WO2006118315A1

WO2006118315A1 - Polyphase voltage converting apparatus and vehicle

Info

Publication number: WO2006118315A1
Application number: PCT/JP2006/309194
Authority: WO
Inventors: Masahiro Shige
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2005-05-02
Filing date: 2006-04-26
Publication date: 2006-11-09
Also published as: JP2006311776A

Abstract

A polyphase voltage converting apparatus (10) is provided with a plurality of voltage converters (31-33) connected in parallel between a first node and a second node; and a controller (30) which selects one or two voltage converters to be driven from the voltage converters (31-33) based on the detection results of the status of the voltage converters (31-33). Preferably, each of the voltage converters (31-33) includes an element temperature sensor (41) for measuring element temperature. The controller (30) decides the voltage converter to be driven based on each element temperature of the voltage converters. The controller (30) decides the voltage converter to be driven so that the voltage converters are used from the one having a lower temperature by giving priority. Thus, while suppressing cost increase, the polyphase voltage converting apparatus having a long product life and a vehicle are provided.

Description

TECHNICAL FIELD Technical Field

The present invention relates to a multiphase voltage converter and a vehicle including the same, and more particularly to a multiphase voltage converter capable of selectively driving some voltage / voltage converters and a vehicle including the same. Background art

Japanese Patent Laid-Open No. 2000-035 5 3 8 8 discloses a multi-phase multiplex type buck-boost converter having both a step-up function and a step-down function as converter functions. Such a buck-boost converter is used in an inverter system such as an electric vehicle to reduce current ripple.

^: Can be reduced.

When the power consumed on the output side is small, the multi-phase multiplex type converter converts the voltage converter corresponding to only a part of the phase (hereinafter referred to as the “voltage converter corresponding to the phase” to “phase”). It may be more efficient to operate the system and pause the remaining phases. However, in such a use, if the use is concentrated only on a specific phase, the deterioration of the specific phase is accelerated compared to other phases. Although the other phases have not deteriorated, the product life is determined by the specific phase when viewed as a whole of the multiphase converter. 'If you try to get a sufficient product life, you need to make room for the design, leading to increased costs.

Disclosure of the invention

An object of the present invention is to provide a multiphase voltage conversion device and a vehicle having a long product life while suppressing an increase in cost.

In summary, the present invention is a multi-phase voltage converter comprising a plurality of voltage variations ^^ connected in parallel between a first node and a second node, and a plurality of voltage variations ^^ And a controller that selects and drives a part of the plurality of voltage converters based on the result of detecting the state. Preferably, each of the plurality of voltage converters includes a temperature sensor that measures an element temperature. The control unit determines a voltage converter to be driven based on each element temperature of the plurality of voltage converters.

More preferably, the control unit determines a voltage converter to be driven to be used in preference to a voltage converter having a low temperature.

Preferably, the control unit includes a storage unit that stores usage histories of the plurality of voltage converters in a nonvolatile manner. The control unit determines a voltage converter to be driven based on the usage history. More preferably, the control unit selects and drives a voltage converter different from the previously driven voltage converter with reference to the use history.

Preferably, the plurality of voltage converters are first to third voltage converters, and one-phase driving for driving only one voltage converter from three-phase driving for driving first to third voltage converters. When receiving a command to switch to, the control unit selects the voltage converter to be driven.

Preferably, when the drive time of the voltage converter being driven has passed a predetermined time, the control unit switches the voltage converter to be driven by another voltage converter that has not been driven. More preferably, the plurality of voltage converters are first to third voltage converters, and perform one-phase driving for driving only one voltage converter from the first to third voltage converters. Inside, the controller switches the voltage converter to be driven.

Preferably, when the temperature of the voltage converter being driven exceeds a predetermined temperature, the control unit switches the voltage converter to be driven by another voltage converter that has not been driven. '

More preferably, the plurality of voltage converters are first to third voltage converters, and one-phase driving for driving only one voltage converter from the first to third voltage converters is being performed. The control unit switches the voltage converter to be driven.

In another aspect, the present invention is a vehicle, which is any one of the multiphase voltage conversion devices described above, a fuel cell connected to a first node, and a power storage device connected to a second node. With.

According to the present invention, when a part of a voltage converter of a plurality of phases is used, by determining the phase to be driven according to the state of each phase, the phase to be used can be optimized, and deterioration bias Can be reduced. Brief Description of Drawings

FIG. 1 is a circuit diagram showing a configuration of a vehicle 100 according to the present invention.

FIG. 2 is a flowchart showing a control structure of a program executed in control device 30 of FIG.

FIG. 3 is a flowchart showing the control structure of the program executed in the second embodiment.

