JP2003230204A - Apparatus and method of controlling hybrid power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set voltage fluctuations in a capacitor (power type device) in a proper range while flattening the burden of a battery (energy type device) used in a hybrid power system. <P>SOLUTION: A current filter 23 sets the average Iave of load current Iload within the latest prescribed period as a current target value *I. A converter control unit 33 controls the current of the battery to the current target value *I. A system voltage booster 27 corrects the current target value *I to pull up the voltage V of the capacitor to a proper level. A system voltage restriction part 29 corrects the current target value *I so that the voltage V of the capacitor may be within its proper variable range. The converter control unit 33 corrects an internal control method so that the voltage V of the capacitor may be within its proper variable range. A current correction part 21 learns the past correction and corrects the target value *I determination method for the current filter 23. An idle current adjuster 31 sets the current target value *I to zero at load idling. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a hybrid power supply system suitable as a power supply device for driving electric vehicles, electric construction vehicles and the like.

[0002]

2. Description of the Related Art As a power supply system for supplying DC power to a three-phase AC motor, which is a power source of an electric vehicle or the like, through an inverter (orthogonal converter), at least two different characteristics are provided.
A hybrid type in which power supply devices of the type are combined is known. One type of power supply device used herein is a power supply device referred to as "energy type" in the present specification, which has a large amount of energy capable of stably supplying power for a long time. The other is a power device called "power type" in this specification, which can supply and absorb a large amount of power in response to a sudden change in load such as during acceleration / deceleration. Energy-type devices include, for example, large-capacity storage batteries, fuel cells, engine-driven generators, and the like, and power-type devices include, for example, capacitors and hybrid batteries.

In the hybrid power supply system, the load of the energy type device is flattened by immediately responding to the load fluctuation such as acceleration / deceleration by the power type device.
Energy and power devices are combined. Generally, energy-type devices and power-type devices are coupled via a power converter. It is important to flatten the load on the energy-type device in order to increase the total amount of electric power that the energy-type device can supply and to keep the life of the energy-type device long. JP-A-10
In the invention disclosed in -80008, a weighted moving average value of past load currents or load powers is calculated in order to flatten the load on the energy type devices, and the output currents or output powers of the energy type devices are calculated as follows. The power converter is controlled so as to obtain the weighted moving average value.

[0004]

When the load circuit suddenly requests a large amount of power, the power type device supplies the large amount of power, and as a result, the output voltage of the power type device drops sharply. . In addition, when a large amount of regenerative energy is suddenly returned from the load circuit, the power device will absorb the large amount of regenerative energy,
As a result, the output voltage of the power device rises sharply. In this way, the output voltage of the power type device is forced to change directly under the influence of the load change. In many systems, the output voltage of the powered device is directly reflected in the input voltage of the load circuit or the output or output voltage of the power converter. Both the load circuit and the power converter can only tolerate input or output voltages within a certain range. Therefore, the output voltage of a power-type device must not fluctuate so much that it exceeds its specified range. Therefore, it is important to have a technique for controlling the fluctuation range of the output voltage of the power type device within an appropriate range regardless of any load fluctuation. Without this technology, it is especially difficult to apply the hybrid power supply system to applications in which load fluctuations are severe, such as construction machinery.

Therefore, an object of the present invention is to provide a technique for controlling the voltage fluctuation of a power type device within an appropriate range while making the load of the energy type device as flat as possible in a hybrid power supply system.

[0006]

A controller for a hybrid power supply system according to one aspect of the present invention determines a target value of an output current of the energy type device based on a past output value to a load circuit. Target value determining means,
If the target value is used, the current control means for controlling the output current of the energy type device and the possibility that the output voltage of the power type device goes out of a predetermined variable range are determined using the target value. , Target value correction means for correcting the target value input to the current control means so as to prevent the output voltage from going out of the variable range.

A controller for a hybrid power supply system according to another aspect of the present invention comprises a target value determining means for determining a target value of an output current of the energy type device based on a past output value to a load circuit, If the target value is used, the current control means for controlling the output current of the energy type device and the possibility that the output voltage of the power type device goes out of a predetermined variable range are determined using the target value. Control correction means for correcting the control method of the output current in the current control means so as to prevent the output voltage from going out of the variable range.

The control device may further include means for modifying the method of determining the target value in the target value determining means based on the output current controlled by the current control means.

