JP2018038137A - Electric power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce control error furthermore when controlling a second step-up converter, in an electric power unit including first and second step-up converters, and a first voltage sensor for detecting the voltage of a first power line to be connected with the first step-up converter.SOLUTION: In an electric power unit including a first step-up converter for supplying power of a second power line while stepping up the voltage, a second step-up converter for supplying power of a fourth power line, while stepping up the voltage, to a third power line to be connected with the first power line, and a first voltage sensor for detecting the voltage of the first power line, and controlling the first and second step-up converters by using at least the voltage detected by the first voltage sensor, control error can be reduced when controlling the second step-up converter, by providing a second voltage sensor for detecting the voltage of the third power line.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device.

  Conventionally, this type of power supply device includes a battery (storage battery), a first boost converter (basic converter), a second boost converter (additional converter), and a first voltage sensor (basic voltage sensor). Has been proposed (see, for example, Patent Document 1). The first boost converter supplies electric power from the battery to the motor with voltage boost. The second boost converter is connected between the battery and the motor in parallel with the first boost converter. The first voltage sensor detects the boosted voltage of the first boost converter. In this device, a current sensor for detecting a current flowing from the battery to the second boost converter side is provided, and the first boost converter is controlled so that the voltage detected by the first voltage sensor becomes a target voltage. The second boost converter is controlled so that the detected current becomes the target current.

JP, 2014-122221, A

  By the way, a first boost converter connected to a first battery, a second battery, a first power line to which two motors are connected, and a second power line to which the first battery is connected, and a first power line A power supply device comprising: a second boost converter connected to a third power line connected to the second power line; a fourth power line connected to the second battery; and a first voltage sensor detecting a voltage of the first power line. Then, the first boost converter is controlled so that the voltage detected by the voltage sensor becomes the target voltage, and the second boost converter is controlled so that the current flowing through the fourth power line becomes the target current. In such a device, when an abnormality occurs in the connection of the voltage sensor or an abnormality occurs in the first boost converter and an abnormality occurs in the detected value of the voltage sensor, the first boost converter cannot be properly controlled. A process for stopping the driving of the first and second boost converters is performed. However, if the driving of the first and second boost converters is stopped, there arises a disadvantage that the two motors cannot be driven. As a method for dealing with such inconvenience, a second voltage sensor is provided in parallel with the first voltage sensor, and when an abnormality occurs in the detection value of the first voltage sensor, the second boost converter is used by using the detection value of the second voltage sensor. A method for controlling the above can be considered. However, in this method, when the first boost converter and the second boost converter are arranged relatively far apart and the third power line connected to the first power line and the second boost converter becomes long, the third power The voltage drop due to the wiring resistance of the line becomes large, and if the second boost converter is controlled using the detection value of the second voltage sensor, the control error becomes large.

  A power supply apparatus according to the present invention controls a second boost converter in a power supply apparatus including first and second boost converters and a first voltage sensor that detects a voltage of a first power line to which the first boost converter is connected. The main purpose is to further reduce the control error.

  The power supply apparatus of the present invention employs the following means in order to achieve the main object described above.

The power supply device of the present invention is
A first battery;
A second battery;
A first power line connected to the first motor and the second motor is connected to a second power line connected to the first battery, and the power of the second power line is increased with a voltage boost. A first boost converter for supplying one power line;
The third power line is connected to the third power line connected to the first power line and the fourth power line to which the second battery is connected, and the power of the fourth power line is increased with a voltage boost. A second boost converter for supplying to
A first voltage sensor for detecting a voltage of the first power line;
A control device for controlling the first and second boost converters using at least the voltage detected by the first voltage sensor;
A power supply device comprising:
A second voltage sensor for detecting a voltage of the third power line;
It is a summary to provide.

  In the power supply device of the present invention, the first power line is connected to the second power line to which the first battery is connected, and the first power line is supplied to the first power line with voltage boost. The third power line is connected to the boost converter, the third power line connected to the first power line, and the fourth power line to which the second battery is connected. And a first voltage sensor that detects the voltage of the first power line, and controls the first and second boost converters using at least the voltage detected by the first voltage sensor. . And the 2nd voltage sensor which detects the voltage of the 3rd electric power line is provided in the 3rd electric power line connected to the 1st electric power line. Thus, when any abnormality occurs in the detection value of the first voltage sensor, the second boost converter can be controlled using the voltage of the third power line detected by the second voltage sensor. Thus, for example, the second boost converter is controlled even when the first boost converter and the second boost converter are arranged relatively apart from each other, and the third power line becomes long and the voltage drop due to the wiring resistance of the third power line is large. In this case, the control error can be further reduced.

