JP2017041926A - Automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make electric charge of a capacitor to be more surely discharged by a motor after termination of regenerative drive of the motor, when a collision of a vehicle is detected during regenerative drive of the motor.SOLUTION: When after predetermined detection of detecting a collision of a vehicle during regenerative drive of a motor, the regenerative drive of the motor is not terminated (S100), if disconnection occurs at a portion in a high voltage system power line on a side closer to a battery than a position where a capacitor is connected and a position where a DC/DC converter is connected (S110), the DC/DC converter is controlled (S120) such that electric power of the high voltage system power line is supplied to a low voltage system power line with step-down of the voltage. When the regenerative drive of the motor is terminated (S100), switching control of transistors T11-T16 of an inverter is performed such that an electric charge of the capacitor is discharged without output of torque from the motor (S140).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an automobile.

  Conventionally, as an automobile, a motor connected to an axle, an inverter that drives the motor, a battery that exchanges power through the inverter and the power line, a relay provided in the power line, and an inverter rather than a relay of the power line A capacitor provided with a capacitor attached to the side has been proposed (see, for example, Patent Document 1). In this automobile, when the collision of the vehicle is detected and the capacitor charge is discharged, when the voltage of the capacitor is larger than the threshold value, the inverter is arranged so that the capacitor charge is discharged by the motor without outputting torque from the motor. MG discharge is performed to control

International Publication No. 2012/164680

  In such an automobile, a motor, an inverter, a capacitor, and the like are disposed in a housing portion at the front portion of the vehicle, and a battery, a relay, and the like are disposed at a rear portion of the vehicle, for example, below the rear seat. The battery side portion (predetermined portion) may be relatively long. When the collision of the vehicle is detected during the regenerative drive of the motor, if the power line is not disconnected, the power generated by the regenerative drive of the motor can be charged to the battery. The MG discharge may be performed with the relay turned off. However, if a disconnection occurs in a predetermined portion of the power line due to a vehicle collision, the battery cannot be charged with the power generated by the regenerative drive of the motor. For this reason, the voltage of the capacitor (power line) reaches an overvoltage, and it is necessary to stop driving the inverter to protect the capacitor and the like, and the MG discharge cannot be performed after the motor regenerative driving is completed. obtain.

  The main object of the automobile of the present invention is to discharge the electric charge of the capacitor more reliably by the motor after the completion of the regenerative driving of the motor when the collision of the vehicle is detected during the regenerative driving of the motor.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
A motor coupled to the axle;
An inverter for driving the motor;
A first battery that exchanges power via the inverter and a first power line;
A relay provided in the first power line;
A capacitor attached to the first position on the inverter side of the relay of the first power line;
A second battery having a rated voltage lower than the first battery;
A DC / DC converter connected to a second position on the inverter side of the relay of the first power line and a second power line to which the second battery is connected;
After the predetermined detection of detecting a vehicle collision during the regenerative drive of the motor with the relay turned on, when the regenerative drive of the motor is finished, the relay is turned off, and torque is not output from the motor. Control means for controlling the inverter so that the electric charge of the capacitor is discharged by the motor;
A car equipped with
When the regenerative drive of the motor is not finished after the predetermined detection, the control means is disconnected on the battery side from the first position and the second position of the first power line. Sometimes, the DC / DC converter is controlled so that the power of the first power line is supplied to the second power line with a voltage step-down.
It is a summary to provide.

  In the automobile according to the present invention, after the predetermined detection that the vehicle collision is detected during the regenerative drive of the motor with the relay on, the relay is turned off when the motor regenerative drive ends, and no torque is output from the motor. The inverter is controlled so that the electric charge of the capacitor is discharged by the motor. After the predetermined detection, when the regenerative drive of the motor is not completed, the electric power generated by the regenerative drive of the motor is charged to the battery via the power line. When the regenerative driving of the motor is completed, the charge of the capacitor can be discharged by turning off the relay and controlling the inverter. In such a control, after the predetermined detection, when the regenerative drive of the motor is not finished, the first position (position where the capacitor is attached) and the second position (the DC / DC converter is connected) of the first power line. When the disconnection occurs on the battery side with respect to the position), the DC / DC converter is controlled so that the power of the first power line is supplied to the second power line with voltage step-down. As a result, when the power generated by the regenerative drive of the motor cannot be charged to the battery, the voltage of the capacitor (first power line) is overvoltaged by supplying the power to the second power line (second battery). Can be suppressed. As a result, it is possible to suppress the necessity of stopping the driving of the inverter for protecting the capacitor and the like, and the electric charge of the capacitor can be more reliably discharged by the motor after the regenerative driving of the motor is completed.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as one Example of this invention. It is a flowchart which shows an example of the control routine performed by ECU50 of an Example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 as an embodiment of the present invention. As illustrated, the electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a high voltage battery 36, a relay 42, a capacitor 44, a low voltage battery 46, a DC / DC converter 48, and electronic control. A unit (hereinafter referred to as ECU) 50.

