JP2016119793A - Power generation control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation control device capable of reducing battery deterioration caused by a discharge current.SOLUTION: A power generation control device comprises: a power generator 3 that is driven in response to a rotational speed of an internal combustion engine 2 and stores power in a battery 6 or supplies power to an electric load 5; a generator control part 7 for controlling a power generation amount; a road information acquisition part for acquiring road information ahead of a vehicle; a power generation amount estimation part for estimating, from the road information, a maximum power generation amount in the case where a power generation amount of the generator 3 is limited; a power consumption amount estimation part for estimating a power consumption amount of the electric load on the basis of the road information; a discharge amount calculation part for calculating a maximum discharge amount to be discharged from the battery 6 for satisfying the power consumption amount in the case where the power consumption amount is greater than the maximum power generation amount; and a battery load determination part for determining whether a load generated in the battery 6 is settled within an allowable range in the case where the battery 6 is discharged for the maximum discharge amount. If the load generated in the battery 6 is out of the allowable range at the time of discharge, the power generation amount of the generator 3 is increased in such a manner that the load generated in the battery 6 is settled within the allowable range.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a power generation control device for a generator such as an alternator that can generate power using a part of engine power.

  In general, the kinetic energy is converted into electric energy by driving the alternator using the kinetic energy of the vehicle and supplied to various electric loads in the vehicle. In this way, the amount of electric power generated by the alternator varies depending on the traveling state. The electric power generated by the alternator is supplied directly to the electric load, or is stored in the battery and then supplied according to the electric power demand at each electric load.

  On the other hand, the electric power demand in each electric load also changes according to the running state. Therefore, it is required to efficiently distribute a limited amount of power generated in the vehicle according to the power demand of each electric load. In response to such a request, Patent Document 1 estimates the future power demand using a navigator or the like, and distributes the electric power stored in the battery or the like according to the estimation result to each electric load, It is said that it will be possible to supply power that matches the power demand of each electrical load.

JP 2014-117957 A

  A battery such as a secondary battery used with such a power generation device is more deteriorated with respect to the battery as the current during discharge is larger. However, in Patent Document 1, since the power is generated by the alternator without considering the influence of the battery deterioration due to the discharge current, the battery may be deteriorated in some cases.

  The present invention has been made in view of the above problems, and at least one embodiment of the present invention aims to provide a power generation control device capable of reducing battery deterioration due to a discharge current.

A power generation control device according to at least one embodiment of the present invention includes:
A generator that is driven according to the rotational speed of the internal combustion engine and that accumulates in the battery or supplies power to the electrical load;
A generator control unit for controlling the power generation amount of the generator;
A road information acquisition unit for acquiring road information ahead of the vehicle;

From the road information, a power generation amount estimation unit that estimates the maximum power generation amount when the power generation amount of the generator is limited,
Based on the road information, a power consumption estimation unit that estimates power consumption of the electrical load;
A discharge amount calculation unit for calculating a maximum discharge amount discharged from the battery in order to satisfy the power consumption amount when the power consumption amount is larger than the maximum power generation amount;
A battery load determination unit that determines whether or not a load generated in the battery is within an allowable range when the battery is discharged by the maximum discharge amount;
With
When the load generated in the battery at the time of discharging is out of an allowable range by the battery load determination unit, the generator control unit causes the generator so that the load generated in the battery is within the allowable range. The power generation amount is increased.

  According to the above configuration, the maximum power generation amount by the generator and the power generation amount consumed by the electric load when the power generation amount is limited are estimated based on the road information, and the battery is based on the maximum power generation amount and the power generation amount consumed. Presence or absence of discharge from the battery (power supply to the electric load by the battery) is estimated. When it is estimated that there is a discharge from the battery, when it is determined that the load of the battery caused by the discharge is out of the allowable range, the deterioration of the battery due to the excessive discharge current from the battery proceeds. In order to suppress this, the amount of power generated by the generator is increased. That is, the increase in power generation amount compensates the power demand due to the electric load, so that the discharge amount from the battery can be reduced, and excessive discharge from the battery is suppressed. Thereby, it is possible to suppress the deterioration of the battery.

  According to at least one embodiment of the present invention, a power generation control device capable of reducing battery deterioration due to a discharge current is provided.