FIG. 4 is a flowchart showing the control structure of the program executed in the third embodiment.

FIG. 5 is a flowchart showing the control structure of the program executed in the fourth embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]

FIG. 1 is a circuit diagram showing a configuration of a vehicle 100 according to the present invention. The vehicle 100 is a fuel cell vehicle shown as an example of a vehicle equipped with a motor.

Referring to FIG. 1, vehicle 1 0 0 includes a battery 2 connected between node N 1 and node N 3, and a smoothing capacitor 8 connected between node N 1 and node N 3. And a multi-phase voltage converter 10 connected between node N 1 and node N 2 and performing voltage conversion between battery voltage VB and inverter voltage VINV. Vehicle 1 0 0 further includes a smoothing capacitor 14 connected between node N 2 and node N 3, diode 16 connected in series between node N 2 and node N 3, and It includes a fuel cell 18, an inverter 20 connected between the node N 2 and the node N 3, and a motor 22 driven by the inverter 20. The diode 16 is a protective element for preventing current from flowing into the fuel cell 18 and is connected with the direction from the fuel cell toward the node N 2 as the forward direction.

The vehicle 1 0 0 further includes a voltage sensor 6 for detecting the battery voltage VB, A voltage sensor 12 for detecting the barter voltage VI NV and a control device 30 are included.

Multiphase voltage converter 10 includes voltage converters 31-33 connected in parallel between nodes N1 and N2. The voltage converters 31 to 33 are connected to a node N 3 that provides reference potentials for voltages V B and V I NV.

Voltage converter 31 is a first arm connected between node N1 and node N3

'A1, second arm A2 connected between node N2 and node N3, rear tutor L 1 connected between arm A 1 and A2, and element temperature in voltage converter 3 1 'Including element temperature sensor 41 to detect.

The first arm A 1 includes an IGBT element GA, GB connected in series between the node N1 and the node N 3, a diode DA connected in parallel with the I GBT element GA, and an I GBT element GB. Including a diode DB connected in parallel.

The collector of the I GBT element GA is connected to the node N1, and the emitter is connected to the node N4. The diode DA is connected with the direction from the node N 4 toward the node N 1 as the forward direction.

The collector of I GBT element GB is connected to node N4, and the emitter is connected to node N3. The diode DB is connected with the direction from node N 3 to node N 4 as the forward direction.

The second arm A 2 includes IG, BT elements GC, GD connected in series between the node N 2 and the node N 3, a diode DC connected in parallel with the I GBT element GC, and an I GBT element Includes diode DD connected in parallel with GD.

The collector of the I GBT element GC is connected to node N2, and the emitter is connected to node N5. The diode DC is connected with the direction from the node N4 to the node N2 as the forward direction.

The collector of the I GBT element GD is connected to the node N 5, and the emitter is connected to the node N 3. Diode DD is connected with the direction from node N3 to node N5 as the forward direction.

The rear tuttle L 1 is connected between the node N 4 and the node N 5.

Since the internal configuration of voltage converters 32 and 33 is the same as that of voltage converter 31, description thereof will not be repeated. However, the element temperature sensor in the voltage converters 32 and 33 The element temperatures T 3 2 and Τ 3 3 are output from the sensor 41, respectively.

In FIG. 1, the IGBT element GB emitter and the IGBT element GD emitter are connected inside the voltage converter 31. In other words, the node Ν3 and the fuel cell are connected inside each of the voltage converters. A configuration for connecting the negative electrode is shown. However, instead of the configuration of Fig. 1, the emitter of IG IG Τ element G と and the emitter of IGBT element GD are not connected inside each voltage converter, and node Ν 3 and the fuel cell are connected to the outside of the voltage converter. One wiring common to the voltage converters 31 to 33 may be provided to connect the negative electrode.

The possible range of the battery voltage V B and the output voltage of the fuel cell 18 partially overlap. For example, a nickel-metal hydride battery is used as the battery, and its power supply voltage varies within a range of, for example, 2 00 V to 30 O V. On the other hand, the output voltage of the fuel cell 1 8 varies within a range of 2 40 V to 4 0 0 V, for example.

Therefore, since the voltage of the battery 2 may be higher or lower than the output voltage of the fuel cell 18, the voltage variations 3 1 to 33 have the first and second arms as described above. It has a configuration like this. With this configuration, it is possible to step up and step down from the battery 2 side to the inverter 20 side, and step up and step down from the inverter 20 side to the battery 2 side.

The control device 30 selects and drives part of the voltage converters 31 to 33 based on the result of detecting the state of the voltage converters 31 to 33.