  The motor 32 is configured as a well-known synchronous generator motor having, for example, a rotor embedded with permanent magnets and a stator wound with a three-phase coil. The motor 32 is connected to a drive shaft 26 connected to the drive wheels 22 a and 22 b via a drive shaft (axle) 23 and a differential gear 24.

  The inverter 34 is connected to the high voltage system power line 40a. The inverter 34 includes six transistors T11 to T16 and six diodes D11 to D16. Two transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side, respectively, with respect to the positive and negative buses of the high-voltage power line 40a. The six diodes D11 to D16 are respectively connected in parallel to the transistors T11 to T16 in the reverse direction. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 32 is connected to each connection point between the transistors T11 to T16 as a pair. Therefore, when the voltage is applied to the inverter 34, the ECU 50 adjusts the ratio of the on-time of the paired transistors T11 to T16, thereby forming a rotating magnetic field in the three-phase coil and rotating the motor 32. Driven. Hereinafter, the transistors T11 to T13 may be referred to as U-phase, V-phase, and W-phase upper arms, and the transistors T14 to T16 may be referred to as U-phase, V-phase, and W-phase lower arms.

  The high voltage battery 36 is configured as a lithium ion secondary battery, for example, and is connected to the high voltage system power line 40a. The relay 42 is provided in the high voltage system power line 40a. The capacitor 44 is attached to a position P1 on the inverter 34 side of the relay 42 of the high voltage system power line 40a.

  The low voltage battery 46 is configured as, for example, a lead storage battery having a rated voltage lower than that of the high voltage battery 36, and is connected to the low voltage system power line 40b. The DC / DC converter 48 is connected to the second position P2 on the inverter side of the relay 42 of the high voltage system power line 40a and the low voltage system power line 40b. The DC / DC converter 48 is controlled by the ECU 50 to supply the power of the high voltage system power line 40a to the low voltage system power line 40b with voltage step-down.

  Although not shown, the ECU 50 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU.

Signals from various sensors are input to the ECU 50 via input ports. Examples of the signal input to the ECU 50 include the following.
The rotational position θm from the rotational position detection sensor 32a that detects the rotational position of the rotor of the motor 32
-Phase currents Iv, Iw of the motor 32 from the current sensors 32v, 32w attached to the power line connecting the motor 32 and the inverter 34 (the direction from the inverter 34 side to the motor 32 side is positive) value)
The battery voltage Vb from the voltage sensor 36a attached between the terminals of the high voltage battery 36
Battery current Ib from the current sensor 36b attached to the output terminal of the high voltage battery 36 (positive value when discharging from the high voltage battery 36)
The voltage VH of the capacitor 44 from the voltage sensor 44a attached between the terminals of the capacitor 44
-Ignition signal from the ignition switch 60-Shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61
Accelerator opening degree Acc from the accelerator pedal position sensor 64 that detects the depression amount of the accelerator pedal 63
-Brake pedal position BP from the brake pedal position sensor 66 that detects the amount of depression of the brake pedal 65
・ Vehicle speed V from the vehicle speed sensor 68
・ Acceleration α from the acceleration sensor 69 attached to the center or both sides of the front side of the vehicle body

Various control signals are output from the ECU 50 via an output port. Examples of the control signal output from the ECU 50 include the following.
・ Switching control signal to transistors T11 to T16 of inverter 34 ・ Control signal to relay 42 ・ Control signal to DC / DC converter 48

  The ECU 50 calculates the rotational speed Nm of the motor 32 based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a. Further, the ECU 50 calculates the storage rate SOC of the high voltage battery 36 based on the integrated value of the battery current Ib detected by the current sensor.

  In the electric vehicle 20 of the embodiment thus configured, the motor 32, the inverter 34, the capacitor 44, the low voltage battery 46, the DC / DC converter 48, and the like are arranged in a housing portion provided in the front portion of the vehicle. The voltage battery 36, the relay 42, etc. are arrange | positioned at the vehicle rear part, for example, the lower side of a rear seat. A portion on the high voltage battery 36 side (hereinafter referred to as “predetermined portion”) from the position P1 (position where the capacitor 44 is attached) and the position P2 (position where the DC / DC converter 48 is connected) in the high voltage system power line 40a. Is relatively long.