It is a figure showing roughly the power generation control device concerning one embodiment of the present invention. It is a block diagram of a control device concerning one embodiment of the present invention. It is a figure which shows an example of the performance map of a generator. It is a figure which shows the electric power generation control flow which concerns on one Embodiment of this invention.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

  FIG. 1 is a diagram schematically showing a power generation control device 1 according to an embodiment of the present invention. As shown in FIG. 1, the power generation control device 1 includes a power generator 3, a control device 7 (a power generator control unit 71, a road information acquisition unit 72, and a power generation amount estimation unit) including an ECU (electronic control unit). 73, a power consumption amount estimation unit 74, a discharge amount calculation unit 75, and a battery load determination unit 76), for example, mounted on various vehicles including commercial vehicles and passenger cars including trucks and buses. .

  A vehicle equipped with this power generation control device 1 is equipped with an internal combustion engine (engine 2) as a driving power source, and outputs from the engine 2 via a power transmission mechanism (not shown) such as a clutch device or a transmission device. It travels by transmitting to the drive wheels. The output from the engine 2 is also transmitted to the generator 3 through a belt or the like, and the generator 3 is driven by the engine 2 and controlled by the control device 7.

  The generator 3 (alternator) is driven according to the rotational speed of the internal combustion engine, and accumulates in the battery 6 or supplies electric power to the electric load 5. More specifically, the generator 3 is composed of an AC generator and a rectifier. The AC generator is composed of a stator and a rotor that rotates inside the stator. A magnetic flux is generated from the rotor by being excited by the field current If, and the rotor rotates in accordance with the rotational speed of the engine 2 inside the stator, so that the magnetic flux from the rotor intersects the stator coil. However, current is generated by electromagnetic induction. The alternating current generated in this way is rectified into direct current by the rectifier and then supplied as a generated current Ig to various electric loads 5 connected via the power line 4 in the vehicle. At the same time, when the power generated by the generator 3 is larger than the power consumed by all the electric loads 5, the surplus power is used for charging the battery 6.

  Further, the generator 3 is subjected to regenerative power generation control (regenerative braking), and generates power by being rotationally driven by the kinetic energy from the drive wheels transmitted via the power transmission mechanism when the vehicle is decelerated. That is, at the time of deceleration, the engine 2 is rotated by the driving wheel that rotates without supplying fuel, and the generator 3 is also rotated by the rotation of the engine 2. In order to improve fuel efficiency, the generator 3 is controlled to increase the amount of power generation (regenerative power generation) during regenerative power generation (deceleration), and conversely to suppress the power generation amount except during regenerative power generation. Specifically, the generated power may be controlled by setting the field current If high during regenerative power generation and setting the field current If small during times other than regenerative power generation. The electric power regenerated in this way is stored in the battery 6. Then, when the voltage generated by the generator 3 is lower than the voltage of the battery 6, the power of the battery 6 is supplied to the electric load 5, thereby reducing the fuel for power generation of the generator 3 and improving the fuel consumption. doing.

  The above-described electric load 5 is a vehicle-mounted component (electrical component) that consumes electric power by electric drive. For example, electronic control units (ECUs) used for vehicle running such as ignition control, various electric devices such as sensors, airbags, air conditioners, blowers, headlights, brake lamps, wipers, turn signals, cigar sockets, audio, car navigation systems, etc. A load is mounted on the vehicle. In the illustration of FIG. 1, for simplification, one electric load 5 is illustrated as a combination of all target electric loads 5.

  The battery 6 is a secondary battery (for example, a lead storage battery) used as a power source for a system mounted on a vehicle, and is used for the electric drive of the electric load 5 described above and the electric drive of a starter motor for starting the engine 2. It is done. Further, when the power generated by the generator 3 is less than or equal to the power consumption of the electric load 5 during operation of the engine 2, the power supply from the battery 6 to the electric load 5 is supplied to the electric load 5 from the generator 3. This is done together with the power supply. In the illustration of FIG. 1, the battery 6 is connected to the generator 3 in parallel with the electric load 5 via the power line 4.