A controller for a hybrid power supply system according to still another aspect of the present invention comprises a target value determining means for determining a target value of an output current of the energy type device based on a past output value to a load circuit. , The current control means for controlling the output current of the energy type device using the target value, and the current control means for increasing the output voltage of the power type device within a predetermined variable range. Target value correcting means for correcting the target value.

A control device for a hybrid power supply system according to still another aspect of the present invention includes a target value determining means for determining a target value of an output current of the energy type device based on a past output value to a load circuit. , The target value input to the current control means is set to substantially zero when the current control means for controlling the output current of the energy type device using the target value and the load circuit are in an idle state Idle current control means for

[0011]

1 and 2 show two types of configuration examples of a hybrid power supply system to which a control device according to an embodiment of the present invention is applied. The present invention is also applicable to a hybrid power supply system having a configuration other than that shown in FIGS.

In the hybrid power supply system shown in FIG. 1, an output terminal of a power converter 3 is connected in series to a storage battery 1 which is a typical example of an energy type device. Then, the series connection body of the storage battery 1 and the power converter 3 and the capacitor 5 which is a typical example of a power type device are connected in parallel to the input terminal of the inverter 7 which is a load circuit. Although not shown, the output terminal of the inverter 7 is
For example, an AC motor that is a power source of an electric vehicle, an electric construction vehicle, or the like is connected. The power converter 3 is a current control type that controls its output current (that is, the output current of the storage battery 1) Ibat to a target value, but is a voltage control type that controls its output voltage to a target value. It may be. In any case, by adjusting the output of the power converter 3 according to the load change and actively changing the voltage V of the capacitor 5, the capacitor 5 is positively charged and discharged to cope with the load change. Therefore, the output current Ibat of the storage battery 1 can be flattened.

In the hybrid power supply system shown in FIG. 2, the storage battery 11 is connected to the input terminal of the power converter 13, and the output terminal of the power converter 13 and the capacitor 1 are connected.
5 and 5 are connected in parallel to the input terminal of the inverter 7. The power converter 13 may be of a current control type or a voltage control type, but in any case, the output of the power converter 3 is adjusted according to the load change to positively change the voltage V of the capacitor 5, so that the capacitor It is possible to positively charge and discharge the battery 15 to cope with the load fluctuation, and thereby the output current Ibat of the storage battery 11 can be flattened. In the example of FIG. 2, one storage battery 11 is connected to the power converter 2, but it is not limited to this. For example, using two storage batteries,
A series-parallel chopper circuit is used as a power converter, and the series-parallel chopper circuit switches the series connection and parallel connection of two storage batteries at high speed, so that the voltage from one storage battery to twice the voltage The output voltage may be continuously variable.

In the power supply system of FIGS. 1 and 2, the voltage V of the capacitors 5 and 15 which are power type devices is the output voltage of this system (hereinafter referred to as "system voltage"). Hereinafter, an embodiment of the present invention applied to a power supply system in which the voltage V of the capacitor is the system voltage will be described. FIG. 3 shows the configuration of the control device according to this embodiment. However, this is not limited to one example, and the scope of application of the present invention is not limited thereto.

The control device 20 shown in FIG. 3 maintains the current of the storage battery, which is an energy type device, at a constant and small value as much as possible, while the load fluctuation and the charging / discharging of a large current are performed by the capacitor which is a power type device. As it does, it is configured to control the power converter. This is
In other words, it is controlled so that the DC component of the fluctuating load power is handled by the storage battery and the AC component is handled by the capacitor as much as possible. More specific control guidelines of the control device 20 are as follows (1) to (5).

(1) The current Ibat of the storage battery is made as constant as possible. In other words, the fluctuation of the battery current Ibat is made as small as possible. The reason is that even if the average value of the battery current Ibat is the same, the more the battery current Ibat fluctuates, the larger the internal loss due to the internal resistance of the storage battery. However, in order to control fluctuation of system voltage V (capacitor voltage) within a certain appropriate range, battery current Ibat
Fluctuate. That is, while varying the battery current Ibat in order to control the variation of the system voltage V within an appropriate range, the variation is suppressed as small as possible.

(2) The battery current Ibat is made as small as possible. The reason is that as the battery current Ibat increases, the internal resistance of the storage battery increases, the internal loss increases, the life of the storage battery decreases, and the amount of power that the storage battery can output decreases.

