JP3050072B2 - Generator control device for hybrid electric vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid electric vehicle equipped with an engine and a motor, and more particularly to a generator control device for controlling a generator driven by an engine and supplying electric power to a motor and a battery.

[0002]

2. Description of the Related Art In a system configuration called a series hybrid vehicle (SHV) among hybrid electric vehicles, driving power is supplied to a vehicle driving motor not only from a vehicle-mounted battery but also from a vehicle-mounted engine driving generator. The engine-driven generator includes an engine and a generator driven by the engine, and the power output of the generator can be supplied to both the battery and the motor. In addition, WOT (wide open throttle)
, It becomes possible to control the number of revolutions of the engine only by the field current of the generator, which is the load, and therefore the power output of the generator can be controlled by the field current. Further, the fuel efficiency and emission can be improved by the WOT operation.

[0003]

In particular, in the technique proposed by the applicant of the present invention in Japanese Patent Application No. 5-23747, the motor output is first detected and smoothed in a certain control cycle. Further, the power generation output of the generator in the next control cycle is controlled based on the control target value set according to the obtained smoothed value (average value or the like). By performing such control, the charge / discharge balance of the battery can be substantially balanced, and therefore the state of charge (SO
Since C) can be maintained within a substantially predetermined range, it is possible to realize a longer battery life and a reduction in the frequency of charging by an external power supply. In addition, the detected value of the motor output is not used as it is as the control target of the power output of the generator, but is used as a control target of the power output of the generator after performing processing such as smoothing on the detected value of the motor output. As a result, it is possible to suppress engine speed fluctuations, thereby improving engine emissions, and achieve a drive feeling similar to that of a gasoline engine vehicle.

[0004] However, only by such a method,
Problems due to motor and generator rating settings may occur. In other words, only the maximum power generation output value of the generator can be set as the control target of the power generation output at most. Therefore, when the smoothed value of the motor output detection value exceeds the maximum power generation output of the generator, the maximum power generation output of the generator and the control Discharge from the battery must be responsible for the difference between the target values, and the charge / discharge balance of the battery will be unbalanced toward the discharge side. This impairs the advantages of extending the life of the battery and suppressing the frequency of charging by an external power supply, and in a remarkable case, lowers the battery voltage and motor output due to overdischarge of the battery.

[0005] To overcome this problem, the maximum power output of the generator may be set to a value larger than, or at least about the same as, the maximum output of the motor. However, such a setting is not rational in terms of miniaturization of a generator and a battery. In other words, the frequency at which the motor must be driven by large power is not so high in daily use, so the generator rating should be set to satisfy the cruising performance required for the vehicle. In addition to miniaturization of the machine, it is reasonable in terms of miniaturization of the battery that receives the power generation output. On the other hand, if high acceleration is required, the motor must be designed to be driven with high power. As described above, the generator rating required according to the cruising performance is usually set to a value as small as about 1/3 of the rating of the motor set according to the required acceleration performance. On the premise of such a rating setting, the above-described imbalance in the charge and discharge balance of the battery has conventionally been difficult to avoid.

Further, the engine has an area where WOT operation cannot be performed. That is, when the required output to the motor is small, the required output cannot be covered by the engine-driven generator alone unless the throttle of the engine is closed. When the throttle is closed, the required output is deviated from the WOT line, so that fuel efficiency is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when the smoothed value of the motor output exceeds the maximum power output of the engine-driven generator, the discharge output of the battery is reduced. By focusing on the control, the imbalance in the charge and discharge balance of the battery can be further reduced while keeping the generator and battery small, thereby achieving a longer battery life and a reduction in the frequency of charging by an external power supply. ,
A first object is to prevent a decrease in battery voltage and a decrease in motor output due to overdischarge of the battery. The present invention reduces the noise and the uncomfortable feeling on the drive feeling by controlling the power generation output immediately after shifting from high-load running with a large motor output to medium-low load running with a small motor output, and reduces the battery voltage. It is a second object to prevent the occurrence of loss and activation of the voltage protection function due to the rise of the voltage. The present invention is to control the power generation output during transition from high-load running to medium-low load running, etc., to prevent discomfort caused by a large increase in power generation output when the motor output is greatly reduced. This is the purpose of 3. According to the present invention, when the smoothed value of the motor output falls below the minimum power generation output at which the engine can be operated with high efficiency, control of the power generation output of the engine-driven generator prevents the engine from operating at low efficiency and deteriorates fuel efficiency. A fourth object is to prevent the above and the like, and to balance the charge and discharge balance of the battery.

[0008]

In order to achieve the above object, a generator control device according to the present invention is arranged such that a power generation output in a current control cycle is determined based on a smoothed value of an index value of a motor output in a previous control cycle. Means for setting a control target for
Means for determining whether the set control target is higher or lower than the maximum power output that can be supplied from the generator, and if it is determined to exceed, while reducing and correcting the control target to be equal to or less than the maximum power output, A means for adding a value obtained by subtracting the control target after the decrease correction from the control target before the decrease correction to the variable for charge / discharge balance management, and when it is determined that the control target is less than the value obtained by subtracting the above-mentioned control target from the maximum power generation output. And a means for controlling the power output of the generator in accordance with the control target.

The generator control device of the present invention has the above-described setting.
When the control objectives is below the maximum power output,
Reduced motor power consumption have a value below the maximum power output
Noise when power generation output increases despite
To suppress the feeling of increase in
In order to prevent the control target after the addition correction from exceeding the power generation target limit value for controlling the control target, means for limiting the amount of addition to the set control target is provided.

