JP2010013011A - Power supply system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply system for a vehicle preventing a decrease in voltage of a main power supply system even when electricity consumption of an electric power load is increased, and preventing the occurrence of waste of energy by adequately accumulating electric power of regenerative power. <P>SOLUTION: This invention relates to the power supply system for the vehicle supplying the electric power to the electric power load of the vehicle, and it is provided with: the main power supply system including a generator, and a first storage means for accumulating the power generated by the generator; a sub power supply system with the power load connected thereto, which includes a second storage means for accumulating the power output from the main power supply system and supplying the power to the power load; a first storage amount detecting means for detecting the amount of storage of the first storage means; a second storage amount detecting means for detecting the amount of storage of the second storage means; and a control means for controlling the amount of power supply from the main power supply system to the sub power supply system, based on storage information obtained by the first storage amount detecting means and that obtained by the second storage amount detecting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle power supply system, and more specifically, the main power supply system voltage does not decrease even when the power consumption of the power load increases, and the power such as regenerative power is sufficiently accumulated to save energy. The present invention relates to a vehicle power supply system that prevents waste.

  2. Description of the Related Art Conventionally, there is a vehicle power supply system that accumulates electric power generated from a generator of an automobile in a battery and supplies the accumulated electric power to a vehicle power load (see, for example, Patent Document 1). A conventional power supply system for a vehicle is connected to a main power supply system including a generator that generates electric power by receiving driving force of an engine, and a first power storage unit that stores electric power generated by the generator, and an electric power load. And a plurality of sub power supply systems including second power storage means for accumulating power output from the main power supply system and supplying power to the power load. The electric power output from the main power supply system is stepped up / down by the converter, and the stepped up / down electric power is stored in the second power storage means.

  In the conventional vehicle power supply system, electric power generated by the generator in response to the driving force of the engine and regenerative electric power generated by the generator during braking of the vehicle are stored in the first power storage means (battery). When the power load is activated, the converter is activated, and the power of the main power supply system is supplied to the sub power supply system even if the amount of power stored in the first power storage means is small. Therefore, when the power consumption of the power load increases, the voltage of the main power supply system may be lower than the normal value. In particular, if a power load that consumes a large amount of power, such as a power steering system or a brake assist system, operates at the same time, the power consumption as a whole increases considerably. In some cases, the voltage of the main power supply system temporarily dropped from a normal value. When the voltage of the main power supply system falls below the normal value, the amount of power supplied to other sub-power supply systems may drop, and other power loads may not operate normally.

Moreover, in the said vehicle power supply system, electric power was not supplied to the corresponding sub-power supply system, unless the electric power load started. For this reason, when there is no active power load or when the stored power of the first power storage means is full when the power storage is full, even if power such as regenerative power is generated in the generator, the power can be stored. In some cases, energy wasted.
JP 2003-70106 A

  The present invention has been made in view of such circumstances, and even if the power consumption of the power load increases, the voltage of the main power supply system does not decrease, and power such as regenerative power is sufficiently accumulated. It is an object of the present invention to provide a vehicle power supply system that prevents energy from being wasted.

The present invention employs the following means in order to solve the above problems.
A vehicle power supply system according to the present invention includes:
A vehicle power supply system for supplying power to a vehicle power load,
A main power supply system including a generator and first power storage means for storing electric power generated by the generator;
A sub-power supply system including second power storage means connected to the power load, storing the power output from the main power supply system, and supplying the power to the power load;
First power storage amount detection means for detecting a power storage amount of the first power storage means;
Second power storage amount detection means for detecting a power storage amount of the second power storage means;
Control means for controlling the amount of power supplied from the main power supply system to the sub power supply system based on the power storage information obtained by the first power storage amount detection means and the power storage information obtained by the second power storage detection means. Prepare.