  In such a power supply device of the present invention, the control device controls the first boost converter so that the voltage of the first power line detected by the first voltage sensor becomes a target voltage, and the second battery. The second boost converter is controlled so that the charge / discharge power of the second boost converter becomes a target power, and the controller stops driving the first boost converter when an abnormality occurs in the first voltage sensor. And controlling the first boost converter so that the charge / discharge power of the second battery becomes the target power, the current flowing through the fourth power line, the voltage of the fourth power line, and the second voltage sensor. The second boost converter may be controlled using the voltage of the third power line detected by the above-mentioned. In this way, when an abnormality occurs in the first voltage sensor, the second boost converter can be driven to drive the first and second motors.

It is a block diagram which shows the outline of a structure of the drive device 20 carrying the power supply device as one Example of this invention. FIG. 6 is an explanatory diagram for explaining the arrangement of first and second boost converters 54 and 55, connection power line 45, and voltage sensors 46b and 46c when drive device 20 is mounted on bus 80. It is a flowchart which shows an example of the pressure | voltage rise control routine performed by ECU70 of an Example. It is explanatory drawing which shows an example of control of the 2nd step-up converter 55 in evacuation control.

  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 a drive device 20 equipped with a power supply device as an embodiment of the present invention. As shown in FIG. 1, the driving device 20 of the embodiment includes motors 30 and 32, inverters 41 and 42, first and second boost converters 54 and 55, first and second batteries 50 and 51, First and second relays 56 and 57 and an electronic control unit (hereinafter referred to as “ECU”) 70 are provided.

  The motors 30 and 32 are configured as, for example, synchronous generator motors. The inverters 41 and 42 are used to drive the motors 30 and 32 and are connected to the high voltage system power line 46. The motors 30 and 32 are rotationally driven by the ECU 70 by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42.

  The first boost converter 54 is connected to a high voltage system power line 46 to which the inverters 41 and 42 are connected, and a first low voltage system power line 47 to which the first battery 50 is connected via the first relay 56. Yes. The first boost converter 54 includes two transistors T11 and T12, two diodes D11 and D12, and a reactor L1. The transistor T <b> 11 is connected to the positive electrode line of the high voltage system power line 46. The transistor T12 is connected to the transistor T11 and the negative line of the high voltage system power line 46 and the first low voltage system power line 47. The two diodes D11 and D12 are respectively connected in parallel to the transistors T11 and T12 in the reverse direction. The reactor L1 is connected to the intermediate point between the transistors T11 and T12 and the positive line of the first low voltage system power line 47. The first boost converter 54 adjusts the ratio of the on-time of the transistors T11 and T12 by the ECU 70, so that the power of the first low voltage system power line 47 is transferred to the high voltage system power line 46 with voltage boost. Or the power of the high voltage system power line 46 is supplied to the first low voltage system power line 47 with voltage step-down.

  The second boost converter 55 is connected to a connection power line 45 connected to the high voltage system power line 46 and a second low voltage system power line 48 to which the second battery 51 is connected via the second relay 57. ing. The second boost converter 55 includes two transistors T21 and T22, two diodes D21 and D22, and a reactor L2. The transistor T21 is connected to the positive electrode line of the connection power line 45. The transistor T22 is connected to the transistor T21 and the negative line of the connection power line 45 and the second low voltage system power line 48. The two diodes D21 and D22 are respectively connected in parallel to the transistors T21 and T22 in the reverse direction. Reactor L2 is connected to the intermediate point of transistors T21 and T22 and the positive line of second low voltage system power line 48. The second boost converter 55 adjusts the ratio of the on-time of the transistors T21 and T22 by the ECU 70, whereby the power of the second low voltage system power line 48 is increased via the connection power line 45 with voltage boost. The power is supplied to the high voltage system power line 46, or the power of the high voltage system power line 46 is supplied to the second low voltage system power line 48 via the connection power line 45 with voltage step-down.

