JP5639119B2 - Charging apparatus and charging method - Google Patents

Description

  The present invention relates to a charging device and a charging method.

  In Patent Document 1, charging is stopped if the charging level is in a fully charged state in the deceleration mode of the vehicle, and if the charging level is less than 100% and 70% or more, the adjustment voltage of the generator is set to 14.4V. The present invention relates to a control device for an idling stop-and-start vehicle generator capable of obtaining a sufficient regeneration effect without impairing the battery life by setting the adjustment voltage to 15.5 V if the charge level is less than 70%. Technology is disclosed.

  Further, in Patent Document 2, when the vehicle is decelerated, the target value of the generator is changed to a high value so that the battery is quickly charged. Then, the technique which implement | achieves the fuel-consumption improvement of a vehicle, without producing overcharge by changing a target value low is disclosed.

Japanese Patent Application Laid-Open No. 07-143686 JP 2000-204995 A

  By the way, in the technique disclosed in Patent Document 1, the maximum charging voltage is 15V, and in the technique disclosed in Patent Document 2, the maximum charging voltage is 15.5V. This is because in a lead storage battery, even if a high voltage of 15 V or higher is applied, a voltage higher than the charging reaction potential is wasted due to the electrolysis of water contained in the electrolytic solution. For this reason, the techniques described in Patent Documents 1 and 2 have a problem in that the generated voltage of the generator cannot be used effectively.

  An object of the present invention is to provide a charging device and a charging method capable of effectively using a generated voltage of a generator.

In order to solve the above problems, the present invention is a battery mounted on a vehicle and configured by connecting a secondary battery and a capacitor in parallel, and is supplied from the alternator to the battery charged by the alternator. In the charging device for controlling the charging current, the capacitor is charged by applying a pulse voltage having an amplitude higher than the terminal voltage of the secondary battery, and the secondary battery is charged by the charge accumulated in the capacitor The secondary battery by controlling the pulse width, pulse interval, or amplitude of the pulse voltage according to the average charging current of the secondary battery and the capacitance value of the capacitor. It is characterized by controlling the charging current flowing through the.
According to such a configuration, it is possible to provide a charging device that can effectively use the generated voltage of the generator.

In addition to the above invention, another invention is characterized in that the charging current flowing through the secondary battery is controlled by controlling the pulse width and / or the pulse interval of the pulse voltage.
According to such a configuration, the generated voltage of the generator can be effectively used by efficiently charging the secondary battery by adjusting at least one of the pulse width and the pulse interval.

In addition to the above invention, another invention is characterized in that the charging current flowing through the secondary battery is controlled by controlling the amplitude of the pulse voltage.
According to such a configuration, the generated voltage of the generator can be effectively used by efficiently charging the secondary battery by adjusting the amplitude of the pulse voltage.

In addition to the above-mentioned invention, another invention includes a charge state detection unit that detects a charge state of the secondary battery, and the control unit is configured to detect the secondary battery detected by the charge state detection unit. The charging current flowing in the secondary battery is controlled according to the state of charge.
According to such a structure, it becomes possible to charge efficiently according to the charge condition of a secondary battery.

In addition to the above-mentioned invention, another invention has a running state detecting means for detecting the running state of the vehicle, and the control means is responsive to the running state of the vehicle detected by the running state detecting means. The charging current flowing in the secondary battery is controlled.
According to such a structure, it becomes possible to charge efficiently according to the driving | running | working state of a vehicle.

In addition to the above invention, another invention is characterized in that a pulse width of the pulse voltage is in a range of 1 to 500 msec.
According to such a configuration, by setting the pulse width in the range of 1 to 500 msec, it is possible to reliably charge the capacitor, thereby efficiently charging the secondary battery.

In addition to the above invention, another invention is characterized in that the pulse interval of the pulse voltage is in the range of 1 to 1000 msec.
According to such a configuration, by setting the pulse voltage pulse interval in the range of 1 to 1000 msec, the capacitor can be reliably discharged, and thereby the secondary battery can be efficiently charged.

In addition to the above invention, another invention is characterized in that the battery is formed by combining a secondary battery using an electrochemical reaction and a capacitor using a charge adsorption phenomenon.
According to such a configuration, space saving can be achieved by using a hybrid battery in which a secondary battery and a capacitor are formed in a composite manner.

