown in FIG. 21, but may be every one cycle or more than one cycle). By increasing ΔTa, it is gradually increased. This increase is repeated until a predetermined value Te is reached. It is necessary to turn on and off the MOS transistors 50 and 51 in accordance with the gradually increasing upper MOS on period and lower MOS on period, but the timing for turning on is the same as in the case of synchronous rectification. 103, determined by the lower MOS on timing determination unit 104, and the MOS transistors 50 and 51 are turned on. The timing for turning off is instructed from the synchronization control start processing unit 102 to the upper MOS off timing calculation unit 107 and the lower MOS off timing calculation unit 109 (or from the synchronization control start processing unit 103 to the drivers 170 and 172 at the off timing. To turn off the MOS transistors 50 and 51 directly).

  The increase ΔTa described above has increased every predetermined period, but may increase every predetermined time. Further, at least one of the initial value Ts and the increment ΔTa described above is based on any one of the rotational speed, the generated current, the temperature of the MOS transistors 50 and 51, or a combination of two or more, in addition to the case where a fixed value is used. May be variably set. In addition, about the structure which detects output current, the structure shown in FIG.22 and FIG.23 mentioned later can be used.

  In parallel with such transition rectification, the synchronous control stop determination unit 122 determines whether or not the synchronous control stop condition is satisfied. When it is satisfied, the transition rectification is stopped, and the diode rectification is immediately started. When the synchronous control stop condition is not satisfied, the synchronous control start processing unit 102 determines whether or not the transition rectification end condition is satisfied. For example, “the upper MOS on period or the lower MOS on period has reached a predetermined value Te” is used as the transition rectification end condition. When the transition rectification termination condition is not satisfied (when the upper MOS ON period or the like does not reach the predetermined value Te), transition rectification is repeated.

  If the transition rectification end condition is satisfied, the process proceeds to synchronous rectification. Thereafter, in parallel with the synchronous rectification, the synchronous control stop determination unit 122 determines whether or not the synchronous control stop condition is satisfied. If not satisfied, synchronous rectification is repeated. If the synchronous control stop condition is satisfied, the process immediately shifts to diode rectification.

  As described above, in the vehicular generator 1 according to the present embodiment, when the transition from the diode rectification to the synchronous rectification is performed, the transition rectification that gradually increases the period during which the MOS transistors 50 and 51 are turned on is performed. The change in the rectifiable period (period in which current can be supplied from the rectifier module 5X and the like to the charging line 12 side via the output terminal) due to the voltage drop of each of the MOS transistors 50 and 51 becomes gradual, and the transition Loss of synchronization when synchronous rectification is started after completion of rectification can be prevented. In addition, since there is no loss of synchronization, it is possible to prevent the occurrence of surge voltage and damage to the MOS transistors 50, 51, etc. due to loss of synchronization, and to reduce the frequency of occurrence of loss of synchronization and shifting to diode rectification. The efficiency rectification operation can be maintained.

  Moreover, transition rectification is performed by repeatedly adding a predetermined increment ΔTa from the initial value Ts to the predetermined value Te and gradually increasing the upper MOS on period and the lower MOS on period. Can be realized.

  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 two stator windings 2 and 3 and the two rectifier module groups 5 and 6 are provided. However, the vehicle including one stator winding 2 and one rectifier module group 5 is provided. 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 above-described embodiment, transition rectification is performed regardless of the rotational speed and output. However, when switching from diode rectification to synchronous rectification without performing transition rectification at low rotation or low output, synchronization is performed. Since detachment is likely to occur, transition rectification may be performed at least at one of low rotation and low output.

  Specifically, the synchronization control start processing unit 102 has a rotation number calculated by the rotation number calculation unit 101 (a rotation number detection unit other than the rotation number calculation unit 101 may be provided outside the control unit 100). The transition control may be performed only at the time of a low rotation of a predetermined value or less. Further, the synchronous control start processing unit 102 may perform transition rectification only when the output current value is a low output that is a predetermined value or less. Alternatively, the synchronization control start processing unit 102 may perform transition rectification at the time of low rotation with the rotation speed being a predetermined value or less and at the time of low output with the output current value being a predetermined value or less.

  The output current value can be determined by monitoring the on-duty of the PWM signal supplied from the F terminal of the power generation control device 7 to the field winding 4. Alternatively, the magnitude of the output current is determined based on, for example, a current detection resistor inserted between the source of the MOS transistor 51 shown in FIG. 2 and the negative terminal (ground) of the battery 9, and the voltage across the current detection resistor. You may make it determine. The configuration shown in FIG. 22 is obtained by adding a current detection resistor 55 to the rectifier module 5X shown in FIG. The configuration shown in FIG. 23 is obtained by adding an output current detection unit 152 to the control circuit 54 shown in FIG. The output current detector 152 detects the output current based on the voltage across the current detection resistor 55. In this case, the magnitude of the output current is determined based on the value of the current flowing through the MOS transistor 51 of the rectifier module 5X. Instead, the value of the current flowing through the charging line 12 or the output terminal is determined by a current sensor. It may be used directly to detect the magnitude of the output current.

