JPH05933B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a vehicle charging generator that controls the output voltage of the vehicle charging generator to keep the uneven charging voltage constant.

A vehicle charging generator is connected to an engine, so its rotational speed varies over a wide range, and the magnitude of electrical loads such as batteries and electrical components connected to the generator is also not constant. Therefore, in order to keep the voltage supplied to the battery constant and properly charge the battery regardless of these variations in rotational speed and load, the generator is equipped with a control device (hereinafter referred to as generated voltage) that controls its output voltage (hereinafter referred to as generated voltage). (hereinafter referred to as a regulator) is attached. By the way, power is supplied from the generator to the battery through the charging output line,
Due to the wiring resistance of the charging output line, the battery charging voltage (hereinafter simply referred to as battery voltage) does not necessarily remain constant even if the generated voltage is kept constant. Conventionally, the so-called battery sensing method was common, which directly feeds back the battery voltage and controls the generated voltage to maintain it at a predetermined voltage.However, in recent years, regulators have been made into ICs and have become more compact, and they are installed integrally with the generator. As this technology has become more popular, the problems with the above-mentioned systems, which require feedback wiring and wiring terminals, have been highlighted.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a regulator that can accurately predict the battery voltage or the state of charge of the battery and maintain them appropriately without directly feeding back the battery voltage. This eliminates the need for feedback wiring and wiring terminals, eliminates the hassle of wiring, and eliminates the risk of wire breakage, significantly improving reliability.

That is, the regulator of the present invention, as shown in its overall configuration in FIG. , a conductivity detection means for detecting the conductivity of the switching means and emitting an output signal according to the conductivity; and a rotation speed detection means for detecting the rotation speed of the charging generator and emitting an output signal according to the rotation speed. and storage means for storing as a map the output current value of the charging generator with the conductivity of the switching means and the rotational speed of the charging generator as parameters under a predetermined set voltage serving as a reference;
The output current is determined by referring to the above map based on the actual conductivity of the switching means and the actual rotation speed of the charging generator when the predetermined set voltage is applied, and the output current is determined according to the magnitude of the determined output current. and set voltage generating means for correcting and changing the set voltage applied to the switching means.

In a preferred embodiment, the set voltage generating means estimates the battery voltage by taking into account the voltage drop in the charging output line leading to the battery from the determined output current, and converts the estimated battery voltage into the target battery voltage. The set voltage applied to the switching means is set to be corrected and changed in order to approach the voltage.

According to the above configuration, since the output current of the charging generator is determined based on the actual conductivity of the switching means and the actual rotation speed of the charging generator, the state of charge of the battery can be well estimated from this output current, and the switching By correcting and changing the set voltage applied to the means, it is possible to maintain a good state of charge of the battery.

Further, according to a preferred embodiment, since the battery voltage is estimated from the output current determined above, the set voltage is corrected and changed so as to bring it closer to the target battery voltage, thereby maintaining a better state of charge of the battery. be able to.

The present invention will be explained below with reference to illustrated embodiments.

In Figure 2, 1 is a charging generator, 2 is a switching circuit, 3 is a conductivity detection circuit, 4 is a rotation speed detection circuit, 5 is a multiplexer, 6 is an A/D converter, 7 is an input interface, and 8 is a microcomputer. , 9 is an output interface, 10 is a D/A converter, 14 is an on-vehicle battery, and 15 is an electrical load such as an electrical component. The on-vehicle battery 14 and the electric load 15 are connected to the charging generator 1 through a charging output line 13, and R in the figure indicates the wiring resistance of the output line 13.

The charging generator 1 has an armature winding 11 and a field winding 12
When the field winding 12 is excited, an electromotive force is generated in the armature winding 11.

The switching circuit 2 is composed of a switching transistor 21 and a comparator 22.
The set voltage signal Vs of the D/A converter 10 is input to the comparator 22, and the generated voltage Vp of the generator 1 is fed back.
By switching the field winding 12, the generated voltage Vp of the generator 1 is controlled so as to always match the set voltage Vs.

The conductivity detection circuit 3 includes a comparator 31 and a smoothing circuit 32, and the negative input terminal of the comparator 31 is connected to the collector of the transistor 21.
The collector voltage of the transistor 21 decreases when the transistor 21 is conductive, and increases when the transistor 21 is non-conductive. Therefore, when the transistor 21 is conductive and its collector voltage drops below the reference voltage Vc, the output of the comparator 31 becomes "1" level, and when the transistor 21 is non-conductive, the output of the comparator 31 becomes "1" level.
The output of 1 becomes the "0" level. The output of the comparator 31, which changes in this way, is averaged by a smoothing circuit 32 and outputted as an output signal 3a proportional to its duty ratio, that is, proportional to the conductivity of the transistor 21.