Further, the present invention is a battery mounted on a vehicle and configured by connecting a secondary battery and a capacitor in parallel, and controls a charging current supplied from the alternator to the battery charged by the alternator. In the charging method, the capacitor is charged by applying a pulse voltage having an amplitude higher than the terminal voltage of the secondary battery, the secondary battery is charged by the charge accumulated in the capacitor, and the pulse voltage The charging current flowing in the secondary battery is controlled by controlling the pulse width, the pulse interval, or the amplitude according to the average charging current of the secondary battery and the capacitance value of the capacitor .
According to such a method, it is possible to provide a charging method capable of effectively using the generated voltage of the generator.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the charging device and charging method which can use effectively the power generation voltage of a generator.

It is a figure which shows the structural example of the charging device which concerns on embodiment of this invention. It is a circuit diagram which shows the equivalent circuit of the hybrid battery of FIG. It is a block diagram which shows the detailed structural example of the control part of FIG. It is a figure which shows the time change of the charging voltage applied to a hybrid battery. It is a figure which shows the electric current which flows into a hybrid battery. It is a figure which shows the time change of the voltage applied to the capacitor component of the hybrid battery shown in FIG. It is a figure which shows the time change of the voltage applied to the secondary battery component of the hybrid battery shown in FIG. It is a flowchart for demonstrating an example of the process performed in the control part shown in FIG.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of Embodiment FIG. 1 is a diagram illustrating a power supply system of a vehicle having a charging device according to an embodiment of the present invention. In this figure, the charging device 1 includes a control unit 10, a voltage sensor 11, a current sensor 12, a temperature sensor 13, and a voltage control circuit 15 as main components, and controls charging of the hybrid battery 14. Here, the control unit 10 refers to the outputs from the voltage sensor 11, the current sensor 12, and the temperature sensor 13, detects the state of the hybrid battery 14, and charges the hybrid battery 14 based on the detection result. The voltage sensor 11 detects the terminal voltage of the hybrid battery 14 and notifies the control unit 10 of it. The current sensor 12 detects the current flowing through the hybrid battery 14 and notifies the control unit 10 of the current. The temperature sensor 13 detects the ambient temperature of the hybrid battery 14 itself or the surrounding environment, and notifies the control unit 10 of it. The voltage control circuit 15 controls the power generation voltage of the alternator 16 by controlling the current flowing through the excitation coil of the alternator 16, for example.

  The hybrid battery 14 is a battery configured by hybridizing an ultracapacitor to the cathode of a lead storage battery. FIG. 2 is a diagram showing an electrical equivalent circuit of the hybrid battery 14. As shown in this figure, the hybrid battery 14 has a resistance component 14a, a capacitor component 14b, a resistance component 14c, and a secondary battery component 14d. A capacitor component 14b is connected in parallel to the resistance component 14c and the secondary battery component 14d connected in series, and the resistance component 14a is connected in series to these. The hybrid battery 14 is charged by the alternator 16, drives the starter motor 18 to start the engine 17, and supplies power to the load 19. The alternator 16 is driven by the engine 17 to generate AC power, convert it into DC power by a rectifier circuit, and charge the hybrid battery 14.

  The engine 17 is composed of, for example, a reciprocating engine such as a gasoline engine and a diesel engine, a rotary engine, or the like. The engine 17 is started by a starter motor 18 and drives driving wheels via a transmission to give propulsive force to the vehicle. Drive to generate power. The starter motor 18 is constituted by, for example, a DC motor, and generates a rotational force by the electric power supplied from the hybrid battery 14 to start the engine 17. The load 19 includes, for example, an electric steering motor, a defogger, an ignition coil, a car audio, a car navigation, and the like, and operates with electric power from the hybrid battery 14.

