JP2015214187A - Engine control device in limp mode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device in a limp mode, capable of charging a secondary battery and a capacitor while protecting the secondary battery and the capacitor from a voltage generated by a motor in a limp mode actuated when a failure causes the stop of an inverter control.SOLUTION: A power management microcomputer 23 determines whether an input/output current to/from a secondary battery 6 and a capacitor 10 measured by an input/output-current measuring device 20 is equal to or lower than 0 A (step S6). If the input/output current is equal to or lower than 0 A, the power management microcomputer 23 monitors a reference voltage Vcc and the input/output current and transmits an instruction to an engine control microcomputer 22 to decrease an engine speed of an engine 2 (step S7). If the input/output current is higher than 0 A, the power management microcomputer 23 transmits an instruction to the engine control microcomputer 22 to increase the engine speed of the engine 2 (step S8).

Description

  The present invention relates to an engine control device during retreat travel of a vehicle in which a rotating shaft of a rotating electrical machine and a rotating shaft of an engine are directly or indirectly connected and the rotating electrical machine and the engine are interlocked.

  Electric vehicles (EV vehicles) that run by a motor that is a rotating electrical machine and plug-in hybrid vehicles (PHV vehicles) that run by using a motor and a gasoline engine in combination have become widespread. These EV cars and PHV cars are equipped with a secondary battery which is a DC power source, and the vehicle is driven by driving a motor with electric energy stored in the secondary battery.

  Currently, as a motor for various vehicles such as EV cars and PHV cars, a motor controlled by an inverter such as a brushless DC motor is generally used. While such a motor is rotating at a high speed, the control of the inverter may stop due to, for example, the secondary battery being disconnected. When all the switching elements are turned off because the control of the inverter is stopped, a current due to the counter electromotive force generated by the rotation of the motor flows through a free wheel diode provided in parallel with the switching element of the inverter. Further, a capacitor is provided in parallel with the secondary battery in order to supply power to auxiliary equipment such as a vehicle headlight. Current due to the back electromotive force that flows through the freewheeling diode may flow into the capacitor. At this time, the capacitor voltage becomes equal to the peak of the back electromotive force voltage of the motor. If the capacitor voltage exceeds the breakdown voltage of the capacitor, the capacitor may be destroyed.

  Patent Document 1 describes a control device that drives a three-phase brushless motor by an inverter. This control device is provided with a protection circuit provided with a switching element. The switching element is used as a switching element for short-circuiting the neutral points of the plurality of coils of the brushless motor and the reference voltage or ground of the drive circuit of the control device. In this control device, when the number of rotations of the motor is increased and the generated voltage is significantly increased, it is possible to prevent the generated voltage from being applied to the capacitor by turning on the switching element provided in the protection circuit.

Japanese Patent Laid-Open No. 10-323079 (FIG. 4)

  However, when the vehicle travels, power is consumed by various auxiliary devices provided in the vehicle even when traveling only by the power of the engine. Therefore, the secondary battery for the necessary power consumed by the auxiliary device and The capacitor needs to be charged. In the drive circuit described in Patent Document 1, since the generated voltage of the motor is not applied to the secondary battery and the capacitor when the switching element is turned on, the secondary battery and the capacitor are not charged. For this reason, when performing evacuation such as moving to repair a vehicle when the inverter is stopped due to an inverter failure, the remaining power of the secondary battery and the capacitor cannot be charged, and the evacuation cannot be performed. There was a point.

  The present invention has been made to solve such a problem, and charges the secondary battery and the capacitor while protecting the secondary battery and the capacitor from the generated voltage of the motor during the evacuation traveling performed when the control of the inverter is stopped due to a failure. It is an object of the present invention to provide an engine control device during retreat travel that enables this.

