JP2005073479A - Vehicular power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular power supply device by which a battery is charged, even if a power generating voltage of a generator is set below an open voltage of the battery. <P>SOLUTION: When a power generation rate D<SB>f</SB>of the generator 1 becomes below a second prescribed power generation rate D<SB>lo</SB>, a timer 5 is set and the measurement of a first prescribed time T<SB>set1</SB>is started. When the power generation rate D<SB>f</SB>continues a state of below a first prescribed power generation rate D<SB>hi</SB>during within the first prescribed time T<SB>set1</SB>, a relay A12 is turned on and a relay B13 is turned off. Further, the output voltage V<SB>alt</SB>of the generator 1 is controlled by a power generating voltage control part 7 so as to become the output voltage V<SB>alteco</SB>of less than the open voltage V<SB>b</SB>of the battery 16 and above the operating voltage of an electric equipment load 17. The battery 16 is charged with a voltage of, for example, the voltage of raising the output voltage V<SB>alteco</SB>to 14.2 V with a DC/DC converter 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle power supply device using a generator mounted on a vehicle.

  In the conventional generator voltage control of the generator, the generator voltage is controlled by the generator temperature, the battery temperature, the running state, etc. in order to maintain the charged state of the battery.

JP-A-7-227047

  If the generator voltage is set to maintain the state of charge of the battery, the generated voltage is always set to a voltage higher than the open circuit voltage of the battery. There was a problem of getting worse.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a vehicular power supply device that charges a battery even when the power generation voltage of the generator is made equal to or lower than the open circuit voltage of the battery.

  In order to achieve the above object, in the present invention, the vehicular power supply apparatus is configured to change the power generation voltage based on the power generation surplus (power generation rate) of the generator.

  According to the present invention, when the power generation surplus of the generator exceeds a predetermined value, the generated voltage is controlled to be equal to or higher than the voltage at which the vehicle electrical load can be operated and less than the open circuit voltage of the battery. The effect of improving fuel consumption can be obtained.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention. The configuration of the first embodiment of the present invention will be described with reference to FIG. The generated voltage generated in the stator winding 101 of the generator 1 that generates power by the rotation of the engine is rectified by the three-phase full-wave rectifier 102, smoothed by the capacitor 106, and then output from the output terminal 110. The output is supplied to the battery 16 via the electrical load 17, the DC / DC converter (boost means) 14 via the relay A (first switch means) 12, and the relay B (second switch means) 13. .

  The generated voltage is controlled by the exciting current supplied to the exciting winding 103 wound around the rotor, and the excitation current is controlled by the load amount detecting unit 105 and the generated voltage control unit (generated voltage control means) 7. On the other hand, by detecting the excitation current, the power generation rate detector (power generation surplus detection means) 4 detects the power generation rate (power generation surplus) of the generator 1, and the output voltage of the generator 1 is detected by the output voltage detection circuit 2. The rotation number is detected by the rotation number detection unit 3 and the output voltage, the rotation number, and the power generation rate are supplied to the general control unit 6, respectively. The comprehensive control unit 6 controls the generated voltage control unit 7 and the relay control unit (switch control means) 8 based on such information.

  The timer 5 receives a time when the power generation rate of the generator 1 is equal to or lower than or exceeds the predetermined power generation rate from the general control unit 6, measures a predetermined time from that time, and informs the general control unit of the elapse of the predetermined time. The relay control unit 8 receives an instruction from the general control unit 6 and controls ON (closed) / OFF (open) of the relay A12 and the relay B13. The DC / DC converter 14 boosts the output voltage of the generator 1 to a voltage necessary for charging the battery 16. The current detector 15 measures the charging current from the DC / DC converter 14 to the battery 16.

  The battery temperature detection unit (battery temperature detection means) 10 and the battery voltage detection unit 11 detect the temperature and voltage of the battery, respectively, and supply these values to the boost voltage control unit (boost control means) 9. The boosted voltage control unit 9 controls the output voltage of the DC / DC converter 14 based on the battery temperature, voltage and battery charging current.