  FIG. 3 is a diagram illustrating a detailed configuration example of the control unit 10 illustrated in FIG. 1. As shown in this figure, the control unit 10 includes a CPU (Central Processing Unit) 10a, a ROM (Read Only Memory) 10b, a RAM (Random Access Memory) 10c, a communication unit 10d, and an I / F (Interface) 10e. ing. Here, the CPU 10a controls each unit based on the program 10ba stored in the ROM 10b. The ROM 10b is configured by a semiconductor memory or the like, and stores a program 10ba or the like. The RAM 10c is configured by a semiconductor memory or the like, and stores data and parameters 10ca generated when the program ba is executed. The communication unit 10d performs communication with an ECU (Engine Control Unit) that is a host device. The I / F 10e converts the signals supplied from the voltage sensor 11, the current sensor 12, and the temperature sensor 13 into digital signals and takes them in, and controls the voltage control circuit 15 to control the generated voltage of the alternator 16. .

(B) Description of Operation of Embodiment Next, the operation of the embodiment will be described with reference to the drawings. FIG. 4 is a diagram showing temporal changes in the charging voltage applied to the hybrid battery 14. In the example of FIG. 4, the charging voltage (Vt in FIG. 2) applied to the hybrid battery 14 has a rectangular pulse waveform. More specifically, the maximum voltage (amplitude) V1 of the rectangular pulse is 18.0 V, and the pulse width T1 is 4 msec. The pulse interval T2 is 16 msec, and the minimum voltage V2 is about 12.4V. These numerical values are examples, and it goes without saying that other values may be used depending on the type of the hybrid battery 14 and the traveling state of the vehicle.

  FIG. 5 is a diagram showing a current flowing through the hybrid battery 14 when the rectangular pulse shown in FIG. 4 is applied. As shown in FIG. 5A, during the period T1 shown in FIG. 4, when a rectangular pulse voltage of voltage V1 is applied, a current I1 is passed to the capacitor component 14b through the resistance component 14a. As a result, charges are accumulated in the capacitor component 14b. At this time, assuming that the capacitance value of the capacitor component 14b is C, when C is in a steady state (when the charging of the capacitor component 14b is completed), C · V1 charges are accumulated in the capacitor component 14b. Subsequently, in the period T2 shown in FIG. 4, as shown in FIG. 5B, the charge accumulated in the capacitor component 14b flows as the current I2 through the resistance component 14c, and the secondary battery component 14d is charged. Is done. Such a current I2 continues until the voltage of the capacitor component 14b becomes substantially the same as the value of the secondary battery component 14d.

  FIG. 6 is a diagram showing temporal changes in the terminal voltage Vc of the capacitor component 14b when the rectangular pulse shown in FIG. 4 is applied. As shown in FIG. 6, the voltage Vc of the capacitor component 14b increases during the period of T1 to reach the applied voltage of 18.0V, and during the period of T2, the voltage decreases due to the discharge, and the secondary battery component 14d It drops to approximately 12.4V.

  FIG. 7 is a diagram showing a temporal change in the voltage Vb of the secondary battery component 14d when the rectangular pulse shown in FIG. 4 is applied. As shown in FIG. 7, the voltage Vb of the secondary battery component 14d goes up and down following the charging voltage (Vt in FIG. 2), but the width of the vertical movement is smaller than the voltage Vc of the capacitor component 14b. Here, when a voltage of 15 V or more is applied to the secondary battery component 14d, the water contained in the electrolyte is electrolyzed, resulting in power loss. In the present embodiment, as shown in FIG. 7, the voltage Vb of the secondary battery component 14d is less than 15.0 V indicated by the broken line, so that the battery is efficiently charged without causing electrolysis of water. Can do. That is, in the present embodiment, charges are accumulated in the capacitor component 14b by the voltage V1 applied to the capacitor component 14b, and this charge is gradually discharged through the resistance component 14c to charge the secondary battery component 14d. For this reason, even if it is a case where the voltage near 18V is applied as the voltage V1, generation | occurrence | production of the loss by the electrolysis of the water in the hybrid battery 14 can be suppressed.

  If the charge accumulated in the capacitor component 14b in the period T1 is completely discharged in the period T2, the charge flowing from the capacitor component 14b to the secondary battery component 14d is C (V1-V2). Here, C (V1-V2) / (T1 + T2) is obtained when the average current flowing during the period of T1 and T2 is obtained. As a specific example, when the capacitance value of the capacitor component 14b is 1F and (T1 + T2) = 20 msec, a current of about 1 × (18.0-12.4) /0.02=280 A flows. Become. Here, in the case of a D23 size battery, the average charging current is about 400 A. In this case, for example, by setting T1 + T2 to 14 msec, 1 × (18.0-12.4) /0.014=400 A It can be.