The engine control device for retreat travel according to the present invention is an engine control device for retreat travel of a vehicle in which the rotating shaft of the rotating electrical machine and the rotating shaft of the engine are directly or indirectly connected and the rotating electrical machine and the engine are interlocked. A secondary battery, a capacitor connected in parallel to the secondary battery, an input / output current measuring device for measuring an input / output current of the secondary battery and the capacitor, a secondary battery on the input side, and A capacitor is connected, a rotating electrical machine is connected to the output side, the output side includes at least two phases, and each phase includes a switching element and a free wheel diode connected in parallel for each switching element, and a terminal of the capacitor When the inter-voltage exceeds a preset overvoltage threshold, the engine speed is limited, and then the engine is set according to the input / output current of the secondary battery and capacitor. And a engine speed control means for controlling the rotational speed.
A DC plus line that is a wiring extending from the positive electrode of the secondary battery and a DC negative line that is a wiring extending from the negative electrode of the secondary battery, and the DC plus line and the DC minus line are connected to the input side of the inverter. A protection circuit active element connected between the neutral point of the DC and either the DC plus line or the DC minus line, and the cathode terminal is connected to the DC plus line side or the anode terminal in parallel with the protection circuit active element. A protection circuit switch having a protection circuit reflux diode connected so as to be on the DC negative line side, and connected between a neutral point of the rotating electrical machine and either the DC positive line or the DC negative line, and a cathode terminal Is a protection circuit connected so that the DC positive line side or anode terminal is on the DC negative line side. The protection circuit switch is turned on when the voltage between the terminals of the capacitor and the capacitor exceeds the overvoltage threshold, and then the protection circuit switch is turned off when the voltage between the terminals of the capacitor drops below a second overvoltage threshold that is lower than the overvoltage threshold. And a switch control unit that performs control.
A DC plus line that is a wiring extending from the positive electrode of the secondary battery, a DC negative line that is a wiring extending from the negative electrode of the secondary battery, and the DC plus line and the DC minus line are connected to the input side of the inverter. The first protection circuit switching element connected between the sex point and either the DC plus line or the DC minus line, and the cathode terminal in parallel with the first protection circuit switching element on the DC plus line side Alternatively, a first protection circuit switch having a first protection circuit free-wheeling diode connected so that the anode terminal is on the DC negative line side, and a neutral point of the rotating electrical machine and either the DC positive line or the DC negative line A second protection circuit switching element connected between the second protection circuit switching element and the second protection circuit switching element; A second protection circuit switch having a second protection circuit return diode connected so that the cathode terminal is on the DC plus line side or the anode terminal is on the DC minus line side, and the voltage between the terminals of the capacitor is the threshold value The first protection circuit switch or the second protection circuit switch is turned on when the voltage is exceeded, and then the first protection switch or the second protection circuit switch when the voltage across the capacitor falls below a second overvoltage threshold lower than the overvoltage threshold. You may provide the switch control part which performs control which turns off the one turned on among 2nd protection switches.
The drive coil of the rotating electrical machine may be a star connection.
The drive coil of the rotating electrical machine is a Δ connection, and the drive coil can be switched to a star connection by a connection changeover switch connected to the winding of the rotating electrical machine. It may be a neutral point when the phase winding is switched to a star connection.

  According to the present invention, the engine speed is limited when the voltage between the terminals of the capacitor exceeds a preset overvoltage threshold, and thereafter the engine speed is set according to the input / output current of the secondary battery and the capacitor. By controlling, it is possible to charge the secondary battery and the capacitor while protecting the secondary battery and the capacitor from the generated voltage of the motor during the evacuation traveling.

1 is a schematic diagram of a vehicle including an engine control device during retreat travel according to Embodiment 1 of the present invention. It is the schematic of the engine control apparatus at the time of evacuation travel which concerns on Embodiment 1 of this invention. It is a flowchart of operation | movement of a vehicle provided with the engine control apparatus at the time of evacuation driving based on Embodiment 1 of this invention. It is the schematic of the engine control apparatus at the time of evacuation travel which concerns on Embodiment 2 of this invention. It is a flowchart of operation | movement of a vehicle provided with the engine control apparatus at the time of evacuation driving based on Embodiment 2 of this invention. It is the schematic of the engine control apparatus at the time of evacuation driving based on Embodiment 3 of this invention. FIG. 6 is an open circuit diagram of a circuit equivalent to a star-connected rotating electrical machine connected to a Δ-connected rotating electrical machine according to Embodiment 3 of the present invention;

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows a vehicle provided with an engine control apparatus according to Embodiment 1 of the present invention. The vehicle 1 is a PHV vehicle, and includes an engine 2, a motor 3 that is a rotating electrical machine, and a control device 4 that drives the engine 2 and the motor 3. The engine 2 and the motor 3 are power of the vehicle 1 and are indirectly connected by a power transmission unit 5 including, for example, a belt and a pulley. Therefore, the motor 3 rotates with the engine 2. The motor 3 is a three-phase brushless DC motor. The engine 2 and the control device 4 are electrically connected. The motor 3 and the control device 4 are electrically connected. Further, the vehicle 1 includes a secondary battery 6 that is a DC power source and a vehicle control unit 7. The secondary battery 6 is electrically connected to the control device 4, the vehicle control unit 7, and the auxiliary machinery 38, and supplies power to these. The auxiliary machinery 38 is, for example, a headlight of the vehicle 1. The vehicle control unit 7 is electrically connected to the engine 2, the control device 4, the secondary battery 6, and the auxiliary machinery 38, and controls these operations.

  As shown in FIG. 2, the wiring extending from the anode of the secondary battery 6 is a DC plus line 8, and the wiring extending from the cathode and common to the ground of the control device 4 is a DC minus line 9. Between the DC plus line 8 and the DC minus line 9, a capacitor 10 for temporarily accumulating driving power of the auxiliary machinery 38 (see FIG. 1) is connected in parallel with the secondary battery 6. Since the voltage between the DC plus line 8 and the DC minus line 9 is the same as the voltage between the terminals of the secondary battery 6 and the capacitor 10 in the control device 4, and the DC minus line 9 is common with the ground, the DC plus line 9 The voltage of the line 8 is represented as the reference voltage Vcc in the control device 4. The capacitor 10 and the auxiliary machinery 38 are electrically connected. An inverter 11 that is a three-phase inverter is provided between the DC plus line 8 and the DC minus line 9. The inverter 11 is provided with switching elements 12u, 12v, 12w, 13u, 13v, and 13w as switching elements. The switching elements 12u, 12v, 12w, 13u, 13v, and 13w are P-channel MOSFETs. An input / output current measuring device 20 is provided between the secondary battery 6 and the capacitor 10 and the inverter 11. The input / output current measuring device 20 is, for example, a current sensor.