  Next, the operation of the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a time chart showing the operation of the first embodiment of the present invention, and FIG. 3 is a flowchart showing an overview of the overall operation of the first embodiment of the present invention. A schematic operation of the vehicle power supply device will be described with reference to FIG.

When the engine is started and the generator 1 starts generating power, first, as shown by 301 in FIG. 3, the relay A12 is turned off and the relay B13 is turned on. The relay state in which the relay A12 is off and the relay B13 is on is maintained to supply power from the battery 16 to the electrical load 17 even when the engine is stopped (the output of the generator 1 is zero). Yes. Further, when these relays A12 are off and the relay B13 is on, when the generator 1 is outputting, the electric load 17 is supplied with power from both the battery 16 and the generator 1 (this relay A12 is off). The mode in which the relay B13 is turned on is referred to as the on mode), and the electric load 17 is large, and is a mode in which a heavy load state in which the power generated by the generator 1 cannot be cut off only by the generated power is taken. Therefore, the generator 1 _starts to increase the output voltage V _alt to the open voltage V _b of the battery 16, for example, _12.8 V or higher (V _althi ) (302), and generates power if the electrical load 17 continues to be large. The output voltage V _alt of the machine 1 maintains V _althi (power generation rate 100%) (in the case of N in 303). This state is the on-mode state of FIG.

On the other hand, the smaller the electrical load 17 as compared to the amount of electric power generated by the generator 1, the generator 1 detects that the electrical load 17 is small load detection unit 105, lowering the controls the exciting current generator ratio D _f. When the power generation rate D _f becomes equal to or lower than the second predetermined power generation rate D _lo (greater than or equal to the second predetermined remaining capacity) (in the case of 303 at Y, in FIG. 2 at time d), the timer 5 is set. Set and start (304) timing of the first predetermined time T _set1 . If the power generation rate D _f exceeds the first predetermined power generation rate D _hi higher than the second predetermined power generation rate D _lo within the first predetermined time T _set1 (if the power generation rate D _f is less than the first predetermined remaining capacity, In the case of N in 305, the timer 5 is reset (R in 304), and the relay A12 is kept off and the relay B13 is kept on (on mode).

However, if the power generation rate D _f continues to be equal to or lower than the first predetermined power generation rate D _hi within the first predetermined time T _set1 (Y in 305), the relay A12 is turned on and the relay B13 is turned off. (307, time point e in FIG. 2) (This mode in which the relay A12 is on and the relay B13 is off is referred to as an off mode). That is, when the power generation rate D _f is equal to or less than the predetermined power ratio (power margin is equal to or greater than a predetermined margin) to off mode in. Further, the generated voltage control unit 7 controls the output voltage V _{alt so} that the output voltage V _alt is less than the open circuit voltage V _b (for example, 12.8 V) of the battery 16 and equal to or higher than the operating voltage of the electrical load 17 (for example, _12.2 V). in but controlled, relay A12 is turned on, the relay B13 to power off and the output voltage _{V Alteco} from the voltage of the output and the battery 1 of the generator 1, the power supply is not generating power output voltage _{V Althi} to the electrical load 17 In order to switch to the generator 1 only, when the generator 1 suddenly changes the output voltage to _Valteco , the voltage fluctuation to the electrical load 17 increases in a short time and the headlamp flickers. The gradual excitation control is performed for the output of 1 toward the output voltage V _alteco (308). This state is shown as slow excitation 1 in FIG. On the other hand, in the off mode, the battery 16 is charged with a voltage obtained by boosting the output voltage _Valteco (for example, _12.2 V) to, for example, 14.2 V by the DC / DC converter 14.

Table 1 shows an example of the load condition, the corresponding power supply, the output voltage V _dd of the DC / DC converter 14, and the output voltage V _alt of the generator 1 in each mode described above.