(3) The central point of the fluctuation of the system voltage V is set to a high value as much as possible. The reason is that even if the same power is supplied to the load, the higher the system voltage V, the more the load current (system current) Ilo.
This is because ad becomes smaller, and the smaller the load current Iload, the smaller the wiring loss and the inverter loss, and the higher the efficiency of the power converter. However, if the system voltage V is too high (that is, too close to the upper limit value of the variable range), the capacitor cannot absorb regenerative energy, so avoid being too high.

(4) Avoid as much as possible a state in which there is no capacity to charge and discharge the capacitor (that is, the system voltage V reaches the upper limit value or the lower limit value of the variable range). Even in such a case, the storage battery supplies or absorbs the necessary electric power so that the electric power cannot be exchanged with the load.

(5) In the idle state of the load, the battery current Ibat is quickly made substantially zero. That way
This is because the total operating time can be extended.

As shown in FIG. 3, the control device 20 includes
Current correction unit 21, current filter 23, system voltage pulling upper part 2
7, a system voltage limiter 29, an idle current controller 31, and a converter controller 33.

It is the current filter 23 that functions under the guidelines (1) and (2) described above. The current filter 23 calculates an average value Iave of the past load current (load required current) Iload, and outputs this stable average value Iave as a target value * I of the battery current Ibat.

It is the system voltage pulling upper part 27 that functions under the above-mentioned guideline (3). The system voltage pulling unit 27 corrects the battery current target value * I output from the current filter 23 so that the system voltage V becomes an appropriate high value.

The system voltage limiting unit 29, the converter control unit 33, and the current correction unit 21 function under the above-mentioned guideline (4). The system voltage limiting unit 29 corrects the battery current target value * I so that the system voltage V does not reach the upper limit value and the lower limit value of the variable range. In addition, the converter control unit 33 determines that the battery current
PW of the power converter 35 based on the deviation between Ibat and the target value * I
M When controlling the switching duty, current system voltage V
Correct the PWM switching duty so that does not reach the upper and lower limits. Further, when the current filter 23 calculates the average value Iave of the load current Iload, the current correction unit 21 prevents the system voltage V from reaching the upper limit value and the lower limit value with respect to the value of the load current Iload. Make a correction for.

It is the idle current controller 31 that functions under the above-mentioned guideline (5). Idle current controller 31
Is the battery current target value * I when the load is in the idle state.
To virtually zero.

The function of each unit will be described in detail below.

First, the current filter 21 will be described. The current filter 21 functions for the guidelines (1) and (2) to make the battery current Ibat as constant and small as possible. That is, the current filter 21 samples and inputs the value of the load current (load required current) Iload in a constant cycle, and calculates a moving average of the load current Iload in the latest past predetermined period (or low-pass filtering of the load current Ibat). Then, the load current average value Iave is calculated, and this load current average value Iave is output as the battery current target value * I. The parameters used here are the battery current target value * I
And the number of data of the load current Iload used in the calculation of the moving average (or the time constant of low-pass filtering).

With respect to the initial value, an appropriate value can be determined according to the kind of operation or operation mode the load is going to perform. For example, in the case of construction machinery, several operation modes such as heavy excavation mode and energy saving mode can be selected on the console panel of the driver's seat, but it is prepared in advance according to the operation mode thus selected. The optimum initial value can be selected.

Regarding the number of data of moving average (or time constant of low-pass filtering), the larger the number of data (or the larger the time constant), the more easily the constant target value * I can be obtained. If it is too large (or the time constant is too large), the target value * I will not match the actual load pattern. Therefore, load patterns of various applications are analyzed at the design stage, the number of data (or time constant) suitable for each is determined, and the optimal number of data (or time constant) is selected according to the application. You can leave it ready. For example, in the case of excavating a power shovel, there is a typical load pattern in which "digging", "turning 90 degrees", and "loading on a dump truck" are performed in sequence, and in the case of V-shape loading of a wheel loader, There is a typical load pattern in which "starting", "pushing into a pile of earth and sand", "backing", "turning to start", "loading the dump truck with earth and sand", and "backing" in sequence. An appropriate number of data (time constant) can be set in advance for each such load pattern.

By controlling the battery current Ibat using the battery current target value * I obtained by the moving average calculation (or low-pass filtering) of the load current Iload as described above, almost only the DC component of the load current is obtained. It can be achieved that it is supplied from a storage battery and the AC component is supplied from a capacitor. However, with this alone, when a sudden large current load occurs, the capacitor may be over-discharged or over-charged, and the system voltage V may reach the upper limit value or the lower limit value of the variable range. In order to avoid this, various modifications described later in detail are made.