  The motor 3 includes therein a U-phase drive coil 18u, a V-phase drive coil 18v, and a W-phase drive coil 18w. The drive coil 18u, the drive coil 18v, and the drive coil 18w are star-connected, and are connected to the neutral point 19, respectively. The switching element 12u is connected between the DC plus line 8 and the drive coil 18u. The switching element 13u is connected between the DC minus line 9 and the drive coil 18u. The switching element 12v is connected between the DC plus line 8 and the drive coil 18v. The switching element 13v is connected between the DC negative line 9 and the drive coil 18v. The switching element 12w is connected between the DC plus line 8 and the drive coil 18w. The switching element 13w is connected between the DC minus line 9 and the drive coil 18w. The gates of the switching elements 12u, 12v, 12w, 13u, 13v, and 13w are connected to a gate driver circuit (not shown), and the gate driver circuit (not shown) is connected to the vehicle control unit 7 (see FIG. 1). The switching elements 12u, 12v, and 12w are provided with free-wheeling diodes 14u, 14v, and 14w in parallel with the switching elements 12u, 12v, and 12w so that the cathode terminals are connected to the DC plus line 8 side. The switching elements 13u, 13v, and 13w are provided with free-wheeling diodes 15u, 15v, and 15w in parallel with the switching elements 13u, 13v, and 13w so that the cathode terminals are connected to the DC plus line 8 side. In the first embodiment, since the active elements 12u to 12w and 13u to 13w are MOSFETs, the respective parasitic diodes may be freewheeling diodes.

  In order to perform measurement of the reference voltage Vcc, control of the inverter 11, and instruction of torque and power of the motor 3, a motor drive microcomputer 21 is provided in the inverter 11. In order to control the torque and the rotational speed of the engine 2 (see FIG. 1), an engine control microcomputer 22 is provided inside the vehicle control unit 7. Further, a power management microcomputer 23 for managing the electric system of the vehicle 1 (see FIG. 1) is provided inside the vehicle control unit 7. The engine control microcomputer 22 is electrically connected to the engine 2 and the power management microcomputer 23. The power management microcomputer 23 is electrically connected to the input / output current measuring device 20 and the motor drive microcomputer 21.

Next, the operation of the rotating electrical machine control apparatus according to Embodiment 1 of the present invention will be described.
As shown in FIG. 1, when the vehicle 1 is driven by the power of the motor 3, the vehicle control unit 7 controls the control device 4. Specifically, as shown in FIG. 2, the power management microcomputer 23 transmits an instruction for torque and power consumption of the motor 3 to the motor drive microcomputer 21. The motor drive microcomputer 21 performs switching control on the gates of the switching elements 12u, 12v, 12w, 13u, 13v, and 13w of the inverter 11 provided in the control device 4 based on the received torque and power consumption instructions of the motor 3. Thus, the motor 3 is rotated by the AC power output from the inverter 11. At this time, the motor drive microcomputer 21 continues to measure and monitor the reference voltage Vcc. Further, the motor drive microcomputer 21 obtains information such as the torque and power consumption of the motor 3. The motor drive microcomputer 21 transmits information such as the reference voltage Vcc, the torque of the motor 3, and power consumption to the power management microcomputer 23. The input / output current measuring device 20 measures the value of the current input / output to / from the secondary battery 6 and the capacitor 10 and transmits it to the power management microcomputer 23. Here, the input / output current has a positive value in the output direction from the secondary battery 6 and the capacitor 10 and a negative value in the input direction. The engine control microcomputer 22 controls the engine 2 based on the torque and rotation speed instructions of the engine 2 transmitted from the power management microcomputer 23. The engine control microcomputer 22 acquires information such as torque and rotation speed of the engine 2 and transmits it to the power management microcomputer 23.

  During normal travel of the vehicle 1 (see FIG. 1), when the control of the inverter 11 is stopped due to a failure of the inverter 11 and all the switching elements are turned off, each phase of the motor 3 is rotated by the rotation of the motor 3. Back electromotive force is generated. As a result, the current from the motor 3 flows into the DC plus line 8 through the freewheeling diodes 14u, 14v, and 14w. At this time, if the capacitance of the capacitor 10 has a margin, the capacitor 10 is charged. When the rotation of the motor 3 is too fast and the back electromotive force generated in the motor 3 is excessive, the reference voltage Vcc rises on the DC plus line 8 and an overvoltage state is established. In the case of an overvoltage state, the power management microcomputer 23 is a temporary travel at the time of malfunction, instead of the control of the normal travel of the vehicle 1, for example, the evacuation for the purpose of moving the vehicle 1 to the repair facility Start driving control.