Preferably, each of voltage converters 31 to 33 includes an element temperature sensor 41 for measuring the element temperature. The control device 30 determines a voltage converter to be driven based on the element temperatures T 3 1 to T 3 3 of the voltage converters 31 to 33 detected by the element temperature sensor 41. The control device 30 determines a voltage converter to be driven so as to be used preferentially from a voltage converter having a low element temperature.

FIG. 2 is a flowchart showing a control structure of a program executed in control device 30 of FIG. The process of this flowchart is called from the main routine and executed every certain time or whenever a predetermined condition is satisfied.

Referring to FIG. 2, when processing is started, first, in step S 1, control device 30 becomes: the power consumed or generated by inverter 20 and the power output from fuel cell 18. In consideration of the state of charge of battery 2, the multi-phase voltage converter It is determined whether or not a switching request is generated. The phase switching request includes a case where the drive phase is reduced from the three-phase drive to the one-phase drive and a case where the drive phase is increased from the one-phase drive to the three-phase drive.

For example, if the power consumption of the inverter 20 increases when the driver depresses the accelerator pedal and sudden acceleration is performed from a standstill, the battery 2 will continue to increase until the output of the fuel cell 18 increases. Large power must be supplied to the inverter 20. In such a case, the drive phase is increased from 1-phase drive to 3-phase drive.

Conversely, if three-phase drive is performed after sudden acceleration, and then the output of the fuel cell 18 becomes sufficient and the power passing through the multi-phase voltage converter 10 becomes less, the total fuel consumption will be reduced. To achieve this, the number of drive phases is reduced from three-phase drive to one-phase drive.

If it is determined in step S 1 that there is no phase switching request, the process proceeds to step S 7. If it is determined that there is a phase switching request, the process proceeds to step S 2.

In step S7, it is determined that the current converter control is to be maintained, and the process proceeds to step S8 where control is returned to the main routine.

In step S2, it is determined whether the phase switching request is a request for switching from three phases to one phase. If the phase switching request is a request to switch from three phases to one phase, the process proceeds to step S3. On the other hand, if not, the process proceeds to step S5.

In step S3, the temperature T3 1 to T3 3 is measured by the element temperature sensor 4

: Done, controller 30 takes this temperature. Then, the process proceeds to step S 4, and the control device 30 selects one of the voltage converters 3 1-3 3 having the lowest element temperature, operates this for one phase, and the other two phases Stop. During three-phase drive, even if an on-time command is given to each phase with the same duty ratio, a slight current variation will occur due to device variations. Since the phase with the lowest heat generation during three-phase driving can be considered as a phase in which no current flows, use of that phase during one-phase driving can level the use of elements. The process then proceeds to step S8, and control is returned to the main routine.

When the process proceeds from step S2 to step S5, the drive phase changes from 1 to 3 This is a case where there is a switching request so as to increase. Therefore, in step S5, the control device 30 determines that a request for switching from 1-phase drive to 3-phase drive has been made, and proceeds to step S6 to drive the currently stopped 2-phase to change to 3-phase drive. Switch. By selecting a voltage converter that does not have a relatively high temperature and driving it in one phase, even if a three-phase converter is used using phase switching control, it can be prevented that only a specific phase is deteriorated. Overall, the life of the three-phase converter can be extended.

[Embodiment 2]

FIG. 3 is a flowchart showing the control structure of the program executed in the second embodiment. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is established.

Since steps S 11 to S 16 in the flowchart of FIG. 3 are performed in the same manner as steps S 1 to S 6 of FIG. 2, their description will not be repeated.

In FIG. 3, if it is determined in step S 11 that there is no phase switching request, the process proceeds to step S 17.

In step S 17, it is determined whether one-phase driving is currently in progress. If the one-phase drive is being performed, the process proceeds to step S 18, and if the one-phase drive is not being performed, that is, if the three-phase drive is being performed, the process proceeds to step S 21.

In step S 18, element temperatures T 3 1 to T 3 3 are measured by the element temperature sensor 41, and the control device 30 takes in this temperature. Then, the process proceeds to step S 19, and control device 30 determines whether or not each element temperature Τ 31 to Τ 33 exceeds a threshold value.

If the element temperature of the drive phase exceeds the threshold value in step S 19, the process proceeds to step S 20, and the operation phase is switched to the phase that is not currently driven. At this time, switching is performed so that the phase with the lowest element temperature is driven by one phase. This is to avoid the continued use in a state that generates a large amount of heat, as it will greatly affect the deterioration of internal elements. The threshold is set to a value that ensures a margin for the maximum allowable temperature of the device. For example, if the element's rated allowable temperature is 105 ° C, it should be set to about 90 ° C. The process then proceeds to step S 22 and control returns to the main routine. It is.