  In the electric vehicle 20 according to the embodiment, the ECU 50 turns on the relay 42 when the ignition switch 60 is turned on. When traveling, the required torque Td * required for traveling is set based on the accelerator opening Acc, the brake pedal position BP, and the vehicle speed V, and the required torque Td * is set as the torque command Tm * of the motor 32. And switching control of the transistors T11 to T16 of the inverter 34 is performed so that the motor 32 is driven by the torque command Tm *.

  Next, the operation of the electric vehicle 20 of the embodiment thus configured, particularly the operation when the collision of the vehicle is detected during the regenerative driving of the motor 32 such as when the brake pedal 65 is depressed during the above-described traveling. explain. FIG. 2 is a flowchart illustrating an example of a control routine executed by the ECU 50 of the embodiment. This routine is executed when a vehicle collision is detected during the regenerative drive of the motor 32. In the embodiment, the vehicle collision is detected when the acceleration α detected by the acceleration sensor 69 exceeds the threshold value αref for collision determination. Further, when a vehicle collision is detected during the regenerative drive of the motor 32, the regenerative drive of the motor 32 is terminated when the rotation of the motor 32 is stopped thereafter. Note that the case where the motor 32 is rotating after the vehicle collision is detected may be when the vehicle is bouncing or moving on a slope after the vehicle collision.

  When the control routine of FIG. 2 is executed, the ECU 50 first determines whether or not the motor 32 is being regeneratively driven (step S100). This determination can be performed using, for example, the torque command Tm * of the motor 32, the V-phase and W-phase currents Iv and Iw of the motor 32 detected by the current sensors 32v and 32w, and the like.

  When the motor 32 is being regeneratively driven, it is determined whether or not a disconnection has occurred in the high voltage system power line 40a (step S110). In the embodiment, as described above, the predetermined portion of the high voltage system power line 40a is relatively long. For this reason, in the process of step S110, it is determined whether or not a disconnection has occurred in the predetermined portion of the high voltage system power line 40a.

  When no disconnection occurs in the high voltage system power line 40a in step S110, the process returns to step S100. At this time, the electric power generated by the regenerative driving of the motor MG2 is charged to the high voltage battery 36 via the high voltage system power line 40a.

  Thus, when the regenerative driving of the motor 32 is completed while the processes of steps S100 and S110 are being repeatedly executed (step S100), the relay 42 is turned off (step S130), and the discharge control is executed (step S140). This routine ends. Here, the discharge control is a control for performing switching control of the transistors T11 to T16 of the inverter 34 so that the torque is not output from the motor 32 (d-axis current flows through the motor 32) and the electric charge of the capacitor 44 is discharged. It is. In the embodiment, the discharge control is executed until the voltage VH of the high voltage system power line 40a becomes less than the threshold value VHref, and when the voltage VH of the high voltage system power line 40a becomes less than the threshold value VHref, the discharge control is terminated. It was. Here, as the threshold value VHref, for example, when the voltage VH of the capacitor 44 is about several hundred V when the relay 42 is on, a value of about several V to several tens V can be used.

  When it is determined in step S110 that the predetermined portion of the high voltage system power line 40a is disconnected, the power of the high voltage system power line 40a is supplied to the low voltage system power line 40b with a voltage step-down. Then, the DC / DC converter 46 is controlled (step S120), and the process returns to step S100. Then, when the regenerative drive of the motor 32 is completed while the processes of steps S100 to S120 are being repeatedly executed (step S100), the relay 42 is turned off (step S130), and the discharge control is executed (step S140). This routine is terminated. In addition, since the case where the disconnection has arisen in the predetermined part of the high voltage type | system | group electric power line 40a is considered, before turning off the relay 42, the high voltage battery 36, the inverter 34, the capacitor | condenser 44, the DC / DC converter 46, etc. The connection with is considered to have been released. For this reason, it is considered that the process of turning off the relay 42 is not necessary, but in the embodiment, the process of turning off the relay 42 is performed in the same manner as when the high voltage system power line 40a is not disconnected. did.