The rotation speed detection circuit 4 has a comparator 41 and F/V.
It consists of a converter 42 , and the positive input terminal of the comparator 41 is connected to one of the armature windings 11 of the charging generator 1 . The armature winding 11 has a generator 1
An alternating voltage with a frequency equal to the rotational speed is generated.
Then, the comparator 41 emits an output signal that becomes "1" level when the above-mentioned AC voltage becomes a positive voltage. Therefore, the output signal frequency of the comparator 41 is equal to the rotation speed of the generator 1. The output signal of the comparator 41 is input to the F/V converter 42,
proportional to the frequency of the output signal, i.e. generator 1
It is output as an output signal 4a proportional to the number of rotations.

The conductivity output signal 3a and the rotation speed output signal 4a are alternately selected by the multiplexer 5,
After being converted into a digital value by the A/D converter 6, it is read into the microcomputer 8 via the input interface 7.

The microcomputer 8 receives each of the above output signals 3.
The battery voltage is predicted from a and 4a, and based on the difference between the predicted battery voltage and the target battery voltage, the power generation setting voltage Vs of the generator 1 is determined in order to reduce the difference, and the output interface 9 and D /A converter 10.

Now, the calculation procedure in the microcomputer 8 and the operation of the regulator controlled thereby will be explained with reference to the flowchart shown in FIG.

In step 301, the set voltage Vs is set to an initial value Vo, and in step 302, this is output. Thereby, the generated voltage Vp of the generator 1 is controlled to the above-mentioned initial value Vo via the switching circuit 2 (see FIG. 2). This initial value is usually around 14.5V for a 12V regulator.

Next, in steps 303 and 304, the conductivity signal 3a and the rotation speed signal 4a are inputted from the conductivity detection circuit 3 and the rotation speed detection circuit 4, respectively.

By the way, when the generated voltage Vp is constant, the average output current Iv of the generator 1 is determined by using the conductivity of the switching transistor 21 as a parameter.
It changes as shown in FIG. 4 as the rotational speed changes. Here, the lines x, y, and z in the figure each have a conductivity of 100%,
It shows the change in output current Iv at 80% and 50%.

In this example, the output current Iv at the above-mentioned conductivity and rotational speed when the power generation voltage was set constant (14.5V in this example) was measured experimentally, and the output current Iv was measured using the computer 8 as an output current map.
is stored in memory.

Therefore, in step 305, the above steps 30
Based on the conductivity signal 3a and the rotational speed signal 4a input in step 3, 304, the output current Iv at that time is determined by referring to the output current map prepared in advance in the memory.

Next, in step 306, the voltage drop Vd in the output line 13 is calculated from the pre-measured wiring resistance R of the charging output line 13 (see Figure 2) and the output current Iv, and in step 307, the current power generation setting voltage is calculated. The battery voltage V _B is calculated by subtracting the voltage drop Vd from Vs. Note that the wiring resistance R is usually about 10 mΩ.

In step 308, the battery voltage V _B calculated in step is compared with the target battery voltage V _BO , and if the battery voltage V _B is smaller than the target battery voltage V _BO , in step 309 the power generation set voltage is changed.
Vs is increased by a certain amount A, and conversely, if the battery voltage V _B is larger than the target battery voltage V _BO , the power generation set voltage Vs is decreased by a certain amount A in step 310, and in the next step 311, each D is increased. /A converter 10 (see FIG. 2). When the battery voltage V _B and the target battery voltage V _BO match, the power generation set voltage Vs remains the same as before.

By periodically repeating each of the above steps, the battery voltage V _B always becomes the target battery voltage V _BO
(14v for a 12v battery) The generated voltage Vp of the generator 1 is controlled so as to match the voltage Vp. Note that the above-mentioned constant amount A is set to an appropriate value in consideration of the calculation cycle of the computer 8, etc.

