JP2008289229A - Power controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power controller which assures a sufficient power to be supplied to a load. <P>SOLUTION: The power controller includes a power supply, a load to which power is supplied from the power supply, a power consumption prediction means for predicting an increase in power consumption, and a means for raising the voltage to be supplied to the load based on the prediction results from the power consumption prediction means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power control apparatus, and more particularly to a power control apparatus that raises a voltage supplied to a load.

2. Description of the Related Art Conventionally, a vehicle is equipped with a large number of devices that consume a large amount of power and become a load of a power source, such as an electric brake, an electric power steering (EPS), and an airbag. As the number of such devices that consume a large amount of power increases, the burden on the power source increases and it becomes difficult to secure sufficient power. For example, the pre-crash system (PCS) is intended to predict the collision of a vehicle and activate a predetermined protective device at the predicted stage to ensure the safety of the occupant. It is necessary to operate the system surely considering the purpose. If sufficient power is not ensured, the power that can be supplied when operation is required is reduced, and normal operation of the system is hindered. In order to ensure the operation of the system for ensuring safety, it is intended to ensure sufficient power by predicting vehicle collisions and shutting off power to loads that are unlikely to contribute to safety at the predicted stage. There is known a power control apparatus that performs such a process (see, for example, Patent Document 1).
JP 2003-165406 A

  However, the conventional power control device tries to secure the power supply to the system for ensuring safety by cutting off the power to some loads. In some cases, the power consumption of the system itself may cause a drop in power supply voltage, and sufficient power supply to the system may not be ensured.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a power control apparatus capable of securing sufficient power to be supplied to a load.

  To achieve the above object, the first invention provides a power source, a load to which power is supplied from the power source, a power consumption prediction unit that predicts an increase in the power consumption, and the power consumption prediction unit. And a voltage raising means for raising the voltage supplied to the load based on the prediction result.

  According to a second invention, in the power control apparatus according to the first invention, the voltage raising means includes a power generation means, and raises a limit value of the power generation means based on a prediction result of the power consumption prediction means. It is characterized by.

  According to the present invention, sufficient power to be supplied to the load can be ensured.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration example of a power control apparatus of the present invention.

  1 includes a high voltage battery 10, an alternator 20, a DC-DC converter 30, a low voltage battery 40, a low voltage battery load 50, an inverter 60, a motor generator 70, a high voltage battery load (1) 80-1 to a high voltage. The battery load (N) 80-N, the battery ECU 90, the MG ECU 100, the load (1) ECU 110-1 to the load (N) ECU 110-N, the PCS ECU 120, and the power management ECU 130 are included.

  The alternator 20 includes a power generating coil 21, a rectifying diode 22, a field coil 23, and a regulator 24.

  The PCS ECU 120 has an obstacle detection sensor 121.

  The high-voltage battery 10 is a storage battery and is a power source that supplies power to a load that consumes a relatively large amount of power. The low-voltage battery 40 is a storage battery, and is a power source that supplies power to a load 50 for a low-voltage battery that consumes relatively little power. The low-voltage battery load 50 is, for example, a light. The DC-DC converter 30 converts the voltage of the high voltage battery 10 into a voltage for the low voltage battery 40, charges the low voltage battery 40, and supplies power to the load 50 for the low voltage battery.

  The inverter 60 is a switching circuit that converts an AC voltage and a DC voltage into each other. The motor generator 70 operates with an AC voltage, and can be driven as an electric motor and can also be driven as a generator. The motor generator 70 is connected to the high-voltage battery 10 and the DC-DC converter 30 via an inverter 60. The MG ECU 100 is an electronic control unit that varies the output voltage of the inverter 60 by controlling the switching circuit of the inverter 60.

  The high-voltage battery load (1) 80-1 to the high-voltage battery load (N) 80-N is a load supplied with electric power from the high-voltage battery 10, the alternator 20, or the inverter 60. For example, an electric brake or electric power steering Etc.

  The high voltage battery 10 is provided with a voltage sensor 11 that measures the voltage across the terminals of the high voltage battery 10, a current sensor 12 that measures the charge / discharge current of the high voltage battery 10, and a temperature sensor 13 that measures the temperature of the high voltage battery 10. The low voltage battery 40 is provided with a voltage sensor 41 that measures the voltage across the terminals of the low voltage battery 40, a current sensor 42 that measures the charge / discharge current of the low voltage battery 40, and a temperature sensor 43 that measures the temperature of the low voltage battery 40. The outputs of the sensors are input to the battery ECU 90.

  The battery ECU 90 is an electronic control unit having a function of checking the state of charge (SOC: State Of Charge) of the high-voltage battery 10 and the low-voltage battery 40 based on signals input from the sensors. Further, the battery ECU 90 outputs a control signal to the DC-DC converter 30.

