JP7347325B2 - vehicle - Google Patents

Description

The technology disclosed in this specification relates to a vehicle having a motor generator for driving.

Cited Document 1 discloses a vehicle. This vehicle is a fuel cell vehicle and includes a fuel cell as a generator, a battery that stores the power generated by the fuel cell, and a motor generator for driving that drives the wheels using the discharged power from the battery. The motor generator is further configured to brake the wheels by supplying regenerative power to the battery. Hereinafter, the motor generator for driving may be simply referred to as a driving motor.

When the battery is fully charged, it is no longer possible to store regenerated power from the driving motor in the battery. That is, it becomes impossible to regeneratively brake the vehicle. To avoid this situation, in conventional vehicles, when the remaining charging capacity of the battery falls below a predetermined level, at least a portion of the regenerated power is consumed as surplus power by multiple auxiliary devices. There is. Hereinafter, control processing for consuming surplus power using such auxiliary equipment will be referred to as surplus power consumption control.

In surplus power consumption control, first, surplus power is determined based on power supply and demand from the driving motor and auxiliary equipment. Next, a required power consumption value for the auxiliary equipment is set based on the determined surplus power. Based on the set request value, one or more auxiliary equipment is operated specially (that is, operated not for the purpose of performing its original function, but for the purpose of controlling surplus power consumption), thereby generating surplus power. can be consumed.

JP2019-161688A

For example, when a vehicle starts on an uphill slope, the vehicle may temporarily move backward and then move forward. In this case, while the vehicle is moving backward, the driving motor generates regenerative power, so surplus power consumption control is executed as necessary. After that, when the vehicle starts moving forward, the driving motor starts consuming power, so the generator starts generating electricity as needed. During this time, the vehicle runs at an extremely low speed, so if there is a fluctuation in the power supplied to the driving motor, the fluctuation is likely to be strongly reflected in the behavior of the vehicle (particularly the speed). In such a state, when the generator starts operating, the behavior of the vehicle may become unstable until the power generated by the generator stabilizes. Such a problem is not limited to starting the vehicle on a slope, but may also occur, for example, when the vehicle switches from reverse to forward.

In view of the above problems, the present specification provides a technique for suppressing unstable behavior that may occur when switching direction of travel in a vehicle that executes surplus power consumption control.

The technology disclosed in this specification is embodied in a vehicle. This vehicle includes a generator, a battery that stores the power generated by the generator, and a motor generator for driving that drives the wheels using the discharged power from the battery and brakes the wheels by supplying regenerative power to the battery. Be prepared. This vehicle further executes surplus power consumption control in which at least a portion of the regenerated power is consumed as surplus power by at least one auxiliary machine and at least one auxiliary machine when the remaining charging capacity of the battery is below a predetermined level. control device.

Surplus power consumption control involves a process of detecting the vehicle speed, which is the speed of the vehicle, and a consumption request value indicating the amount of power to be consumed by at least one auxiliary device based on the surplus power and the vehicle speed, and a process of detecting the amount of power generated by the generator. and a process of setting a power generation request value indicating the desired power value. Then, when the vehicle speed is lower than the first speed, the consumption request value is set to a value larger than the surplus power, and the power generation request value is set according to the difference between the consumption request value and the surplus power.

According to the above configuration, when the speed of the vehicle is lower than the first speed, even if there is surplus power, the auxiliary machine consumes more power, and the generator generates power. Therefore, for example, when the vehicle starts on a slope, the generator starts generating electricity from the stage where the vehicle is moving backward. In this way, if power generation by the generator is started in advance before the direction of travel of the vehicle is switched, the operation of the generator can be stabilized by the time the direction of travel of the vehicle is subsequently switched. Thereby, it is possible to avoid fluctuations in the power supplied to the driving motor and to stabilize the behavior of the vehicle.

By the way, in surplus power consumption control, an error may occur between a consumption request value set for an auxiliary machine and an actual power consumption value by the auxiliary machine. Since the occurrence of such an error affects the regenerated power and power supply of the driving motor, it is important to note that the behavior of the vehicle may be affected in situations where the direction of travel of the vehicle changes, such as when starting on a hill as described above. There is a risk of stabilization.