To explain a specific example, the power generation set voltage Vs is
When the target battery voltage V _BO is 14.5V, the output current determined from the generator rotation speed and conductivity is
60A, the estimated battery voltage V _B is
Considering the voltage drop of 0.6V, it becomes 13.9V. Therefore, for example, 0.01V is added to the above-mentioned Vs as the above-mentioned fixed amount A, and the above-mentioned power generation setting voltage Vs is changed to 14.51V.

The conductivity decreases slightly when the generation set voltage Vs is increased, so reading the output current map based on 14.5V in this state will cause an error, but the most steady output current value (50A) If the battery voltage before and after is compensated within a range of about ±0.1V, the above error will not be a problem.

In this way, the regulator of the present invention determines the generator output current from the current conductivity of the switching transistor and the generator rotational speed based on the output current map prepared in advance in the computer, and adjusts the voltage in the charging output line. The voltage drop is calculated to accurately predict the battery voltage, and the generated voltage of the generator is controlled so that it matches the target battery voltage, so there is no need to feed back the actual battery voltage. No wiring or wiring terminals are required for this purpose. However,
This eliminates the hassle of wiring, eliminates disconnections and poor connections, and provides extremely high reliability.

Note that in the above embodiment, the ripple component in the output current increases as the current increases. Therefore, the average value of the actual battery voltage tends to become slightly lower than the predicted battery voltage as the current increases. Therefore, in anticipation of this tendency, if the computer corrects the power generation setting voltage of the generator to be higher as the output current increases, it is possible to control the battery voltage with even higher accuracy.

In that case, the target battery voltage V _BO for each output current Iv is stored and set in the map in advance, and the V _BO corresponding to the current output current Iv is read each time, and this V _BO and the calculated battery voltage V are used. _B
It may be possible to compare.

In the above embodiment, a map for reading out the output current Iv of the generator from both the conductivity and rotational speed parameters is prepared in advance, and the voltage drop Vd is determined each time from the output current Iv and the wiring resistance R. Calculate and
The battery voltage V _B is calculated from Vs - Vd = V _B , but the wiring resistance R is taken into consideration in advance, and the optimum target power generation voltage V _G is calculated directly from the conductivity and rotation speed.
Prepare a map to read out the voltage, read out the target power generation voltage V _G from the conductivity and rotation speed each time, and control the power generation state so that the actual power generation voltage of the generator matches this voltage V _G. You can do it like this. In this case, as the target power generation voltage V _G , the value read at each predetermined timing may be used as is, or the value read out immediately before may be averaged. Various processes can be considered to stably control the voltage to a target value.

Further, in the embodiments described above, the present invention is realized by a digital circuit, but it may be realized by an analog circuit using various function generators and the like.

In the above embodiment, the battery voltage is estimated from the determined output current in anticipation of the voltage drop in the charging output line, and the power generation setting voltage is changed. It is also possible to change the power generation setting voltage by estimating the state of charge of the battery.

As described above, the vehicle charging generator control device of the present invention exhibits extremely excellent performance.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of the present invention, Fig. 2 is its circuit diagram, Fig. 3 is a calculation flowchart of the microcomputer, and Fig. 4 is the generator rotation speed when changing the conductivity of the switching transistor. FIG. 3 is a diagram showing the relationship between the output current and the output current. 1...Charging generator, 2...Switching circuit,
3...Conductivity detection circuit, 4...Rotation speed detection circuit,
8...Microcomputer, 13...Charging output line, 14...Battery.

Claims (1)

[Scope of Claims] 1. Switching means for controlling the field winding current of a vehicle charging generator to maintain the output voltage of the generator at a given set voltage, and detecting the conductivity of the switching means; conductivity detection means for emitting an output signal according to the conductivity; rotation speed detection means for detecting the rotation speed of the charging generator and emitting an output signal according to the rotation speed; storage means for storing the output current value of the charging generator as a map using the conductivity of the switching means and the rotational speed of the charging generator as parameters; and the actual conduction of the switching means when the predetermined set voltage is applied. a set voltage generating means that determines an output current by referring to the map based on the rate and the actual rotational speed of the charging generator, and corrects and changes the set voltage to be applied to the switching means in accordance with the magnitude of the determined output current; A control device for a vehicle charging generator, comprising: 2 The set voltage generating means estimates the battery voltage by taking into account the voltage drop in the charging output line leading to the battery from the determined output current, and the switching means so as to bring the estimated battery voltage closer to the target battery voltage. 2. The vehicle charging generator control device according to claim 1, wherein the control device is configured to correct and change the set voltage applied to the vehicle charging generator.