  A smoothing capacitor 46 a is attached to the positive and negative buses of the high voltage power line 46. A smoothing capacitor 47 a is attached to the positive and negative buses of the first low-voltage power line 47. A smoothing capacitor 48 a is attached to the positive and negative buses of the second low voltage system power line 48.

  The first battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the first low voltage system power line 47 via the first relay 56 as described above. The second battery 51 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the second low voltage system power line 48 via the second relay 57 as described above. In the embodiment, the first battery 50 is configured as a high capacity type battery, and the second battery 51 is configured as a battery having a smaller rated capacity (and higher output density) than the first battery 50. It was supposed to be. The first and second batteries 50 and 51 are managed by the ECU 70.

  The first relay 56 is provided in the first low voltage system power line 47 and connects and disconnects the first boost converter 54 and the first battery 50. The second relay 57 is provided in the second low voltage system power line 48 and connects and disconnects the second boost converter 55 and the second battery 51.

  Although not shown, the ECU 70 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.

  The ECU 70 receives signals from various sensors necessary for driving and controlling the motors 30 and 32 and the first and second boost converters 54 and 55 through an input port. Examples of the signal input to the ECU 70 include rotational positions θm1 and θm2 from a rotational position detection sensor that detects the rotational positions of the rotors of the motors 30 and 32. In addition, voltage VH1 of capacitor 46a (high voltage system power line 46) from voltage sensor 46b attached between terminals of capacitor 46a, voltage sensor attached between the positive and negative lines of connection power line 45. The voltage VH2 of the connecting power line 45 from 46c2 and the voltage VL1 of the capacitor 47a (first low voltage system power line 47) from the voltage sensor 47b attached between the terminals of the capacitor 47a are attached between the terminals of the capacitor 48a. The voltage VL2 of the capacitor 48a (second low voltage system power line 48) from the voltage sensor 48b and the first and second voltages from the voltage sensors 50a and 51a installed between the terminals of the first and second batteries 50 and 51. The voltage Vb1, Vb2, etc. of the batteries 50 and 51 can also be mentioned. Furthermore, the current IL of the reactor L1 from the current sensor 54a attached to the positive bus of the first low voltage system power line 47, and the reactor L2 from the current sensor 55a attached to the positive bus of the second low voltage system power line 48. Current IL2, currents Ib1 and Ib2 of the first and second batteries 50 and 51 from the current sensors 50b and 51b attached to the output terminals of the first and second batteries 50 and 51, and the like. In the figure, the broken line arrows representing the input to the ECU 70 of the currents Ib1 and Ib2 of the first and second batteries 50 and 51 from the current sensors 50b and 51b and the current IL1 of the reactor L1 from the current sensor 54a are as follows. Description in the figure is omitted.

  From the ECU 70, switching control signals to a plurality of switching elements (not shown) of the inverters 41, 42, switching control signals to a plurality of switching elements (not shown) of the first and second boost converters 54, 55, first and second relays. The on / off control signals to 56 and 57 are output through the output port. In the figure, broken line arrows representing the output of on / off control signals from the ECU 70 to the first and second relays 56 and 57 are not shown in the figure.

  The ECU 70 calculates the rotational speeds Nm1 and Nm2 of the motors 30 and 32 based on the rotational positions θm1 and θm2 of the rotors of the motors 30 and 32 from a rotational position detection sensor (not shown). The ECU 70 calculates the storage ratios SOC1 and SOC2 based on the integrated values of the currents Ib1 and Ib2 of the first and second batteries 50 and 51 from the current sensors 50b and 51b. Here, the storage ratios SOC1 and SOC2 are ratios of the capacity of electric power that can be discharged from the first and second batteries 50 and 51 to the rated capacities (total capacities) Sr1 and Sr2 of the first and second batteries 50 and 51. .

  ECU 70 performs switching control of transistors (not shown) of inverters 41 and 42 so that motors 30 and 32 are driven by torque commands Tm1 * and Tm2 *.

  When driving the first boost converter 54, the ECU 70 performs switching control of the transistors T11 and T12 of the first boost converter 54 so that the voltage VH1 of the high voltage system power line 46 becomes the target voltage VH *. Furthermore, when driving the second boost converter 55, the ECU 70 performs switching control of the transistors T21 and T22 of the second boost converter 55 so that the charge / discharge power of the second battery 51 becomes the target power Pb2 *. More specifically, the target voltage Pb2 * is divided by the battery voltage Vb2 of the second battery 51 to obtain the target current IL * of the reactor L2, and the second boost converter so that the current IL of the reactor L2 becomes the target current IL *. This is done by switching control of 55 transistors T21 and T22. Hereinafter, such control of the first boost converter 54 and the second boost converter 55 is referred to as “normal control”.