  The load (1) ECU 110-1 through the load (N) ECU 110-N are electronic control units that control the high voltage battery load (1) 80-1 through the high voltage battery load (N) 80-N.

  The PCS ECU 120 is an electronic control unit that controls a so-called pre-crash safety system that judges a vehicle collision in advance and reduces damage by operating safety equipment. The obstacle detection sensor 121 in the PCS ECU 120 is a sensor that detects an obstacle around the vehicle from the relative speed and the relative distance, and for example, a millimeter wave sensor or the like is used. Information detected by the obstacle detection sensor 121 is input to the power consumption prediction unit 132 in the power management ECU 130 by communication.

  The power management ECU 130 includes a voltage raising unit 131 and a power consumption prediction unit 132. The battery ECU 90, the MG ECU 100, the load (1) ECU 110-1, the load (N) ECU 110-N, and the PCS ECU 120, It is an electronic control unit that is connected in a communicable state and exchanges information and various control signals obtained by communication from the ECUs to control the power of the entire system. The voltage raising means 131 in the power management ECU 130 controls the amount of power generated by the alternator 20. The voltage raising means 131 in the power management ECU 130 controls the regeneration amount of the motor generator 70 via the MG ECU 100. The power consumption prediction unit 132 in the power management ECU 130 obtains information detected by the obstacle detection sensor 121 through communication, determines the possibility of collision based on the obtained information, and determines that there is a possibility of collision. This is a prediction means for predicting that the power consumption will increase when it is determined.

  The voltage raising means 131 in the power management ECU 130 sets a charging voltage limit value of the high voltage battery 10. The charge voltage limit value is a value set to prevent overcharging of the high-voltage battery 10 and extend its life, and is a limit value of received power. FIG. 4 is a diagram showing an example of the relationship between the SOC and the charging voltage limit value, but the charging voltage limit value is not a constant value as shown by the curve in FIG. 4A, but a value set based on the SOC. is there. When the power consumption prediction means 132 in the power management ECU 130 predicts an increase in power consumption, the voltage raising means 131 in the power management ECU 130 causes the regulator 24 in the alternator 20 to raise the power supply voltage of the high voltage battery 10. And issues a command to the MG ECU 100.

  The operations of the alternator 20, the inverter 60, and the motor generator 70 will be described in more detail.

  The alternator 20 is a power generation means for generating electric power by utilizing the rotation of the engine, and the AC voltage generated by the power generation coil 21 in the alternator 20 is rectified by the rectifier diode 22 in the alternator 20 and converted into a DC voltage. The voltage raising means 131 in the power management ECU 130 is connected to a state in which the regulator 24 in the alternator 20 can be controlled. The voltage raising means 131 in the power management ECU 130 transmits information on the charging voltage limit value to the regulator 24 in the alternator 20, and the output voltage of the alternator 20 (the voltage on the cathode side of the rectifier diode 22) is the limit value. The regulator 24 in the alternator 20 is instructed to perform control so as to converge to a predetermined charging target voltage value set within a range not exceeding. The regulator 24 in the alternator 20 receives a command and adjusts the current flowing in the field coil 23 in the alternator 20 to converge the output voltage of the alternator 20 (the voltage on the cathode side of the rectifier diode 22) to the charging target voltage value. Let

  When the motor generator 70 operates as an electric motor, the inverter 60 converts the DC voltage supplied from the high voltage battery 10 or the alternator 20 into an AC voltage by a switching operation based on a control signal from the MG ECU 100. The converted AC voltage is supplied to the motor generator 70 to drive the motor.

  The motor generator 70 is also power generation means that operates as a generator during regenerative braking of the vehicle. Inverter 60 converts the AC voltage generated by motor generator 70 into a DC voltage by a switching operation based on a control signal from MG ECU 100. The converted DC voltage is used to charge the high voltage battery 10. As described above, the voltage raising means 131 in the power management ECU 130 sets the charging voltage limit value of the high voltage battery 10 in order to prevent overcharging of the high voltage battery 10. The voltage raising means 131 in the power management ECU 130 transmits information on the limit value to the MG ECU 100, and the voltage converted into direct current by the inverter 60 (voltage at the connection portion between the inverter 60 and the high voltage battery 10) is the limit. The MG ECU 100 is instructed to control the inverter 60 so as to converge to a predetermined charging target voltage value set within a range not exceeding the value. The MG ECU 100 receives the command and controls the switching circuit of the inverter 60 to converge the output voltage of the inverter 60 (the voltage at the connection between the inverter 60 and the high voltage battery 10) to the charging target voltage value.

  Here, regenerative braking means braking with regenerative power generation when there is a brake operation by a person who operates the vehicle, and no braking operation, but regenerating power by turning off the accelerator pedal while driving Saying that the vehicle is decelerated.

