JP6933121B2 - Converter device - Google Patents

Description

The present invention relates to a converter device, and more particularly to a converter device including a buck-boost converter having two switching elements, an upper arm and a lower arm, and a reactor.

Conventionally, as a converter device of this type, it has been proposed to execute one-arm drive control in which one-arm drive is performed by only one of the first arm including the first switching element and the second arm including the second switching element. (See, for example, Patent Document 1). In this device, when the one-arm drive is switched to each other, the duty command signal that turns off both the first switching element and the second switching element is controlled to be generated for a predetermined period.

Japanese Unexamined Patent Publication No. 2013110932

In a device equipped with a buck-boost converter having two switching elements, an upper arm and a lower arm, and a reactor, the upper arm is raised when power is boosted and supplied from the low voltage side power line to the high voltage side power line. In some cases, the lower element single element control is performed to turn on / off the switching element constituting the lower arm while the constituent switching element is fixed to off. On the other hand, when supplying the power of the low-voltage side power line to the high-voltage side power line without changing the voltage, the switching element constituting the upper arm is fixed on and the switching element constituting the lower arm is fixed off. There is a case where the upper element on fixed control is executed. When switching between the upper element on fixed control and the lower element single element control, depending on the switching timing, the switching element constituting the lower arm may be turned on. In this case, although a dead time is provided, if the timing is slightly deviated for some reason, both the switching element constituting the upper arm and the switching element constituting the lower arm are turned on, and there is a concern that a short circuit may occur. At the time of regeneration, the upper element single element control for turning on / off the switching element constituting the upper arm and the upper element on / fixed control for turning on / off the switching element constituting the upper arm are switched with the switching element constituting the lower arm fixed off. Since the switching elements that make up the lower arm are fixed to off in both single-element control and upper element on-fixed control, the switching elements that make up the upper arm and the switching elements that make up the lower arm can be switched at any timing. Will never be turned on together.

In the converter device of the present invention, when switching between the upper element on fixed control and the lower element single element control during power running, both the switching element constituting the upper arm and the switching element constituting the lower arm are turned on. The main purpose is to ensure prevention.

The converter device of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The converter device of the present invention
A buck-boost converter that has two switching elements, an upper arm and a lower arm, and a reactor, and exchanges power between the low-voltage side power line and the high-voltage side power line with a change in voltage.
When power is supplied from the low-voltage side power line to the high-voltage side power line, the switching elements that make up the upper arm are fixed on and the switching elements that make up the lower arm are fixed off. The upper element is fixed on and the switching element that constitutes the upper arm is fixed off, and the switching element that constitutes the lower arm is turned on on the mountain side with respect to the duty in the carrier of the triangular wave. A control device that switches and executes lower element one-sided element control that is turned off at the valley side together with
It is a converter device equipped with
When switching between the upper element on-fixed control and the lower element single element control, the control device switches at the timing of the valley of the carrier.
It is characterized by that.

In the converter device of the present invention, when power is supplied from the low voltage side power line to the high voltage side power line, the switching element constituting the upper arm is fixed on and the lower arm is configured. The upper element on-fixed control is set to the off-fixed state for the switching element, and the off-fixed state is set to the switching element that constitutes the upper arm, and the duty is applied to the switching element that constitutes the lower arm in the triangular wave carrier. On the other hand, the lower element one-sided element control, which is turned on on the mountain side and turned off on the valley side, is switched and executed. Then, when switching between the upper element on fixed control and the lower element single element control, the switching is performed at the timing of the valley of the carrier. As for the timing of the carrier valley, the switching element constituting the lower arm is in the off state in the control of the lower element single element, so even if the timing is slightly deviated for some reason, the switching element constituting the lower arm is in the off state. To maintain. Therefore, it is possible to more reliably prevent both the switching element constituting the upper arm and the switching element constituting the lower arm from being turned on.

It is a block diagram which shows the outline of the structure of the electric vehicle 20 which mounts the converter device as one Example of this invention. It is a flowchart which shows an example of the power running control switching processing routine executed by the electronic control unit 50 of an Example. It is explanatory drawing which shows the time change of the state of the transistor T31, T32 which constitutes the carrier and the upper arm and the lower arm together with the comparative example.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 equipped with a converter device as an embodiment of the present invention. As shown in the figure, the electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a battery 36, a boost converter 40, a high voltage side capacitor 46, a low voltage side capacitor 48, a system main relay SMR, and the like. It includes an electronic control unit 50. Here, in the embodiment, the boost converter 40 and the electronic control unit 50 correspond to the “converter device”.