The generator control device of the present invention has the above-described setting.
When the control objectives is below the maximum power output, the
The control target after the addition correction is the difference between the power generation output and the motor output.
Power generation target increase limit set to be within specified limits
It is characterized by comprising means for limiting the amount of addition to the set control target so as not to increase by more than the value .

The generator control device according to the present invention includes means for determining whether a set control target is higher or lower than a minimum power generation output capable of operating the engine with high efficiency, and, if determined to be lower, the control target. Means for forcibly setting to 0 or a value equal to or more than the minimum power generation output, and adding a value obtained by subtracting the control target after the forcible setting from the control target before the forcible setting to the charge / discharge balance management variable. In this case, there is provided a means for reducing the charge / discharge balance management variable by an amount equal to or less than the value obtained by subtracting the control target from the maximum power generation output, and adding the control target to the reduced amount.

[0012] generator control apparatus of the present invention, the control period immediately before that motor output falls below the minimum power output substantially
Means for detecting based on the index value of the motor output in the above, means for idling or stopping the engine when it is detected that the motor output has fallen below, and the above-mentioned index indicating that the motor output has substantially exceeded the minimum power generation output. It is characterized by comprising means for detecting based on the value, and means for forcibly setting the control target to a value equal to or higher than the minimum power generation output when exceeding the value is detected.

[0013]

In the present invention, first, a control target of the power generation output in the current control cycle is set based on the index value smoothed value of the motor output in the immediately preceding control cycle. The set control target is compared with the maximum power output that can be supplied from the generator. As a result, if it is determined that the output exceeds the control target, the control target is reduced and corrected so as to be equal to or less than the maximum power generation output. A value obtained by subtracting the control target after the decrease correction from the control target before the decrease correction is added to the variable for charge / discharge balance management. When the control of the power generation output is executed according to the corrected control target,
The charge / discharge balance of the battery temporarily tilts toward the discharge side. This imbalance is compensated in a later control cycle. That is, when it is determined that the control target set based on the smoothed value of the index value of the motor output is lower than the maximum power generation output, the value of the charge / discharge balance management variable is reduced, and the control target is increased and corrected by the reduced amount. You. When the power generation control is performed based on this control target, the battery discharge generated in the previous control cycle is compensated, and as a result, the charge / discharge balance of the battery is corrected to a balance closer to the balanced state from the previous discharge side. As described above, in the present invention, the imbalance of the charge / discharge balance of the battery is reduced, so that effects such as prolonging the life of the battery, suppressing the frequency of charging by the external power supply, and preventing overdischarge of the battery are generated. Also, the size of the generator and the battery is not increased.

In the present invention, the amount of correction for increasing the control target of the power generation output is limited in the control cycle in which the battery discharge is to be compensated.

First, by limiting the increase correction amount, the control target is prevented from exceeding the allowable output. This allowable output is set to a value equal to or less than the maximum power generation output. In this case, for example, in a control cycle in which the motor output is lower than the immediately preceding control cycle, such as immediately after shifting from high-load running to medium-low-load running, the power generation target, and thus the power generation output increases. The appearance of noise is prevented. This leads to a reduction in discomfort in driving feeling. Further, when the battery voltage rises with an increase in the power generation output, a loss occurs due to a decrease in the charging efficiency of the battery. In the present invention, such a loss is also prevented. Further, in the case where a system configuration in which power generation is stopped when the battery voltage rises is adopted from the viewpoint of preventing overcharging of the battery and generation of gas in the battery, activation of such a protection function can be prevented.

Second, by limiting the increase correction amount, the increase amount of the control target is prevented from exceeding the allowable increase amount. In this case, even when the motor output is greatly reduced compared to the immediately preceding control cycle, such as when shifting from high load traveling to medium to low load traveling, for example, the power generation target, and thus the power generation output There is no discomfort because no sudden increase occurs.

In the present invention, it is determined whether the control target set based on the smoothed value of the index value of the motor output is higher or lower than the minimum power generation output capable of operating the engine with high efficiency. If it is determined to be lower, the control target is forcibly set to 0 or a value equal to or higher than the minimum power generation output. At the same time, the difference between the control target before the forcible setting and the control target after the forcible setting, that is, the newly generated imbalance of the charge / discharge balance is integrated into the charge / discharge balance management variable. Therefore, the engine is controlled to either the high-efficiency operation state or the stopped (or idling) state, so that the engine is not operated with low efficiency, and deterioration of fuel efficiency and the like are prevented. If it is determined that the value exceeds the value, the value of the charge / discharge balance management variable is reduced, and the control target is corrected by the reduced amount. As a result, a difference is generated between the motor output and the power generation output in accordance with the power generation target correction when the motor output decreases, and even if the charging / discharging balance of the battery is temporarily inclined to the discharging side or the charging side, the imbalance is maintained. Is resolved early.

In the present invention, alternatively, the motor output is compared with the minimum power generation output, and if the former can be considered to be substantially lower than the latter, the engine is idling or stopped. Thereafter, when the motor output substantially exceeds the minimum power generation output, the power generation control is executed with a target value equal to or higher than the minimum power generation output. Therefore, in the present invention, since the engine is controlled to either the high-efficiency operation state or the stop or idling state, the engine is not operated at low efficiency, and deterioration of fuel efficiency and the like are prevented. . Further, since the engine is idling or stopped based on the index value of the motor output instead of the smoothed value of the index value of the motor output, the period during which the motor output decreases and the period during which the engine is idling or stopping match. This makes it possible to prevent the engine noise from appearing and, consequently, the drive feeling from deteriorating.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an S suitable for practicing the present invention.
The system configuration of the HV is shown. In this system, a three-phase AC motor is used as a motor 10 for driving the vehicle, and an output shaft of the motor 10 is driven by a driving wheel 1 via a differential gear (diff) 12 and other mechanisms.
4.

