JP3415168B2 - Alternator control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator control device for controlling a generator voltage of an alternator to control a battery voltage to a target voltage, and more particularly to an alternator. Overpower generation prevention measures. 2. Description of the Related Art Conventionally, as this type of alternator control device, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-184300, a vehicle-mounted battery charged by an alternator is provided, and the voltage of the vehicle-mounted battery is controlled. Is smaller than the set value, the field current flowing through the field coil of the alternator is increased to increase the power generation voltage, and the amount of charge to the vehicle battery is increased. Controls the battery voltage to the target voltage by reducing the field current, lowering the power generation pressure and reducing the charge amount of the vehicle-mounted battery, and further, even when the electric load is suddenly changed, By gradually controlling the change of the field current and gradually changing the power generation pressure, the power generation flow of the alternator is gradually changed to prevent a sudden change in the driving torque and prevent the engine rotation. There is known an arrangement in which a sudden change in the number of revolutions is suppressed, and in particular, the idling speed is stably maintained. However, the above-mentioned conventional alternator control device has the following disadvantages. That is, when performing the gradual excitation control to make the change of the field current gradual as described above, as shown in FIG. 7, when the electric load starts to operate, the power generation flow of the alternator is controlled by the gradual excitation control. The current gradually increases, and then increases beyond the load required current indicated by the broken line in the figure to compensate for the shortage caused by the gradual excitation control, and then gradually decreases to become equal to the load required current value. Therefore, at the time of such a request to increase the power generation flow of the alternator at the time of starting the operation of the electric load, etc., it is possible to suppress the sudden change of the driving torque while controlling the battery voltage satisfactorily. At times, as shown in the figure, the generated power flow does not decrease rapidly due to the gradual excitation control, but becomes a large value with respect to the load demand current indicated by the broken line, and the alternator is in an over-power generation state. As a result, when the alternator is required to reduce the generated current, such as when the operation of the electric load is stopped, a sudden change in the driving torque can be suppressed. This causes problems such as melting of the fuse. [0004] The present invention has been made in view of such a point, and an object of the present invention is to control the field current of the alternator gradually as described above while effectively suppressing a sudden change in drive torque. An object of the present invention is to effectively prevent overpower generation at the time of a request for reduction of the power flow of the alternator. In order to achieve the above object, according to the present invention, the change rate of the alternator flow is changed between when the alternator requires a decrease and when the increase is required. Configuration. Specifically, as shown in FIG. 1, a specific solution of the present invention is an alternator 1, a battery 3 charged by the alternator 1, and a battery for detecting the voltage of the battery 3. A proportional control gain iap and an integral control gain iai are set according to a voltage detecting means 13 and a deviation of the battery voltage detected by the battery voltage detecting means 13 from a target voltage, and the proportional and integral control gains iap, iai are set. And a control means 25 for controlling the voltage of the battery 3 to a target voltage by controlling the generated current of the alternator 1 on the basis of the alternator 1 when the load of the alternator 1 changes. The proportional control gain iap and the integral control gain so as to gradually change a current changing means 26 for setting the ai to a small value, the proportional control gain iap and integral control gain iai set by the current changing means 26, a positive value of the deviation which the battery voltage is lower than the target voltage Area and the battery voltage above the target voltage
While the rate of change of the proportional control gain iap with respect to the change of the deviation is set to be the same in the region of the negative value that is becoming smaller, the range of the negative value of the deviation with respect to the change of the deviation of the integral control gain iai is set. And a change speed control means for setting the change ratio to be larger than the change ratio in the positive value region of the deviation. According to the above construction, according to the first aspect of the present invention,
When the load of the alternator 1 increases, the current control means 26 controls the proportional control gain iap and the integral control gain i.
ai is set to a small value, the increasing change rate of the power generation current is set to a small value, and the battery voltage is set to a target voltage.
And the deviation of the battery voltage from the target voltage enters a positive value area, and its proportional and integral control gain ia
Since both the changing speeds of p and iai are set to be small by the changing speed control means 27, the engine load is gradually increased, and a sudden change in the driving torque is prevented. Moreover, the power generation current once rises above the load required current, then decreases and becomes equal to the required current, so that the shortage of the power generation current is compensated, and the battery voltage is quickly controlled to the target voltage. Is done. On the other hand, when the load of the alternator 1 decreases, for example, when the electric load stops operating or when the target value of the battery voltage is changed to a small value, for example, as the battery temperature of the battery increases. Battery voltage is not
Then, the deviation of the battery voltage from the target voltage enters a negative value area, and the rate of change of the integral control gain iai is set to be larger than the rate of change of the deviation in the positive value area. The rate of decrease of the flow is controlled to a large value as compared with the above increase request, and the power generation flow is rapidly reduced,
As a result, over-power generation of the alternator 1 is effectively suppressed, and battery deterioration, fuse blowing, and the like are effectively prevented. Moreover, the voltage generated by the alternator 1 is substantially
When in a steady state with a constant value, the generated voltage is microscopic.