As described above, when the power generated by the generator 3 is small, the power of the battery 6 is supplied to the electric load. However, the battery 6 has a characteristic that the progress of deterioration is accelerated when the discharge current is excessively large. Yes. For this reason, if the power generation amount of the generator 3 is suppressed indefinitely from the viewpoint of improving fuel efficiency, the discharge amount from the battery 6 increases excessively, so that the progress of deterioration of the battery 6 may be accelerated and the life thereof may be shortened. . Therefore, when the discharge from the battery 6 is predicted to be excessively large, an increase control (described later) of the power generation amount of the generator 3 is executed in order to suppress the discharge from the battery 6 under certain conditions. .
Specifically, the life of the battery 6 is extended by controlling the generator 3 and the battery 6 by the control device 7 described below. As shown in FIG. 2, the control device 7 includes a generator control unit 71, a road information acquisition unit 72, a power generation amount estimation unit 73, a power consumption amount estimation unit 74, a discharge amount calculation unit 75, A battery load determination unit 76.

  The generator control unit 71 controls the amount of power generated by the generator 3. Further, the generator control unit 71 performs the above-described increase control of the amount of power generation (described later). The power generation amount may be controlled by controlling the above-described field current If. For example, as is well known, the optimum field current If may be calculated based on information acquired from various sensors such as the voltage of the battery 6 measured in real time and the amount of current flowing in an actual circuit. In addition, during regenerative power generation, the regenerative power generation amount of the power generator 3 may be controlled so that the amount of charge supplied from the power generator 3 to the battery 6 is maximized, and further, in cooperation with the road information acquisition unit 72. The regenerative power generation amount may be controlled.

  The road information acquisition unit 72 acquires road information De ahead of the vehicle. The road information De may include, for example, road alignment information, road traffic information (congestion information, traffic regulation information), speed limit, facility information, inter-vehicle distance, vehicle speed, weather information, and the like. This road alignment information is information about the road shape, such as what kind of straight line and curved line the planar road shape is, and how the slope such as uphill and downhill is composed. It is. The facility information is, for example, information on intersections, railroad crossings, parking lots, toll road tolls, and the like.

  Moreover, the acquisition timing of road information De may be every fixed time (periodic). Alternatively, the road information De may be acquired when it is determined that the situation ahead of the vehicle changes. Both of these timings may be used. For example, the situation ahead of the vehicle may change when the road is turned, when the vehicle stops, when the predicted value of the rotational speed Ne of the engine 2 changes greatly, when the road traffic information is changed, or the like.

Further, as illustrated in FIG. 1, road alignment information and road traffic information may be acquired from the navigation device 81. The vehicle speed, the inter-vehicle distance, and the weather information may be acquired by a vehicle state acquisition unit 82 such as a sensor or a camera provided in the vehicle. In the example of FIG. 1, the navigation device 81 and the vehicle status acquisition means 82 are connected to the control device 7 via an in-vehicle network 9 made of CAN (Controller Area Network), LIN (Local Interconnect Network), or the like. As is well known, the navigation device 81 (car navigation system) can specify the traveling position of the vehicle based on position information obtained from, for example, GPS and map information. This map information includes road alignment information (for example, road shape, presence / absence of branching, altitude, etc.) and facility information (for example, intersections, railroad crossings, parking lots, toll road tolls, etc.) associated with coordinate data. It is prescribed. Further, as is well known, the navigation device 81 can receive road traffic information such as traffic congestion and traffic regulations from, for example, VICS (registered trademark) (Vehicle Information and Communication System).
The acquired road information De is input to a power generation amount estimation unit 73 and a power consumption amount estimation unit 74 described below each time it is acquired.

  The power generation amount estimation unit 73 estimates the maximum power generation amount Wg when the power generation amount of the generator 3 is limited from the road information De. For this reason, the power generation amount estimation unit 73 is connected to the road information acquisition unit 72 to receive an input of the road information De. Then, the power generation amount estimation unit 73 analyzes the road information De from the road information acquisition unit 72 to thereby determine the maximum power generation amount Wg (hereinafter referred to as the maximum power generation amount) when the power generation amount of the generator 3 is limited (when power generation is limited). The power generation amount Wg) is estimated. More specifically, the amount of power generated by the generator 3 can be estimated by obtaining information about the field current If and the rotational speed Ne of the engine 2 because the rotational speed N of the generator 3 is determined by the rotational speed Ne of the engine 2. .