As a drive power source for the motor 10, a battery 16 and an engine drive generator 18 are mounted.
Both the discharge output of the battery 16 and the output of the engine-driven generator 18 are DC power, and are supplied to the motor 10 after being converted into three-phase AC by the inverter 20.
The power output of the engine-driven generator 18 is also used for charging the battery 16. Further, when the vehicle is regeneratively braked, the battery 16 is charged by the electric power regenerated by the motor 10.

The engine-driven generator 18 is composed of an engine 22 exclusively driven by WOT and a generator 24 driven by the engine 22. That is, the output of the engine 22 is supplied to the generator 24 after being increased to a rotation speed suitable for the generator 24 by the speed increaser 26. When the field current If is supplied to the generator 24 in this state, a power generation output is obtained from the generator 24. In this figure, a three-phase AC generator is used as the generator 24, and the generated output is rectified by a rectifier 28 at the subsequent stage and then supplied to the inverter 20 and the battery 16.

The output of the motor 10 and the engine-driven generator 1
The power generation output 8 and the SOC of the battery 16 are controlled or managed by the controller 30. The controller 30 includes a motor controller 32 that controls the motor 10 and a generator controller 34 that controls the engine generator 18. These motor controller 32 and generator controller 34
In the operation, information is appropriately exchanged with each other. further,
The SOC of the battery 16 is managed by the motor controller 3
2 and the generator controller 34 in cooperation, that is, as a control of the power generation output in accordance with the motor output.

The motor controller 32 inputs an accelerator amount, a brake amount, and the like indicating an acceleration / deceleration request from a vehicle operator, and detects a motor rotation speed N using a rotation sensor 36 attached to the motor 10. Motor controller 3
2 determines an output torque to be generated by the motor 10, that is, a torque command, based on the information. The motor controller 32 controls the motor current I based on the determined torque command and detected by the current sensor 38.
The power conversion operation by the inverter 20 is controlled with reference to M. Here, the inverter 20 is composed of a predetermined number of switching elements, and has a function of converting a DC voltage into a three-phase AC current by switching operations of these elements. Therefore, the motor controller 3
2 to the inverter 20 with the switching control signal SW
Is supplied to the motor 10 so that the current required for realizing the torque command in the motor 10 becomes the motor current IM.
Can be controlled. As will be apparent from the following description, the present invention should not be limited by the details of the operation of the motor controller 32, for example, the presence or absence of the rotation sensor 36 and the current sensor 38 and the operation algorithm of the motor controller 32.

In the system shown in FIG.
2 employs a method of operating with high efficiency, that is, in an area where fuel consumption is high and emission is low. In particular,
By operating the engine 22 generally at WOT, deterioration of fuel efficiency due to throttle operation is prevented. Also,
When the engine 22 performs the WOT operation, the output of the engine-driven generator 18 can be controlled by the field current If of the generator 24. In the system shown in this figure, the generator controller 34 controls the power output of the engine-driven generator 18 by the field current If. At this time, the generator controller 34 controls the engine 22 to feed back the power output of the engine-driven generator 18 to the control target Pg.
Input the number of rotations.

The generator controller 34 determines the control target Pg
Is determined, in addition to the above-described feedback, the output power of the motor 10 or the input power to the inverter 20 (hereinafter, these are collectively referred to as “motor power consumption Pm”. Consumption by zu) is included. The motor power consumption Pm is calculated by multiplying the above-mentioned torque command by the motor rotation speed N, or by input current Ii to inverter 20 and battery voltage V
can be obtained by multiplying by b. The generator controller 34 smoothes (averages) the motor power consumption Pm obtained as described above over a control cycle having a predetermined length T, and controls the average power consumption Pave obtained as a result in the next control cycle. Used as target Pg. The generator controller 34 controls the field current If while referring to the engine speed so that the determined control target Pg is realized as the power output of the engine-driven generator 18. In the present invention, instead of the motor power consumption Pm,
The present invention can be implemented using another index that reflects this. For example, a motor rotation speed (vehicle speed) N, a torque command, or an estimated value may be used. When the vehicle speed or the motor rotation speed N is used, the feeling is further improved.

In order to realize such control, in FIG. 1, the current sensor 40 for detecting the output current Ig of the rectifier 28, the current sensor 42 for detecting the charge / discharge current Ib of the battery 16, and the input current to the inverter 20 A current sensor 44 for detecting Ii and a voltage sensor 46 for detecting a terminal voltage Vb of the battery 16 (accordingly, a terminal voltage of the rectifier 28 and the inverter 20) are used. Current sensor 44
The product IiVb of the output of the voltage sensor 46 and the output of the voltage sensor 46 represents the motor power consumption Pm as described above, and can be used as a basis for determining the average power consumption Pave. Also, the product IgVb of the output of the current sensor 40 and the output of the voltage sensor 46
Represents the power output of the engine-driven generator 18 and can be used as a feedback amount during the target control. However, these sensors are not essential in practicing the present invention.

Incidentally, the average power consumption Pave may exceed the maximum power generation output PgMax of the engine drive generator 18, or may fall below the minimum power generation output PgMin. The maximum power output PgMax refers to the maximum power output that can be output from the engine-driven generator 18 with high efficiency due to the rating of the generator 24 and the like, and the minimum power output PgMax is the power that can be output from the engine-driven generator 18 with high efficiency. It refers to the minimum power generation output that can be output (for example, about 1/5 of PgMax). In the system described above, since the efficiency of the engine 22 is maintained by the WOT operation, the relationship between the power generation output and the engine speed, and the relationship between the maximum power output PgMax and the minimum power output PgMin and the engine speed are shown in FIG. The relationship is as follows.