On the other hand, if the element temperature does not exceed the threshold value in step S 19, the process proceeds to step S 21.

In step S 21, it is determined that the current converter control is to be maintained, and the process proceeds to step S 22 and control is returned to the main routine.

By adopting such control, the cumulative driving time of the voltage converters of each phase can be averaged compared to the case of the first embodiment, and the life can be further extended.

[Embodiment ³ ]

In FIG. 1, the control device 30 includes a nonvolatile memory 50 that stores usage histories of the voltage converters 31 to 33 in a nonvolatile manner. The control device 30 may determine a voltage converter to be driven based on this usage history. In this case, the control device 30 refers to the usage history and selects and drives a voltage converter that is different from the previously driven voltage converter.

FIG. 4 is a flowchart showing the control structure of the program executed in the third embodiment. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is established.

Referring to FIG. 1 and FIG. 4, when the process is first started, in step S 3 1, control device 30 outputs power consumed or generated by inverter 20 and power output from fuel cell 18. And whether or not a phase switching request is generated in the multiphase voltage converter 1 Ό in consideration of the state of charge of the battery 2. The phase switching request includes a case where the drive phase is decreased from the three-phase drive to the one-phase drive and a case where the drive phase is increased from the one-phase drive to the three-phase drive.

If it is determined in step S 3 1 that there is no phase switching request, the process proceeds to step S 3 8. If it is determined that there is a phase switching request, the process proceeds to step S 3. Proceed to step 2.

In step S 3 8, it is determined that the current converter control is maintained, and the process proceeds to step S 39 and control is returned to the main routine.

In step S 3 2, it is determined whether or not the phase switching request is a request for switching from three phases to one phase. When the phase switching request is a request to switch from 3 phase to 1 phase The process proceeds to step S 3 3. On the other hand, if not, the process proceeds to step S 35.

In step S 33, the control device 30 reads out the last drive phase information in the previous one-phase drive from the nonvolatile memory 50. In step S 3 4, one of the phases positioned next to the final drive phase in the predetermined rotation order is selected as the drive phase, this is operated for one phase, and the other two phases are stopped. For example, this rotation order is determined so that the voltage converter 31 is driven again after switching from the voltage converter 3 1 → 3 2 → 3 3 and the switching in the same order is returned. Then, the process proceeds to step S 39 and the control is returned to the main routine.

When the process proceeds from step S 3 2 to step S 3 5, there is a switching request to increase the drive phase from 1 phase to 3 phases. Therefore, the control device 30 determines that there is a request for switching from the one-phase drive to the three-phase drive, and the process proceeds to step S36, where the current drive phase is stored in the nonvolatile memory 50 as the last drive phase information. Write. Then, the process proceeds to step S 37 to drive the currently stopped two phases and switch to the three-phase drive.

In this way, in the case of single-phase driving, by avoiding bias in the phase to be driven in one phase based on a predetermined rotation order, even if a three-phase converter is used with phase switching control, only a specific phase is used. Deterioration can be prevented and overall life of the three-phase converter can be extended.

[Embodiment 4]

FIG. 5 is a flowchart showing the control structure of the program executed in the fourth embodiment. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is established.

Since steps S 4 1 to S 47 in the flowchart of FIG. 5 are performed in the same manner as steps S 31 to S 37 in FIG. 4, their description will not be repeated.

In FIG. 5, when it is determined in step S 4 1 that there is no phase switching request, the process proceeds to step S 48.

In step S 48, it is determined whether one-phase driving is currently in progress. During 1-phase drive If YES, the process proceeds to step S 49, and if not one-phase driving, that is, if three-phase driving is being performed, the process proceeds to step S 51.

■ In step S 4 9, control device 30 determines whether or not the drive phase currently driven in phase has been driven for one phase for a predetermined time.

If one-phase driving has been performed for a predetermined time in step S 4 9, the process proceeds to step S 5 0 and the operation phase is switched to the non-driven phase. The drive phase is changed based on the rotation order. For example, this rotation order is determined so that the voltage converter 3 1 is started again after the voltage converters 3 1 → 3 2 → 3 3 are switched in order and the same order is repeated thereafter. Then, the process proceeds to step S 52 and control is returned to the main routine.

On the other hand, if the threshold is not exceeded in step S 4 9, the process proceeds to step S 51. .

In step S 51, it is determined that the current converter control is to be maintained, the process proceeds to step S 52, and control is returned to the main routine. By adopting such control, the life can be further extended as compared with the case of the third embodiment.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims

The scope of the claims

1. a plurality of voltage converters (31 to 33) connected in parallel between a first node and a second node;

A control unit (3'0) for selecting and driving a part of the plurality of voltage changes (31-33) based on the result of detecting the states of the plurality of voltage converters (31-33); A multiphase voltage converter.