Next, the operation of the engine control apparatus during retreat travel will be described using the flowchart of FIG.
After the vehicle 1 starts running (step S1), the motor drive microcomputer 21 determines whether the reference voltage Vcc is in an overvoltage state and exceeds a threshold voltage (overvoltage threshold) VLim preset in the motor drive microcomputer 21 ( Step S2). If the reference voltage Vcc is equal to or lower than VLim, the vehicle 1 continues normal running. The motor drive microcomputer 21 that has measured that the reference voltage Vcc has exceeded the threshold voltage VLim determines that the reference voltage Vcc is an abnormal overvoltage. When it is determined that the reference voltage Vcc is an overvoltage abnormality, the motor drive microcomputer 21 transmits a reference voltage Vcc overvoltage abnormality detection signal to the power management microcomputer 23 (step S3). The power management microcomputer 23 that has received the reference voltage Vcc overvoltage abnormality detection signal transmits an instruction for limiting the rotational speed of the engine 2 to the engine control microcomputer 22 in order to cause the vehicle 1 to start retreat (step S4). The power generated by the counter electromotive force of the motor 3 depends on the rotational speed of the motor 3, and the higher the rotational speed of the motor 3, the larger the generated power. Conversely, the lower the rotation speed of the motor 3, the smaller the generated power, and eventually the generated power becomes zero. The rotational speed of the motor 3 depends on the rotational speed of the engine 2 that rotates with the motor 3. In step S4, the rotational speed limit instruction of the engine 2 is such that the rotational speed of the motor 3 rotating with the engine 2 decreases and the generated power due to the counter electromotive force of the motor 3 decreases, and the input / output current measuring device The value of the input / output current is monitored so that the input / output current to the secondary battery 6 and the capacitor 10 being measured is greater than 0A and the secondary battery 6 and the capacitor 10 are not charged. The number of revolutions of the engine 2 to be instructed to be limited is determined. The engine control microcomputer 22 limits the engine speed of the engine 2 based on the received engine speed limit instruction (step S5). Therefore, the engine control microcomputer 22 constitutes an engine speed control means of the engine 2.

  That is, by limiting the rotational speed of the engine 2, the rotational speed of the motor 3 that is being driven is also limited, so that the amount of power generated by the counter electromotive force in the motor 3 is reduced. In addition, power is consumed by the auxiliary machine 38. Therefore, the input / output current to the secondary battery 6 and the capacitor 10 is on the output side, and the input / output current is greater than 0A. Since the secondary battery 6 and the capacitor 10 are discharged and power is consumed to operate the auxiliary machinery 38, the reference voltage Vcc is lowered.

  Thereafter, the power management microcomputer 23 determines whether the input / output current to the secondary battery 6 and the capacitor 10 measured by the input / output current measuring device 20 is 0 A or less (step S6). If the input / output current is 0 A or less, the power generation amount exceeds the power consumption by the auxiliary machine 38, and the current is being input to the secondary battery 6 and the capacitor 10, that is, the secondary battery 6 and the capacitor. 10 is charged. Therefore, in order to prevent the reference voltage Vcc from becoming an overvoltage state again, the power management microcomputer 23 monitors the reference voltage Vcc and the input / output current and calculates an appropriate amount of decrease in the rotational speed of the engine 2. An instruction to reduce the rotational speed of the engine 2 is transmitted to the engine control microcomputer 22 (step S7). The engine control microcomputer 22 that has received the instruction to reduce the rotational speed of the engine 2 reduces the rotational speed of the engine 2. As the rotational speed of the engine 2 decreases, the rotational speed of the motor 3 that rotates with the engine 2 also decreases. Accordingly, the electric power generated by the motor 3 is also reduced, and the reference voltage Vcc is lowered, so that the overvoltage state in which the reference voltage Vcc exceeds the threshold voltage VLim is not achieved.

  On the other hand, if the input / output current to the secondary battery 6 and the capacitor 10 is larger than 0 A in step S6, the power consumption by the auxiliary machine 38 exceeds the power generation amount, and the current is output from the secondary battery 6 and the capacitor 10. In other words, the secondary battery 6 and the capacitor 10 are discharged. If the state in which the secondary battery 6 and the capacitor 10 are discharged continues, the remaining battery capacity of the secondary battery 6 will be lower than the remaining battery capacity of the secondary battery 6 required for the vehicle 1 to travel. In order to cope with this, the power management microcomputer 23 monitors the reference voltage Vcc and the input / output current, calculates an appropriate amount of increase in the rotation speed of the engine 2, and then sends the rotation of the engine 2 to the engine control microcomputer 22. An instruction to increase the number is transmitted (step S8). The engine control microcomputer 22 that has received the instruction to increase the rotational speed of the engine 2 increases the rotational speed of the engine 2. As the rotational speed of the engine 2 increases, the rotational speed of the motor 3 that rotates with the engine 2 also increases. Therefore, since the electric power generated by the motor 3 also increases, the reference voltage Vcc increases and the secondary battery 6 and the capacitor 10 are charged. Thereafter, step S6 and subsequent steps are repeated. Then, either step S7 or step S8 is performed depending on whether the input / output current to / from the secondary battery 6 and the capacitor 10 is greater than 0 A or less than 0 A, thereby maintaining the value of the reference voltage Vcc appropriately. The secondary battery 6 and the capacitor 10 are charged.