車両速度が遅くなり、発電機１の発電率Ｄ_ｆが増加したり、電装負荷１７が大きくならない限り発電機１は低い出力電圧Ｖ_{ａｌｔｅｃｏ}を維持（３０９のＮの場合）し続けるため、エンジンの消費トルクを低減することになり、車両の燃費向上に貢献する（オフモード＝エコノミーモード）。一方、バッテリ１６は出力電圧Ｖ_{ａｌｔｅｃｏ}をＤＣ／ＤＣコンバータ１４で昇圧した電圧、例えば１４．２Ｖで充電されるため、充電不足にはならない。更にバッテリ１６は図４に示すようなバッテリ温度−充電電圧特性があり、バッテリの温度をバッテリ温度検出部１０で検出し、昇圧電圧制御部９がＤＣ／ＤＣコンバータ１４の出力電圧Ｖ_ｄｄを制御することによって、効率的にバッテリ１６を充電できる。また、バッテリ１６への充電電流を電流検出部１５で測定し、バッテリ電圧をバッテリ電圧検出部１１で測定し、それら測定値に基づき昇圧電圧制御部９がＤＣ／ＤＣコンバータ１４の出力電圧Ｖ_ｄｄを制御することにより、更に効率的にバッテリ１６を充電することが可能となりバッテリ１６の寿命も延ばせる。

Since the generator 1 _continues to maintain a low output voltage _Valteco (in the case of 309 N) unless the vehicle speed decreases, the power generation rate D _f of the generator 1 increases, or the electrical load 17 increases, This reduces torque consumption and contributes to improved vehicle fuel efficiency (off mode = economy mode). On the other hand, since the battery 16 is charged with a voltage obtained by boosting the output voltage V _alteco by the DC / DC converter 14, for example, 14.2V, charging does not become insufficient. Further, the battery 16 has a battery temperature-charge voltage characteristic as shown in FIG. 4. The battery temperature is detected by the battery temperature detector 10, and the boost voltage controller 9 controls the output voltage V _dd of the DC / DC converter 14. By doing so, the battery 16 can be charged efficiently. Further, the charging current to the battery 16 is measured by the current detection unit 15, the battery voltage is measured by the battery voltage detection unit 11, and the boost voltage control unit 9 outputs the output voltage V _dd of the DC / DC converter 14 based on these measurement values. By controlling this, the battery 16 can be charged more efficiently, and the life of the battery 16 can be extended.

Next, when the low output voltage V _alteco is supplied to the electrical load 17, as shown in FIG. 2, when the vehicle speed decreases and the power generation amount of the generator 1 decreases, the generator 1 generates the power generation rate D _f. When the power generation rate D _f exceeds the first predetermined power generation rate D _hi (in the case of Y of 309, as shown in FIG. 2a), the timer 5 is set. Then, the timing of the second predetermined time T _set2 is started (310). If the power generation rate D _f becomes less than the second predetermined power generation rate D _lo within the second predetermined time T _set2 (N of 311), the timer 5 is reset (R of 310) and the relay A12 Is on and relay B13 is off (off mode).

However, if the power generation rate D _f continues to be greater than or equal to the second predetermined power generation rate D _lo within the second predetermined time (T _set2 ) (in the case of 311 Y), first, the relay A12 and Both relays B13 are turned off (313), and the battery open circuit voltage _Vb is detected (314) by the battery voltage detection circuit 11. Further, in order to avoid a sudden voltage fluctuation to the electrical load 17 that changes from the output voltage V _alteco to the voltage of the battery 16 by turning off the next relay A12 and turning on the relay B13, the generator 1 is connected to the output voltage V _Gradual excitation (315, described as gradual excitation 2 in FIG. 2) toward althi. Thereafter, with the relay A12 turned off, the relay B13 is switched on (316, at time c in FIG. 2), and power is supplied from the generator 1 and the battery 16 to the electrical load 17. That is, power factor D _f is the on mode in the case of exceeding a predetermined power generation rate (if surplus electricity is less than the predetermined margin).

Next, as shown in FIG. 2, when the vehicle speed increases and the power generation rate D _f becomes equal to or lower than the second predetermined power generation rate D _lo (when Y in 303), the timer 5 is set, The timing of a predetermined time T _set1 of 1 is started (304). Since the description after this operation has been made earlier, the description is omitted.