  In the embodiment shown in FIG. 2, the maximum power generation amount Wg is estimated based on the road information De and the efficiency map of the engine 2 (for example, a map showing fuel consumption with respect to the engine speed and the engine load). . More specifically, the power generation amount estimation unit 73 predicts the rotational speed Ne of the engine 2 based on the road information De, and obtains the rotational speed N of the generator 3 from the predicted rotational speed Ne of the engine 2. Specifically, the rotation speed N of the generator 3 is calculated by multiplying the predicted rotation speed Ne of the engine 2 by the reduction ratio in the generator 3. At the same time, the amount of power generated by the generator 3 is adjusted based on the efficiency of the engine 2 such as, for example, the amount of power generation is suppressed when climbing uphill. The current If is obtained. Then, with reference to the performance map of the generator 3 at the field current If (see FIG. 3), the generated current corresponding to the rotational speed N of the generator 3 is acquired. By calculating this power generation current Ig and power generation time Tr (estimated period based on road information De), the maximum power generation amount Wg is estimated.

In addition, various methods can be employed for this calculation depending on the accuracy to be estimated. For example, the estimation may be performed by multiplying the average power generation current Ig in all sections included in the road information De and the power generation time Tr. Alternatively, the power generation current Ig may be estimated by integrating with the power generation time Tr. In the performance map of the generator 3, as shown in FIG. 3, the generated current Ig increases according to the rotational speed N of the generator 3.
In some other embodiments, a remaining battery amount estimation unit that estimates the remaining capacity (SOC) of the battery 6 based on the road information De, and a torque that estimates a required torque required for the engine 2 based on the road information De An estimation unit, and the maximum power generation amount Wg may be estimated from the road information De, the remaining amount, and the required torque.

The power consumption amount estimation unit 74 estimates the power consumption amount Wc of the electric load 5 based on the road information De. For this reason, the power consumption estimation unit 74 is configured to receive the input of the road information De from the road information acquisition unit 72 by being connected to the road information acquisition unit 72 described above. The individual power consumption of the electric load 5 constituting the electric load 5 is specified in advance, and the power consumption of the electric load 5 is predicted based on the data related to the power consumption of the electric load 5 specified in advance. For example, even in the case of an electric load that is turned ON / OFF by a driver's operation, such as a headlight or a turn signal, the power consumption when the switch is ON and the power consumption when the switch is OFF are also defined in advance.
Further, the estimation timing of the power consumption amount Wc may be when the road information De is input from the road information acquisition unit 72. Moreover, the case where it is judged that the use state of each electric load 5 changes and it is necessary to estimate the electric load 5 again may be sufficient. Both of these timings may be used.

The maximum power generation amount Wg and the power consumption amount Wc estimated based on the road information De described above are input to the discharge amount calculation unit 75, the charge / discharge state of the battery 6 is determined, and the estimated value of the discharge amount is Calculated.
That is, the discharge amount calculation unit 75 calculates the maximum discharge amount Wb discharged from the battery 6 in order to satisfy the power consumption amount Wc when the power consumption amount Wc is larger than the maximum power generation amount Wg. For this reason, the discharge amount calculation unit 75 is connected to the power generation amount estimation unit 73 and the power consumption amount estimation unit 74 described above, so that the power consumption amount Wc and the maximum power generation amount Wg in the section included in the road information De are calculated. It is configured to accept input. When the power consumption amount Wc is larger than the maximum power generation amount Wg (power consumption amount Wc> maximum power generation amount Wg), the power consumption amount Wc by the electric load 5 is larger than the maximum power generation amount Wg by the generator 3, It is estimated that the amount of power generated by the machine 3 is insufficient. That is, it is estimated that power is discharged (supplied to the electric load 5) from the battery 6 in order to cover this shortage of power (power consumption Wc−maximum power generation Wg).

However, as described above, there is a risk that deterioration of the battery 6 may be accelerated due to an excessive amount of discharge from the battery 6, so that the amount of power generation for avoiding overdischarge from the battery 6 is avoided by the battery load determination unit 76. The need for increase control is determined.
That is, the battery load determination unit 76 determines whether or not the load generated in the battery 6 is within an allowable range when the battery 6 is discharged with the maximum discharge amount Wb. Therefore, the battery load determination unit 76 is connected to the discharge amount calculation unit 75 so as to receive an input of the maximum discharge amount Wb from the discharge amount calculation unit 75, and the battery 6 is based on the maximum discharge amount Wb. It is determined whether or not the load generated in the above is within an allowable range.