Therefore, simply determining the control target Pg according to the average power consumption Pave results in insufficient power generation output and a decrease in the operating efficiency of the engine 22. For example,
In a high-load running state in which the motor power consumption Pm is remarkably large, the average power consumption Pave becomes large, so that the control target Pg may exceed the maximum power generation output PgMax. In this case, the power generation output actually obtained from the engine drive generator 18 remains at the maximum power generation output PgMax, so that the power corresponding to the difference between the control target Pg and the maximum power generation output PgMax is covered by the discharge of the battery 16. This problem,
This becomes apparent when the rating of the generator 24 is set smaller than the rating of the motor 10. Conversely, in the low-load running state where the motor power consumption Pm is remarkably small, the average power consumption Pave
Becomes smaller, the control target Pg becomes the minimum power generation output PgMi.
n. In this case, the throttle of the engine 22 must be closed in order to obtain a power output corresponding to the control target Pg from the engine-driven generator 18.
Deterioration of the operation efficiency of the engine 22 and, consequently, deterioration of fuel efficiency and the like occur.

In each of the following embodiments, if the control target Pg is simply determined in accordance with the average power consumption Pave, the control target Pg may be reduced in a situation where the power generation output is insufficient or the operating efficiency of the engine 22 is reduced. These problems are prevented or mitigated by performing a predetermined operation.

First embodiment. FIG. 3 shows a control procedure executed by the generator controller 34 in the first embodiment of the present invention. As shown in this figure, the generator controller 34 first clears the built-in timer and sample data to 0 (100), and then reduces the motor power consumption Pm for one control cycle having a predetermined length T seconds. Sampling is performed (104). When the count value of the built-in timer reaches T seconds, the generator controller 34 (10
2), motor power consumption Pm sampled so far
Is calculated (106). In this way, the average power consumption P as the basis for determining the control target Pg of the power generation output
ave is obtained.

Next, the generator controller 34 compares the average power consumption Pave with the maximum power generation output PgMax and the minimum power generation output PgMin (108). As a result, when detecting that the average power consumption Pave exceeds the maximum power generation output PgMax, the generator controller 34 integrates the difference Pave-PgMax between the variables Pd for managing the charge / discharge balance of the battery 16 ( 110), the power generation output of the engine generator 18 is controlled using the maximum power generation output PgMax as the control target Pg (112). That is,
If the average power consumption Pave exceeds the maximum power generation output PgMax, the engine drive generator 18 cannot realize this even if the average power consumption Pave is used as the control target Pg as it is, so in this case, the maximum power generation output PgM
ax is set to the control target Pg to control the field current If. When the engine-driven generator 18 is controlled with the maximum power generation output PgMax as the control target Pg, Pave-P
Since the electric power corresponding to gMax is carried by the discharge of the battery 16 and the charge / discharge balance thereof is inclined toward the discharge side, Pave-PgMax is set as the management variable Pd in order to quantitatively handle the degree of inclination toward the discharge side. Integrate.

In step 108, the average power consumption Pa
When it is detected that ve falls below the minimum power generation output PgMin, the generator controller 34 integrates the average power consumption Pave with the management variable Pd (114), and the control target Pg
Is set to 0 to control the engine-driven generator 18 (11
6). That is, when the average power consumption Pave is lower than the minimum power generation output PgMin, the average power consumption Pave
If the engine drive generator 18 is controlled with the ve as it is as the control target Pg, the throttle of the engine 22 must be controlled to the closed side, resulting in a decrease in efficiency. In this case, the engine 22 is idled or stopped and the field current is reduced. By controlling If to 0, the output of the engine-driven generator 18 is controlled to 0. As a result, deterioration of fuel efficiency due to low-efficiency operation can be avoided. When the power output of the engine-driven generator 18 is controlled to 0, Pa
Since the power corresponding to ve is carried by the discharge of the battery 16 and the charge / discharge balance thereof is inclined toward the discharge side, the average power consumption Pave is integrated into the management variable Pd.

In step 108, the average power consumption Pa
ve is greater than or equal to the minimum power generation output PgMin and the maximum power generation output PgM
ax or less, the generator controller 34 sets the control target Pg by using the amount integrated in the management variable Pd in the previous processing, thereby setting the battery 16 in the previous processing. The charge / discharge balance compensates for the inclination to the discharge side. Specifically, the sum of the average power consumption Pave and the value of the management variable Pd is determined as an addition value Pref (11).
8) Using this as the control target Pg of the power generation output, the engine drive generator 18 is controlled (120). As a result, the battery 16 is charged with the amount of power corresponding to the power accumulated by the management variable Pd. Therefore, the integrated value of the shortage of the power generation output generated in the previous process, that is, the portion of the motor power consumption Pm covered by the discharge of the battery 16 is compensated, and the charge and discharge balance of the battery 16 is changed. Returns to a balanced state. Also, in order to reflect the balance between charge and discharge, the control variable Pd is also reset to 0 at the time of execution of step 120 (12).
2).

However, only the processing of steps 118 to 122 cannot cope with the case where the addition value Pref exceeds the maximum power generation output PgMax. That is, when the addition value Pref exceeds the maximum power generation output PgMax, the addition value Pref is set as the control target Pg and the engine-driven generator 18 is used.
Is controlled, this control target Pg cannot be realized. Therefore, in this embodiment, steps 122 and 12
Prior to 0, the addition value Pref is compared with the maximum power generation output PgMax (124). As a result, if the addition value Pref is equal to or less than the maximum power generation output PgMax, the above-described step 1 is performed.
Steps 22 and 120 are executed. Conversely, if the added value Pref exceeds the maximum power generation output PgMax, the control target P
Step 11 to limit g to the maximum power generation output PgMax
2 is executed. At this time, step 110 is also executed, and the power PgMax-Pave corresponding to the amount of power charged to the battery 16 by the current power generation is set to the management variable Pd.
Reduced from.