  By setting the first and second predetermined power generation rates and the first and second predetermined times as described above, the relay A12 and the relay B13 can be immediately switched due to sudden load fluctuations or power generation fluctuations. It can be protected and unnecessary switching operations can be suppressed.

In the above description, the case where the speed of the vehicle becomes slow and the generator 1 increases the power generation rate _Df has been described. However, even if the speed of the vehicle does not change, the electrical load 17 can be reduced by using a cooler, for example. when also increased, since the power ratio D _f increases, turns off the relay A12, it is clear that may occur situations to switch the relay B13 on, also, margin generator conditions of the relay switch (power ratio) However, it is also possible to estimate relay switching conditions from the engine speed, vehicle speed, and the like.

  Next, the operation of the second embodiment of the present invention will be described with reference to FIG. 1, FIG. 5, and FIG. The circuit configuration is the same as in FIG.

In the second embodiment of the present invention, the threshold for determining the surplus power of the generator 1 in the on mode is set to be smaller than the threshold for determining the surplus power in the off mode (the power generation rate is set to be large). is there. As shown in FIG. 5, in the on-mode, the fourth predetermined power generation rate D _lon (fourth predetermined _remaining power) exceeds the second predetermined power generation rate D _lo and is less than the first predetermined power generation rate (D _1o <D _lon <D _hi ), and a third predetermined power generation rate D _hin (third predetermined _remaining power) is set to a value that exceeds the first predetermined power generation rate D _hi (D _hin > D _hi ).

Next, a description will be given using the flowchart of FIG. In the flowchart of FIG. 6, as indicated by 301 in the same manner as FIG. 3, first, the relay A12 is set to OFF, the relay B13 is set to ON, and the on mode is set. The generator 1 is controlled by the power generation voltage control unit 7 to increase the output voltage to V _althi , but the power generation rate D _f is equal to or lower than the fourth predetermined power generation rate D _lon (more than the fourth predetermined _remaining capacity). (In the case of Y in 603) At the time point (time point d in FIG. 5), the timer 5 is set and the time _measurement of the first predetermined time T _set1 is started (304). If the power generation rate D _f exceeds the third predetermined power generation rate D _hin within the first predetermined time T _set1 (if it is less than the third predetermined remaining capacity, N in 605), the timer 5 is reset ( 304 R), and the relay A12 is off and the relay B13 is on (on mode).

But first predetermined time _{T set1} within between, if power ratio _{D f} is continued following the third predetermined power ratio _{D hin} (If Y in 605), and turns on the relay A12, turns off the relay B13 (307) Yes (becomes off mode). Since the subsequent operation flow is the same as that described in the first embodiment, the description thereof will be omitted.

In this way, by setting the fourth predetermined power generation rate D _lon , which is the power generation rate threshold in the on mode, to a value higher than the second predetermined threshold D _{lo and} lower than the first predetermined power generation rate D _hi. Since the frequency of entering the off mode can be increased, the fuel consumption can be further improved. In addition, only the fourth predetermined power generation rate D _lon may be increased, but when only the fourth predetermined power generation rate D _lon is increased, the first predetermined power generation rate D _hi and the fourth predetermined power generation rate D Since the difference from the power generation rate D _lon is small, the possibility that the power generation rate D _f exceeds the first predetermined power generation rate D _hi during the timer measurement (during T _set1 ) is increased, and the frequency of entering the off mode may be decreased. If there is sex, it is preferable to set the first third predetermined power ratio D _hin exceeding a predetermined power generation rate D _hi oN mode as shown in the second embodiment.