  Next, the flowchart of FIG. 2 will be described.

  FIG. 2 is a flowchart showing an example of processing when the power consumption prediction unit 132 in the power management ECU 130 predicts an increase in power consumption consumed by the load in the power control apparatus of FIG. FIG. 2 shows an example in which there is a possibility of collision with an obstacle as an example in which an increase in the amount of power consumed by the load is predicted.

  In step 100, the power consumption prediction means 132 in the power management ECU 130 predicts an increase in power consumption of the load. A specific method for predicting an increase in power consumption of the load will be described below.

  The obstacle detection sensor 121 in the PCS ECU 120 emits an electromagnetic wave such as a millimeter wave, a light wave such as a laser wave, a sound wave such as an ultrasonic wave as a search wave while the host vehicle is traveling, and an object such as a preceding vehicle. The search object is detected by receiving the search wave reflected by. The power consumption prediction unit 132 in the power management ECU 130 obtains information detected by the obstacle detection sensor 121 through communication, organizes information such as a time lag and a phase lag of the received search wave, and The distance is calculated.

  For example, when the search target is a preceding vehicle, the power consumption prediction unit 132 in the power management ECU 130 obtains the detected information by communication when the obstacle detection sensor 121 detects the preceding vehicle, Based on the information, the inter-vehicle distance between the host vehicle and the preceding vehicle is calculated. For example, when the inter-vehicle distance becomes smaller than a preset value, it is determined that there is a possibility of collision with the host vehicle. When the power consumption prediction unit 132 determines that there is a possibility of a collision, it determines that a load with a relatively large power consumption such as an electric brake or an electric power steering is likely to be operated. Predicting an increase in the amount of power consumed by the load. The prediction result is transmitted to the voltage raising means 131 in the power management ECU 130 (S100).

  If no increase in the amount of power consumed by the load is predicted in step 100, the power generation amount of the alternator 20 is controlled in a normal range in step 101 (S101). Next, in step 102, the regeneration amount of the motor generator 70 is controlled within a normal range (S102), and the process returns. Here, the normal range means that the high voltage battery converges to the charge target voltage value within a range not exceeding the charge voltage limit value of the high voltage battery 10 set by the voltage raising means 131 in the power management ECU 130 described above. The amount of power generation and the amount of regeneration that can charge 10 is said.

In step 100, if an increase in the amount of power consumed by the load is predicted,
The process of step 103 is executed. The voltage raising means 131 in the power management ECU 130 changes the setting of the charging voltage limit value of the high voltage battery 10 to a value higher by ΔV (hereinafter referred to as a setting change limit value). The curve in Fig. 4 (2) shows the charge voltage limit value (setting change limit value) after the setting change. Here, changing the set value to a higher value is disadvantageous for the life of the high-voltage battery 10, but priority is given to securing electric power in an emergency, and the set value is increased within a range where the high-voltage battery 10 does not break down due to overvoltage. . The voltage raising means 131 in the power management ECU 130 transmits information on the setting change limit value to the regulator 24 in the alternator 20 and the MG ECU 100 (S103).

  Next, the process of step 104 is performed. The voltage raising means 131 in the power management ECU 130 controls so that the output voltage of the alternator 20 (the voltage on the cathode side of the rectifier diode 22) converges to the setting change limit value within a range not exceeding the setting change limit value. To the regulator 24 in the alternator 20. That is, in this case, the charge target voltage value is equal to the setting change limit value. The regulator 24 in the alternator 20 receives a command and adjusts the current flowing through the field coil 23 in the alternator 20 to converge the output voltage of the alternator 20 (the voltage on the cathode side of the rectifier diode 22) to the setting change limit value. Let When the voltage raising means 131 in the power management ECU 130 determines that the amount of power generated by the alternator 20 is small and the output voltage of the alternator 20 does not increase to the setting change limit value only by the control of the regulator 24, the alternator 20. The alternator 20 is controlled so that the amount of power generated by the power generating coil 21 increases (S104). As a result, the amount of power generation increases.

  Next, the process of step 105 is executed and returns. In step 105, the voltage raising means 131 in the power management ECU 130 determines that the voltage converted into direct current by the inverter 60 (the voltage at the connection between the inverter 60 and the high voltage battery 10) does not exceed the setting change limit value. The MG ECU 100 is instructed to control the inverter 60 to converge to the setting change limit value. That is, in this case, the charge target voltage value is equal to the setting change limit value. The MG ECU 100 receives the command and controls the switching circuit of the inverter 60 to converge the output voltage of the inverter 60 (the voltage at the connection between the inverter 60 and the high voltage battery 10) to the setting change limit value. Thereby, the amount of regeneration increases.

  The above steps shown in FIG. 2 (from start to return) are repeated, and a predetermined process is executed.