Next, the system voltage pulling upper portion 27 shown in FIG. 3 will be described. The system voltage pulling upper part 27 has the above-mentioned guideline that the center point of the fluctuation of the system voltage V is set as high as possible.
Works for (3).

FIG. 4 is a flow chart for explaining the operation of the system voltage pulling upper part 27. FIG. 5 explains various values used in FIG.

As shown in FIG. 5, the system voltage V can be varied only within a specific upper limit value VlimH to lower limit value VlimL depending on the characteristics of the load circuit such as the inverter and the characteristics of the power converter. Be done. In a region outside this variable range VlimH to VlimL (shown by hatching in the figure), it becomes impossible to control the electric power exchanged with the load. The central threshold value Vth is set in advance within such a variable range VlimH to VlimL. The central threshold value Vth is a reasonably high (but not too high) level within the variable range VlimH to VlimL, for example, the variable range Vl.
A simple center point of imH to VlimL, or, for example, the variable range Vlim
Such as the center point of the power from H to VlimL (that is, the square of the voltage),
Is set to. Further, the high-side safety threshold VthH is preset at a level slightly lower than the variable upper limit VlimH, and the low-side safety threshold VthL is slightly higher than the variable lower limit VlimL.
Is preset. High side safety threshold VthH to low side safety threshold
In the range up to VthL, as long as the system voltage V is within that range, the system voltage V is variable upper limit value Vli under normal load fluctuation.
It is a safe range where it is judged that the possibility of reaching mH or the variable lower limit value VlimL is considerably small.

As shown in FIG. 4, the system voltage pulling upper part 27
First, in step 41, the average value Vave of the system voltage V in the latest past predetermined period is calculated, and this system voltage average value Va
ve is compared with the central threshold voltage Vth shown in FIG. As a result, if the system voltage average value Vave is less than the central threshold voltage Vth (YES in step 41), then step 43
Then, the maximum value Vmax in the locus of fluctuations of the system voltage V in the predetermined period is selected, and this system voltage maximum value Vmax is compared with the high-side safety threshold voltage VthH. As a result, when the system voltage maximum value Vmax is less than the high-side safety threshold voltage VthH,
Since it is assumed that the system voltage V is always at a low level, the system voltage pulling section 27 proceeds to step 45, and
The predetermined positive correction value F (Vave) is added to the load current average value Iave output from the current filter 23 shown in FIG. * I is increased from the value determined by the current filter 23). Here, the correction value F (Vave) may be a function of the system voltage average value Vave that becomes larger as the system voltage average value Vave is lower, or may be a constant value.

On the other hand, in step 41, the system voltage average value Va
When ve is higher than the central threshold voltage Vth (N in Step 41)
Since the system voltage V is not too low in (O), the load current average value Iave from the current filter 23 is directly used as the battery current target value * I (step S47). Even if the system voltage average value Vave is less than the central threshold voltage Vth, if the system voltage maximum value Vmax is higher than the high-side safety threshold voltage VthH (NO in step 47), the battery current target value * I is set. If it is increased, the system voltage V may reach the variable upper limit value VlimH. Therefore, the load current average value Iave from the current filter 23 is increased.
Is directly set as the battery current target value * I (step S4
7).

By the above processing of the system voltage pulling upper part 27,
The fluctuation center level of the system voltage V is the center threshold value V shown in FIG.
Control will be performed in the direction of maintaining the level at th or higher.

Next, the system voltage limiting unit 29 shown in FIG. 3 will be described. The system voltage limiting unit 29 functions for the above-mentioned guideline (4) of preventing the system voltage V from entering the uncontrollable region shown by hatching in FIG.

FIG. 6 is a flowchart showing the operation of the system voltage limiting unit 29. FIG. 7 is a diagram illustrating various voltage values used in FIG.

As shown in FIG. 7, the variable upper limit value of the system voltage
A high-side safety margin VmH is set immediately below VlimH, and a low-side safety margin VmL is set immediately above the variable lower limit value VlimL. High-side safety margin VmH and low-side safety margin
VML is a voltage width in which it is considered that the possibility that the system voltage V reaches the variable upper limit value VlimH or the variable lower limit value VlimH is considerably low if the capacitor has a remaining capacity for charging or discharging by the voltage width. The high-side safety voltage VlimH−VmH and the low-side safety voltage VlimL + VmL may be at the same level as the high-side safety threshold VthH and the low-side safety threshold VthL shown in FIG. 5, or may be different.