The motor 32 is configured as a synchronous generator motor, and includes a rotor in which a permanent magnet is embedded and a stator in which a three-phase coil is wound. The rotor of the motor 32 is connected to a drive shaft 26 connected to the drive wheels 22a and 22b via a differential gear 24.

The inverter 34 is connected to the motor 32 and also to the high voltage side power line 42. The inverter 34 has 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 with respect to the positive electrode bus and the negative electrode bus of the high voltage side power line 42, respectively. The six diodes D11 to D16 are connected in parallel to the transistors T11 to T16 in opposite directions, respectively. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 32 is connected to each of the connection points between the transistors paired with the transistors T11 to T16. Therefore, when a voltage is applied to the inverter 34, the electronic control unit 50 adjusts the ratio of the on-time of the paired transistors T11 to T16, so that a rotating magnetic field is formed in the three-phase coil and the motor. 32 is rotationally driven. Hereinafter, the transistors T11 to T13 may be referred to as an “upper arm”, and the transistors T14 to T16 may be referred to as a “lower arm”.

The battery 36 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the low voltage side power line 44.

The boost converter 40 is connected to the high voltage side power line 42 and the low voltage side power line 44. The boost converter 40 has two transistors T31 and T32, two diodes D31 and D32, and a reactor L. The transistor T31 is connected to the positive electrode bus of the high voltage side power line 42. The transistor T32 is connected to the transistor T31 and the negative electrode bus of the high voltage side power line 42 and the low voltage side power line 44. The two diodes D31 and D32 are connected in parallel to the transistors T31 and T32 in opposite directions, respectively. The reactor L is connected to a connection point between the transistors T31 and T32 and a positive electrode bus of the low voltage side power line 44. In the boost converter 40, the electronic control unit 50 adjusts the ratio of the on-time of the transistors T31 and T32 by the duty command, so that the power of the low voltage side power line 44 is boosted by the voltage of the high voltage side power line. It supplies power to 42, or supplies power from the high-voltage side power line 42 to the low-voltage side power line 44 with a voltage step-down.

The high-voltage side capacitor 46 is connected to the positive electrode bus and the negative electrode bus of the high-voltage side power line 42. The low-voltage side capacitor 48 is attached to the positive electrode bus and the negative electrode bus of the low-voltage side power line 44. The system main relay SMR is provided on the battery 36 side of the low voltage side capacitor 48 in the low voltage side power line 44. The system main relay SMR connects and disconnects the battery 36 from the boost converter 40 and the low voltage side capacitor 48 by being controlled on and off by the electronic control unit 50.

The electronic control unit 50 is configured as a microprocessor centered on a CPU 52, and includes a ROM 54 for storing a processing program, a RAM 56 for temporarily storing data, and an input / output port in addition to the CPU 52.

Signals from various sensors are input to the electronic control unit 50 via input ports. As signals input to the electronic control unit 50, for example, the rotation position θm from the rotation position detection sensor (for example, resolver) 32a that detects the rotation position of the rotor of the motor 32, and the current flowing in each phase of the motor 32 are detected. The phase currents Iu and Iv from the current sensors 32u and 32v can be mentioned. Further, the voltage VB from the voltage sensor 36a attached between the terminals of the battery 36 and the current IB from the current sensor 36b attached to the output terminal of the battery 36 can also be mentioned. Further, the voltage VH of the high voltage side capacitor 46 (high voltage side power line 42) from the voltage sensor 46a attached between the terminals of the high voltage side capacitor 46, and the voltage sensor attached between the terminals of the low voltage side capacitor 48. The voltage VL of the low voltage side capacitor 48 (low voltage side power line 44) from 48a and the reactor current IL from the current sensor 40a attached to the reactor L of the boost converter 40 can also be mentioned. Further, the ignition signal from the ignition switch 60, the shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61, the accelerator opening Acc from the accelerator pedal position sensor 64 that detects the amount of depression of the accelerator pedal 63, The brake pedal position BP from the brake pedal position sensor 66 that detects the depression amount of the brake pedal 65 and the vehicle speed VS from the vehicle speed sensor 68 can also be mentioned.

