JPH07212986A - Generation control equipment for vehicle - Google Patents

Abstract

PURPOSE:To provide a generation control equipment for vehicles wherein the overcharge and overdischarge of a battery are prevented even through the control of generator output without any added current sensor. CONSTITUTION:A target voltage changing means 51 changes a target voltage Vreg based on the states of a vehicle detected by a vehicle state detecting means 6. A generator output control means 52 controls the output of a generator based on the changed target voltage Vreg and a battery voltage Vb detected by a battery voltage detecting means 20. When a battery is being discharged, a battery discharge calculating means 54 accumulates the products of the amount of battery voltage drop and the duration of voltage drop to obtain the amount of battery discharge. When the thus obtained amount of battery discharge exceeds a specified value, control to discharge the battery is canceled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power generation control device for controlling the output of a vehicle generator.

[0002]

2. Description of the Related Art FIG. 1 shows, for example, JP-A-4-140026.
It is a block diagram which shows the general structure of the general vehicle control apparatus shown by the publication. In the figure, 1 is a battery charged by a generator 3 driven by an engine 2, 4 is an electric load supplied with electric power by the battery 1 and the generator 3, SW is a switch for turning on / off the electric load,
Reference numeral 5 is a control device having a microcomputer for controlling this power generation system based on the detection result from the vehicle state detection means 6 for detecting various states of the vehicle, 7 is a field coil of the generator 3, and Tr is the field. A semiconductor switch for controlling the field current If flowing in the magnetic coil 7, L1 is the battery 1
L2 is a detection line for inputting the detection result of the vehicle state detection means 6 to the control device 4.

In such a general vehicular power generation control device, the control device 5 includes the battery 1 through the detection line L1.
Of the semiconductor switch T so that the detected voltage Vb becomes a predetermined target voltage Vreg.
r to PWM (Pulse Width Modulat)
Ion) to control the field current If flowing in the field coil 7 to control the output of the generator 3.

Further, the control device 5 detects various vehicle states from the vehicle state detecting means 6 via the detection line L2, for example, engine speed, throttle opening, vehicle speed, cooling water temperature, and the like. When acceleration is detected, control for discharging the battery 1, that is, control for changing the target voltage Vreg to a lower level than usual to reduce the output of the generator 3 or stop the power generation (hereinafter referred to as power generation stop control) is performed. Further, the control for rapidly charging the discharged battery 1 when the deceleration of the vehicle is detected, that is, the control for changing the target voltage Vreg to a higher level than usual to increase the output of the generator 3 and rapidly charging the battery 1 (hereinafter referred to as rapid Charge control).

[0005]

In the general vehicle power generation control device as described above, it is expected that the fuel consumption or the acceleration performance is improved at the time of acceleration, but if the acceleration continues for a relatively long time, the power generation stop time is stopped. However, there is a problem that the battery becomes longer and the battery is over-discharged. On the contrary, if the deceleration is continued for a relatively long time, the rapid charging becomes excessive and the battery is overcharged. Further, in order to prevent these, it is necessary to add a current sensor to detect the charge / discharge current of the battery.

The present invention has been made in order to solve the above-mentioned problems, and even if the control for changing the target voltage Vreg of the generator is performed, the battery is always brought into a proper charge state without the current sensor. An object is to provide a vehicle power generation control device that can be maintained.

[0007]

In the power generation control device according to the present invention, means for calculating the battery discharge amount by accumulating the product of the battery voltage decrease amount and the voltage decrease state, and the battery discharge amount. When the value exceeds a predetermined value, means for canceling the power generation stop control is provided.

In the power generation control, the control circuit detects the generated current as a calculation result inside the control circuit, and the detected generated current does not change after the battery is discharged. Means for determining that charging of the battery has been completed by detecting this, and means for prohibiting the power generation stop control until the completion of charging of the battery is determined after the discharge of the battery is released.

Further, in the power generation control, the control circuit detects the generated current as a calculation result inside the control circuit, and after the discharge of the battery is released, the detected generated current does not change. Means for determining that the charging of the battery is completed by detecting this, and means for permitting quick charge control after the discharge of the battery is released until the completion of charging the battery is determined.

[0010]

In the vehicular power generation control device configured as described above, the discharge amount of the battery is calculated by accumulating the product of the amount of decrease in the battery voltage and the duration of the voltage decrease state. When the discharge amount exceeds the predetermined value, the power generation stop control is released.

Further, after the discharge of the battery is released, the generated current which is stored as a calculation result in the control device is detected,
The power generation stop control is prohibited until the means for determining the completion of charging the battery by detecting that the detected generated current has stopped changing, determines the completion of charging.

Further, after the discharge of the battery is released, the generated current stored as a calculation result in the control device is detected, and it is detected that the detected generated current has stopped changing, thereby completing the charging of the battery. The quick charge control is permitted until the means for determining is complete charge.