From the perspective of fluctuations due to ripple fluctuations,
Change ratio of proportional control gain iap with respect to ripple
Set the deviation to a larger value in the negative value area than in the positive value area.
In this case, the control for decreasing the generated voltage
Too large, the balance between the two controls is lost, and hunting
, But this proportional control gain iap
The rate of change in the negative value area is the same as the positive value area.
Hunting for control in this steady state
It is unlikely to occur. As described above, according to the alternator control device of the first aspect, when the load of the alternator is changed gradually, the rate of change of the integral control gain is reduced. When the battery voltage is
In the negative range of the deviation, which is higher than the positive range, the change rate of the proportional control gain was set to be the same in the positive range and the negative range of the deviation. Without causing hunting of the control in the steady state, the occurrence of shock when the alternator load is increased and the stabilization of the idling speed are ensured, and the overpower generation when the alternator load is reduced is suppressed. Thus, the reliability of the battery and the power supply system can be improved. An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 shows an overall configuration diagram in which the present invention is applied to an alternator control device for a vehicle. In the figure, reference numeral 1 denotes an alternator which is composed of a separately-excited AC generator and is driven and linked to the output shaft of the engine. The alternator 1 includes a three-phase armature coil 1a and nine rectifying diodes D1 to D1. D9
And a field coil 1b. Reference numeral 2 denotes a controller for controlling the flow of power generated by the alternator 1, reference numeral 3 denotes a vehicle-mounted battery which is charged from the alternator 1 via a power supply harness 4, and reference numeral 5 denotes an ignition key 6 for the vehicle. This is a vehicle-mounted electric load such as a power window or a rear heat wire connected via the power window. The controller 2 includes a control transistor Tr1 for duty-controlling the energization of the field coil 1b of the alternator 1, and a control unit 10 having a CPU therein. / D
Terminal 10a has rectifier diodes D7-
While the internal output voltage signal Vt is input via D9,
The terminal voltage V of the vehicle-mounted battery 3 is applied to the other A / D terminal 10b.
s is input, and constitutes a battery voltage detecting means 13 for detecting the terminal voltage Vs of the vehicle-mounted battery 3 by the A / D terminal 10b. An intake air temperature signal of an intake air temperature sensor 11 for detecting an intake air temperature of the engine is input to another A / D terminal 10c, and a base of the control transistor Tr1 is connected to a PWM terminal 10d.
e is connected to the base of a transistor Tr2 for controlling lighting of a warning lamp 12 arranged around the driver's seat in the vehicle cabin. Next, the power generation control of the alternator 1 by the controller 2 will be described with reference to the block diagram of FIG. In the drawing, reference numeral 15 estimates the temperature of the electrolyte of the vehicle-mounted battery 3 based on the intake air temperature signal of the intake air temperature sensor 11, and the target voltage Vreg of the vehicle-mounted battery 3 based on the estimated temperature.
Is a subtractor for subtracting the terminal voltage Vs of the vehicle-mounted battery 3 from the target voltage Vreg of the target voltage setting means 15. Reference numeral 17 denotes target generator current setting means for setting the target generator current of the alternator 1 by proportional-integral control. The voltage deviation ΔV (= Vreg−Vs) obtained by the subtracter 16 and the proportional constant Kp
The target power generation flow ia is calculated and set from the following equation ia = Kp 下 記 ΔV + ＝ Ki ・ ΔVdt based on the integration constant ki. Further, 18 receives the target power generation flow ia set by the target power generation flow setting means 17 and an engine speed Ne signal as the rotation speed of the alternator 1,
A target field current calculating means for calculating a target field current ift corresponding to the engine speed Ne and the target power generation flow ia from a map stored in advance;
8 is performed based on the following formula to perform a first-order advance correction for compensating for a delay in a change in the field current caused by the inductance of the field coil 1b with respect to the target field current if calculated in step 8; Control field current calculating means. Ifc = [ift (i) −α · ift (i−1)] / (1−α) (α is a sensitivity coefficient) Further, reference numeral 20 denotes a control field calculated by the control field current calculation means 19. Control duty ratio fduty according to magnetic current ifc
And outputs the control duty ratio fduty to the base of the transistor tr1. In the figure, reference numeral 21 denotes an idle speed electric load correcting means for correcting the idle speed of the engine when the on-vehicle electric load 5 is operated, based on the target power flow ia set by the target power flow setting means 17. . Next, the power generation control of the alternator 1 by the controller 2 will be described with reference to the control flow of FIG. After starting, in step S1, the battery voltage V
In addition to inputting the s signal, an intake air temperature signal is input in step S2, and a target voltage Vreg of the vehicle-mounted battery 3 is corrected and calculated based on the input intake air temperature in step S3. Then, in step S4, a deviation ΔV (Vreg−Vs) between the target voltage Vreg of the on-vehicle battery 3 and the battery voltage Vs calculated above is calculated. In step S5, according to the deviation ΔV, FIG. The proportional control gain iap and the integral control gain iai are read from the control gain tables shown in (b). Here, the control gain table shown in FIG. 5 indicates the load of the alternator 1 when the on-vehicle electric load 5 starts or stops operating, or when the target voltage Vreg of the on-vehicle battery 3 is changed and set according to a change in the intake air temperature. The control gains iap and iai are set to small values and the rate of change in advance so that the power generation flow of the alternator 1 basically gradually changes when the change occurs. And FIG.