  Although it depends on the element values of the internal resistance components 14a and 14c and the capacitor component 14b, it is desirable to set T1 in the range of 1 to 500 msec for a general hybrid battery, and for T2 Is preferably set in the range of 1 to 1000 msec.

  In the above, a sufficient time for the electric charge accumulated in the capacitor component 14b to reach a steady state is assumed as T1 and T2, but when the steady state is not reached, it can be expressed as follows. First, when the charge accumulated in the capacitor component 14b is Q1, at the end of the period T1, Q1 can be expressed by the following equation.

  Q1 = α · C · V1 (1)

Here, α is a constant determined according to the resistance value Ra of the resistance component 14a, the capacitance value C of the capacitor component 14b, and the value of T1, and can be expressed by the following equation. Note that f _α (Ra, C, T1) indicates a function having Ra, C, T1 as variables.

α = f _α (Ra, C, T1) (2)
However, 0 <α ≦ 1

  Further, when the charge remaining in the capacitor component 14b at the end of the period of T2 is Q2, Q2 can be expressed by the following equation.

  Q2 = β · C · V2 (3)

Here, β is a constant determined according to the resistance value Rc of the resistance component 14c, the capacitance value C of the capacitor component 14b, and the value of T2, and can be expressed by the following equation. Note that f _β (Rc, C, T2) represents a function having Rc, C, T2 as variables.

β = f _β (Rc, C, T2) (4)
However, 1 ≦ β <(V1 / V2)

  If the charge flowing from the capacitor component 14b to the secondary battery component 14d during the period T2 is ΔQ, this ΔQ can be obtained by the following equation.

  ΔQ = Q1-Q2 = α · C · V1−β · C · V2 (5)

  Here, the average current flowing from the capacitor component 14b to the secondary battery component 14d during the period of T1 and T2 can be obtained by ΔQ / (T1 + T2). Since C, Ra, Rc, and V2 are parameters determined by the type of the hybrid battery 14, the average current that flows from the capacitor component 14b to the secondary battery component 14d during the period T1 and T2 is that of T1, T2, and V1. The value can be adjusted.

  Therefore, the current flowing from the capacitor component 14b to the secondary battery component 14d can be set by setting the values of parameters such as T1, T2, and V1 based on the above formula.

  As described above, in the present embodiment, the voltage waveform generated by the alternator 16 by the control unit 10 by the voltage control circuit 15 is a rectangular pulse as shown in FIG. And the secondary battery component 14d is gradually charged with the charge accumulated in the capacitor component 14b during the period T2, thereby charging the secondary battery component 14d while suppressing the occurrence of water electrolysis. be able to. For this reason, charging efficiency can be improved. In particular, when braking the vehicle (when decelerating or stopping), the voltage generated by the alternator 16 by the voltage control circuit 15 is changed to a rectangular pulse waveform as shown in FIG. be able to.

  Next, an example of processing executed in the control unit 10 shown in FIG. 1 will be described with reference to FIG. When the process shown in FIG. 8 is started, the following steps are executed.

  In step S <b> 10, the CPU 10 a detects the state of the hybrid battery 14. Specifically, the CPU 10 a refers to the voltage, current, and temperature of the hybrid battery 14 detected by the voltage sensor 11, current sensor 12, and temperature sensor 13, and determines the charge rate (SOC: State) of the hybrid battery 14. of Charge).

  In step S11, the CPU 10a detects the state of the vehicle from the host ECU via the I / F 10e. Specifically, for example, it is detected whether the vehicle is stopping, accelerating, traveling at a constant speed, or decelerating.

  In step S12, the CPU 10a determines whether the vehicle is decelerating, traveling at a constant speed, or stopping, and if it is decelerating, traveling at a constant speed, or stopping (step S12: Yes). ), The process proceeds to step S13. In other cases (step S12: No), the process returns to step S10 and the same process as described above is repeated. Specifically, if the vehicle is decelerating, traveling at a constant speed, or stopping, the process proceeds to step S13, and if it is accelerating, the process returns to step S10. Thereby, when it is accelerating, the charge to the hybrid battery 14 is suspended.