[0013]

【Example】

Example 1. The power generation control device according to the present invention has a general configuration as shown in FIG.
This is done as shown in. The internal structure of the control device 5 in FIG. 1 will be described with reference to FIG. The target voltage changing means 51 sets the target voltage Vreg for power generation based on the various states of the vehicle detected by the vehicle state detecting means 6. Next, the battery voltage detection means 20 detects the battery voltage Vb, and the generator output control means 52 detects this battery voltage Vb.
And the target voltage Vreg are compared with each other, the generated current Ia is calculated based on this result by a calculation method described later, and the field current If necessary for generating the generated current Ia flows through the field coil 7 in the semiconductor. Switch Tr is duty D
PWM drive at f to set the battery voltage Vb to the target voltage Vre
control to g.

Here, a method of calculating the generated current Ia will be described. The voltage deviation ΔVa between the battery voltage Vb, which is the output of the battery voltage detecting means 20, and the target voltage Vreg, which is the output of the target voltage changing means 51, is obtained by a subtractor. Assuming that the proportional constant is Kp and the integral constant is Ki, the relationship between the generated current Ia and the voltage deviation ΔVa is as follows. Ia = Kp · ΔVa + ∫Ki · ΔVadt Therefore, the generated current Ia can be obtained from the voltage deviation based on the above equation.

Next, a method of calculating the battery discharge amount W will be described. FIG. 3 shows the power supply system circuit when the output of the generator is stopped, and the generator whose output is stopped is omitted. Reference numeral 1 denotes a battery, which is represented by an internal resistance Rb and a battery open terminal voltage Eb. Vb is the battery voltage, r1,
r2 and r3 represent electric loads, and SW1, SW2, SW3
Is a switch for turning on and off each electric load. The figure shows a state in which only the switch SW1 is turned on and only the electric load r1 is energized, and the battery voltage Vb1 at this time is represented by Vb1 = Eb.R / (Rb + R), where R = r1. Next, when the switch SW2 is also turned on, the battery voltage Vb2 becomes Vb2 = Eb.R /
(Rb + R), where R = r1 · r2 / (r1 + r2)
It is represented by. Furthermore, when the switch SW3 is also turned on,
The battery voltage Vb3 is Vb3 = Eb.R / (Rb
+ R), where R = r1 · r2 · r3 / (r1 · r2 +
r2 · r3 + r3 · r1), and it can be seen that the detected battery voltage Vb decreases as the electric load increases.

A series of these operations is shown in the time chart of FIG. In the figure, at time t0, the electric load r1
Is energized, and the load current i1 is flowing. next,
When the electric load r2 is energized at time t1, the load current is i
When the electric load r3 is energized at time t2, the load current increases to i1 + i2 + i3. In each case, the predetermined voltage Vconst,
For example, the voltage deviation ΔV between the battery open terminal voltage and the battery voltage Vb that decreases with the energization of the electric load is ΔV =
As shown in Vconst-Vb, the relationship between the voltage deviation ΔV obtained here and the battery discharge current Ib is shown in FIG.
The proportional relationship is as shown in (b), and Ib = K · ΔV when K is a proportional constant. Therefore, by accumulating the product of the battery discharge current Ib obtained by the above equation and its duration Δt, the battery discharge amount W is W = Σ (K · Δ
V · ΔT) can be obtained.

The operation described above will be described with reference to the flowchart of FIG. In step S501, the calculated battery discharge amount W is cleared to zero. Next, in S502, various states of the vehicle are detected, and based on these, the target voltage Vr is detected in S503.
Set eg. Then, in S504, the battery voltage Vb
Is detected, the target voltage Vreg set in S503 above and the battery voltage V detected in S504 above are detected in S505.
The generator current Ia of the generator is calculated from b and b. In S506, the field current If for outputting the generated current Ia is calculated (If is determined from Ia based on the characteristics of the generator), and in S507, the field current If is applied to the field coil 7. The PWM duty Df is output to the semiconductor switch Tr so that it is energized. So far S501 to S50
The battery voltage Vb is controlled to the target voltage Vreg by repeating the flow of 7.