As shown in FIG. 6, the system voltage limiting unit 29
In step 51, the system voltage V and the high-side safe voltage VlimH−
Compare with VmH. As a result, if the system voltage V is higher than the high-side safe voltage VlimH-VmH (YES in step 51), it means that the system voltage V is too high, and thus step 57
3 to the predetermined positive correction value G {V- (VlimH from the load current average value Iave output from the current filter 23 shown in FIG.
−VmH)} is subtracted and the subtracted value is the battery current target value * I
(That is, the battery current target value * I is
3 less than the value decided). Here, the correction value G (V− (Vlim
H-VmH)} is a variable according to the excessively high level of the system voltage V. For example, from the system voltage V to the high-side safety voltage VlimH-VmH
Or a value proportional to the difference (positive value) obtained by subtracting the square of the high-side safety voltage VlimH-VmH from the square of the system voltage V, for example. be able to.

On the other hand, if NO in step 51, then the system voltage limiting unit 29 determines in step 53 the system voltage.
Compare V with the low-side safety voltage VlimL + VmL. as a result,
If the system voltage V is lower than the low-side safe voltage VlimL + VmL (YES in step 53), it means that the system voltage V is too low, so the procedure proceeds to step 59, and the average load current value from the current filter 23 shown in FIG. A predetermined negative correction value from Iave
G {V- (VlimL + VmL)} is subtracted, and the subtracted value is set as the battery current target value * I (that is, the battery current target value * I is increased above the value determined by the current filter 23). Where the correction value
G {V− (VlimH−VmH)} is a variable according to the extent to which the system voltage V is too low. For example, from the system voltage V to the low-side safe voltage V
A value proportional to the difference (negative value) obtained by subtracting limL + VmL, or, for example, from the square of the system voltage V to the low-side safety voltage VlimL +
A value proportional to the difference (negative value) obtained by subtracting the square of VmL can be used.

On the other hand, if NO also in step 53, that is, if the system voltage V is within the range between the high-side safety voltage VlimH-VmH and the low-side safety voltage VlimL + VmL, in step 55, the current filter 23. Average load current from Iave
Is used as is as the battery current target value * I.

By the processing of the system voltage limiting unit 29 described above, control is performed so that the system voltage V falls within the range between the high-side safety voltage VlimH-VmH and the low-side safety voltage VlimL + VmL.

Next, the converter control unit 33 shown in FIG. 3 will be described. The converter control unit 33 basically feeds back the value of the battery current Ibat and outputs the battery current Ibat.
Is configured to operate the PWM switching duty of the power converter 33 so that the deviation between the value of 1 and the battery current target value * I becomes zero. In addition to this basic configuration, the converter control unit 33 also has a configuration for limiting the system voltage V so as not to reach the variable upper limit value VlimH and the variable lower limit value VlimL.

FIG. 8 shows an example of the configuration of the converter control unit 33. This example is of the current control type.

As shown in FIG. 8, in the converter control unit 33, in the current main loop composed of the blocks 61 and 63, the battery current target value * I and the battery current fed back are fed back.
The deviation from Ibat is obtained, and the current deviation is subjected to a predetermined PID control calculation to output the system voltage target value * V. Next, the voltage limiter 66 limits the system voltage target value * V to a predetermined range within the variable range VlimH to VlimL shown in FIG. Next, in the voltage minor loop composed of blocks 67 and 69, the deviation between the limited system voltage target value * V and the fed back system voltage V is obtained, and the predetermined PID control calculation is applied to the voltage deviation, and the calculation is performed. The result is used to manipulate the PWM switching duty of power converter 35.

Due to the actions of the above voltage limiter and the voltage minor loop, the system voltage target value * V does not reach the variable upper limit value VlimH and the variable lower limit value VlimL.

FIG. 9 shows another structural example of the converter control unit 33. This example is of the current control type. This example
An observer is used to predict how the system voltage V will change thereafter, and control is performed so that the predicted value does not reach the variable upper limit value VlimH and the variable lower limit value VlimL.