  The drive device 20 of the embodiment configured in this way is mounted on, for example, an automobile such as a bus intended for mass passenger transportation. FIG. 2 is an explanatory diagram for explaining the arrangement of the first and second boost converters 54 and 55, the connection power line 45, and the voltage sensors 46 b and 46 c when the driving device 20 is mounted on the bus 80. As shown in the drawing, the first boost converter 54 is disposed behind the rearmost seat 82, and the second boost converter 55 is disposed below the seat 82. The connecting power line 45 is routed from the second boost converter 55 toward the first boost converter 54. The voltage sensor 46 b is disposed behind the seat 82. The voltage sensor 46 c is disposed in the vicinity of the second boost converter 55. In FIG. 2, the arrangement of the motors 30 and 32, the inverters 41 and 42, the first and second batteries 50 and 51, the first and second relays 56 and 57, and the ECU 70 does not form the core of the present invention. Therefore, illustration is abbreviate | omitted.

  Next, the operation of the drive device 20 of the embodiment configured as described above, particularly the operation when an abnormality has occurred in the detection value of the voltage sensor 46b will be described. FIG. 3 is a flowchart illustrating an example of a boost control routine executed by the ECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, several msec).

  When this routine is executed, the ECU 70 executes a process of inputting the voltages VH1 and VH2 (step S100). Here, the voltages VH1 and VH2 are detected by the voltage sensors 46b and 46c.

  Subsequently, it is determined whether or not an abnormality has occurred in the input voltage VH1 (step S110). This determination is made when the voltage VH1 is a fixed value for a relatively long period, or exceeds the range of values that the voltage VH1 can normally take with respect to the battery voltage VB1 from the voltage sensor 50a and the voltage VL1 from the voltage sensor 47b. Sometimes, it is determined that an abnormality has occurred in the voltage VH1.

  When it is determined in step S110 that there is no abnormality in the voltage VH1, the above-described normal control is executed for the first and second boost converters 54 and 55 (step S120), and this routine is terminated. .

  When it is determined in step S110 that the voltage VH1 is abnormal, the evacuation control using the voltage VH2 is executed (step S130), and this routine is terminated.

  Here, the evacuation control will be described. FIG. 4 is an explanatory diagram showing an example of control of the second boost converter 55 in the evacuation control. The first boost converter 54 controls the transistors T11 and T12 so as to stop driving.

  In the evacuation control, first, the current command IL * is calculated by dividing the target power Pb2 * by the voltage VL2 from the voltage sensor 48b (step S200). The target power Pb2 * is set as a target value for the charge / discharge power of the second battery 51 based on the torque commands Tm1 *, Tm2 * of the motors 30, 32 and the rotational speeds Nm1, Nm2 of the motors 30, 32.

  Subsequently, the provisional value Dfbtmp of the feedback term of the second boost converter 55 is calculated by the equation (1) using the set current command IL * and the current IL2 of the reactor L2 from the current sensor 55a (step S210). In equation (1), “Kp” is the gain of the proportional term. “L / S” is the integral of the PI control feedback. “Ki” is the gain of the integral term.

Dfbtmp = Kp (IL * -IL2) + l / s ・ Ki ・ Σ (IL * -IL) (1)

  Subsequently, the value Dfbtmp is guarded at the upper and lower limits and set to the feedback term Dfb (step S220). Here, the upper / lower limit guard is a process of setting the smaller value of the value Dfbtmp and the allowable upper limit value Dfbmax and the larger value of the allowable lower limit value Dfbmin in the feedback term Dfb. The allowable upper limit value Dfbmax and the allowable lower limit value Dfbmin are values set based on the specifications of the second boost converter 55 and the like.

  Subsequently, the provisional duty ratio Dtmp obtained by subtracting the feedback term Dfb from the feedforward term Dff, which is a value obtained by dividing the voltage VL2 from the voltage sensor 48b by the voltage VH2 from the voltage sensor 46c, is subjected to a lower limit guard and a target duty ratio. Duty * is set (step S230). Here, the lower limit guard is a process of setting the larger value of the temporary value Dtmp and the allowable lower limit value Dmin as the target duty ratio Duty *. The allowable lower limit value Dmin is a value determined by the specification of the second boost converter 55 as the lower limit of the duty ratio of the second boost converter 55.