  In step S13, the CPU 10a determines whether or not the vehicle is decelerating. If the vehicle is decelerating (step S13: Yes), the process proceeds to step S14, and otherwise (step S13: No), step S16. Proceed to Specifically, if the accelerator of the vehicle is returned or the brake is operated, the process proceeds to step S14.

  In step S14, the CPU 10a determines the duty and voltage for performing rectangular pulse charging according to the state of the hybrid battery 14 detected in step S10 and the state of the vehicle detected in step S11. Specifically, the duty and voltage are determined by any of the following methods. Thereby, the charge amount to the hybrid battery 14 can be adjusted. In addition, as a setting method of the charge amount with respect to the hybrid battery 14, for example, it can be determined according to the charging rate of the hybrid battery 14, or can be determined according to the magnitude of braking of the vehicle. Specifically, when the charging rate of the hybrid battery 14 is low, the charging amount can be set to be large. Further, when the vehicle is suddenly braked, the charging amount can be set to be large. Of course, you may make it combine these.

(1) When the voltage is fixed and the duty is variable The voltage V1 of the rectangular pulse is fixed at, for example, 18.0 V, and the charge amount of the hybrid battery 14 is adjusted by changing T1 and T2. be able to. More specifically, the current flowing from the capacitor component 14b to the secondary battery component 14d during this period can be controlled by adjusting T1 and T2 in the above-described equations (1) to (5). As a method for adjusting T1 and T2, a method of changing both T1 and T2 and a method of changing one while fixing one are assumed. Moreover, when changing, the method of changing continuously or changing in steps is assumed.

(2) When the voltage is variable and the duty is fixed The charging amount of the hybrid battery 14 can be adjusted by adjusting T1 and T2 to a predetermined value and adjusting the voltage V1 of the rectangular pulse. . More specifically, in the above-described formulas (1) to (5), T1 and T2 are fixed and the voltage V1 is adjusted, so that the capacitor component 14b to the secondary battery component 14d are adjusted during the period T1 and T2. The current flowing through can be controlled. In addition, as a method of changing V1, the method of changing continuously, for example, and the method of changing in steps are assumed. As a method of changing in stages, for example, a case of selecting from two stages and a method of selecting from three or more stages are assumed.

(3) When both voltage and duty are variable By making all of V1, T1, and T2 variable, the charge amount of the hybrid battery 14 can be adjusted. More specifically, the current flowing from the capacitor component 14b to the secondary battery component 14d in the period of T1 and T2 is adjusted by adjusting all of V1, T1, and T2 in the above-described formulas (1) to (5). Can be controlled. Note that the method of making T1, T2, and V1 variable can be realized by a combination of the above-described methods.

  In the above description, some or all of V1, T1, and T2 are variable. However, all of them may be fixed, and a constant charging current may flow during deceleration.

  In step S15, the CPU 10a applies a rectangular pulse to the hybrid battery 14 and charges it based on the duty and voltage V1 determined in step S14. More specifically, the CPU 10a controls the voltage control circuit 15 on the basis of the parameter determined in step S14, so that a rectangular pulse as shown in FIG. 4 is applied to the hybrid battery 14, thereby the secondary battery component. 14d is charged.

  In step S16, the CPU 10a controls the voltage control circuit 15 to charge the hybrid battery 14 with a constant voltage. More specifically, for example, the hybrid battery 14 is charged by applying a voltage (for example, 13.0 V) higher than the terminal voltage of the hybrid battery 14. Instead of charging with a constant voltage, charging with a constant current may be performed.

  In step S17, the CPU 10a determines whether or not to end the process. If it is determined not to end the process (step S17: No), the process returns to step S10 and repeats the same process as described above. Otherwise (step S17: Yes), the process ends.

  According to the above process, the hybrid battery 14 can be efficiently charged according to the state of the hybrid battery 14 and the state of the vehicle.