Various control signals are output from the electronic control unit 50 via the output port. Examples of the signal output from the electronic control unit 50 include a switching control signal for the transistors T11 to T16 of the inverter 34 and a switching control signal for the transistors T31 and T32 of the boost converter 40.

The electronic control unit 50 calculates the electric angle θe, the angular velocity ωm, and the rotation speed Nm of the motor 32 based on the rotation position θm of the rotor of the motor 32 from the rotation position detection sensor 32a. Further, the electronic control unit 50 calculates the storage ratio SOC of the battery 36 based on the integrated value of the current IB of the battery 36 from the current sensor 36b. Here, the storage ratio SOC is the ratio of the capacity of electric power that can be discharged from the battery 36 to the total capacity of the battery 36.

In the electric vehicle 20 of the embodiment configured in this way, the electronic control unit 50 performs the following traveling control. In the traveling control, the required torque Td * required for the drive shaft 26 is set based on the accelerator opening degree Acc and the vehicle speed VS, the set required torque Td * is set as the torque command Tm * of the motor 32, and the motor 32. Is driven by the torque command Tm *, the switching control of the transistors T11 to T16 of the inverter 34 is performed. Further, the target voltage VH * of the high voltage side power line 42 is set so that the motor 32 can be driven by the torque command Tm *, and the boost converter 40 is set so that the voltage VH of the high voltage side power line 42 becomes the target voltage VH *. The switching control of the transistors T31 and T32 of the above is performed.

The following controls are executed to control the boost converter 40. When supplying the power of the low voltage side power line 44 to the high voltage side power line 42 as it is during power running, the transistor T31 forming the upper arm is fixed on and the transistor T32 forming the lower arm is turned off. The upper element to be fixed is fixed on and fixed. When the power of the low voltage side power line 44 is boosted and supplied to the high voltage side power line 42 during power running, the transistor T31 forming the upper arm is fixed off and the transistor T32 forming the lower arm is dutyd. The lower element single element control that turns on and off based on the command is executed. When the power of the high voltage side power line 42 is stepped down and supplied to the low voltage side power line 44 at the time of regeneration, the transistor T32 constituting the lower arm is fixed off and the transistor T31 forming the upper arm is dutyd. The upper element single element control that turns on and off based on the command is executed. When supplying the power of the high voltage side power line 42 to the low voltage side power line 44 at the time of regeneration, the transistor T31 constituting the upper arm is fixed on and the transistor T32 constituting the lower arm is turned off. The upper element to be fixed is fixed on and fixed.

Next, the operation of the converter device mounted on the electric vehicle 20 of the embodiment configured in this manner, particularly the operation when switching between the upper element on fixed control and the lower element single element control during power running will be described. FIG. 2 is a flowchart showing an example of a power running control switching processing routine executed by the electronic control unit 50 when switching between upper element on fixed control and lower element single element control.

When the power running control switching processing routine is executed, the electronic control unit 50 first determines whether or not the upper element is on fixed state (upper element on fixed control) (step S100). When it is determined that the upper element is on-fixed state (upper element on-fixed control), a release request is made to release the on-fixed state of the transistor T31 constituting the upper arm (step S110), and the timing of the carrier valley is waited (step). S120). Then, at the timing of the valley of the carrier, the on-fixing of the transistor T31 constituting the upper arm is released to stop the on-fixing control of the upper element and start the one-element control of the lower element (step S130). To finish.

When it is determined in step S100 that the upper element is not in the on-fixed state (upper element on-fixed control), the transistor T31 constituting the upper arm is requested to be on-fixed (step S140), and the timing of the carrier valley is waited (step). S150). Then, at the timing of the valley of the carrier, the transistor T31 constituting the upper arm is fixed on to start the upper element on-fixing control and stop the lower element single element control (step S160) to end this routine. do.