  As described above, when the voltage between the terminals of the capacitor 10 exceeds a preset overvoltage threshold, the number of revolutions of the engine 2 is limited, and thereafter, the engine 2 according to the input / output current of the secondary battery 6 and the capacitor 10. By controlling the rotation speed, it is possible to charge the secondary battery 6 and the capacitor 10 while protecting the secondary battery 6 and the capacitor 10 from the generated voltage of the motor 3 during the retreat travel.

  In the first embodiment, the drive coils 18u, 18v, 18w of the motor 3 are star-connected, but may be Δ-connected.

Embodiment 2
Next, an engine control apparatus according to Embodiment 2 of the present invention will be described. In the following embodiments, the same reference numerals as those in FIGS. 1 to 3 are the same or similar components, and thus detailed description thereof is omitted.
The engine control apparatus according to Embodiment 2 of the present invention is obtained by adding a protection circuit to Embodiment 1.

  As shown in FIG. 4, a protective circuit diode 27 is provided between the DC negative line 9 and the neutral point 19 of the control device 4 ′ so that the cathode terminal is connected to the neutral point 19 side. Further, a protection circuit switching element 25 that is a P-channel MOSFET is provided between the DC plus line 8 and the neutral point 19. Further, a protection circuit reflux diode 26 is provided in parallel with the protection circuit switching element 25 so that the cathode terminal is connected to the DC plus line 8 side. A parasitic diode may also be used as the protection circuit return diode 26. The protection circuit switching element 25 and the protection circuit free wheel diode 26 constitute a protection circuit switch 24. The protection circuit diode 27 and the protection circuit switch 24 constitute a protection circuit of the control device 4 ′. A power management microcomputer 23 that is a switch control unit of the protection circuit switch 24 is connected to the gate terminal of the protection circuit switching element 25. Other configurations are the same as those of the first embodiment.

Next, the operation of the engine control apparatus according to Embodiment 2 of the present invention will be described.
During normal travel of the vehicle 1, the protection circuit switching element 25 is off and the protection circuit switch 24 is also off. Therefore, the normal running operation of the vehicle 1 is the same as that of the first embodiment.

  Next, the operation during retreat travel will be described with reference to the flowchart of FIG. The operations from step S1 to step S3 are the same as those in the first embodiment. The power management microcomputer 23 that has received the reference voltage Vcc overvoltage abnormality detection signal turns on the gate terminal of the protection circuit switching element 25. That is, the protection circuit switch 24 is turned on (step S9).

  As shown in FIG. 4, when the protection circuit switch 24 is on, the current from the motor 3 sequentially passes through the freewheeling diodes 14 u, 14 v and 14 w to the DC plus line 8 due to the counter electromotive force generated in the motor 3. From the DC plus line 8, the protection circuit switch 24 is sequentially passed to the neutral point 19 of the motor 3. Since the current generated in the motor 3 is fed back to the motor 3 through the protection circuit switch 24, no current flows from the DC plus line 8 to the secondary battery 6 and the capacitor 10, and to the secondary battery 6 and the capacitor 10. No charge will occur. Further, the reference voltage Vcc is lowered by the current flowing through the drive coils 18u, 18v, 18w of the motor 3. Furthermore, as the vehicle 1 travels, the power charged in the secondary battery 6 and the capacitor 10 is consumed by the auxiliary machinery 38, so that the secondary battery 6 and the capacitor 10 are discharged over time.

  As shown in FIG. 5, simultaneously with step S <b> 9, the power management microcomputer 23 determines the number of revolutions of the engine 2 to be limited while monitoring the value of the input / output current, and notifies the engine control microcomputer 22 of the rotation of the engine 2. A number limit instruction is transmitted (step S4). At this time, the limited number of rotations of the engine 2 is calculated by the power management microcomputer 23 because a reduction in the reference voltage Vcc due to the protection circuit switch 24 being turned on is taken into account, compared with the first embodiment. Become bigger. The engine control microcomputer 22 limits the engine speed of the engine 2 based on the received engine speed limit instruction (step S5). Since the limitation on the rotational speed of the engine 2 in step S5 is milder than that in the first embodiment, the degree of freedom in driving when the user of the vehicle 1 retreats the vehicle 1 during retreat travel is increased.

  If the ON state of the protection circuit switch 24 and the limitation on the rotational speed of the engine 2 are continued, the reference voltage Vcc gradually decreases. The motor drive microcomputer 21 determines whether or not the reference voltage Vcc is lower than a second threshold voltage (second overvoltage threshold) VLim2, which is a value lower than the threshold voltage Vlim (step S10). If the reference voltage Vcc is equal to or higher than the second threshold voltage Vlim2, the ON state of the protection switch 24 and the limitation on the rotational speed of the engine 2 are continued. When the reference voltage Vcc drops below the threshold voltage VLim2, the power management microcomputer 23 turns off the protection circuit switch 24 (step S11).