(C) Description of Modified Embodiment It goes without saying that the above embodiment is merely an example, and the present invention is not limited to the case described above. For example, in the above embodiment, the voltage generated by the alternator 16 is controlled by the voltage control circuit 15 to generate a rectangular pulse voltage as shown in FIG. 4, but the voltage generated by the alternator 16 is A rectangular pulse may be generated by adjusting (step-up or step-down) with a regulator or the like.

  In the above embodiment, the rectangular pulse shown in FIG. 4 is applied to the hybrid battery 14, but a pulse having a waveform other than the rectangular pulse may be applied. For example, a triangular pulse, a trapezoidal pulse, or a sine wave pulse may be applied.

  Moreover, in the above embodiment, the rectangular pulse has a constant period. However, for example, the period may be a variable period without making the period constant. Specifically, the processing shown in FIG. 8 may be executed for each period of the rectangular pulse, and T1 and T2 may be dynamically changed according to the state of the hybrid battery 14 and the state of the vehicle.

  In the above embodiment, the hybrid battery 14 is used. For example, an ordinary secondary battery (for example, a lead storage battery, a nickel cadmium battery, a lithium ion battery) and a super capacitor connected in parallel are used. It may be used.

  Further, in the flowchart shown in FIG. 8, the charging by the rectangular pulse is executed only during the deceleration. However, for example, when the charging rate of the hybrid battery 14 is lowered, the rectangular battery is stopped or running at a constant speed. You may make it perform the charge by a pulse. Of course, even during deceleration, if the charging rate of the hybrid battery 14 is high, constant voltage charging may be performed or charging may not be performed.

DESCRIPTION OF SYMBOLS 1 Secondary battery state detection apparatus 10 Control part 10a CPU (a control means, a part of charge state detection means, a driving | running state detection means)
10b ROM
10c RAM
10d Communication unit 10e I / F
11 Voltage sensor (part of charge state detection means)
12 Current sensor (part of charge state detection means)
13 Temperature sensor (part of charge state detection means)
14 Hybrid Battery 15 Voltage Control Circuit 16 Alternator 17 Engine 18 Starter Motor 19 Load

Claims (9)

In a charging device that is mounted on a vehicle and configured by connecting a secondary battery and a capacitor in parallel and controls a charging current supplied from the alternator to the battery that is charged by an alternator ,
Control means for charging the capacitor by applying a pulse voltage having an amplitude higher than the terminal voltage of the secondary battery, and charging the secondary battery with the charge accumulated in the capacitor ;
The charging current flowing through the secondary battery is controlled by controlling the pulse width, pulse interval, or amplitude of the pulse voltage according to the average charging current of the secondary battery and the capacitance value of the capacitor. Charging device.   The charging device according to claim 1, wherein a charging current flowing through the secondary battery is controlled by controlling a pulse width and / or a pulse interval of the pulse voltage.   3. The charging device according to claim 1, wherein a charging current flowing in the secondary battery is controlled by controlling an amplitude of the pulse voltage. 4. Having a charge state detection means for detecting a charge state of the secondary battery;
The control means controls the charging current flowing through the secondary battery according to the charge state of the secondary battery detected by the charge state detection means.
The charging device according to any one of claims 1 to 3, wherein A running state detecting means for detecting the running state of the vehicle;
The control means controls a charging current flowing through the secondary battery according to the running state of the vehicle detected by the running state detecting means.
The charging device according to any one of claims 1 to 4, wherein   The charging device according to claim 1, wherein a pulse width of the pulse voltage is in a range of 1 to 500 msec.   7. The charging device according to claim 1, wherein a pulse interval of the pulse voltage is in a range of 1 to 1000 msec.   8. The charging according to claim 1, wherein the battery is formed by combining a secondary battery using an electrochemical reaction and a capacitor using a charge adsorption phenomenon. apparatus. In a charging method for controlling a charging current supplied from the alternator to a battery mounted on a vehicle and configured by connecting a secondary battery and a capacitor in parallel, the battery being charged by the alternator ,
Charging the capacitor by applying a pulse voltage having an amplitude higher than the terminal voltage of the secondary battery, charging the secondary battery with the charge accumulated in the capacitor ;
The charging current flowing through the secondary battery is controlled by controlling the pulse width, pulse interval, or amplitude of the pulse voltage according to the average charging current of the secondary battery and the capacitance value of the capacitor. Charging method.

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