FIG. 4 is a timing chart showing the above control procedure. Here, control periods A, B,... Each having a predetermined length T seconds are assumed, and a situation is considered in which the motor power consumption Pm gradually decreases with temporary fluctuation. In this situation, the average power consumption Pave gradually decreases as the motor power consumption Pm decreases. Therefore, at first, the maximum power generation output PgMa
The average power consumption Pave exceeding x also becomes equal to or less than the maximum power generation output PgMax in a certain control cycle. In this embodiment, the shortage of the power generation output is compensated for in a control cycle after the control cycle in which the average power consumption Pave in the immediately preceding control cycle has started to be equal to or less than the maximum power generation output PgMax.

For example, since the average power consumption Pave in the control cycle A exceeds the maximum power generation output PgMax as shown in the column of the control cycle B, the maximum power generation output PgMax is set as the control target Pg in the control cycle B. Control is performed. At this time, the shortage Pave-PgMax is added to the management variable Pd (). Since the average power consumption Pave in the control cycle B also exceeds the maximum power generation output PgMax, the same processing is executed in the control cycle C. The average power consumption Pave in the control cycle C is equal to or less than the maximum power generation output PgMax as shown in the column of the control cycle D, but since Pref> PgMax, in the control cycle D, PgMax is set as the control target Pg, and Control is performed, and the management variable Pd to PgMax-
Pave is reduced (). The average power consumption Pave in the control cycle D is equal to or less than the maximum power generation output PgMax as shown in the column of the control cycle E.
Since ≦ PgMax, the power generation output is controlled with the Pref as the control target Pg in the control cycle E, and the management variable Pd is reset to 0 ().

As described above, according to the present embodiment, the generator 2
4 is set smaller than that of the motor 10, the deterioration of the charge / discharge balance of the battery 16 can be avoided even though the average power consumption Pave may exceed the maximum power generation output PgMax. In addition, since the throttle of the engine 22 is not closed even when the average power consumption Pave falls below the minimum power generation output PgMin, deterioration of fuel efficiency of the engine 22 due to low-efficiency operation can be prevented. Furthermore, the deviation of the charge / discharge balance that occurs when the average power consumption Pave is not in the WOT operation region, that is, in the region from the minimum power generation output PgMin to the maximum power generation output PgMax, is such that the average power consumption Pave then enters the WOT operation region. It can be solved suitably with a reduced control cycle.

Second embodiment. FIG. 5 shows a control procedure executed by the generator controller 34 in the second embodiment of the present invention. However, in this figure, only a part different from FIG. 3 is shown. In this example,
After the execution of step 106, the average power consumption Pave is compared with the minimum power generation output PgMin, the power generation target limit value PhMax, and the maximum power generation output PgMax in step 124.
However, the power generation target limit value PhMax is at least PgM
For example, the value is set to about 60% of the maximum power generation output PgMax so that in <PhMax <PgMax. As a result of this comparison, the average power consumption Pave is equal to the maximum power generation output Pg.
The operation in the case where it is detected that the output exceeds Max, or in the case where it is detected that the output falls below the minimum power generation output PgMin is the same as that of the first embodiment.

In step 124, PhMax ≦ Pa
If it is detected that ve ≦ PgMax, the first
If the same control as in the embodiment is performed, the maximum is PgMax-Pav
In this embodiment, although the charge / discharge balance of the battery 16 can be improved by an amount corresponding to e, the average power consumption Pav
The control of the engine generator 18 is performed using e as the control target Pg (126). Such control is performed to prevent an increase in noise, generation of loss, activation of the voltage protection function, and the like. That is, the processing of the first embodiment for eliminating or reducing the imbalance of the charge / discharge balance generated in the previous control cycle in the subsequent control cycle is performed by the motor as shown in the example of FIG. It is often executed in a situation where the power consumption Pm is gradually changing from a large value to a small value.
In other words, since the power output increases even though the output of the motor 10 has already decreased, the noise generated by the generator 24 often stands out. this is,
Invites a sense of incongruity in drive feeling. In addition, when the battery 16 is charged with a large amount of power, the battery voltage Vb increases, and the charging efficiency decreases. Furthermore, in order to prevent overcharging and gas generation in the battery 16, in a system having a voltage protection function of reducing the power generation output to 0 or a very small value when the battery voltage Vb rises, power generation with high power is commanded. As a result, power generation may be suspended. In this embodiment, PhMax ≦ Pav in order to realize a system with better drive feeling, lower loss, and not conflicting with the voltage protection function.
When e ≦ PgMax is satisfied, the power generation output is limited to Pave.

In step 124, PgMin ≦ Pa
When it is detected that ve <PhMax, the generator controller 34 executes Step 116 and then executes Step 128 in which PgMax in Step 124 is replaced with the power generation target limit value PhMax.
If it is determined in step 128 that Pref ≦ PhMax, the generator controller 34 determines in steps 122 and 1
Execute 20. Pref> PhM in step 128
If it is determined to be ax, the generator controller 34 replaces PgMax in Steps 110 and 112 with the power generation target limit value PhMax.
Execute Step 2. These replacements are due to the introduction of the power generation output limitation according to steps 124 and 126 in this embodiment.

As described above, according to the present embodiment, the same advantages as those of the first embodiment can be enjoyed, and an increase in noise, generation of a loss, activation of a voltage protection function, and the like can be prevented.

Third Embodiment FIG. 6 shows a control procedure executed by the generator controller 34 in the third embodiment of the present invention. In this figure, parts common to FIG. 3 or FIG. 5 are omitted.