  Specifically, the determination of the necessity for the increase control of the power generation amount by the generator 3 may be made based on whether the discharge amount per unit is equal to or greater than a predetermined threshold (discharge amount threshold Tp). For example, the discharge amount per unit may be a maximum discharge amount Wb with the road information De as a unit, or a discharge current that becomes a discharge amount per unit time. The discharge amount threshold value Tp is a value defined as damaging the battery 6 when the discharge amount (current amount) from the battery 6 per unit is a certain value or more.

  When the battery load determination unit 76 determines that the increase in power generation amount is necessary, the generator control unit 71 executes the control. That is, when the load generated in the battery 6 during discharge is out of the allowable range by the battery load determination unit 76, the generator control unit 71 causes the generator 3 so that the load generated in the battery 6 is within the allowable range. Increase the amount of power generation. Specifically, the power generation amount increase control by the power generator 3 may be increased by controlling the above-described field current If for exciting the rotor of the power generator 3 to be increased. That is, the optimum field current If calculated by the generator control unit 71 is raised by the increase control of the power generation amount.

  Power generation control as shown in FIG. 4 is performed by the control device 7 having such a configuration. That is, FIG. 4 is a diagram illustrating a power generation control flow of the battery 6 by the control device 7 in some embodiments.

  The road information De is acquired in step S41 of FIG. 4, and the maximum power generation amount Wg by the generator 3 and the power consumption amount Wc by the electric load 5 are estimated based on the road information De (steps S42 to S43). In step S44, if the maximum power generation amount Wg <the power consumption amount Wc, it is determined that the battery 6 is being discharged, and the process proceeds to step S45. On the contrary, when the maximum power generation amount Wg ≧ the power consumption amount Wc, it is determined that the battery 6 is not in a state of being discharged, and the flow ends.

  In step S45, the maximum discharge amount Wb of the battery 6 is calculated. In step S46, it is determined whether the maximum discharge amount Wb is equal to or greater than the discharge amount threshold value Tp. When it is determined that the maximum discharge amount Wb is equal to or greater than the discharge amount threshold value Tp, in step S47, the power generation amount is increased by the generator 3 so that the battery 6 does not deteriorate due to overdischarge. Conversely, when it is determined in step S46 that the maximum discharge amount Wb is smaller than the discharge amount threshold value Tp, it is determined that there is no overdischarge, so that the increase in power generation amount is not controlled.

  According to said structure, when the load estimated to generate | occur | produce in the battery 6 at the time of discharge becomes out of an allowable range, in order to reduce the discharge amount from the battery 6, the electric power generation amount by the generator 3 is increased. For this reason, the progress of the deterioration of the battery 6 due to the discharge current from the generator 3 can be suppressed, and the life of the battery 6 can be extended.

  The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

DESCRIPTION OF SYMBOLS 1 Power generation control apparatus 2 Engine 3 Generator 4 Power supply line 5 Electric load 6 Battery 7 Power generation control apparatus 71 Road information acquisition part 72 Maximum power generation amount estimation part 73 Generator control part 74 Battery information acquisition part 75 Power consumption amount estimation part 76 Charging Amount calculation unit 77 Battery load determination unit 78 Power generation amount restriction unit 81 Navigation device 82 Vehicle status acquisition means 9 In-vehicle network De Road information If Field current Ig Power generation current N Generator speed Ne Engine speed Tp Charge threshold Tr Time Wb Maximum charge Wc Power consumption Wg Maximum power generation

Claims (1)

A generator that is driven according to the rotational speed of the internal combustion engine and that accumulates in the battery or supplies power to the electrical load;
A generator control unit for controlling the power generation amount of the generator;
A road information acquisition unit for acquiring road information ahead of the vehicle;
From the road information, a power generation amount estimation unit that estimates the maximum power generation amount when the power generation amount of the generator is limited,
Based on the road information, a power consumption estimation unit that estimates power consumption of the electrical load;
A discharge amount calculation unit for calculating a maximum discharge amount discharged from the battery in order to satisfy the power consumption amount when the power consumption amount is larger than the maximum power generation amount;
A battery load determination unit that determines whether or not a load generated in the battery is within an allowable range when the battery is discharged by the maximum discharge amount;
With
When the load generated in the battery at the time of discharging is out of an allowable range by the battery load determination unit, the generator control unit causes the generator so that the load generated in the battery is within the allowable range. The power generation control apparatus characterized by increasing the power generation amount.

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