  According to the present invention, the power supply amount from the main power supply system to the sub power supply system is controlled based on the power storage information obtained by the first power storage amount detection means and the power storage information obtained by the second power storage detection means. That is, the power supply amount from the main power supply system to the sub power supply system is adjusted according to the respective power storage amounts of the first power storage means and the second power storage means. Therefore, even when the amount of power stored in the first power storage means is small, power is not supplied from the main power supply system to the sub power supply system, and when the power consumption of the power load increases, the voltage of the main power supply system is It is possible to prevent the decrease. Further, when the amount of power stored in the first power storage means is large and the amount of power stored in the second power storage means is small, it is possible to actively supply power from the main power supply system to the sub power supply system. Thereby, when the 1st electrical storage means is in a saturated state, electric power, such as regenerative power, can be positively accumulated in the 2nd electrical storage means.

In the present invention,
It is preferable that the sub power supply system further includes voltage adjusting means for adjusting the voltage output from the main power supply system and supplying the electric power after voltage adjustment to the second power storage means.

  According to this configuration, the voltage output from the main power supply system can be adjusted, and the electric power after the voltage adjustment can be stored in the second power storage unit.

In the present invention,
Preferably, the voltage adjusting means steps up and down the voltage output from the main power supply system.

  According to this configuration, the voltage output from the main power supply system can be stepped up and down, and the electric power after the step-up and step-down can be stored in the second power storage unit.

In the present invention,
The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the amount of power stored in the first power storage means is equal to or greater than a threshold, the first control means informs the second control means that power can be supplied from the main power supply system to the sub power supply system. The second control means is configured to cause the sub-power supply system to receive power when the amount of power stored in the second power storage means is equal to or less than a threshold when receiving a notification that power supply is possible. It is preferable to control the voltage adjusting means.

  According to this configuration, when the power storage amount of the first power storage means is equal to or greater than the threshold value and the power storage amount of the second power storage means is equal to or less than the threshold value, power is supplied from the main power supply system to the sub power supply system, Electric power can be positively accumulated in the second power storage means.

In the present invention,
The electric power stored in the first power storage means is preferably regenerative electric power.

  According to this configuration, when the power storage amount of the first power storage means is equal to or greater than the threshold value and the power storage amount of the second power storage means is equal to or less than the threshold value, regenerative power is supplied from the main power supply system to the sub power supply system. The regenerative power can be positively accumulated in the second power storage means.

In the present invention,
The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the second control means requests the first control means to supply power from the main power supply system to the sub power supply system, if the amount of power stored in the first power storage means is less than or equal to a threshold value, the first control means The control means notifies the second control means that power cannot be supplied, and the second control means receives the notice and controls the voltage adjusting means to prevent the sub power supply system from receiving power. It is preferable to control.

  According to this configuration, when the second control unit requests the first control unit to supply power from the main power supply system to the sub-power supply system, the second storage unit can store the second storage unit when the storage amount of the first storage unit is equal to or less than the threshold. The control means controls the voltage adjusting means so that the sub power supply system does not receive power. Therefore, the voltage drop of the main power supply system can be reliably prevented.

In the present invention,
When the second control means receives notification that power cannot be supplied, the power load preferably receives power from the second power storage means.

  According to this configuration, since the power load receives power from the second power storage means, it is possible to reliably prevent a voltage drop in the main power supply system.

In the present invention,
When the second control means receives notification that power cannot be supplied, the power load preferably suppresses power consumption.

  According to this configuration, since the power consumption of the power load can be suppressed, a voltage drop in the main power supply system can be reliably prevented.

In the present invention,
The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the second control means requests the first control means to supply power from the main power supply system to the sub power supply system, if the amount of power stored in the first power storage means is less than or equal to a threshold value, the first control means The control means requests the second control means to wait for the power supply until the power generation amount of the generator rises to a threshold value, and the power load until the power supply from the main power supply system is started. It is preferable to receive power from the second power storage means.

  According to this configuration, since the power load receives power from the second power storage unit until the power supply from the main power supply system is started, it is possible to reliably prevent a voltage drop in the main power supply system.

In the present invention,
When the second control unit receives a power supply standby request, it is preferable that the power load is delayed in starting.