In this embodiment, when it is detected in step 124 that PgMin ≦ Pave <PhMax, the value of the management variable Pd is compared with a predetermined power generation target increase amount limit value Ptr (134). As a result, P
When it is detected that d <Ptr, the generator controller 34 executes steps 118 to 1 in the second embodiment.
Step 118 having the same contents as steps 22 and 128 to 132
A to 122A and 128A to 132A are executed. Pd
If it is detected that ≧ Ptr, the generator controller 34 determines in steps 118 to 122 and 128 to 13
Steps 118B to 122B and 12 having the same contents as in step 2
8B to 132B are executed. However, in step 122B, the power generation target increase amount limit value Ptr is subtracted from the management variable Pd instead of resetting the management variable Pd to zero.

Therefore, in this embodiment, when the imbalance of the charge / discharge balance generated in the previous control cycle is eliminated or reduced based on the information accumulated in the management variable Pd, the increase amount of the control target Pg is reduced. Power generation target increase limit value Pt
r. Therefore, the power generation target increase amount limit value Ptr
By appropriately setting the value, the difference between the power generation output and the motor output can be prevented from widening greatly, and the uncomfortable feeling in drive feeling can be reduced. In this embodiment, the same effects as those of the first and second embodiments can be obtained.

Fourth Embodiment Note that the present invention is not limited to a configuration in which the power generation output of the engine generator 18 is controlled to be 0 when the average power consumption Pave falls below the minimum power generation output PgMin. For example, as shown in FIG.
When it is detected that ve falls below the minimum power generation output PgMin, the minimum power generation output PgMin may be set as the control target Pg in the current control cycle (138). In that case,
Since a power generation surplus corresponding to PgMin-Pave occurs, the value of the management variable Pd is reduced by PgMin-Pave (13).
6). In this case, the engine 22 is always operated in WOT except when the vehicle is stopped. Further, instead of the minimum power generation output PgMin, a higher value, for example, a control target Pg in the immediately preceding control cycle may be set as the control target Pg in the current control cycle.

Fifth embodiment. Further, as shown in FIG. 8, the engine may be idling (or stopped) immediately when the motor power consumption Pm substantially falls below the minimum power generation output PgMin. In this figure, first, the motor power consumption Pm obtained in step 104 is compared with an idling transition value Px set to a value smaller than the minimum power generation output PgMin by a very small amount of about 1 kW (140). As a result of this comparison, if Pm <Px is established, the operation from step 142 is executed, and if not, the operation from step 102 is executed.

In step 142, the generator controller 34 controls the power generation output to zero by idling the engine 22 and controlling the field current If to a predetermined value such as zero. Thereafter, the generator controller 34
Repeatedly samples motor power consumption until Pm> Py is satisfied (144) (146). This Py
Is a threshold value for returning to the WOT operation, and is set, for example, about 1 kW larger than the minimum power generation output PgMin. When Pm> Py is satisfied, the generator controller 34
Executes the control of the power generation output such that the power generation output of the engine-driven generator 18 becomes equal to or more than the minimum power generation output PgMin (148). Thereafter, the operation of the generator controller 34 returns to Step 140 or Step 100.

Such an operation, that is, the motor power consumption Pm is compared with the minimum power generation output PgMin (or values Px and Py close thereto), and if a decrease in the motor output is detected, the engine 22 immediately starts idling. By stopping (or stopping), the period during which the engine 22 is idling (or stopped) can be matched with the period during which the motor output is reduced. This prevents the noise of the engine 22 from appearing and leads to an improvement in drive feeling.

Further, the idling shift value Px and WOT
Since the hysteresis characteristic is given to the control by the return value Py, even when the motor power consumption Pm or its smoothed value fluctuates near the minimum power generation output PgMin, the operation state of the engine 22 is changed from WOT to idling or from the idling state. Conversely, it does not fluctuate frequently, and the fuel efficiency is also good in that respect. Further, since the control target used in step 148 can be, for example, the minimum power generation output PgMin or the previous power generation target Pg, the power generation output rapidly increases immediately after the idling period of the engine 22 ends, and as a result, the noise of the engine 22 It is also possible to prevent a situation in which the drive feeling is deteriorated due to the manifestation of.

Sixth embodiment. The present invention is not limited to the configuration in which the control target Pg is limited by the upper limit of the power generation target limit value PhMax as in the second embodiment. For example,
In order to limit the lower limit of the control target Pg, a new power generation target limit value PhMin is used, and the power generation target limit values PhMax and PMax are used.
hMin may limit the correction by the management variable Pd. When the average power consumption Pave falls below the minimum power generation output PgMin, the engine 22 is not simply idled or the engine drive generator 18 is operated at the minimum output power generation, but the imbalance of the charge / discharge balance is ignored as a result of the idling. The engine-driven generator 18 may be caused to perform the minimum output power generation operation at the time when it becomes impossible.

FIG. 9 shows a control procedure executed by the generator controller 34 in the sixth embodiment of the present invention. In this embodiment, in step 124, the average power consumption Pave is compared with the maximum power output PgMax and the minimum power output PgMin. As a result, PgMax
If <Pave is satisfied, steps 110 and 112 are executed in the same manner as in the above-described embodiments.