In view of the above problems, the technology disclosed in this specification is also implemented in the following vehicles. This vehicle includes a generator, a battery that stores the power generated by the generator, and a motor generator for driving that drives the wheels using the discharged power from the battery and brakes the wheels by supplying regenerative power to the battery. Be prepared. This vehicle further executes surplus power consumption control in which at least a portion of the regenerated power is consumed as surplus power by at least one auxiliary machine and at least one auxiliary machine when the remaining charging capacity of the battery is below a predetermined level. control device.

Surplus power consumption control includes a process of detecting the vehicle speed, which is the speed of the vehicle, a discharge request value indicating the amount of power that should be discharged by the battery, and a discharge request value that indicates the amount of power that should be consumed by at least one auxiliary device based on the surplus power and the vehicle speed. and a process of setting a consumption request value indicating a power value. Then, when the vehicle speed is lower than the second speed, the discharge request value is set to a non-zero value, and the consumption request value is set to a value obtained by adding the set discharge request value to the above-mentioned surplus power. Ru.

According to the above configuration, when the speed of the vehicle is lower than the second speed, even if there is surplus power, the auxiliary equipment consumes the power that exceeds the surplus power, thereby discharging the battery. Therefore, for example, when the vehicle starts on a slope, the battery starts discharging from the stage where the vehicle is moving backward. As a result, even if there is an error between the consumption request value set for the auxiliary equipment and the actual power consumption value by the auxiliary equipment, the discharged power of the battery can be passively fluctuated accordingly. , the influence on the traveling motor can be avoided or suppressed. In this way, by starting discharging the battery before the direction of travel of the vehicle is changed, it is possible to tolerate errors in power consumption by the auxiliary equipment. As a result, the behavior of the vehicle can be stabilized even when the vehicle is traveling at extremely low speeds.

FIG. 1 is a block diagram schematically showing the configuration of a vehicle 10 according to an embodiment. 5 is a flowchart showing surplus power consumption control that can be executed by the control device 30. 2 is a graph showing the relationship between vehicle speed V and power generation request value FC_RQ in surplus power consumption control. 7 is a flowchart showing another example of surplus power consumption control that can be executed by the control device 30. 7 is a flowchart showing yet another example of surplus power consumption control that can be executed by the control device 30.

In one embodiment of the present technology, when the vehicle speed exceeds the first speed, the consumption request value may be set to a value equal to the surplus power, and the power generation request value may be set to zero. That is, if the vehicle speed is not particularly low, there is no need for the generator to generate power unnecessarily in a situation where surplus power is generated.

In an embodiment of the present technology, when the vehicle speed is equal to the first speed, the required consumption value is set to a value larger than the surplus power, and the required power generation value is determined according to the difference between the required consumption value and the surplus power. may be set. That is, when the vehicle speed is equal to the first speed, the consumption request value and the power generation request value may be set in the same way as when the vehicle speed is less than the first speed. However, in another embodiment, when the vehicle speed is equal to the first speed, the consumption request value is set to a value equal to the surplus power, and the power generation request value is set to zero, as in the case where the vehicle speed exceeds the first speed. may be set to .

In one embodiment of the present technology, the value set as the consumption request value, which is larger than the surplus power described above, may be a predetermined fixed value. According to such a configuration, it is possible to avoid complexity in the process of setting the consumption setting value and the process of setting other required values accordingly.

In one embodiment of the present technology, the surplus power consumption control described above may further include processing for setting a discharge request value indicating a power value to be discharged from the battery based on the vehicle speed. In this case, when the vehicle speed is lower than the second speed, the discharge request value is set to a value other than zero, and in the process of setting the consumption request value and power generation request value described above, the set discharge request value is set to be the surplus power. It would be good if it was added to According to such a configuration, when the speed of the vehicle is lower than the second speed, even if there is surplus power, the auxiliary equipment consumes the power exceeding the surplus power, thereby discharging the battery. Therefore, as understood from the above explanation, even if there is an error between the consumption request value set for the auxiliary equipment and the actual power consumption value by the auxiliary equipment, the battery is discharged accordingly. By passively varying the electric power, the influence on the driving motor can be avoided or suppressed. Therefore, the behavior of the vehicle can be stabilized even when the vehicle is traveling at extremely low speeds.

In addition to the above, the discharge request value may be set to zero when the vehicle speed exceeds the second speed. That is, if the vehicle speed is not particularly low, there is no need to discharge the battery unnecessarily in a situation where surplus power is generated.