In the proportional control gain table of (a), the ratio of the change of the proportional control gain iap to the change of the difference ΔV is the same in the region where the voltage deviation ΔV is positive and in the region where the voltage deviation ΔV is negative, but FIG. In the integral control gain table, the rate of change of the integral control gain iai with respect to the change of the deviation ΔV has a characteristic that the voltage deviation ΔV is larger in the negative value region than in the normal value in the positive value region. Is set. Thereafter, in step S6, a target power generation flow ia is calculated based on the following two control gains iap and iai based on the following equation: ia = iap + ∫iaidt. Subsequently, at step S7, the engine speed Ne is input as the speed of the alternator 1, and at step S7
At 8, the engine speed Ne and the field current if corresponding to the generated power flow ia are read out from a power generation characteristic map stored in advance, and then, at step S 9, the field caused by the presence of the inductance of the field coil 1 b of the alternator 1. In order to compensate for the current change delay, the read field current ift is subjected to first-order advance correction to calculate the control field current ifc, and the control duty ratio fduty of the transistor Tr1 corresponding to the control field current ifc is calculated. In step S10, a calculation is performed from a table stored in advance, the duty ratio of the transistor Tr1 is controlled using the control duty ratio fduty, and the process returns. It should be noted that the target power generation current ia and the field current i
As shown in the control flow of FIG. 6, the calculation of ft and the control duty ratio fduty are performed when the vehicle speed Vsp is higher than the set vehicle speed Vo at an extremely low speed, or at a low vehicle speed including idle operation when Vsp ≦ Vo. However, when the headlamp of the vehicle is turned on, the gradual change control of the power generation flow is prohibited, and the integral control gain table shown in FIG. 5B is the same as the proportional control gain table shown in FIG. The rate of change of the integral control gain iai with respect to the change of the deviation ΔV is set to be the same in the region where the voltage deviation ΔV is a positive value and in the region where the voltage deviation ΔV is a negative value. Is prevented from decreasing. Therefore, in the control flow of FIG.
By the steps S1 to S10, the terminal voltage Vs of the vehicle-mounted battery 3 input to the input terminal 10b of the control unit 10
And the control gains iap and iai for the proportional and integral operations are calculated and set according to the deviation ΔV (= Vreg−Vs) between the target voltage Vreg and the target voltage Vreg corrected according to the intake air temperature. By calculating the field current if and the control field current ifc, feedback control of the generated current of the alternator 1 is performed, so that the terminal voltage Vs of the vehicle-mounted battery 3 is obtained.
Means 2 for controlling the voltage to the target voltage Vreg.
5. Further, in the respective control gain tables of FIGS. 5A and 5B, each of the proportional and integral control gains iap, i
ai is set to a small value in principle,
When the load on the alternator 1 changes, such as when the operation of the on-vehicle electric load 5 starts or stops, or when the target voltage Vreg of the on-vehicle battery 3 changes, the target power generation flow ia of the alternator 1 is gradually reduced.
The current changing means 26 is configured to change the actual power generation flow of the alternator 1 gradually by the control gains iap and iai of the small value proportional and integral. Further, according to the proportional control gain table and the integral control gain table of FIGS. 5A and 5B, the terminal voltage Vs of the vehicle-mounted battery 3 and the target voltage Vreg in the proportional control gain table of FIG. Voltage deviation ΔV
With rate of change of the proportional control gain iap both positive value of the region and the region of negative values (= Vreg -Vs) is set to the same, the integral control gain table in Fig. (B),
The battery voltage Vs becomes higher than the target voltage Vreg.