  When the predetermined portion of the high voltage system power line 40a is disconnected, the high voltage battery 36 cannot be charged with the power generated by the regenerative drive of the motor 32. For this reason, there is a possibility that the voltage VH of the capacitor 44 (voltage of the high voltage system power line 40a) rises and becomes overvoltage. When the high voltage system power line 40a becomes overvoltage, the inverter 34 is stopped for protection (all the transistors T11 to T16 are turned off). On the other hand, in the embodiment, by driving the DC / DC converter 46, the power of the high voltage system power line 40a is supplied to the low voltage system power line 40b with voltage step-down, thereby driving the motor 32 to regenerate. The voltage VH (voltage of the high voltage system power line 40a) of the capacitor 44 reaches an overvoltage by supplying the power generated by the above to the low voltage system power line 40b (low voltage battery 48, auxiliary equipment not shown). Therefore, it is possible to suppress the necessity of stopping the driving of the inverter 34 in order to protect the capacitor 44 and the like. As a result, after the regenerative driving of the motor 32 is completed, the discharge control can be more reliably performed, that is, the electric charge of the capacitor 44 can be more reliably discharged by the motor 32.

  In the electric vehicle 20 according to the embodiment described above, the position in the high voltage system power line 40a when the regenerative drive of the motor 32 is not finished after the predetermined detection of the collision of the vehicle during the regenerative drive of the motor 32. When disconnection occurs in a part (predetermined part) on the high voltage battery 36 side from P1 (position where the capacitor 44 is attached) and position P2 (position where the DC / DC converter 48 is connected), the high voltage system power line The DC / DC converter 46 is controlled so that the power of 40a is supplied to the low voltage system power line 40b with voltage step-down. When the regenerative driving of the motor 32 is completed, switching control of the transistors T11 to T16 of the inverter 34 is performed so that the electric charge of the capacitor 44 is discharged without outputting torque from the motor 32. After the predetermined detection, when a disconnection occurs in a predetermined portion of the high voltage system power line 40a, the DC / DC converter 46 is controlled in this manner, thereby suppressing the voltage VH of the capacitor 44 from reaching an overvoltage. be able to. As a result, it is possible to suppress the necessity of stopping the drive of the inverter 34 for protecting the capacitor 44 and the like, and the electric charge of the capacitor 44 is more reliably discharged by the motor 32 after the regeneration drive of the motor 32 is completed. be able to.

  In the embodiment, the electric vehicle including the motor 32 is configured. However, it is good also as a structure of an electric vehicle provided with two or more motors. Moreover, it is good also as a structure of a parallel type or a series type hybrid vehicle.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor 32 corresponds to the “motor”, the inverter 34 corresponds to the “inverter”, the high voltage battery 36 corresponds to the “first battery”, the relay 42 corresponds to the “relay”, and the capacitor 44. Corresponds to a “capacitor”, the low voltage battery 46 corresponds to a “second battery”, the DC / DC converter 48 corresponds to a “DC / DC converter”, and the ECU 50 corresponds to a “control unit”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the automobile manufacturing industry.

  20 electric vehicle, 22a, 22b drive wheel, 23 drive shaft, 24 differential gear, 26 drive shaft, 32 motor, 32a rotational position detection sensor, 32v, 32w current sensor, 34 inverter, 36 battery, 36a voltage sensor, 36b current sensor 40a High voltage system power line, 40b Low voltage system power line, 42 Relay, 44 capacitor, 44a Voltage sensor, 46 Low voltage battery, 48 DC / DC converter, 50 Electronic control unit (ECU), 60 Ignition switch, 61 Shift lever 62 shift position sensor, 63 accelerator pedal, 64 accelerator pedal position sensor, 65 brake pedal, 66 brake pedal position sensor, 68 vehicle speed sensor, 69 acceleration sensor, D11 ~ D16 diode, T11-T16 transistor, P1, P2 position.

Claims (1)

A motor coupled to the axle;
An inverter for driving the motor;
A first battery that exchanges power via the inverter and a first power line;
A relay provided in the first power line;
A capacitor attached to the first position on the inverter side of the relay of the first power line;
A second battery having a rated voltage lower than the first battery;
A DC / DC converter connected to a second position on the inverter side of the relay of the first power line and a second power line to which the second battery is connected;
After the predetermined detection of detecting a vehicle collision during the regenerative drive of the motor with the relay turned on, when the regenerative drive of the motor is finished, the relay is turned off, and torque is not output from the motor. Control means for controlling the inverter so that the electric charge of the capacitor is discharged by the motor;
A car equipped with
When the regenerative drive of the motor is not finished after the predetermined detection, the control means is disconnected on the battery side from the first position and the second position of the first power line. Sometimes, the DC / DC converter is controlled so that the power of the first power line is supplied to the second power line with a voltage step-down.
Automobile.

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