  As in the first embodiment, the power management microcomputer 23 determines whether the input / output current to the secondary battery 6 and the capacitor 10 measured by the input / output current measuring device 20 is 0 A or less (step). S6). If the input / output current is 0 A or less, as in the first embodiment, the power management microcomputer 23 uses the reference voltage Vcc and the input / output current to prevent the reference voltage Vcc from being overvoltage again. After monitoring and calculating an appropriate amount of decrease in the rotation speed of the engine 2, an instruction to decrease the rotation speed of the engine 2 is transmitted to the engine control microcomputer 22 (step S7). As the rotational speed of the engine 2 decreases, the reference voltage Vcc decreases as in the first embodiment.

  On the other hand, if the input / output current is larger than 0 A in step S6, the power management microcomputer 23 monitors the reference voltage Vcc and the input / output current, as in the first embodiment, and determines the appropriate engine speed. After calculating the amount of increase, an instruction to increase the rotational speed of the engine 2 is transmitted to the engine control microcomputer 22 (step S8). As the rotational speed of the engine 2 increases, the rotational speed of the motor 3 that rotates with the engine 2 also increases. Therefore, since the electric power generated by the motor 3 also increases, the reference voltage Vcc increases and the secondary battery 6 and the capacitor 10 are charged. Thereafter, step S6 and subsequent steps are repeated. Thus, as in the first embodiment, either step S7 or step S8 is performed by the input / output current to the secondary battery 6 and the capacitor 10, so that the value of the reference voltage Vcc is appropriately maintained, The secondary battery 6 and the capacitor 10 can be charged.

  As described above, the protection circuit switch 24 and the protection circuit diode 27 are provided, and when the overvoltage of the reference voltage Vcc is detected, the power management microcomputer 23 turns on the protection circuit switch 24 to compare with the case of the first embodiment. Thus, since the instruction to limit the rotational speed of the engine 2 during the evacuation travel becomes gentle, the degree of freedom in the rotational speed of the engine 2 during the evacuation travel increases, and the user can detect the vehicle 1 after the overvoltage state of the reference voltage Vcc occurs. The degree of freedom in operation when retreating is increased.

Embodiment 3
Next, an engine control apparatus according to Embodiment 3 of the present invention will be described.
The engine control apparatus according to Embodiment 3 of the present invention is such that the connection of the motor 3 is changed from a star connection to a Δ connection with respect to Embodiment 2.

  As shown in FIG. 6, the motor 28 is a three-phase brushless DC motor having a Δ connection, and is provided with drive coils 29u, 29v, 29w, 30u, 30v, and 30w. The drive coils 29u and 30u are connected between the U-phase output and the V-phase output of the inverter 11 to constitute the U-phase connection of the motor 28. Similarly, the drive coils 29v and 30v are connected between the V-phase output and the W-phase output of the inverter 11 to constitute the V-phase connection of the motor 28. Further, the drive coils 29 w and 30 w are connected between the W-phase output and the U-phase output of the inverter 11 to constitute the W-phase connection of the motor 28. The drive coils 29u and 30u, the drive coils 29v and 30v, and the drive coils 29w and 30w are Δ-connected. In the control device 4 ″, the connection changeover switch active element 31 is provided between the point where the drive coil 29u and the drive coil 30u are connected to the point where the drive coil 29w and the drive coil 30w are connected. Similarly, the connection changeover switch active element 32 is provided between the point where the drive coil 29v and the drive coil 30v are connected to the point where the drive coil 29w and the drive coil 30w are connected. The connection changeover switch active elements 31 and 32 are P-channel MOSFETs, and the point where the connection changeover switch reflux diodes 33 and 34 are connected to the drive coil 30w in parallel with the connection changeover switch active elements 31 and 32 on the cathode side. Parasitic diodes may also be used as the return diodes 33 and 34. The changeover switch active element 31 and the connection changeover switch reflux diode 33 constitute a connection changeover switch 35. The connection changeover switch active element 32 and the connection changeover switch reflux diode 34 constitute a connection changeover switch 36. A protection circuit switch 24 is provided between the DC plus line 8 and the point where the drive coil 29w and the drive coil 30w are connected to the power management microcomputer 23. Connected to the gate.

  A protective circuit diode 27 is provided between the DC minus line 9, the drive coil 29w, and the point where the drive coil 30w is connected so that the anode terminal is connected to the DC minus line 9 side. Other configurations are the same as those of the second embodiment.

Next, the operation of the engine control apparatus according to Embodiment 3 of the present invention will be described.
As shown in FIG. 6, when the vehicle 1 travels by the power of the motor 28, the vehicle control unit 7 controls the control device 4 ″. Specifically, as in the first embodiment, the control device 4 ″. The motor 28 is rotated by the AC power output from the inverter 11 provided at. At this time, since there is no output from the power management microcomputer 23, that is, a voltage output Low state, the protection circuit switching element 25 and the connection changeover switch active elements 31, 32 are in an off state.

  Similarly to the second embodiment, during normal travel of the vehicle 1, when the control of the inverter 11 is stopped due to a failure of the inverter 11 and all the switching elements are turned off, each motor 28 is rotated by the rotation of the motor 28. A counter electromotive force is generated in the phase. Thereby, the current from the motor 28 flows into the DC plus line 8 through the freewheeling diodes 14u, 14v, 14w. When the rotation of the motor 28 is too fast and the back electromotive force generated in the motor 28 is excessive, the reference voltage Vcc rises on the DC plus line 8 and an overvoltage state is established.