In an embodiment of the present technology, when the vehicle speed is equal to the second speed, the discharge request value is set to a value other than zero, and in the process of setting the consumption request value and the power generation request value, the discharge request value is set to a value other than zero. may be added to the surplus power. That is, when the vehicle speed is equal to the second speed, the discharge request value, consumption request value, and power generation request value may be set in the same way as when the vehicle speed is less than the second speed. However, as another embodiment, when the vehicle speed is equal to the second speed, the discharge request value may be set to zero, similarly to when the vehicle speed exceeds the second speed.

In an embodiment of the present technology, the value set as the discharge request value, which is not zero, may be determined according to the value of surplus power. However, the value set as the discharge request value may be a fixed value, for example, or may be determined according to other indicators.

In an embodiment of the present technology, the surplus power consumption control may further include processing for temporarily relaxing the upper limit value of discharge power set for the battery when the vehicle speed is lower than the second speed. . Usually, an upper limit value of discharge power is set for a battery for the purpose of protecting the battery. The upper limit value of discharge power is changed depending on, for example, the temperature of the battery, and may be set to a relatively small value. In this case, even if the above-mentioned discharge request value is set for the battery, the actual discharge power of the battery may be limited by the upper limit value. Therefore, when the vehicle speed is lower than the second speed, it is preferable to perform a process of relaxing the upper limit value of the discharge power, if necessary. Note that since the situation in which the vehicle speed is lower than the second speed is temporary, even if the upper limit value of the discharge power is relaxed, the effect on the battery is relatively small.

In one embodiment of the present technology, the first speed may be greater than the second speed. However, the magnitude relationship between the first speed and the second speed is not particularly limited, and in other embodiments, the first speed may be equal to the second speed, or the first speed may be smaller than the second speed. It's okay.

In one embodiment of the present technology, the generator may be a fuel cell. A fuel cell is characterized in that it takes a certain amount of time after the start of operation until the generated power becomes stable. Therefore, when the generator of the vehicle is a fuel cell, the present technology can be suitably adopted and its effects can be significantly obtained.

A vehicle 10 according to an embodiment will be described with reference to the drawings. As shown in FIG. 1, the vehicle 10 of this embodiment is a fuel cell vehicle equipped with a fuel cell 12 as a generator. The vehicle 10 further includes a battery 14 that stores the power generated by the fuel cell 12, and a travel motor 18 (hereinafter referred to as the travel motor 18) that drives the wheels 2 using the discharged power from the battery 14. The traveling motor 18 can also brake the wheels 2 by supplying regenerative power to the battery 14 . Although not particularly limited, the traveling motor 18 in this embodiment is a three-phase synchronous motor generator. Therefore, the driving motor 18 is connected to the fuel cell 12 and battery 14 via the inverter 16.

Here, a DC-DC converter may be provided between the fuel cell 12 and the battery 14, if necessary. This allows the fuel cell 12 and the battery 14 to have different rated voltages. Similarly, a DC-DC converter may be provided between the fuel cell 12 and the inverter 16, or between the battery 14 and the inverter 16, if necessary. As a result, it is possible to have different rated voltages between the fuel cell 12 and the inverter 16 (i.e., the traction motor 18) or between the battery 14 and the inverter 16 (i.e., the traction motor 18). can.

Vehicle 10 further includes a plurality of auxiliary machines 22 and a control device 30. Each of the auxiliary machines 22 and the control device 30 are low voltage components that operate at a low voltage of, for example, 12 volts or less (or 24 volts or less). On the other hand, the aforementioned fuel cell 12, battery 14, traveling motor 18, and the like are high-voltage components that operate at a high voltage of, for example, 100 volts or more. Therefore, the plurality of auxiliary machines 22 are connected via the DC/DC converter 20 to a high voltage circuit including the fuel cell 12, battery 14, travel motor 18, and the like. Although not particularly limited, the plurality of auxiliary devices 22 include, for example, a heater for space heating (HEAT), a water pump for heat circuits (W/P), a radiator fan (R/F), a blower (ACP), etc. Machine battery included. However, in implementing the present technology, the specific type of each auxiliary machine 22 is not particularly limited.