That is, as shown in FIG. 9, the observer 71 uses the battery current target value * I, the system voltage V and the load power Plo.
Values such as ad are input, and using these input values, the future value of the system voltage V is predicted from the known capacity and internal resistance of the capacitor of the power supply system. And
If the predicted future value of the next system voltage reaches the variable upper limit value VlimH or the variable lower limit value VlimL, the observer 71 determines the upper limit value or the lower limit value of the battery current target value * I necessary to prevent it. A value is calculated, and the calculated upper limit value or lower limit value is output to the comparator 73. The comparator 73 compares the input battery current target value * I with the upper limit value or the lower limit value from the observer 71. Then, the comparator 73, as a result of the comparison,
If the input battery current target value * I is less than or equal to the upper limit value and greater than or equal to the lower limit value, the input battery current target value * I is output as it is as a new battery current target value ** I. When the current target value * I exceeds the upper limit value or falls below the lower limit value, the upper limit value or the lower limit value is output as a new battery current target value ** I.

Then, by the blocks 75 and 77, the new battery current target value ** I from the comparator 73 is set to the battery current Iba.
The PWM switching duty of the power converter 35 is manipulated so that t matches.

FIG. 10 shows still another configuration example of the converter control unit 33. This example is of the voltage control type. In this example, the observer is used to calculate the system voltage target value * V required to achieve the current target value * I, and the system voltage target value is calculated.
* V is limited by the variable range VlimH to VlimL.

That is, as shown in FIG. 10, the observer 81 has a battery current target value * I, a system voltage V, and a load power Pload.
Input the values such as the battery current Ibat, and use these input values to match the battery current Ibat with the battery current target value * I from the known capacity and internal resistance of the capacitor of the power supply system. Calculate the required system voltage target value * V. Next, the limiter 83 limits the system voltage target value * V from the observer 81 to a predetermined range within the variable range VlimH to VlimL. And blocks 85 and 87
The PWM switching duty of the power converter 35 is operated so that the system voltage V fed back to the limited system voltage target value * V matches.

When the system voltage V approaches or reaches the variable upper limit value VlimH or the variable lower limit value VlimL by the action of the converter control unit as shown in FIGS. 8 to 10, the system voltage V becomes the variable upper limit value. The battery current Ibat is modified so as to prevent the value VlimH or the variable lower limit value VlimL from becoming less than or equal to the value VlimH. As a result, the system voltage V is kept within the variable range VlimH to VlimL, and when the system voltage V reaches the variable upper limit value VlimH or the variable lower limit value VlimL, the power required by the load circuit is supplied from the storage battery. become.

Next, the current correction section 21 shown in FIG. 3 will be described. The current correction unit 21 changes the system voltage V to the variable range V
It works because of the above-mentioned guideline (4) of keeping within limH to VlimL.

That is, the system voltage V reaches the variable upper limit value VlimH or the variable lower limit value VlimL even if the power supply system has an appropriate capacitor capacity, and the above-mentioned limit by the converter control unit 33 works. As a root cause of the battery current target value, the moving average of the load current is calculated or filtered in the current filter 23.
There may be the following problems 1) to 3) in the method of determining * I. 1) The initial value of the battery current target value * I is not appropriate. 2) The load pattern as a model analyzed at the time of design is different from the actual situation. 3) The moving average or filtering output is in a transient state. That is, the battery current target value * I is in the process of rising or falling.

In order to avoid such a case, the current correction unit 21 sets the battery current target value * I (or the load current average value Ia) which is generated when the limit is applied by the converter control unit 33.
ve) and the battery current Ibat difference ΔI (= * I-Ibat or Iave-I
bat) is calculated, a correction value G (ΔI) corresponding to this current difference ΔI is calculated, and this correction value G (ΔI) is input to the current filter 23.

The current filter 23 calculates (or filters) the moving average of the load current (load required current) Iload.
When performing, the above correction value is added. That is, for example, the load current average value Iave is obtained by the following equation Iave = FIL {Iload−G (ΔI)}. Where the function FI
L {} means moving average calculation or low-pass filtering.

In this way, the load current average value Ia by the current filter 23 is learned by learning using the past control results.
The calculation method of ve is modified. By using the thus-corrected load current average value Iave as the battery current target value * I, the system voltage V becomes the variable upper limit value VlimH or the variable lower limit value Vlim.
Since the frequency of correction by the system voltage limiting unit 29 and the limit by the converter control unit 33 being close to L decreases,
The fluctuation of the battery current Ibat is further suppressed.

Finally, the idle current controller 31 shown in FIG. 3 will be described. The idle current control unit 31 functions for the above-mentioned guideline (5) that the battery current Ibat is substantially zero when the load circuit is idle.

FIG. 11 shows the operation flow of the idle current control section 31.