FIG. 3 is an explanatory diagram showing the time change of the states of the carriers and the transistors T31 and T32 constituting the upper arm and the lower arm together with a comparative example. In the figure, the alternate long and short dash line in the carrier indicates the duty when switching between the upper element on fixed control and the lower element single element control. In the embodiment, the timing of turning on the transistor T32 constituting the lower arm in the lower element single element control is on the mountain side of the duty in the carrier. As shown in the comparative example, when the upper element on fixed control is switched to the lower element single element control at the time T2 which is the timing of the peak of the carrier of the triangular wave, the transistor T32 constituting the lower arm in the lower element single element control is turned on. Even if the dead time is set, if the switching timing is slightly different, the transistor T31 that constitutes the upper arm and the transistor T32 that constitutes the lower arm are both turned on and short-circuited. I am concerned. On the other hand, as shown in the embodiment, when the upper element on fixed control is switched to the lower element single element control at the time T1 which is the timing of the valley of the carrier of the triangular wave, the transistor T32 constituting the lower arm is formed even if the switching timing is slightly deviated. Is in the off state, so that neither the transistor T31 forming the upper arm nor the transistor T32 forming the lower arm is turned on. As shown in the comparative example, when the lower element single element control is switched to the upper element on fixed control at the time T4, which is the timing of the peak of the carrier of the triangular wave, the transistor T32 constituting the lower arm in the lower element single element control is turned on. Even if the dead time is set, if the switching timing is slightly different, the transistor T31 that constitutes the upper arm and the transistor T32 that constitutes the lower arm are both turned on and short-circuited. Is a concern. On the other hand, as shown in the embodiment, when the lower element single element control is switched to the upper element on fixed control at the time T3 which is the timing of the valley of the carrier of the triangular wave, the transistor T32 constituting the lower arm is formed even if the switching timing is slightly deviated. Is in the off state, so that neither the transistor T31 forming the upper arm nor the transistor T32 forming the lower arm is turned on.

In the converter device mounted on the electric vehicle 20 of the above-described embodiment, when switching between the upper element on fixed control and the lower element single element control during power running, the lower arm in the lower element single element control is configured. Switching is performed at the timing of the carrier valley in which the transistor T32 is off. As a result, even if the switching timing is slightly deviated, it is possible to more reliably prevent the transistor T31 forming the upper arm and the transistor T32 forming the lower arm from being turned on and short-circuited.

In the embodiment, the converter device is mounted on the electric vehicle 20, but it may be mounted on a hybrid vehicle, it may be mounted on a moving body such as a vehicle other than a vehicle, or it may be constructed. It may be incorporated into equipment such as equipment.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the transistor T31 and the transistor T32 correspond to "two switching elements of the upper arm and the lower arm", the reactor L corresponds to the "reactor", the boost converter 40 corresponds to the "boost converter", and the electrons. The control unit 50 corresponds to a "control device".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the manufacturing industry of converter devices and the like.

20 Electric vehicle, 22a, 22b drive wheel, 24 differential gear, 26 drive shaft, 32 motor, 32a rotation position detection sensor, 32u, 32v, 36b current sensor, 34 inverter, 36 battery, 36a, 46a, 48a voltage sensor, 40 Boost converter, 40a current sensor, 42 high voltage side power line, 44 low voltage side power line, 46 high voltage side capacitor, 48 low voltage side capacitor, 50 electronic control unit, 52 CPU, 54 ROM, 56 RAM, 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 to D16, D31, D32 diode, L reactor, SMR system main relay, T11-T16, T31, T32 transistors.

Claims (1)

A buck-boost converter that has two switching elements, an upper arm and a lower arm, and a reactor, and exchanges power between the low-voltage side power line and the high-voltage side power line with a change in voltage.
When power is supplied from the low-voltage side power line to the high-voltage side power line, the switching elements that make up the upper arm are fixed on and the switching elements that make up the lower arm are fixed off. The upper element is fixed on and the switching element that constitutes the upper arm is fixed off, and the switching element that constitutes the lower arm is turned on on the mountain side with respect to the duty in the carrier of the triangular wave. A control device that switches and executes lower element one-sided element control that is turned off at the valley side together with
It is a converter device equipped with
When switching between the upper element on-fixed control and the lower element single element control, the control device switches at the timing of the valley of the carrier.
A converter device characterized by that.

Images