  According to this configuration, since the power load delays its start-up, a voltage drop in the main power supply system can be prevented.

In the present invention,
When the second control means receives a standby request for power supply, the power load first receives power from the second power storage means, and the main power supply is started when power supply from the main power supply system is started. It is preferable to receive power from the power supply system.

  According to this configuration, the power load receives power from the second power storage unit until power supply from the main power supply system is started, and when power supply from the main power supply system is started, power is supplied from the main power supply system. Supply and demand. Therefore, the voltage drop of the main power supply system can be reliably prevented.

  According to the present invention, the voltage of the main power supply system does not decrease even when the power consumption of the power load increases. Therefore, even if the power consumption of the power load increases, the operation of other power loads is not affected. Further, it is possible to sufficiently accumulate power such as regenerative power so that energy is not wasted.

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the vehicle power supply system according to the first embodiment.

  As shown in FIG. 1, the vehicle power supply system 1 according to the first embodiment is a system that supplies power to a power load of a vehicle such as an automobile. The power load in the present embodiment includes a large power load 2 with large power consumption and a small power load 20 with small power consumption. “Power load” in the claims mainly refers to the large power load 2. The large power load 2 is, for example, a power steering system, a brake assist system, or the like. It is also possible to apply the “power load” in the claims to the small power load 20.

  The vehicular power supply system 1 includes a main power supply system 3, a sub power supply system 4, a first storage amount detection unit 5, a second storage amount detection unit 6, and a control unit 7.

  The main power supply system 3 receives the driving force of an engine (not shown) to generate electric power, generates a regenerative electric power during braking, and first power storage means 9 that stores electric power generated by the electric generator 8. Including.

  Although the kind of generator 8 is not specifically limited, For example, it is an alternator. The first power storage means 9 is a battery. The power storage capacity of the first power storage means 9 is larger than the power storage capacity of the second power storage means 10.

  Sub power supply system 4 includes second power storage means 10 and voltage adjustment means 15.

  The second power storage unit 10 stores the power output from the main power supply system 3 and supplies the power to the large power load 2. Although the kind of the 2nd electrical storage means 10 is not specifically limited, For example, it can be set as a battery or a capacitor | condenser.

  A large power load 2 is connected to the second power storage means 10 in parallel. The sub power system 4, the second control unit 12, the second charged amount detection unit 6, and the large power load 2 constitute a large power load system 13.

  The voltage adjusting means 15 adjusts the voltage output from the main power supply system 3 and supplies the electric power after the voltage adjustment to the second power storage means 10 and the large power load 2. The voltage adjusting means 15 is a DC-DC converter, for example. The voltage adjusting means 15 steps down the voltage output from the main power supply system 3. Note that the voltage adjusting means 15 may boost the voltage output from the main power supply system 3 in accordance with the voltage required by the large power load 2.

  At least one high power load system 13 is provided. In the example shown in FIG. 1, N large power load systems 13 (N is an integer of 2 or more) are connected to the main power supply system 3 in parallel.

  The main power supply system 3 is connected to at least one small power load system 14. In the example shown in FIG. 1, N (N is an integer of 2 or more) small power load systems 14 are connected to the main power supply system 3 in parallel. The small power load system 14 includes a small power load 20, a voltage adjusting unit, and a power storage unit (none of which are shown).

  The first power storage amount detection unit 5 detects the power storage amount of the first power storage unit 9. The method for detecting the storage amount of the first storage amount detection means 5 is not particularly limited. For example, the voltage between the positive and negative terminals of the first storage means 9 and the current flowing through the positive terminal are measured, and based on the measurement results. To detect the charged amount.

  The second power storage amount detection unit 6 detects the power storage amount of the second power storage unit 10. The method for detecting the storage amount of the second storage amount detection means 6 is not particularly limited. For example, the voltage between the positive and negative terminals of the second storage means 10 and the current flowing through the positive terminal are measured, and based on the measurement results. To detect the charged amount.