(Vs> Vreg) The above voltage deviation ΔV (= Vreg−V
s) In the negative value region, the rate of change of the integral control gain iai is set to a large value as compared with the positive value region, and the direction in which the power generation current is gradually changed by the current changing means 26 is a decreasing direction. In the case of, the large value (absolute value) of the integral control gain iai
The change speed control means 27 is configured such that the change speed of the power generation flow is increased as compared with the case where the power generation flow is increased by setting. [0026] Thus, in this embodiment, in the feedback control of the power s flow ia of the alternator 1, the integral control gain iai, as shown in FIG. 5 (b), the terminal voltage Vs of the battery 3 is the target voltage Vreg
Deviation is lower with respect to ΔV (= Vreg -Vs) is small rate of change in the case of positive end of the battery 3
Deviation of the slave voltage Vs with respect to the target voltage Vreg.
When the difference ΔV (= Vreg−Vs) is a negative value, the change rate is set to a large characteristic, and therefore, when the operation of the on-vehicle electric load 5 starts, or when the target voltage Vreg of the on-vehicle battery 3 is changed to a high value. For example, when the load on the alternator 1 increases, the deviation ΔV increases as a positive value, but the power generation flow ia of the alternator 1 gradually increases with the integral control gain iai having a small change rate. The increase in the load is moderated, and a sudden change in the driving torque is prevented.
Shock is effectively suppressed. On the other hand, when the operation of the on-vehicle electric load 5 is stopped, or when the target voltage Vreg of the on-vehicle battery 3 is changed to a low value in accordance with a rise in the intake air temperature (liquid temperature of the on-vehicle battery 3), the alternator is used. When the load of 1 decreases,
The terminal voltage Vs of the vehicle-mounted battery 3 is higher than the target voltage Vreg.
And the voltage deviation ΔV (= Vreg−Vs ) becomes a negative value, and the rate of change of the integral control gain iai is large in this negative value range. Changes quickly and decreases early, so that over-power generation does not occur and the terminal voltage V
s is quickly converged to the target voltage Vreg. Therefore,
Deterioration of the in-vehicle battery 3 can be suppressed to improve its reliability, and the fuse can be prevented from being blown by a large current due to over-power generation. In addition, even in the case where the generated voltage of the alternator 1 is in a steady state with a substantially constant value, the generated voltage fluctuates microscopically due to ripple fluctuation, but the change in the proportional control gain iap As shown in FIG. 5A, the ratio is set to be the same in the positive value region and the negative value region of the voltage deviation ΔV, and is not set to a large value in the negative value region like the integral control gain iai. Therefore, the balance between the control for decreasing the generation voltage and the control for increasing the generation voltage is maintained, and hunting of the control in the steady state can be effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of the invention described in claim 1. FIG. 2 is an electric circuit diagram showing the entire configuration of the alternator control device. FIG. 3 is a block diagram showing power generation flow control of the alternator. FIG. 4 is a flowchart showing the power generation flow control. FIG. 5 is a diagram showing respective control gain tables for proportional and integral. FIG. 6 is a flowchart showing another power generation control. FIG. 7 is an explanatory diagram of a state of a change in power generation current during a gradual excitation control of a field current. [Description of Signs] 1 Alternator 1b Field coil 2 Controller 3 In-vehicle battery 10b Input terminal 13 Battery voltage detecting means Tr1 Transistor 25 Control means 26 Current changing means 27 Changing speed control means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tetsuro Takaba 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-2-184300 (JP, A) JP-A Sho 59 -8008 (JP, A) JP-A-4-133700 (JP, A) JP-A-1-308135 (JP, A) Control Engineering Handbook Editing Committee "Control Engineering Handbook" (Showa 44-4-1) Asakura Bookstore p. 639 (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 9/30 H02J 7/16

Claims (1)

(57) [Claim 1] An alternator, a battery charged by the alternator, battery voltage detecting means for detecting a voltage of the battery, and the battery detected by the battery voltage detecting means The voltage of the battery is controlled to the target voltage by setting the proportional control gain and the integral control gain in accordance with the deviation of the voltage of the battery from the target voltage, and controlling the generated current of the alternator based on the proportional and integral control gains. An alternator control device comprising: a current changing means for setting the proportional control gain and the integral control gain to small values so as to gradually change the power generation flow of the alternator when the load of the alternator changes. The proportional control gain and the integral control gain set by the current changing means. The battery voltage is the target voltage
Region and the positive value of the deviation which is lower than the battery
In the negative value region where the re-voltage is higher than the target voltage, the change rate of the proportional control gain with respect to the change of the deviation is set to be the same, while the integral control gain has the same change ratio with respect to the change of the deviation. An alternator control device comprising: a change speed control means for setting a change rate in a negative value area to be larger than a change rate in a positive value area of the deviation.