2. Each of the plurality of voltage converters (31 to 33)

Including temperature sensor (41) to measure element temperature,

The multi-phase voltage converter according to claim 1, wherein the control unit (30) determines a voltage converter to be driven based on each element temperature of the plurality of voltage converters (31 to 33).

,

3. The multiphase voltage conversion device according to claim 2, wherein the control unit (30) determines a voltage converter to be driven so as to be used preferentially from a voltage converter having a low temperature.

4. The control unit (30)

The storage unit (50) that stores usage histories of the plurality of voltage converters in a non-volatile manner, and the control unit (30) determines a voltage converter to be driven based on the usage histories. The multiphase voltage conversion device according to item 1.

5. The multiphase voltage converter according to claim 4, wherein the control unit (30) selects and drives a voltage converter different from the voltage converter driven last with reference to the use history. .

6. The plurality of voltage converters are first to third voltage converters,

When receiving an instruction to switch from three-phase driving for driving the first to third voltage converters to one-phase driving for driving only one voltage converter, the control unit (30) drives the voltage to be driven. The multiphase voltage converter according to claim 1, wherein a converter is selected.

7. When the drive time of the voltage converter being driven has exceeded a predetermined time, the control unit (30) switches the voltage converter to be driven by another voltage converter that is not being driven. The multiphase voltage conversion device according to claim 1.

8. The plurality of voltage converters are first to third voltage converters, The control unit (30) performs switching of a voltage converter to be driven during execution of one-phase driving for driving only one voltage converter among the first to third voltage converters. The multiphase voltage converter according to Item 7.

9. When the temperature of the voltage converter being driven exceeds a predetermined temperature, the control unit (30) switches the voltage converter to be driven by another voltage converter that has not been driven. A multi-phase voltage converter as set forth in claim 1,

10. The plurality of voltage converters are first to third voltage converters,

10. The voltage converter to be driven is switched while the one-phase driving for driving only one voltage converter from among the first to third voltage converters is being executed. A multiphase voltage conversion device according to claim 1.

1 1. A vehicle with a multi-phase voltage converter,

The multi-phase voltage converter is

• Multiple voltage converters (31 to 33) connected in parallel between the first node and the second node;

A control unit (30) that selects and drives a part of the plurality of voltage changes (31 to 33) based on a result of detecting a state of the plurality of voltage converters (31 to 33). Including, '

The vehicle

A fuel cell (18) connected to the first node;

And a power storage device (2) connected to the second node.

12. Each of the plurality of voltage converters (31-33)

Including temperature sensor (41.) to measure element temperature,

The vehicle according to claim 11, wherein the control unit (30) determines a voltage converter to be driven based on each element temperature of the plurality of voltage converters (31 to 33).

13. The vehicle according to claim 12, wherein the control unit (30) determines a voltage converter to be driven so as to be used preferentially from a voltage converter having a low temperature.

14. The control unit (30)

A storage unit (50) for storing usage histories of the plurality of voltage converters in a non-volatile manner; • the control unit (30) determines a voltage converter to be driven based on the usage histories; The vehicle according to claim 11.

15. The vehicle according to claim 14, wherein the control unit (3 0) selects and drives a voltage converter different from the voltage converter driven last time with reference to the use history.

1 6. The plurality of voltage converters are first to third voltage converters,

When receiving a command to switch from three-phase driving for driving the first to third voltage converters to one-phase driving for driving only one voltage change, the control unit (30) is driven to perform voltage conversion. The vehicle according to claim 11, wherein the vehicle is selected.

17. The control unit (30) controls the voltage converter to be driven by another voltage converter that has not been driven when the drive time of the voltage converter being driven has exceeded a predetermined time. The vehicle according to claim 11, wherein the vehicle can be switched.

1 8. The plurality of voltage converters are first to third voltage converters,

The control unit (3 0) performs switching of a voltage change to be driven during execution of one-phase driving for driving only one voltage converter among the first to third voltage converters. A vehicle as set forth in paragraph 17 of

1 9. When the temperature of the voltage converter being driven exceeds a predetermined temperature, the control unit (30) switches the voltage converter to be driven by another voltage converter that has not been driven. The vehicle according to claim 11.

2 0. The plurality of voltage converters are first to third voltage converters,

While performing one-phase driving for driving only one voltage converter among the first to third voltage converters, the control unit switches the voltage converter to be driven. The vehicle according to item 9.