  FIG. 3 is a diagram illustrating an example of a relationship between a charging voltage limit value (setting change limit value), a power generation amount (regeneration amount), and power consumption when the process of the flowchart illustrated in FIG. 2 is executed.

  In FIG. 3, a dotted line shows an example of a change in the amount of power generation (regeneration amount) when the amount of power consumption increases in the conventional power control apparatus. When the power consumption increases, the power generation amount (regeneration amount) increases to compensate for this, but since the charge voltage limit value has not been changed, the increase in power generation amount (regeneration amount) is slow and the power consumption amount It can not be said that sufficient power supply is possible in the part where the number of slashes increases.

  On the other hand, an example of the power control device of the present invention is shown by a solid line. When the power consumption prediction unit 132 predicts an increase in the consumption of power consumed by the load, the charging voltage limit value of the high-voltage battery 10 is Since the power generation amount of the alternator 20 and the regeneration amount of the motor generator 70 are increased, the power generation amount and the regeneration amount increase with time, and converge to a predetermined value while charging the high-voltage battery 10. Thereafter, a load with a large amount of power consumption is activated, so that the power consumption temporarily increases. However, at this time, the power supply is already sufficiently possible.

  As described in detail above, there is a possibility of collision as a result of the processing shown in the flowchart of FIG. 2 executed by the power control device of FIG. 1, and an increase in power consumption consumed by the load is predicted. In addition, the power supply voltage can be increased in advance by increasing the charging voltage limit value of the high-voltage battery 10 and increasing the power generation amount of the alternator 20 and the regeneration amount of the motor generator 70. As a result, sufficient power can be secured, and sufficient power can be supplied to the load even when a load with large power consumption actually operates.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the present embodiment, an example of a power control device having two batteries of the high voltage battery 10 and the low voltage battery 40 has been shown. However, the power control device having only one battery or the power control device having three or more batteries. The present invention can be similarly applied.

  Further, in this embodiment, as an example in which an increase in the amount of power consumed by the load is predicted, the power consumption prediction unit 132 determines whether the vehicle and the preceding vehicle are based on information received by the obstacle detection sensor 121. Although the example in the case of measuring the inter-vehicle distance and determining that the own vehicle may collide with the preceding vehicle has been shown, the present invention is not limited to this example. For example, if a vehicle speed sensor is installed and the power consumption predicting means 132 is faster than the vehicle speed is normally assumed, the electric brake may be suddenly operated. In an example of predicting an increase or when a car navigation system equipped with GPS is expected to travel on a steep hill with many curves, an electric brake and electric power An example in which an increase in power consumption is predicted in consideration of the possibility that the steering is operated at a frequency higher than normal may be considered.

  Further, in this embodiment, when an increase in power consumption is predicted, the power generation amount of the alternator 20 and the regeneration amount of the motor generator 70 are increased. However, only one of them may be increased.

  In this embodiment, the vehicle is described as an example, but the present invention is not necessarily limited to the vehicle.

It is a figure which shows the structural example of the outline of the power control apparatus of this invention. 2 is a flowchart illustrating a processing example when the power consumption prediction unit 132 in the power management ECU 130 predicts an increase in power consumption consumed by a load in the power control apparatus of FIG. FIG. 3 is a diagram illustrating an example of a relationship between a charging voltage limit value (setting change limit value), a power generation amount (regeneration amount), and power consumption when the process of the flowchart illustrated in FIG. 2 is executed. It is a figure which shows the example of the relationship between SOC and a charging voltage limiting value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 High voltage battery 11 Voltage sensor 12 Current sensor 13 Temperature sensor 20 Alternator 21 Generator coil 22 Rectifier diode 23 Field coil 24 Regulator 30 DC-DC converter 40 Low voltage battery 41 Voltage sensor 42 Current sensor 43 Temperature sensor 50 Low voltage battery load 60 Inverter 70 Motor generator 80-1 Load for high voltage battery (1)
80-N High voltage battery load (N)
90 Battery ECU
100 MG ECU
110-1 ECU for load (1)
110-N ECU for load (N)
120 PCS ECU
121 Obstacle detection sensor 130 Power management ECU
131 Voltage raising means 132 Power consumption prediction means

Claims (3)

Power supply,
A load to which power is supplied from the power source;
Power consumption prediction means for predicting an increase in the power consumption;
Voltage raising means for raising the voltage supplied to the load based on the prediction result of the power consumption prediction means;
A power control apparatus comprising: Having power generation means,
The power control apparatus according to claim 1, wherein the voltage raising unit raises a limit value related to a power generation amount of the power generation unit based on a prediction result of the power consumption prediction unit.   3. The power control apparatus according to claim 1, wherein the voltage raising unit raises a limit value related to the received power of the power source based on a prediction result of the power consumption prediction unit.

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