The control device 30 can control the operations of various electrical devices provided in the vehicle 10, including the fuel cell 12, the battery 14, the inverter 16, and the plurality of auxiliary devices 22. For example, the control device 30 can adjust the drive power supplied to the travel motor 18 and the regenerated power generated by the travel motor 18 by controlling the inverter 16 . Further, the control device 30 can selectively operate or stop the operation of each of the plurality of auxiliary machines 22. Here, the control device 30 in this embodiment is not particularly limited, but refers to a collection of a plurality of electronic control units (ECUs), and the plurality of electronic control units include, for example, a device integrated with the fuel cell 12. It includes a fuel cell ECU that is installed in the system, a battery ECU that is integrated with the battery 14, a system ECU that centrally controls these ECUs, and the like.

As described above, the traveling motor 18 can brake the wheels 2 by supplying regenerative power to the battery 14. However, for example, when the battery 14 is fully charged, the regenerated power generated by the driving motor 18 cannot be stored in the battery 14. In this case, the vehicle 10 cannot be regeneratively braked. In order to avoid such a situation, the control device 30 is configured to execute surplus power consumption control when the remaining charging capacity of the battery 14 falls below a predetermined level. In the surplus power consumption control, at least a portion of the regenerated power is made into surplus power, which is consumed by the plurality of auxiliary machines 22. As a result, even if the battery 14 is fully charged or close to being fully charged and the regenerative power generated by the driving motor 18 cannot be stored in the battery 14, regenerative braking of the vehicle 10 can be prevented from becoming impossible.

Regarding surplus power consumption control, for example, when the vehicle 10 starts uphill, the vehicle 10 may temporarily move backward and then move forward. In this case, while the vehicle 10 is moving backward, the traveling motor 18 generates regenerative power, so surplus power consumption control is executed as necessary. Thereafter, when the vehicle 10 begins to move forward, the driving motor 18 starts consuming power, so the fuel cell 12 starts generating electricity as necessary. During this time, the vehicle 10 travels at an extremely low speed, so if there is a fluctuation in the power supplied to the driving motor 18, the fluctuation is likely to be strongly reflected in the behavior (particularly the speed) of the vehicle 10. In such a state, when the operation of the fuel cell 12 is started, the behavior of the vehicle 10 may become unstable until the power generated by the fuel cell 12 becomes stable.

Regarding the above problem, in the surplus power consumption control in this embodiment, first, a process of detecting the vehicle speed, which is the speed of the vehicle 10, is executed, and then one or more auxiliary equipment 22 is detected based on the surplus power and the vehicle speed. A process of setting a power value that should be consumed by the fuel cell 12 (hereinafter referred to as a consumption request value) and a power value that the fuel cell 12 should generate (hereinafter referred to as a power generation request value) is executed. In particular, when the vehicle speed is lower than a predetermined threshold value (first speed D described later) and is judged to be extremely slow, the consumption request value for one or more auxiliary equipment 22 is set to a value larger than the surplus power. be done. Then, the power generation request value for the fuel cell 12 is set according to the difference between the consumption request value and the surplus power. That is, when the vehicle speed is extremely low, even if there is surplus power, the auxiliary equipment 22 consumes more power, so that the fuel cell 12 generates power.

Therefore, for example, when the vehicle 10 starts on a slope, power generation by the fuel cell 12 is started from the stage when the vehicle 10 is moving backward. In this way, if power generation by the fuel cell 12 is started in advance before the direction of travel of the vehicle 10 is switched, the operation of the fuel cell 12 can be stabilized by the time the direction of travel of the vehicle 10 is subsequently switched. be able to. Thereby, it is possible to avoid fluctuations in the power supplied to the traveling motor 18 and to stabilize the behavior of the vehicle 10.

An example of the surplus power consumption control described above will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing the flow of surplus power consumption control executed by the control device 30. FIG. 3 is a graph showing the power generation request value FC_RQ set by the surplus power consumption control in relation to the vehicle speed (V). First, in step S12, the control device 30 determines whether the allowable charging power Win of the battery 14 is larger than a predetermined threshold value A. Note that the allowable charging power Win is an index indicating the upper limit of the charging power that the battery 14 can allow, and is adjusted as appropriate depending on, for example, the temperature of the battery 14, mainly for the purpose of protecting the battery 14. Although not particularly limited, the allowable charging power Win in this embodiment is an index that is always negative, and the smaller the value of the allowable charging power Win is, the larger the allowable charging power is, and the larger the remaining charging capacity of the battery 14 is. means. If the allowable charging power Win is larger than the predetermined threshold A (YES in step S12), the control device 30 determines that the remaining charging power of the battery 14 is relatively small, and proceeds to the process of step S14. On the other hand, if not (NO in step S12), the control device 30 determines that the battery 14 has sufficient remaining charging capacity, and proceeds to the process of step S18.