Next, in S508, a predetermined value Vcons
The voltage deviation ΔV between t and the battery voltage Vb detected in S504 is obtained, and in the next S509, it is determined whether or not this voltage deviation ΔV is positive. If ΔV> 0, the process proceeds to S510, the battery discharge amount W is calculated, and it is determined in S511 whether the power generation stop control is being executed. If it is being executed, the process proceeds to S512, and whether the battery discharge amount W exceeds a predetermined value or not. To determine. In the case of no, both S511 and S512 return to S502. S51
If the battery discharge amount W exceeds the predetermined value in step 2, S513
Releases and prohibits the power generation stop control, and returns to S502.
If ΔV> 0 is not obtained in S509, the process proceeds to S514, the battery discharge amount W is cleared to zero, and the process returns to S502. S50
After returning to 2, the above control is repeated. It should be noted that the above-mentioned predetermined value is set in advance as a discharge amount within a range in which the battery performance required by the vehicle can be maintained according to the capacity of the battery mounted on the vehicle, the electric load, the startability of the vehicle, or the like. Further, in S513, the power generation stop control may be canceled, the control may be ended, and the control may be restarted after a certain time. With this control, the amount of discharge of the battery can be detected and an overdischarge of the battery can be prevented without adding a current sensor to the outside.

Example 2. First, FIG. 6 shows the charge acceptance characteristics of the battery. Generally, the acceptable current of a battery varies depending on the capacity, temperature, state of charge, charging voltage, etc. However, in all cases, when the charge rate reaches 100%, that is, when the battery reaches full charge, the acceptable current tends to settle to a fixed value.
Therefore, it can be determined that the discharged battery is sufficiently charged by detecting that the generated current of the generator has stopped changing.

Next, the above phenomenon will be supplemented with reference to the time chart of FIG. In the figure, from time t0 to time t1
During this period, it is assumed that the generator performs steady power generation, the battery is fully charged, and a certain electric load is energized.
In this state, the generated current Ia of the generator maintains a constant value,
The electric load and the battery are supplied with electric power by the generated current Ia. Further, the battery voltage is maintained at the target voltage. Next, when the power generation stop control is executed at time t1, the generated current becomes zero, the battery is discharged at the same time, and the electric load is supplied with electric power by discharging the battery. After this time t1, the battery voltage drops below the open terminal voltage. Then, when this state is released at time t2, the battery is charged after time t2, and the battery voltage is restored to the target voltage. The electric load is again supplied with power from the generator. This time t
After 2, the generated current Ia decreases as the battery is charged, and reaches a constant value when the battery is fully charged at time t3. It is possible to determine that charging of the battery is completed by detecting the state at time t3. By the way, since the control device internally has the generated current Ia as the calculated value as described in the first embodiment, the change state of the generated current Ia does not change even if the detecting means for the generated current Ia is not provided outside. It can be easily determined. Further, the rate of change of the generated current Ia due to the turning on / off of the electric load is extremely faster than the rate of change of the battery receiving current accompanying the battery charging rate, and the battery voltage drops at the moment of turning on / off the electric load. Since the rise occurs sharply, the generated current I
If the change in a is due to battery charging,
It can be easily determined whether it is due to the off state.

Next, the operation described above will be supplemented according to the flowchart shown in FIG. First, step S8
In 01, the flag F indicating the completion of charging of the battery is reset, that is, set to zero. The following operations from S802 to S809 are the same as the operations from S502 to S509 in the above-described first embodiment, and will be omitted. If ΔV> 0 in S809, the process returns to S802 and the same operation is repeated. In addition, S809
Is not ΔV> 0, the process proceeds to S810, the change state of the generated current Ia is detected, and the process proceeds to S811. In S811, it is determined whether or not the generated current Ia has settled to a constant value.
If the generated current Ia has settled to a constant value, it is determined that the battery is fully charged, the process proceeds to S812, the charge completion flag F is set (F = 1), and the process proceeds to S814. If the generated current Ia has not settled to a constant value, it is determined that the battery has not been fully charged, the process proceeds to S813, the charging completion flag F is reset (F = 0), and S8 is performed.
Proceed to 14. In S814, a power generation not saturated is selected, and in S815, it is determined whether or not the charging completion flag F is set, that is, whether or not the battery is restored to full charge, and if charging is completed, S816 is performed. If the power generation stop control is permitted and charging is not completed, the process proceeds to step S817.
Proceed to and prohibit the power generation stop control. Then S816,
In S817, the process returns to S802 and the above control is repeated.
With this control, it is possible to detect the completion of battery charging without adding a current sensor to the outside.
In addition, it is possible to prevent control such that the discharged battery is further discharged.

Example 3. The flowchart shown in FIG. 9 will be described. Since S901 to S915 are the same as those in the second embodiment, the description thereof will be omitted. If the charging is completed in S915, the process proceeds to S916, and the rapid charging control is prohibited. If the charging is not completed, the rapid charging control is permitted in S917.
Then, in S916 and S917, the process returns to S902 and the above control is repeated. By this control, it is possible to detect the completion of charging of the battery without adding a current sensor to the outside, and it is possible to prevent control such that the battery in the fully charged state is further charged.