Also, PgMin ≦ Pave ≦ PgMax
Is satisfied, first, the sign of the management variable Pd is determined (150). If it is determined that the value of the management variable Pd is 0, it can be considered that the charge and discharge balance of the battery 16 is balanced.
6 is executed. When the value of the management variable Pd is positive, it can be considered that the charge / discharge balance of the battery 16 is inclined toward the discharge side.
The value obtained by adding the value of the management variable Pd to ave is the control target P
g (118C), the power generation output is controlled (120C).
C) At the same time, the management variable Pd is reset to 0 (1
22C). Thereby, the inclination of the charge / discharge balance generated in the previous control cycle toward the discharge side can be eliminated or reduced.
Conversely, when the value of the management variable Pd is negative, it can be considered that the charge / discharge balance of the battery 16 is inclined to the charging side. Therefore, in principle, the average power consumption Pave is changed to the average power consumption Pave. The value obtained by adding the values is set as the control target Pg (118D), the power generation output is controlled (120D), and the management variable Pd is reset to 0 (122D).
Thereby, the inclination of the charge / discharge balance generated in the previous control cycle toward the charge side can be eliminated or reduced.

In this embodiment, in order to continue the WOT operation when the value obtained by adding the value of the management variable Pd to the average power consumption Pave is out of the range in which the engine 22 can perform the WOT operation, in this embodiment, step 118C or step 118C is performed. 118D
After the execution, Pref is compared with the minimum power generation output PgMin and the maximum power generation output PgMax (124A, 124A).
B). When Step 118C is executed, Pref> P
When gMax is satisfied, steps 110A and 112A having the same contents as steps 110 and 112 are executed without executing steps 122C and 120C.
If Pref ≦ is satisfied at the time when step 118D is executed, steps 122D and 120D
Are not executed, steps 136A and 138A having the same contents as steps 136 and 138 are executed.

If the value of the management variable Pd is not 0, step 152 or 154 is executed. In step 152, the average power consumption Pave is compared with the power generation target limit value PhMax, and as a result, Pave ≧ Ph
If Max is satisfied, the process moves to step 126 without moving to step 118C. Thus, when the average power consumption Pave is large, steps 118C and 120C
Can be prevented from being executed, and therefore, a sudden increase in the power generation output can be prevented. Conversely, in step 154, the average power consumption Pave is reduced to the power generation target limit value PhMin.
(PgMin <PhMin <PhMax),
As a result, if Pave ≦ PhMin is satisfied, the flow shifts to step 126 without shifting to step 118D. Thus, it is possible to prevent steps 118D and 120D from being executed when the average power consumption Pave is small, thereby preventing a sharp decrease in the power generation output. These lead to an improved feeling.

In step 124, Pave <Pg
When Min is satisfied, steps 136 and 138 are executed in principle, similarly to the fourth embodiment shown in FIG. By causing the engine drive generator 18 to generate the minimum output instead of idling the engine 22 when the average power consumption Pave decreases in this manner,
The same effects as in the fourth embodiment can be obtained. However, with this alone, if the minimum output power generation continues for a long time, the battery 1
The problem that the charge / discharge balance of No. 6 gradually tilts toward the charge side remains. Therefore, in this embodiment, the engine stop threshold value PsFull having a negative value is compared with the value of the management variable Pd (156). Pd ≧ PsFull is satisfied when the value of the management variable Pd is a positive value (that is, when the charge / discharge balance is inclined to the discharge side)
Alternatively, step 138 is executed because the value is a negative value but its absolute value is not so large (that is, the charge / discharge balance is inclined to the charging side but the degree is not significant). Conversely, Pd <P
Since sFull is established when the value of the management variable Pd is a negative value and its absolute value is large (that is, when the charge / discharge balance is remarkably inclined to the charge side), sFull is satisfied. The engine 22 is stopped to prevent the occurrence of balance (158).

After the engine 22 is stopped, the generator controller 34 clears the timer to 0 and starts counting (160), and continuously samples the motor power consumption Pm (162). When the timer measures T seconds (164), the generator controller 34 calculates an average power consumption Pave for T seconds (166). At this time, since the engine 22 is stopped and the power generation output is 0, the calculated average power consumption Pave is the power generation shortage that occurred during T seconds while the engine 22 was stopped, that is, the discharge from the battery 16. It represents the amount of power. Then, the generator controller 34 reflects this discharge on the value of the management variable Pd by executing step 114. If the value of the management variable Pd is 0 or more at that time (168), it can be considered that the inclination of the charge / discharge balance toward the charging side has been eliminated, and the generator controller 34 starts the engine 22 (170). . While the value of the management variable Pd is less than 0, the generator controller 34
Returning to step 60, the aforementioned operation is executed.

Therefore, even when the motor power consumption Pm is kept low for a long time, such an operation can prevent the charge / discharge balance from remarkably leaning toward the charge side. By stopping the engine 22, fuel consumption by the engine 22 can be reduced.

[0059]

As described above, according to the present invention,
The control target of the power generation output set based on the smoothed value of the motor output in the immediately preceding control cycle is compared with the maximum power output that can be supplied from the generator. Is integrated into the control variable, and the battery discharge in the previous control cycle is determined based on the control variable in the control cycle in which the control target set based on the motor output smoothed value falls below the maximum power generation output. Since the balance is compensated, even when the generator or the battery is set to a small rating for the required acceleration performance or the like, the charge / discharge balance of the battery can be satisfactorily and quickly balanced. This can prolong the life of the battery, reduce the frequency of charging by an external power supply, and prevent the battery from being over-discharged. This can prevent a decrease in battery voltage and motor output, and prevent the generator and the battery from becoming large. be able to.

According to the present invention, since the increase correction amount is limited so that the control target does not exceed the allowable output, the immediately preceding control cycle, for example, immediately after shifting from high-load running to medium-low load running, or the like, is performed. Even in a control cycle in which the motor output is reduced and the motor noise is reduced as compared with the above, it is possible to prevent the noise from appearing due to the increase in the power generation output, and reduce the uncomfortable feeling in drive feeling. In addition, it is possible to prevent an increase in battery voltage due to an increase in power generation output, and thus, a loss due to a decrease in battery charging efficiency. Further, in the case where a system configuration in which power generation is stopped when the battery voltage rises is adopted from the viewpoint of preventing overcharging of the battery and generation of gas in the battery, activation of such a protection function can be prevented.