Proceeding to step S14, the control device 30 determines whether the charge amount SOC of the battery 14 is larger than a predetermined threshold value B. If the amount of charge SOC is larger than the predetermined threshold B (YES in step S14), the control device 30 determines that the remaining charging capacity of the battery 14 is relatively small, and proceeds to the process of step S16. On the other hand, if not (NO in step S14), the control device 30 determines that the battery 14 has sufficient charging capacity, and proceeds to the process of step S18. Through the above steps S12 and S14, the control device 30 determines whether or not the remaining charging capacity of the battery 14 is below a predetermined level from the viewpoints of both the allowable charging power Win and the charging amount SOC.

Proceeding to step S16, control device 30 determines whether vehicle power VP is a negative value. Here, the vehicle power VP is an index indicating the power value obtained by subtracting the charge/discharge request value BAT_RQ from the sum of the motor drive power and the vehicle maintenance power. The motor drive power is the drive power supplied to the travel motor 18, and when the motor drive power has a negative value, it means that the travel motor 18 generates regenerative power. Vehicle maintenance power is power required by the plurality of auxiliary machines 22 and the like in order to maintain the normal operation of the vehicle 10. The charge/discharge request value BAT_RQ is an index indicating the power value at which the battery 14 should be charged or discharged.If the charge/discharge request value BAT_RQ is a negative value, it indicates that the battery 14 should be charged, If the request value BAT_RQ is a positive value, it indicates that the battery 14 should be discharged. Therefore, when the vehicle power VP takes a negative value, it means that the traveling motor 18 is generating regenerative power, and at least a part of the regenerative power is surplus power. If vehicle power VP is a negative value (YES in step S16), control device 30 determines that it is necessary to execute surplus power consumption control, and proceeds to the process of step S30. On the other hand, if not (NO in step S16), the control device 30 determines that surplus power consumption control is unnecessary, and proceeds to the process of step S18.

Proceeding to step S30, the control device 30 sets the charge/discharge request value BAT_RQ to zero. That is, charging and discharging by the battery 14 is prohibited. Note that, as will be understood from other embodiments described later, the charging/discharging request value BAT_RQ does not necessarily need to be set to zero, and discharging by the battery 14 may be allowed as necessary.

In the next step S32, the control device 30 detects the vehicle speed V, which is the speed of the vehicle 10, and determines whether the detected vehicle speed V exceeds a predetermined first speed D. If the vehicle speed V exceeds the first speed D (YSE in step S32), the control device 30 determines that the vehicle speed V is not extremely low, and proceeds to the process of step S34. In step S34, the control device 30 sets the consumption request value AUX_RQ to a value equal to the surplus power, similar to known surplus power consumption control. That is, the relationship AUX_RQ=VP×(-1) holds true. Next, in step S36, the control device 30 sets the power generation request value FC_RQ to zero. Here, the consumption request value AUX_RQ is an index indicating the electric power value that one or more auxiliary machines 22 should consume, and the power generation request value FC_RQ is an index indicating the electric power value that the fuel cell 12 should generate.

On the other hand, if the vehicle speed V is lower than the first speed D or equal to the first speed D (NO in step S32), the control device 30 determines that the vehicle speed V is extremely low and proceeds to the process of step S38. move on. In step S38, the control device 30 sets the consumption request value AUX_RQ to a predetermined fixed value FIX. This fixed value FIX is set to a value larger than the expected surplus power. Note that the consumption request value AUX_RQ set here does not necessarily have to be a fixed value FIX, but may be a value that changes according to one or more indicators as long as it is larger than the expected surplus power. Good too. Next, in step S40, the control device 30 sets the power generation request value FC_RQ to a value equal to the difference between the consumption request value AUX_RQ and the surplus power (-VP). That is, the relationship FC_RQ=VP+AUX_RQ holds true.

Through the above processing, the charging/discharging request value BAT_RQ, the consumption request value AUX_RQ, and the power generation request value FC_RQ for surplus power consumption control are respectively set. The control device 30 controls the fuel cell 12, battery 14, inverter 16, etc. based on the set request values. As a result, surplus power consumption control is actually executed.