As shown in FIG. 11, the idle current control section 31 determines in step 91 whether the load circuit is in the idle state, and if it is in the idle state, the step 9
3, the process checks whether the system voltage V is within the vicinity range Vth ± α of the central threshold value Vth shown in FIG. As a result, if the system voltage V is within the central threshold value vicinity range Vth ± α, the idle current control unit 31 proceeds to step 95,
Forcibly set the battery current target value * I to zero. As a result, the battery current Ibat is controlled to zero.

On the other hand, the system voltage V is in the vicinity of the central threshold value Vth +
If it is higher than α, the system voltage V is in the vicinity of the central threshold Vth ± α
In order to bring the battery current target value * I to the predetermined value,
Forced to Iy. The charging current value Iy is set to a small value that does not cause substantial damage to the storage battery (that is, it can be regarded as substantially zero from the viewpoint of the storage battery life), or an appropriate charging according to the discharge state of the storage battery. It may be a current value. Is. As a result, an appropriate charging current flows from the capacitor to the storage battery, the capacitor is discharged, and the storage battery is charged accordingly.

On the other hand, the system voltage V is in the vicinity of the central threshold value Vth−
If it is lower than α, the idle current control unit 31 proceeds to step 99 in order to raise the system voltage V to within the central threshold near range Vth ± α, and sets the battery current target value * I to the predetermined discharge current value Ix.
Set to forcibly. The discharge current value Ix is a small value that does not damage the storage battery (that is, it can be regarded as substantially zero from the viewpoint of the life of the storage battery). As a result, a minute discharge current flows from the storage battery to the capacitor, and the capacitor is charged.

The embodiment of the present invention has been described above.
This is an example for explaining the present invention and is not intended to limit the scope of the present invention only to this embodiment. Therefore,
The present invention can be implemented in various other modes without departing from the gist thereof.

For example, in an application where regenerative energy is hardly expected to be returned from the load circuit, the central threshold Vth is set to a considerably high level in the variable range of the system voltage, or the system voltage V is varied. The treatment to prevent the upper limit value VlimH from being reached may be rough. When a device that cannot be charged, such as a fuel cell, is used as the energy type device, the step of setting the discharge current Iy in step 97 shown in FIG. 11 can be omitted.

In the above embodiment, the capacitor is directly connected to the system voltage line, and the voltage of the capacitor becomes the system voltage as it is. However, the application of the present invention is not limited to such a power supply system. Absent. The present invention can also be applied to a power supply system in which another circuit element or circuit is interposed between the capacitor and the system voltage line, and the capacitor voltage and the system voltage do not necessarily match. In that case, various controls performed for the same purpose as the above-described embodiment based on the level of the system voltage can be performed based on the voltage level of the capacitor.

Instead of the storage battery (secondary battery) as the energy type device, a fuel cell, an engine driven generator or the like can be used. Further, as the power type power supply device, a hybrid power supply battery or the like can be used instead of the capacitor.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of a hybrid power supply system to which a control device according to an embodiment of the present invention is applied.

FIG. 2 is a circuit diagram showing another example of a hybrid power supply system to which the control device according to the embodiment of the present invention is applied.

FIG. 3 is a block diagram showing a configuration of a control device for a hybrid power supply system according to an embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of the system voltage pulling upper part 27.

FIG. 5 is an explanatory diagram of various voltage values used in FIG.

FIG. 6 is a flowchart showing the operation of the system voltage limiting unit 29.

7 is an explanatory diagram of various voltage values used in FIG.

FIG. 8 is a block diagram showing a configuration example of a converter control unit 33.

FIG. 9 is a block diagram showing another configuration example of the converter control unit 33.

FIG. 10 is a block diagram showing another configuration example of the converter control unit 33.

FIG. 11 is a flowchart showing the operation of the idle current control section 31.

[Explanation of symbols]

1,11 Storage battery (energy type device) 3, 13 Power converter 5, 15 Capacitor (power type device) 7 Inverter (load circuit) 21 Current correction unit 23 Current filter 25, * I Battery current target value 27 system voltage upper part 29 System voltage limiter 31 Idle current controller 33 Converter control unit 35 power converter V system voltage (capacitor voltage) Ibat battery current Iload load current (request current of load) Iave load current average

Claims (13)