According to the present invention, since the increase correction amount is further limited so that the increase amount of the control target does not exceed the allowable increase amount, for example, when shifting from high-load running to medium-low load running. Even when the motor output is greatly reduced as compared with the immediately preceding control cycle as in the above case, the power generation target and, consequently, the power generation output do not suddenly increase, so that the user does not feel uncomfortable.

According to the present invention, when the control target set based on the smoothed value of the motor output is determined to be lower than the minimum power generation output capable of operating the engine with high efficiency, the control target is set to 0 or the minimum power generation. The difference between the control target before the forced setting and the control target after the forced setting is integrated into the management variable, and the value of the management variable is reduced if it is determined that the difference is exceeded. Since the control target is corrected by the amount, the engine is controlled to either the high-efficiency operation state or the stop (or idling) state, so that it is possible to preferably prevent the fuel consumption from deteriorating and reduce the motor output. Accordingly, the charge / discharge balance of the battery temporarily inclined to the discharging side or the charging side can be quickly balanced.

According to the present invention, the engine is idled or stopped when it is recognized that the motor output has substantially fallen below the minimum power generation output, and thereafter when the motor output has substantially exceeded the minimum power generation output. Since the power generation output is controlled with the value equal to or greater than the minimum power generation output as the control target, the period during which the engine is idling or can be matched with the period during which the motor output is reduced, and the engine noise Deterioration of drive feeling can be prevented. Also, by appropriately setting the control target value adopted after the engine idling or the stop control is completed, it is possible to supplement the imbalance of the battery charge / discharge balance during the period when the engine is idling or the stop and extend the life of the battery. It is possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration suitable for implementing the present invention.

FIG. 2 is a diagram showing control characteristics of an engine-driven generator.

FIG. 3 is a flowchart showing a control procedure of a generator controller according to the first embodiment of the present invention.

FIG. 4 is a timing chart showing a control procedure of a generator controller in this embodiment.

FIG. 5 is a flowchart illustrating a control procedure of a generator controller according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a control procedure of a generator controller according to a third embodiment of the present invention.

FIG. 7 is a flowchart illustrating a control procedure of a generator controller according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart illustrating a control procedure of a generator controller according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart illustrating a control procedure of a generator controller according to a sixth embodiment of the present invention.

[Explanation of symbols]

10 motor, 16 battery, 18 engine drive generator, 22 engine, 24 generator, 30 controller, 32 motor controller, 34 generator controller, If field current, PgMax maximum power output,
PgMin Minimum power output, Pm Motor power consumption, P
ave Average power consumption, Pd management variable, Pg control target, PhMax, PhMin power generation target limit value, Pt
r Power generation target increase limit value.

Claims (5)

(57) [Claims] 1. A hybrid electric vehicle capable of driving a motor for driving a vehicle using a discharge output of a chargeable / dischargeable battery and a generation output of a generator driven by an engine and charging a battery by the generation output. A generator control device for controlling the power generation output and managing the state of charge of the battery, comprising: means for setting a control target of the power generation output in the current control cycle based on the smoothed value of the index value of the motor output in the immediately preceding control cycle. Means for determining whether the set control target is higher or lower than the maximum power output that can be supplied from the generator; and, if it is determined that the control target is higher than the maximum power output, the control target is reduced and corrected so as to be equal to or less than the maximum power output. Means for adding a value obtained by subtracting the control target after the decrease correction from the control target before the decrease correction to the variable for charge / discharge balance management; Means for subtracting an amount equal to or less than the value obtained by subtracting the control target from the maximum power generation output from the variable for charge / discharge balance management and adding the reduced amount to the control target, and generating power according to the control target. Means for controlling the power output of the generator. In the generator control device 2. A method according to claim 1, wherein, when the set control target is below the maximum power output, consumption motor have a value below the maximum power output
Generated output increases despite lower power consumption
To reduce the feeling of increased noise when
The power generation target limit value for suppressing pressure rise
Set the above so that the control target after the right will not be exceeded
Generator controller, characterized in that it comprises means for limiting the addition amount of the control target is. 3. The generator control device according to claim 1, wherein, when the set control target is lower than a maximum power generation output, the control target after the addition correction is a power generation output and a motor.
A power generation item whose difference from the output is set within a predetermined limit.
So as not to increase target increase limit value or more, the generator control unit, characterized in that it comprises means for limiting the addition amount to the configured braking <br/> your goal. 4. The generator control device according to claim 1, further comprising: means for determining whether the set control target exceeds or falls below a minimum power generation output capable of operating the engine with high efficiency. Means for forcibly setting the control target to 0 or a value equal to or greater than the minimum power generation output, and adding a value obtained by subtracting the control target after the forcible setting from the control target before the forcible setting to a variable for charge / discharge balance management. When it is determined that the control target is reduced by an amount equal to or less than the value obtained by subtracting the control target from the maximum power generation output, and a means for adding the reduced amount to the control target is added to the control target. Generator control device. 5. The generator control system according to claim 1, wherein a straight that the motor output falls below the minimum power output substantially
Means for detecting based on the index value of the motor output in the previous control cycle; means for idling or stopping the engine when it is detected that the motor output has fallen below; and the motor output has substantially exceeded the minimum power generation output. A generator control device comprising: means for detecting the above based on the index value; and means for forcibly setting the control target to a value equal to or higher than the minimum power generation output when the value exceeds the minimum power generation output.