  The control unit 7 controls the power supply amount from the main power supply system 3 to the sub power supply system 4 based on the storage information obtained by the first storage amount detection unit 5 and the storage information obtained by the second storage amount detection unit 6. To do.

  The control means 7 includes a first control means 11 that controls the main power supply system 3 and a second control means 12 that controls the sub power supply system 4 and can communicate with the first control means 11.

FIG. 2 is a diagram illustrating a first example of operations of the first control unit 11 and the second control unit 12.
When the power storage amount of the first power storage means 9 is equal to or greater than the threshold value due to the power generation of the generator 8, the first control means 11 sends the main power supply system 3 to the second control means 12 as shown in FIG. 2. That the power supply to the sub power supply system 4 is possible (see arrow 16). If the amount of power stored in the second power storage unit 10 is less than or equal to the threshold when the notification 16 that power supply is possible is received from the first power storage unit 9, the second control unit 12 In addition to notifying that power is received (see arrow 17), the voltage adjusting means 15 is controlled so that the sub-power supply system 4 receives power (see arrow 21). As a result, power is supplied from the main power supply system 3 to the sub power supply system 4 (see arrow 22). Specifically, the power output from the main power supply system 3 is adjusted to a voltage required by the high power load 2 by the voltage adjusting means 15. The electric power after the voltage adjustment is supplied to the large power load 2 and the second power storage means 10 (see arrow 23). The electric power supplied to the second power storage unit 10 is stored in the second power storage unit 10. When the large power load 2 is stopped, most or all of the power after voltage adjustment is supplied to the second power storage means 10.

  In the example shown in FIG. 2, the power that the first control means 11 performs notification 16 to supply from the main power supply system 3 to the sub power supply system 4 may be power generated by driving the engine. Alternatively, it may be regenerative electric power generated while the engine brake is applied.

FIG. 3 is a diagram illustrating a second example of the operation of the first control unit 11 and the second control unit 12. FIG. 3A shows a second example 1 and FIG. 3B shows a second example 2.
In the example shown in FIG. 3A, the second control means 12 requests the first control means 11 to supply power from the main power supply system 3 to the sub power supply system 4 (see arrow 18). If the amount of power stored in the first power storage means 9 is equal to or less than the threshold when this request is made, the first control means 11 notifies the second control means 12 that power cannot be supplied (see arrow 19). Upon receiving the notification 19, the second control means 12 controls the voltage adjusting means 15 so that the sub power supply system 4 does not receive power from the main power supply system 3 (see arrow 23). That is, the second control unit 12 controls the output voltage of the voltage adjusting unit 15 to 0 (V). As a result, power supply from the main power supply system 3 to the sub power supply system 4 is not performed, so that a voltage drop in the main power supply system 3 is prevented.

  In the example shown in FIG. 3A, when the second control unit 12 receives the notification 19 that the power cannot be supplied from the first control unit 11, the high power load 2 is the second control unit. 12 (see arrow 24), and receives power from the second power storage means 10 (see arrow 25).

  The example shown in FIG. 3 (b) is different from the example of FIG. 3 (a) in the contents of instructions from the second control means 12 to the large power load 2 and the operation of the large power load 2, and other operations. Is the same as in the case of FIG. In the example shown in FIG. 3B, an instruction 26 is given instead of the instruction 24. That is, the second control unit 12 issues an instruction 26 to the high power load 2 so as to keep power consumption low. In response to the instruction 26, the large power load 2 receives less power than usual from the second power storage means 10 (see arrow 27).

FIG. 4 is a diagram illustrating a third example of the operation of the first control unit 11 and the second control unit 12. 4A shows the first example, FIG. 4B shows the third example, and FIG. 4C shows the third example.
In the example shown in FIG. 4A, the second control means 12 requests the first control means 11 to supply power from the main power supply system 3 to the sub power supply system 4 (see arrow 27). If the amount of electricity stored in the first electricity storage means 9 is less than or equal to the threshold when this request 27 is made, the first control means 11 sends power to the second control means 12 until the amount of electricity generated by the generator 8 rises to the threshold. Request to wait for supply (see arrow 28). Upon receiving the request 28, the second control means 12 controls the voltage adjusting means 15 so that the sub power supply system 4 does not receive power from the main power supply system 3 (see arrow 29). That is, the second control unit 12 controls the output voltage of the voltage adjusting unit 15 to 0 (V). As a result, power supply from the main power supply system 3 to the sub power supply system 4 is not performed, so that a voltage drop in the main power supply system 3 is prevented.