On the other hand, in the processing of steps S12, S14, and S16, if it is determined that surplus power consumption control is unnecessary, the control device 30 proceeds to step S18. In step S18, control device 30 sets charge/discharge request value BAT_RQ as a function of vehicle power VP, for example. That is, the relationship BAT_RQ=f(VP) holds true. In the next step S20, the control device 30 sets the consumption request value AUX_RQ to zero. Next, the control device 30 proceeds to step S22 and determines the power generation request value FC_RQ. The power generation request value FC_RQ at this time is not particularly limited, but can be set to a value equal to the vehicle power VP. Note that when the vehicle power VP is a negative value, it is preferable to set the power generation request value FC_RQ to zero.

The series of processes shown in FIG. 3 has been described above as an example of surplus power consumption control executed by the control device 30. According to this series of processing, as mentioned above, when the vehicle speed V is lower than the first speed D, even if there is surplus power (that is, VP<0), more power is used by the auxiliary equipment. 22, power generation by the fuel cell 12 is implemented. Therefore, as shown in FIG. 3, for example, when the vehicle 10 starts on a slope, the power generation request value FC_RQ is set to a non-zero value and power generation by the fuel cell 12 is started from the stage when the vehicle 10 is moving backward. Ru. As a result, when the vehicle speed V is extremely low (range Operation can be stabilized. Thereby, it is possible to avoid fluctuations in the power supplied to the traveling motor 18 and to stabilize the behavior of the vehicle 10.

Next, with reference to FIG. 4, another example of surplus power consumption control that can be employed in the control device 30 of the vehicle 10 described above will be described. In addition, in the series of processes shown in FIG. 4, the same reference numerals are given to the same parts as those in FIG. 2 to avoid redundant explanation. First, since the processing from steps S12 to S22 shown in FIG. 4 is the same as the processing from steps S12 to S22 shown in FIG. 2, a description thereof will be omitted.

In step S16, if the vehicle power VP is a negative value (YES in step S16), the control device 30 determines that it is necessary to execute surplus power consumption control, and proceeds to the process of step S102. In step S102, the control device 30 detects a vehicle speed V, which is the speed of the vehicle 10, and determines whether the detected vehicle speed V exceeds a predetermined second speed C. If the vehicle speed V exceeds the second speed C (YSE in step S102), the control device 30 determines that the vehicle speed V is not extremely low, and sequentially executes the processes of steps S30, S34, and S36. The processes of these steps S30, S34, and S36 are the same as the processes of steps S30, S34, and S36 shown in FIG. 2, so a redundant explanation will be omitted here. That is, when the vehicle speed V exceeds the second speed C, normal surplus power consumption control is executed. Here, the second speed C may be the same as the first speed D described above, or may be a different value from the first speed D.

On the other hand, in step S102, if the vehicle speed V is lower than or equal to the second speed C (NO in step S102), the control device 30 determines that the vehicle speed V is extremely low, and steps The process advances to S104.

In step S104, the control device 30 sets a non-zero positive value to the charge/discharge request value BAT_RQ. In this case, although not particularly limited, the charge/discharge request value BAT_RQ may be a value that changes depending on the vehicle speed V. That is, the relationship BAT_RQ=f(V) may hold true. In this specification, when the charge/discharge request value BAT_RQ is a positive value, the charge/discharge request value BAT_RQ may be simply referred to as the discharge request value BAT_RQ. For example, setting the discharge request value BAT_RQ to a non-zero value means setting the charge/discharge request value BAT_RQ to a non-zero positive value on the premise that the battery 14 is to be discharged.

In the next step S106, the control device 30 determines whether the allowable discharge power Wout of the battery 14 is smaller than a predetermined threshold value E. Note that the allowable discharge power Wout is an index indicating the upper limit of the discharge power that the battery 14 can allow, and is adjusted as appropriate depending on, for example, the temperature of the battery 14, mainly for the purpose of protecting the battery 14. If the allowable discharge power Wout is smaller than the predetermined threshold E (YES in step S106), the control device 30 determines that the allowable discharge power Wout is relatively small, and proceeds to the process of step S108. On the other hand, if not (NO in step S106), the control device 30 proceeds to the process of step S34.