  When the target duty ratio Duty * is set in this way, the duty signal (the time corresponding to the target duty ratio Duty * of the switching periods of the transistors T21 and T22 is turned on based on the target duty ratio Duty *, and the remaining of the switching period A signal that turns off with respect to time is generated (step S240), and a PWM signal for controlling the second boost converter 55 is generated and output based on the duty signal (step S250). Using the PWM signal thus output, the transistors T21 and T22 of the second boost converter 55 are subjected to switching control. By such control, when an abnormality occurs in voltage VH1, second boost converter is used using current command IL * of reactor L2, current IL2, voltage VL2 from voltage sensor 48b, and voltage VH2 from voltage sensor 46c. The motors 30 and 32 can be driven by driving 55. Thereby, for example, as shown in FIG. 2, even when the first boost converter 54 and the second boost converter 55 are arranged relatively apart from each other and the voltage drop due to the wiring resistance of the connection power line 45 is large, Since the second boost converter 55 is controlled by using the voltage sensor 46c arranged in the vicinity of the second boost converter 55, a voltage sensor is provided separately from the voltage sensor 46b in the capacitor 46a, and the detected value of the voltage sensor is used to The control error can be reduced as compared with the case where the two boost converter 55 is controlled.

  According to the driving device 20 of the embodiment described above, by providing the voltage sensor 46c that detects the voltage of the connecting power line 45, the control error when controlling the second boost converter 55 can be further reduced. .

  In the embodiment, FIG. 2 illustrates the case where the first boost converter 54 and the second boost converter 55 are disposed at relatively distant positions in the power supply device of the present invention. However, even when the first boost converter 54 and the second boost converter 55 are arranged close to each other, when the voltage drop in the connection power line 45 becomes large, for example, the wiring of the connection power line 45 becomes thin and the wiring resistance is reduced. It is considered that the same effect is produced when the number is increased. Further, it is considered that the same effect can be obtained when the rated capacity of the second battery 51 is increased (for example, approximately the same as that of the first battery 50) and the current flowing through the second low voltage system power line 48 is increased. .

  In the driving device 20 of the embodiment, the case where it is mounted on the bus 80 in FIG. 2 is illustrated. However, what mounts the drive device 20 may be anything, for example, it may be mounted on a car having a passenger capacity of less than 10 people, or may be mounted on a device different from the car.

  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 first battery 50 corresponds to a “first battery”, the second battery 51 corresponds to a “second battery”, the first boost converter 54 corresponds to a “first boost converter”, and the second Boost converter 55 corresponds to a “second boost converter”, voltage sensor 46 b corresponds to a “first voltage sensor”, ECU 70 corresponds to a “control device”, and voltage sensor 46 c corresponds to a “second voltage sensor”. To do.

  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 power supply device manufacturing industry.

  20 drive device, 30, 32 motor, 41, 42 inverter, 45 connecting power line, 46 high voltage system power line, 46a, 47a, 48a capacitor, 47 first low voltage system power line, 48 second low voltage system power Line, 46b, 46c, 47b, 48b, 50a, 51a Voltage sensor, 50 First battery, 50b, 51b, 54a, 55a Current sensor, 51 Second battery, 54 First boost converter, 55 Second boost converter, 56 First 1 relay, 57 2nd relay, 70 electronic control unit (ECU), 80 bus, 82 seat, L1, L2 reactor, T11, T12, T21, T22 transistor, D11, D12, D21, D22 diode.

Claims (1)

A first battery;
A second battery;
A first power line connected to the first motor and the second motor is connected to a second power line connected to the first battery, and the power of the second power line is increased with a voltage boost. A first boost converter for supplying one power line;
The third power line is connected to the third power line connected to the first power line and the fourth power line to which the second battery is connected, and the power of the fourth power line is increased with a voltage boost. A second boost converter for supplying to
A first voltage sensor for detecting a voltage of the first power line;
A control device for controlling the first and second boost converters using at least the voltage detected by the first voltage sensor;
A power supply device comprising:
A second voltage sensor for detecting a voltage of the third power line;
A power supply device comprising:

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