  In the example shown in FIG. 4A, when the second control unit 12 receives the standby request 28 from the first control unit 11, the high power load 2 receives an instruction from the second control unit 12. In response (see arrow 30), power is received from the second power storage means 10 until power supply from the main power supply system 3 to the sub power supply system 4 is started (see arrow 31).

  The example shown in FIG. 4 (b) is different from the example of FIG. 4 (a) in the contents of instructions from the second control means 12 to the large power load 2 and the operation of the large power load 2, and other operations. Is the same as in the case of FIG. In the example shown in FIG. 4B, an instruction 32 is given instead of the instruction 30. That is, when a standby request for power supply is received from the first control unit 11, the second control unit 12 issues an instruction 32 to the high power load 2 so as to delay activation. The large power load 2 receives the instruction 32 and delays activation.

  In the example shown in FIG. 4C, the contents of instructions from the second control means 12 to the large power load 2 and the voltage adjusting means 15 and the operations of the large power load 2 and the voltage adjusting means 15 are shown in FIG. The other operations are the same as those in FIG. 4A. In the example shown in FIG. 4C, the state transitions from (1) to (2).

  In FIG. 4C, when the second control means 12 receives a power supply standby request from the first control means 11, first, as shown in (1), the second control means 12 The voltage adjusting means 15 is controlled so that the sub power supply system 4 does not receive power from the main power supply system 3 (see arrow 29). That is, the second control unit 12 controls the output voltage of the voltage adjusting unit 15 to 0 (V). The large power load 2 receives power from the second power storage means 2 (see arrow 33).

  Next, when the power generation amount of the generator 8 is increased to a threshold value according to an instruction from the first control means 11 and the main power supply system 3 is in a state where power can be supplied, the first control means 11 becomes the second control means. 12 is notified of this. Upon receiving the notification, the second control means 11 controls the voltage adjusting means 15 so that power is supplied from the main power supply system 3 to the sub power supply system 4 as shown in (2) (arrow 34). reference). That is, the second control unit 12 controls the output voltage of the voltage adjusting unit 15 to a voltage required by the high power load 2. In response to the instruction 34 from the second control unit 12, the voltage adjustment unit 15 adjusts the voltage of the power (see arrow 35) input from the main power supply system 3, and converts the voltage-adjusted power to the large power load 2 and It supplies to the 2nd electrical storage means 10 (refer arrow 36). The large power load 2 receives an instruction from the second control means 12 (see arrow 37) and receives power from the main power supply system 3 when power supply from the main power supply system 3 is started (see arrow 36). ).

  As described above, according to the vehicular power supply system 1, the sub power supply system 3 is connected to the sub power supply system 3 based on the power storage information obtained by the first power storage amount detection means 5 and the power storage information obtained by the second power storage detection means 6. The amount of power supplied to the power supply system 4 is controlled. In other words, the amount of power supplied from the main power supply system 3 to the sub power supply system 4 is adjusted according to the respective power storage amounts of the first power storage means 9 and the second power storage means 10. Therefore, the main power supply system 3 does not supply power to the sub power supply system 4 despite the small amount of power stored in the first power storage means 9, and the power consumption of the large power load 2 increases. It is possible to prevent the voltage of the power supply system 3 from being lowered (see the second and third examples). Further, when the amount of power stored in the first power storage unit 9 is large and the amount of power stored in the second power storage unit 10 is small, it is possible to actively supply power from the main power supply system 3 to the sub power supply system 4. . Thereby, when the first power storage unit is in a saturated state, power such as regenerative power can be actively stored in the second power storage unit (see the first example).