In step S108, the control device 30 temporarily increases the allowable discharge power Wout. The allowable discharge power Wout may be set to a relatively small value depending on, for example, the temperature of the battery 14. In this case, even if the above-mentioned discharge request value BAT_RQ is set for the battery 14, the actual discharge power by the battery 14 may be unintentionally limited by the allowable discharge power Wout. In order to avoid such a situation, in the process of step S108, the allowable discharge power Wout, which is the upper limit of the discharge power, is temporarily relaxed. Note that since the situation in which the vehicle speed V is lower than the second speed C is temporary, even if the allowable discharge power Wout is relaxed, the effect on the battery 14 is relatively small. After that, the control device 30 proceeds to the process of step S34.

In the process of step S34, as in the process of step S34 described above, vehicle power with the sign reversed is set to the consumption request value AUX_RQ. That is, the relationship AUX_RQ=VP×(-1) holds true. However, in the process of step S34 described above, the discharge request value BAT_RQ was set to zero, so the consumption request value AUX_RQ was set to a value equal to the surplus power. On the other hand, in the process of step S34 described here, since the discharge request value BAT_RQ is set to a non-zero value, the consumption request value AUX_RQ includes the set discharge request value BAT_RQ in addition to the surplus power. will be added. Finally, in step S36, the control device 30 sets the power generation request value FC_RQ to zero.

Through the above processing, the charging/discharging request value BAT_RQ, the consumption request value AUX_RQ, and the power generation request value FC_RQ for surplus power consumption control are respectively set. The control device 30 controls the fuel cell 12, battery 14, inverter 16, etc. based on the set request values. As a result, surplus power consumption control is actually executed.

In the surplus power consumption control shown in FIG. 4, when the vehicle speed V is lower than the second speed C, even if surplus power is generated, the power exceeding the surplus power is consumed by the auxiliary equipment 22, so that the battery 14 is not discharged. Implemented. Therefore, for example, when the vehicle 10 starts on a slope, discharging by the battery 14 is started from the stage when the vehicle 10 is moving backward. As a result, even if an error occurs between the consumption request value AUX_RQ set for the auxiliary machine 22 and the actual power consumption value by the auxiliary machine 22, the discharge power of the battery 14 is passively adjusted accordingly. By varying, the influence on the traveling motor 18 can be avoided or suppressed. In this manner, by starting discharging by the battery 14 in advance before the traveling direction of the vehicle 10 is switched, an error in power consumption by the auxiliary machine 22 can be tolerated. As a result, the behavior of the vehicle 10 can be stabilized even in a situation where the vehicle 10 travels at an extremely low speed.

Next, with reference to FIG. 5, yet another example of surplus power consumption control that can be employed in the control device 30 of the vehicle 10 will be described. The surplus power consumption control shown in FIG. 5 is a combination of the surplus power consumption control shown in FIG. 2 and the surplus power consumption control shown in FIG. 4. In the series of processes shown in FIG. 5, the same reference numerals are given to the same parts as those in FIGS. 2 and 3. First, the processing from steps S12 to S22 shown in FIG. 5 is the same as the processing from steps S12 to S22 shown in FIGS. 2 and 3, so a description thereof will be omitted.

In step S16, if the vehicle power VP is a negative value (YES in step S16), the control device 30 determines that it is necessary to execute surplus power consumption control, and proceeds to the process of step S102. The processing from step S102 to step S32 is generally the same as the surplus power consumption control shown in FIG. In step S102, the control device 30 detects a vehicle speed V, which is the speed of the vehicle 10, and determines whether the detected vehicle speed V exceeds a predetermined second speed C. If the vehicle speed V exceeds the second speed C (YSE in step S102), the control device 30 determines that the vehicle speed V is not extremely low, and proceeds to step S32.

On the other hand, in step S102, if the vehicle speed V is lower than or equal to the second speed C (NO in step S102), the control device 30 determines that the vehicle speed V is extremely low, and steps The processes of S104, S106, and S108 are executed in order. The processing at these steps S104, S106, and S108 is the same as the processing at steps S104, S106, and S108 shown in FIG. That is, in step S104, the discharge request value BAT_RQ is set to a value other than zero, and in steps S106 and S108, the allowable discharge power Wout is temporarily relaxed as necessary. After that, the control device 30 proceeds to the process of step S32.