  As described above, according to the present invention, when the transition from the diode rectification to the synchronous rectification is performed, the transition rectification is performed to gradually increase the period during which the switching element is turned on. The change in the rectification possible period due to the rectification becomes moderate, and the loss of synchronization when the synchronous rectification is started after the completion of the diode rectification can be prevented.

2, 3 Stator winding 5, 6 Rectifier module group 50, 51 MOS transistor 54 Control circuit 101 Rotational speed calculation unit 152 Output current detection unit

Claims (10)

An armature winding (2, 3) having two or more phase windings;
A plurality of upper and lower arms of the bridge circuit are configured by switching elements (50, 51) in which diodes are connected in parallel, and switching units (5, 6) for rectifying the induced voltage of the armature winding;
A diode rectification operation in which the switching element is turned off to rectify by the diode, and a synchronous rectification operation in which the switching element is turned on for a predetermined period and then energized through the diode, and from the diode rectification operation to the synchronous rectification operation. A control circuit (54) for performing a transition rectification operation for gradually increasing the predetermined period of turning on the switching element at the time of transition by controlling the switching element on and off;
A rotational speed detection unit (101) for detecting the rotational speed;
And the control circuit performs the transition rectifying operation at a low rotation speed detected by the rotation speed detection unit at a predetermined value or less . An armature winding (2, 3) having two or more phase windings;
A plurality of upper and lower arms of the bridge circuit are configured by switching elements (50, 51) in which diodes are connected in parallel, and switching units (5, 6) for rectifying the induced voltage of the armature winding;
A diode rectification operation in which the switching element is turned off to rectify by the diode, and a synchronous rectification operation in which the switching element is turned on for a predetermined period and then energized through the diode, and from the diode rectification operation to the synchronous rectification operation. A control circuit (54) for performing a transition rectification operation for gradually increasing the predetermined period of turning on the switching element at the time of transition by controlling the switching element on and off;
An output current detector (152) for detecting an output current;
And the control circuit performs the transition rectification operation when the current value detected by the output current detection unit is a low output of a predetermined value or less . An armature winding (2, 3) having two or more phase windings;
A plurality of upper and lower arms of the bridge circuit are configured by switching elements (50, 51) in which diodes are connected in parallel, and switching units (5, 6) for rectifying the induced voltage of the armature winding;
A diode rectification operation in which the switching element is turned off to rectify by the diode, and a synchronous rectification operation in which the switching element is turned on for a predetermined period and then energized through the diode, and from the diode rectification operation to the synchronous rectification operation. A control circuit (54) for performing a transition rectification operation for gradually increasing the predetermined period of turning on the switching element at the time of transition by controlling the switching element on and off;
A rotational speed detection unit (101) for detecting the rotational speed;
An output current detector (152) for detecting an output current;
The control circuit includes the rotation speed detected by the rotation speed detection unit at a low rotation speed of a predetermined value or less and the current value detected by the output current detection unit at a low output of a predetermined value or less. A vehicular rotating electrical machine that performs a transition rectification operation . In any one of Claims 1-3,
The vehicular rotating electrical machine, wherein the switching element is a MOS transistor. In any one of Claims 1-4,
The control circuit sets the predetermined period to a predetermined initial value at the start of the transition rectification operation, and gradually increases the predetermined period by adding a predetermined increment for each predetermined period of the rectification operation. Rotating electric machine for vehicles. In any one of Claims 1-4,
The control circuit sets the predetermined period to a predetermined initial value at the start of the transition rectification operation, and gradually increases the predetermined period by adding a predetermined increment every predetermined time. Rotating electric machine. In claim 5 or 6,
The vehicular rotating electrical machine according to claim 1, wherein the control circuit changes an initial value of the predetermined period at the start of the transition rectification operation and the predetermined increment according to a rotation speed. In claim 5 or 6,
The control circuit changes the initial value of the predetermined period at the start of the transition rectification operation and the predetermined increment by a generated current. In claim 5 or 6,
The vehicular rotating electrical machine characterized in that the control circuit changes the initial value of the predetermined period and the predetermined increment at the start of the transition rectification operation according to the temperature of the switching element. In any one of Claims 1-9,
A rotating electrical machine for 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 switching unit and the control circuit.

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