  The present invention is particularly applicable to a power supply system for automobiles equipped with a large number of power loads with large power consumption.

The block diagram which shows the structure of the vehicle power supply system which concerns on 1st Embodiment of this invention. The figure which shows the 1st example of operation | movement of the control means in 1st Embodiment of this invention. The figure which shows the 2nd example 1 of operation | movement of the control means in 1st Embodiment of this invention. The figure which shows the 2nd example 2 of operation | movement of the control means in 1st Embodiment of this invention. The figure which shows the 3rd example 1 of operation | movement of the control means in 1st Embodiment of this invention. The figure which shows the 3rd example 2 of operation | movement of the control means in 1st Embodiment of this invention. The figure which shows the 3rd example 3 of operation | movement of the control means in 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply system for vehicles 2 Large power load 3 Main power supply system 4 Sub power supply system 5 1st electrical storage amount detection means 6 2nd electrical storage amount detection means 7 Control means 8 Generator 9 1st electrical storage means 10 2nd electrical storage Means 11 First control means 12 Second control means 13 High power load system 14 Low power load system 15 Voltage adjustment means

Claims (11)

A vehicle power supply system for supplying power to a vehicle power load,
A main power supply system including a generator and first power storage means for storing electric power generated by the generator;
A sub-power supply system including second power storage means connected to the power load, storing the power output from the main power supply system, and supplying the power to the power load;
First power storage amount detection means for detecting a power storage amount of the first power storage means;
Second power storage amount detection means for detecting a power storage amount of the second power storage means;
Control means for controlling the amount of power supplied from the main power supply system to the sub power supply system based on the power storage information obtained by the first power storage amount detection means and the power storage information obtained by the second power storage detection means; A vehicle power supply system provided.   2. The sub power supply system further comprising voltage adjusting means for adjusting a voltage output from the main power supply system and supplying electric power after voltage adjustment to the second power storage means. Vehicle power system.   The vehicle power supply system according to claim 2, wherein the voltage adjusting means steps up and down a voltage output from the main power supply system. The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the amount of power stored in the first power storage means is greater than or equal to a threshold value, the first control means informs the second control means that power can be supplied from the main power supply system to the sub power supply system. The second control unit is configured to notify the sub power supply system when the amount of power stored in the second power storage unit is equal to or less than a threshold when the second control unit receives the notification that power supply is possible. The vehicle power supply system according to claim 2, wherein the voltage adjusting means is controlled.   5. The vehicle power supply system according to claim 4, wherein the electric power stored in the first power storage means is regenerative electric power. The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the second control means requests the first control means to supply power from the main power supply system to the sub power supply system, the first power storage means has a power storage amount equal to or less than a threshold value. The control means notifies the second control means that power cannot be supplied, and the second control means receives the notice and controls the voltage adjusting means to prevent the secondary power supply system from receiving power. The vehicle power supply system according to claim 2, wherein the vehicle power supply system is controlled.   The vehicle power supply according to claim 6, wherein when the second control means receives a notification that power cannot be supplied, the power load receives power from the second power storage means. system.   The vehicle power supply system according to claim 6, wherein, when the second control unit receives a notification that power cannot be supplied, the power load suppresses power consumption. The control means includes first control means for controlling the main power supply system, and second control means for controlling the sub power supply system and capable of communicating with the first control means,
When the second control means requests the first control means to supply power from the main power supply system to the sub power supply system, the first power storage means has a power storage amount equal to or less than a threshold value. The control means requests the second control means to wait for power supply until the power generation amount of the generator rises to a threshold value, and the power load until power supply from the main power supply system is started. The power supply system for a vehicle according to claim 2, wherein power is received from the second power storage means.   10. The vehicle power supply system according to claim 9, wherein, when the second control unit receives a power supply standby request, the power load delays activation thereof.   When the second control means receives a power supply standby request, the power load first receives power from the second power storage means, and the main load power supply is started when power supply from the main power supply system is started. The vehicle power supply system according to claim 9, wherein power is received from a power supply system.

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