  The motor drive microcomputer 21 detects that the reference voltage Vcc is an overvoltage abnormality, transmits a reference voltage Vcc overvoltage abnormality detection signal to the power management microcomputer 23, and the power management microcomputer 23 receives the reference voltage Vcc overvoltage abnormality detection signal. The steps up to (steps S1 to S2 in FIG. 5) are the same as those in the second embodiment.

  The power management microcomputer 23 turns on the gate terminals of the connection changeover switch active elements 31 and 32. That is, the connection changeover switches 35 and 36 are turned on. Then, the connection between the motor 28, the protection circuit switching element 17, and the protection circuit free wheel diode 26 is omitted by omitting the connection change switch active elements 31 and 32 in the ON state and the connection change switch free current diodes 33 and 34 in parallel therewith. If it describes, it will become equivalent to a connection as shown in FIG. Therefore, the motor 28 when the connection changeover switch active elements 31 and 32 are switched on is driven by the drive coil 30w with respect to the drive coil 29u, the drive coil 29v with respect to the drive coil 30u, and the drive coil 30v. Each of the coils 29w is connected in parallel as a set. Each pair of drive coils connected in parallel is star-connected to the neutral point 37. That is, the drive coil can be switched from the Δ connection to the star connection by turning on the connection changeover switches 35 and 36. Further, a protection circuit switch 24 is provided between the neutral point 37 and the DC plus line 8. Since the configuration in which the protection circuit switch 24 is provided between the neutral point 37 and the DC plus line 8 is the same as that in the second embodiment, the subsequent steps are the same as those in step S3 and subsequent steps in FIG. The same effect as in the second embodiment can be obtained by turning on and off the protection circuit switching element 25 by the power management microcomputer 23 as in the second embodiment.

  In the second and third embodiments, the protection circuit switch 24 is provided on the DC plus line 8 side and the protection circuit diode 27 is provided on the DC minus line 9 side. On the contrary, the DC plus line 8 side is provided. Are provided so that the cathode terminal is connected to the side to which the capacitor 10 is connected, the protection circuit switch 24 is provided on the DC minus line 9 side, and the anode side of the DC minus line 9 and the protection circuit reflux diode 26 is provided. You may provide so that a terminal may be connected. In this case, when the protection circuit switching element 25 is turned on, the current flows from the motor 3 or 28 through the protection circuit switching element 25 to the DC minus line 9 and passes through the return diodes 15u, 15v, and 15w. Return to motor 3 or 28.

  In the second and third embodiments, the protection circuit diode 27 is provided on the DC minus line 9 side. However, the protection circuit diode 27 is not provided, and the switching element 25 (first protection circuit switching element is provided on the DC plus line 8 side. ) And a protection circuit return diode 26 (first protection circuit return diode), a protection circuit switch 24 (first protection circuit switch) is provided, and a protection circuit switching element 25 (second protection) is provided on the DC negative line 9 side. A protection circuit switch 24 (second protection circuit switch) including a circuit switching element) and a protection circuit return diode 26 (second protection circuit return diode) may be provided. In this case, the power management microcomputer 23 can switch between switching the protection circuit switching element 25 provided on the DC plus line 8 side or switching the protection circuit switching element 25 provided on the DC minus line 9 side. It is. When switching the protection circuit switching element 25 provided on the DC plus line 8 side, the protection circuit switching element 25 provided on the DC minus line 9 side is kept in an off state, so that the second and third embodiments Same operation. When switching the protection circuit switching element 25 provided on the DC minus line 9 side, the protection circuit switching element 25 provided on the DC plus line 8 side is kept in an off state, so that the second and third embodiments Same operation.

  In the first to third embodiments, the switching elements 12u, 12v, 12w and 13u, 13v, 13w of the inverter 11 are P-channel MOSFETs, but other types of switching elements such as N-channel MOSFETs and bipolar transistors are used. It may be used.

  In the first to third embodiments, the protection circuit switching element 25 of the protection circuit switch 24 is a P-channel MOSFET, and in the third embodiment, the connection changeover switch active elements 31 and 32 of the connection changeover switches 35 and 36 are respectively P Although it is a channel type MOSFET, other types of elements and components may be used as long as they are elements and components that can be used as switches. For example, an IGBT may be used for the protection circuit switching element 17 and the connection changeover switch active elements 31 and 32, or a mechanical switch such as a relay may be used. In other words, the active element in this case refers to an element that outputs an output current from the output side when the switch becomes conductive as an input current is input to the input side.

  In the first to third embodiments, the motors 3 and 28 are three-phase brushless DC motors, but may be other types of three-phase motors as long as the motors are controlled by an inverter. Moreover, the motor which uses the electric current of the at least 2 phase controlled by an inverter may be sufficient. In this case, the number of phases of the inverter is also changed according to the number of phases of the motor.