[Claims] 1. A controller for a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
Target value determining means (23) for determining I), and current control means (33) for controlling the output current (Ibat) of the energy type device using the target value (* I)
And determining the possibility that the output voltage (V) of the power device goes out of a predetermined variable range, and if there is the possibility,
Control including target value correction means (29) for correcting the target value (* I) input to the current control means so as to prevent the output voltage (V) from going out of the variable range. apparatus. 2. A control device for a hybrid power supply system that outputs power to a load circuit using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
Target value determining means (23) for determining I), and current control means (33) for controlling the output current (Ibat) of the energy type device using the target value (* I)
And determining the possibility that the output voltage (V) of the power device goes out of a predetermined variable range, and if there is the possibility,
In order to prevent the output voltage (V) from going out of the variable range, the output current (Ib
at) and a control modifying means (33) for modifying the control method. 3. A target value determining means (23) based on the output current (Ibat) controlled by the current control means.
3. The control device according to claim 2, further comprising a target value determination method correction means (21) for correcting the determination method of the target value (* I) in step 1. 4. A control device for a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, wherein the energy is based on a past output (Iload) value to the load circuit. Target value of output current (Ibat) of type device (*
Target value determining means (23) for determining I), and current control means (33) for controlling the output current (Ibat) of the energy type device using the target value (* I)
And target value correction means (2) for correcting the target value (* I) input to the current control means so as to raise the output voltage (V) of the power type device within a predetermined variable range.
7) and a control device. 5. A controller for a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
Target value determining means (23) for determining I), and current control means (33) for controlling the output current (Ibat) of the energy type device using the target value (* I)
And an idle current control means (31) for setting a target value (* I) input to the current control means (33) to substantially zero when the load circuit is in an idle state. . 6. A control method for a hybrid power supply system that outputs electric power to a load circuit using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
I), a step of controlling the output current (Ibat) of the energy type device using the target value (* I), and an output voltage (V) of the power type device within a predetermined variable range. If there is a possibility of going out of
A step of modifying the target value (* I) input to the current control means so as to prevent the output voltage (V) from going out of the variable range. 7. A control method for a hybrid power supply system that outputs electric power to a load circuit using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
I), a step of controlling the output current (Ibat) of the energy type device using the target value (* I), and an output voltage (V) of the power type device within a predetermined variable range. If there is a possibility of going out of
In order to prevent the output voltage (V) from going out of the variable range, the output current (Ib
at) and the step of modifying the control method. 8. A control method for a hybrid power supply system that outputs power to a load circuit using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
I), a step of controlling the output current (Ibat) of the energy type device using the target value (* I), and an output voltage (V) of the power type device within a predetermined variable range. To correct the target value (* I) input to the current control means so that the current value is raised in the control method. 9. A control method for a hybrid power supply system that outputs electric power to a load circuit using an energy type device and a power type device, wherein the energy is based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of type device (*
I), controlling the output current (Ibat) of the energy-type device using the target value (* I), and the current control means (I) when the load circuit is in an idle state. 33) setting the target value (* I) input to 33) to substantially zero. 10. A computer program for controlling a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of the energy type device (*
I) a program code for determining the step, controlling the output current (Ibat) of the energy type device using the target value (* I), and the output voltage (V) of the power type device. Determines the possibility of going out of the predetermined variable range, and if there is the possibility,
And a program code for modifying the target value (* I) input to the current control means so as to prevent the output voltage (V) from going out of the variable range. . 11. A computer program for controlling a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, based on a past output (Iload) value to the load circuit. Target value of output current (Ibat) of the energy type device (*
I) a program code for determining the step, a program code for controlling the output current (Ibat) of the energy type device by using the target value (* I), and a program code for the power type device. Judging the possibility that the output voltage (V) goes out of the predetermined variable range, and if there is the possibility,
In order to prevent the output voltage (V) from going out of the variable range, the output current (Ib
at) and a program code for modifying the control method. 12. A computer program for controlling a hybrid power supply system that outputs electric power to a load circuit by using an energy type device and a power type device, based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of the energy type device (*
I) a program code for determining the step, a program code for controlling the output current (Ibat) of the energy type device by using the target value (* I), and a program code for the power type device. And a program code for modifying the target value (* I) input to the current control means so as to raise the output voltage (V) within a predetermined variable range. 13. A computer program for controlling a hybrid power supply system that outputs electric power to a load circuit using an energy type device and a power type device, based on a past output value (Iload) to the load circuit. Target value of output current (Ibat) of the energy type device (*
I), a program code for controlling the output current (Ibat) of the energy-based device using the target value (* I), and when the load circuit is in an idle state, And a program code for setting the target value (* I) input to the current control means (33) to substantially zero.