In step S32, the control device 30 determines whether the vehicle speed V exceeds a predetermined first speed D. If the vehicle speed V exceeds the first speed D (YSE in step S32), the control device 30 determines that the vehicle speed V is not extremely low, and sequentially executes the processes of steps S34 and S36. The processing in these steps S34 and S36 is the same as the processing in steps S34 and S36 shown in FIGS. 2 and 4. That is, in step S34, consumption request value AUX_RQ is set according to vehicle power VP, and in step S36, power generation request value FC_RQ is set to zero. Note that if the discharge request value BAT_RQ is set to a value other than zero in the previous step S104, the consumption request value AUX_RQ set in step S34 is a value larger than the surplus power by the discharge request value BAT_RQ. is set to

On the other hand, if the vehicle speed V is lower than the first speed D or equal to the first speed D (NO in step S32), the control device 30 determines that the vehicle speed V is extremely low and performs steps S38 and S40. Execute processing in order. The processing in these steps S38 and S40 is the same as the processing in steps S38 and S40 shown in FIG. That is, in step S38, the consumption request value AUX_RQ is set to a predetermined fixed value FIX, and in step S40, the power generation request value FC_RQ is set to a value equal to the difference between the consumption request value AUX_RQ and the surplus power (-VP). Ru. Furthermore, in the previous step S104, if the discharge request value BAT_RQ is set to a value other than zero, the set discharge request value BAT_RQ is added to the surplus power (-VP) here.

As described above, the surplus power consumption control shown in FIG. 5 includes the characteristics of the two surplus power consumption controls shown in FIGS. 2 and 4, and has the effects of each of these two surplus power consumption controls. . Therefore, according to the surplus power consumption control shown in FIG. 5, the behavior of the vehicle 10 can be controlled even when the traveling direction of the vehicle 10 is changed, such as when starting on a slope, and the vehicle 10 is traveling at an extremely low speed. can be stabilized.

2: Wheels 10: Vehicle 12: Fuel cell 14: Battery 16: Inverter 18: Motor generator 20: DC/DC converter 22: Auxiliary equipment 30: Control device

Claims (10)

generator and
a battery that stores the power generated by the generator;
a motor generator for driving that drives wheels using discharged power from the battery and brakes the wheels by supplying regenerative power to the battery;
at least one auxiliary machine;
a control device capable of executing surplus power consumption control in which at least a portion of the regenerated power is used as surplus power to be consumed by the at least one auxiliary device when the remaining charge capacity of the battery is below a predetermined level; And,
The surplus power consumption control includes:
A process of detecting a vehicle speed that is the speed of the vehicle;
a process of setting a consumption request value indicating a power value to be consumed by the at least one auxiliary device and a power generation request value indicating a power value to be generated by the generator, based on the surplus power and the vehicle speed; , including;
When the vehicle speed is lower than a first speed, the consumption request value is set to a value larger than the surplus power, and the power generation request value is set according to a difference between the consumption request value and the surplus power. Re,
When the vehicle speed exceeds the first speed, the consumption request value is set to a value equal to the surplus power, and the power generation request value is set to zero.
vehicle. When the vehicle speed is equal to the first speed, the consumption request value is set to a value larger than the surplus power, and the power generation request value is set according to a difference between the consumption request value and the surplus power. The vehicle according to claim 1 . The vehicle according to claim 1 or 2 , wherein a value larger than the surplus power, which is set as the consumption request value, is a predetermined fixed value. The surplus power consumption control further includes processing for setting a discharge request value indicating a power value to be discharged from the battery based on the vehicle speed,
When the vehicle speed is lower than the second speed, the discharge request value is set to a value other than zero, and in the process of setting the consumption request value and the power generation request value, the set discharge request value is set to a value other than zero. 4. A vehicle according to any one of claims 1 to 3 , which is added to the electric power. The vehicle according to claim 4 , wherein the discharge request value is set to zero when the vehicle speed exceeds the second speed. When the vehicle speed is equal to the second speed, the discharge request value is set to a value other than zero, and in the process of setting the consumption request value and the power generation request value, the set discharge request value is set to a value other than zero. The vehicle according to claim 4 or 5 , wherein the vehicle is added to surplus power. The vehicle according to any one of claims 4 to 6 , wherein the non-zero value set to the discharge request value is determined according to the value of the surplus power. Claims 4 to 7 , wherein the surplus power consumption control further includes processing for temporarily relaxing an upper limit value of discharge power set for the battery when the vehicle speed is lower than the second speed. A vehicle described in any one of the following. 9. A vehicle according to any one of claims 4 to 8 , wherein the first speed is greater than the second speed. The vehicle according to any one of claims 1 to 9 , wherein the generator is a fuel cell.

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