  In the first to third embodiments, the motor drive microcomputer 21, the engine control microcomputer 22, and the power management microcomputer 23 perform the overvoltage abnormality detection of the reference voltage Vcc and the rotation speed control of the engine 2. The control may be performed by a single control unit in which the functions of the motor drive microcomputer 21, the engine control microcomputer 22, and the power management microcomputer 23 are integrated. Further, this series of control may be controlled by a control circuit capable of similar control instead of a microcomputer.

  In the first to third embodiments, the engine 2 and the motors 3 and 28 are connected by the power transmission unit 5 including a belt and a pulley. However, the rotation shaft of the engine 2 and the rotation of the motor 3 can be rotated by another known configuration. A method of indirectly connecting the shaft may be used. Further, the rotating shaft of the engine 2 and the rotating shaft of the motor 3 may be shared and directly connected. In any case, the motor 3 and 28 may be configured to rotate with the engine 2.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 2 engine, 3,28 Motor (rotary electric machine), 4, 4 ', 4 "Control apparatus (engine control apparatus), 6 Secondary battery, 8 DC plus line, 9 DC minus line, 10 capacitor | condenser, 11 Inverter 12u, 12v, 12w, 13u, 13v, 13w Switching element, 14u, 14v, 14w, 15u, 15v, 15w Reflux diode, 18v, 18w, 19u, 29u, 29v, 29w, 30u, 30v, 30w Drive coil, 19 Neutral point, 20 input / output current measuring device, 22 engine control microcomputer (engine speed control means), 23 power management microcomputer (switch control unit), 24 protection circuit switch, 25 protection circuit switching element (protection circuit active element), 26 Protection circuit free-wheeling diode, 27 Protection circuit die Aether, 35, 36 Connection changeover switch.

Claims (5)

An engine control device during retreat travel of a vehicle in which a rotating shaft of a rotating electrical machine and a rotating shaft of an engine are directly or indirectly connected and the rotating electrical machine and the engine are interlocked,
A secondary battery,
A capacitor connected in parallel to the secondary battery;
An input / output current measuring device for measuring an input / output current of the secondary battery and the capacitor;
The secondary battery and the capacitor are connected to the input side, the rotating electrical machine is connected to the output side, the output side has at least two phases, and the switching element and the switching element are connected in parallel to each phase. An inverter comprising a freewheeling diode;
When the voltage between the terminals of the capacitor exceeds a preset overvoltage threshold, the engine speed is limited, and thereafter, the engine speed is controlled according to the input / output current of the secondary battery and the capacitor. An engine control device during retreat travel, comprising engine speed control means. A DC plus line that is a wiring extending from the positive electrode of the secondary battery;
DC negative line that is a wiring extending from the negative electrode of the secondary battery,
The DC plus line and the DC minus line are connected to the input side of the inverter,
A protection circuit active element connected between a neutral point of the rotating electrical machine and one of the DC plus line or the DC minus line; and a cathode terminal in parallel with the protection circuit active element and having the cathode terminal A protection circuit switch having a protection circuit reflux diode connected so that a positive line side or an anode terminal is on the DC negative line side;
Connected between the neutral point of the rotating electrical machine and either the DC plus line or the DC minus line, and the cathode terminal is connected to the DC plus line side or the anode terminal is connected to the DC minus line side Protective circuit diodes,
The protection circuit switch is turned on when the voltage between the terminals of the capacitor exceeds the overvoltage threshold, and then the protection circuit switch when the voltage between the terminals of the capacitor drops below a second overvoltage threshold lower than the overvoltage threshold. The engine control device at the time of evacuation travel according to claim 1, further comprising: a switch control unit that performs control to turn off the engine. A DC plus line that is a wiring extending from the positive electrode of the secondary battery;
A DC negative line that is a wiring extending from the negative electrode of the secondary battery;
The DC plus line and the DC minus line are connected to the input side of the inverter,
A first protection circuit switching element connected between a neutral point of the rotating electrical machine and either the DC plus line or the DC minus line; and in parallel with the first protection circuit switching element. A first protection circuit switch having a first protection circuit reflux diode connected so that the cathode terminal is on the DC plus line side or the anode terminal is on the DC minus line side;
A second protection circuit switching element connected between a neutral point of the rotating electrical machine and either the DC plus line or the DC minus line; and the second protection circuit switching element in parallel. A second protection circuit switch having a second protection circuit return diode connected so that the cathode terminal is on the DC plus line side or the anode terminal is on the DC minus line side;
When the voltage between the terminals of the capacitor exceeds the threshold voltage, the first protection circuit switch or the second protection circuit switch is turned on, and then the second voltage between the terminals of the capacitor is lower than the overvoltage threshold. A switch control unit that performs control to turn off one of the first protection switch and the second protection switch that is turned on when the threshold voltage is lower than an overvoltage threshold. Engine control device.   The engine control device during retreat travel according to any one of claims 1 to 3, wherein the drive coil of the rotating electrical machine has a star connection. The drive coil of the rotating electrical machine is a Δ connection, and the drive coil can be switched to a star connection by a connection changeover switch connected to the winding of the rotating electrical machine,
The engine control device during retreat travel according to claim 2 or 3, wherein the neutral point of the rotating electrical machine is a neutral point when the winding of each phase of the rotating electrical machine is switched to a star connection.

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