The circuit block diagram which shows the schematic whole structure of 1st Embodiment. The time chart which shows operation | movement of 1st Embodiment. The flowchart which shows the outline | summary of the whole operation | movement of 1st Embodiment. Battery temperature-charge voltage characteristic diagram. The time chart which shows operation | movement of 2nd Embodiment. The flowchart which shows the outline | summary of the whole operation | movement of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Generator 4 Power generation rate detection part 7 Power generation voltage control part 8 Relay control part 9 Boost voltage control part 11 Battery voltage detection part 12 Relay A 13 Relay B
14 DC / DC converter 16 Battery 17 Electrical load

Claims (7)

A generator that generates electricity by rotating the engine;
A battery connected in parallel with the electrical load connected to the generator via the generator and a second switch means;
Boosting means connected to the generator via first switch means, boosting the output voltage of the generator to a voltage equal to or higher than the open circuit voltage of the battery, and supplying the boosted voltage to the battery;
Power generation surplus detection means for detecting the power generation surplus power of the generator;
Power generation voltage control means for controlling the output voltage of the generator based on at least the power generation surplus detected by the power generation surplus detection means;
Switch control means for controlling closing and opening of the first switch means and the second switch means,
When the power generation surplus detected by the power generation surplus detection means is greater than or equal to a predetermined surplus power, the switch control means closes the first switch means, opens the second switch means, and generates power generation voltage control. The means controls the output voltage of the generator to a predetermined voltage that is equal to or higher than a voltage at which the electrical load is operable and less than an open voltage of the battery,
When the power generation surplus detected by the power generation surplus detection means is less than the predetermined power reserve, the switch control means opens the first switch means and closes the second switch means. A vehicle power supply device.   When the power generation surplus detected by the power generation surplus detection means is less than the predetermined surplus power, the power generation voltage control means controls the output voltage of the generator to at least a voltage equal to or higher than the open circuit voltage of the battery. The vehicle power supply device according to claim 1.   The first predetermined surplus power is obtained for a second predetermined time after the power generation surplus detected by the power generation surplus detecting means is greater than or equal to a first predetermined surplus power and less than the first predetermined surplus power. When the second predetermined remaining capacity is exceeded, the generated voltage control means controls the output voltage of the generator to at least the open circuit voltage of the battery after the second predetermined time. 2. The vehicle power supply device according to claim 1, wherein the switch control means opens the first switch means and closes the second switch means.   When the power generation surplus detected by the power generation surplus detection means becomes less than the second predetermined surplus to be greater than or equal to the second predetermined surplus, the first time from when the power exceeds the second predetermined surplus. The power generation voltage control means, after the first predetermined time, determines the output voltage of the generator to be a voltage at which the electrical load can operate when the power exceeds the first predetermined remaining power within a predetermined time. The control is performed to the predetermined voltage lower than the open circuit voltage of the battery, and the switch control means closes the first switch means and opens the second switch means. 4. The vehicle power supply device according to 3.   The power generation surplus detected by the power generation surplus detection means is less than the second predetermined surplus and less than the fourth predetermined surplus exceeding the first predetermined surplus to be greater than or equal to the fourth predetermined surplus. In the case where the power generation voltage control means is greater than or equal to the first predetermined surplus power within the first predetermined time from when the fourth predetermined surplus power is reached, the generated voltage control means After the predetermined time, the output voltage of the generator is controlled to the predetermined voltage that is equal to or higher than the voltage at which the electrical load can operate and less than the open voltage of the battery, and the switch control means includes the first switch. 4. The vehicle power supply device according to claim 3, wherein the means is closed and the second switch means is opened.   The power generation surplus detected by the power generation surplus detection means is less than the second predetermined surplus and less than the fourth predetermined surplus exceeding the first predetermined surplus to be greater than or equal to the fourth predetermined surplus. And when it is equal to or more than a third predetermined remaining force less than the first predetermined remaining force within the first predetermined time from when the fourth predetermined remaining force is exceeded. The generated voltage control means controls, after the first predetermined time, the output voltage of the generator to be equal to or higher than the voltage at which the electrical load is operable and less than the open voltage of the battery, and the switch 4. The vehicle power supply device according to claim 3, wherein the control means closes the first switch means and opens the second switch means.   2. A battery temperature detecting means for detecting the temperature of the battery, and a boost control means for setting an output voltage of the boosting means based on the battery temperature detected by the battery temperature detecting means. The power supply device for vehicles in any one of -4.

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