Example 4. Although the above-described first to third embodiments have been described separately, all of them may be controlled as one, as shown in FIG. In this way, by controlling all of them into one, it is possible to monitor the charging / discharging state of the battery without adding a current sensor to the outside, and it is possible to always keep the battery in an appropriate charging state.

[0024]

Since the present invention is constructed as described above, it has the following effects.

By calculating the battery discharge amount based on accumulating the product of the battery voltage decrease amount and the duration of the decreased state, the battery discharge amount can be calculated without adding an external current sensor or the like. Can be detected,
When the battery discharge amount exceeds a predetermined value, the over-discharge of the battery can be prevented by canceling the power generation stop control.

By determining the completion of charging of the battery from the calculation result stored in the control device, it is not necessary to add a current sensor to the outside, and after the discharging of the battery is released, until the completion of charging is determined. During this period, over-discharge can be prevented by prohibiting the power generation stop control.

By determining the completion of charging of the battery from the calculation result inside the control device, it is not necessary to add a current sensor to the outside, and after the discharging of the battery is released, until the completion of charging is determined. During this period, overcharge can be prevented by permitting quick charge control.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a general power generation control device.

FIG. 2 is a configuration diagram showing an internal configuration of a power generation control device according to an embodiment of the present invention.

FIG. 3 is a power supply system circuit diagram during generator stop control.

4A and 4B are diagrams for explaining a method for detecting battery discharge according to the first embodiment of the present invention, in which FIG. 4A is a time chart, and FIG. 4B is a relationship diagram between a battery voltage decrease amount and battery discharge.

FIG. 5 is a flowchart illustrating control according to the first embodiment of the present invention.

FIG. 6 is a battery acceptance characteristic diagram.

FIG. 7 is a time chart for explaining detection of battery charging completion according to the second embodiment of the present invention.

FIG. 8 is a flowchart illustrating control according to the second embodiment of the present invention.

FIG. 9 is a flowchart illustrating control according to the third embodiment of the present invention.

FIG. 10 is a flowchart illustrating control according to the fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Engine 3 Generator 4 Electric load 5 Control device 6 Vehicle state detection means 7 Field coil 20 Battery voltage detection means 51 Target voltage change means 52 Generator output control means 54 Battery discharge amount calculation means L1 Battery voltage detection line L2 Vehicle status signal detection line Vb Battery voltage SW Electric load switch Tr Semiconductor switch If Field current

Claims (3)

[Claims] 1. A generator driven by an engine, a battery charged by the output of the generator, an electric load supplied with electric power by the generator or the battery, and a battery voltage detection for detecting a terminal voltage of the battery. Means, means for controlling the output of the generator based on the detected voltage of the battery voltage detecting means and the target voltage of the generator, vehicle state detecting means for detecting various states of the vehicle, and detection by the vehicle state detecting means By changing the target voltage based on the result, in a power generation control device having a target voltage changing means for controlling the output of the generator, the product of the amount of decrease in the battery voltage and the duration of the voltage decrease state. A means for calculating the battery discharge amount by accumulating, and when the calculation result of the battery discharge amount calculating means exceeds a predetermined value. A power generation control device for a vehicle, comprising means for canceling a control for reducing the output of the generator or stopping the power generation. 2. A generator driven by an engine, a battery charged by the output of the generator, an electric load supplied with electric power by the generator or the battery, and battery voltage detection for detecting a terminal voltage of the battery. Means, means for controlling the output of the generator based on the detected voltage of the battery voltage detecting means and the target voltage of the generator, vehicle state detecting means for detecting various states of the vehicle, and detection by the vehicle state detecting means In a power generation control device having target voltage changing means for controlling the output of the generator by changing the target voltage based on the result, the power generation of the generator is calculated from the internal calculation result of the generator output control means. Means for detecting current, detecting that the generated current has stopped changing after discharge of the battery is released A means for determining that the charging of the battery is completed, and a means for prohibiting the control for reducing the output of the generator or stopping the power generation until it is determined that the charging of the battery is completed. Characteristic vehicle power generation control device. 3. A generator driven by an engine, a battery charged by the output of the generator, an electric load supplied with electric power by the generator or the battery, and a battery voltage detection for detecting a terminal voltage of the battery. Means, means for controlling the output of the generator based on the detected voltage of the battery voltage detecting means and the target voltage of the generator, vehicle state detecting means for detecting various states of the vehicle, and detection by the vehicle state detecting means In a power generation control device having target voltage changing means for controlling the output of the generator by changing the target voltage based on the result, the power generation of the generator is calculated from the internal calculation result of the generator output control means. Means for detecting current, detecting that the generated current has stopped changing after discharge of the battery is released Means for deciding that the charging of the battery has been completed, and means for increasing the output of the generator and permitting control to rapidly charge the battery until it is judged that the charging of the battery has been completed. A vehicle power generation control device characterized by the above.