JP2010076532A - Power supply system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the practicality of a power supply system for a vehicle mounted on the vehicle, which is provided with an electromagnetic suspension device arranged between the upper part and lower part of a spring. <P>SOLUTION: In this power supply system, when the terminal voltage of an electromagnetic motor 54 that the electromagnetic suspension device has is not more than a first threshold voltage E<SB>1</SB>(48V) higher than a set voltage E<SB>D</SB>(46V), which is a voltage driving the electromagnetic motor 54, that is, when the electromagnetic motor 54 requires power, the power is supplied by depressing the electric discharge voltage of a first battery 100 with a first converter 102 from the first battery, which is regarded as a nominal voltage E<SB>N1</SB>(288V) higher than the set voltage E<SB>D</SB>thereby feeding power. When the power is generated with the electromagnetic motor 54 when the terminal voltage of the motor 54 exceeds the first threshold voltage E<SB>1</SB>, the generated power is regenerated to a second battery 120, which is regarded as a nominal voltage E<SB>N2</SB>(12V) lower than the set voltage E<SB>D</SB>via a second converter 122. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle power supply system mounted on a vehicle including an electromagnetic suspension device disposed between an upper part and an unsprung part.

  In recent years, a suspension apparatus for a vehicle is configured to include an electromagnetic shock absorber that generates a force in a direction in which the spring upper part and the spring lower part approach and separate from each other based on the force of an electromagnetic motor. Electromagnetic suspension devices have been studied. For example, there are devices described in Patent Documents 1 and 2 below. The electromagnetic motor included in the electromagnetic suspension device is supplied with relatively large power and is driven with a relatively high voltage. A battery that supplies power to electrical components such as lamps and audios provided in a general vehicle is insufficient in voltage (electromotive force), capacity, and the like. Is equipped with a battery dedicated to the electromagnetic suspension device. In addition, other proposals have been made regarding a power supply system for a vehicle equipped with an electromagnetic suspension device (hereinafter sometimes referred to as an “electromagnetic suspension-equipped vehicle power supply system”). The system is equipped with a capacitor such as an electric double layer capacitor that takes a short time to charge and discharge in addition to a battery that takes a long time to charge and discharge because a chemical reaction is involved at the time of charging and discharging. Based on these parameters, the electrical connection of the battery, the capacitor, and the electromagnetic motor is switched.

In recent years, development of hybrid vehicles and electric vehicles has been energetically advanced. Proposals have also been made regarding such a power supply system for a vehicle. For example, there is a system described in Patent Document 3. A vehicle such as a hybrid vehicle or an electric vehicle is provided with a motor that gives a driving force to the vehicle, and the motor requires very large electric power. The battery includes a battery having a very large capacity. In general, the battery included in the power system of the hybrid vehicle or electric vehicle has a nominal voltage higher than the voltage at which the electromagnetic motor of the electromagnetic suspension device is driven.
Japanese Patent Laid-Open No. 2003-102425 JP 2007-118714 A JP 2007-42493 A

  The electromagnetic suspension-equipped vehicle power supply system described above is still in the process of development, leaving plenty of room for improvement and examination. More specifically, when the electromagnetic suspension-equipped vehicle power supply system includes a battery whose nominal voltage is higher than the voltage at which the electromagnetic motor is driven as described above, that is, in an electromagnetic system such as a hybrid vehicle or an electric vehicle. It is thought that the practicality of the system will be improved by examining and adopting the specific configuration of the power supply system when the suspension device is mounted. This invention is made | formed in view of such a situation, and makes it a subject to improve the practicality of the power supply system of the vehicle carrying an electromagnetic suspension apparatus.

  In order to solve the above-described problem, an electromagnetic suspension-equipped vehicle power supply system according to the present invention includes a first battery having a nominal voltage higher than a set voltage, which is a voltage for driving an electromagnetic motor, and a nominal voltage lower than the set voltage. When the terminal voltage of the electromagnetic motor is equal to or lower than a first threshold voltage higher than the set voltage, the discharge voltage of the first battery is stepped down to the set voltage and the electromagnetic motor is driven from the first battery. When the second battery and the electromagnetic motor are electrically disconnected from each other when the power supply to the motor is permitted and the terminal voltage of the electromagnetic motor exceeds the first threshold voltage, the electromagnetic motor is switched from the first battery to the electromagnetic motor. It is configured to realize a state in which the supply of electric power to is prohibited and the electromagnetic motor and the second battery are electrically connected.

  In the vehicle power supply system of the present invention, when the electromagnetic motor of the electromagnetic suspension device requires electric power, the discharge voltage from the first battery having a nominal voltage higher than the set voltage at which the electromagnetic motor is driven. When the electromagnetic motor generates power by stepping down the voltage, the generated power is regenerated in a second battery having a nominal voltage lower than the set voltage. Therefore, according to this invention, compared with the case where the electric power generated by the electromagnetic motor is regenerated to the first battery, it is possible to regenerate efficiently. By having such advantages, the vehicle power supply system of the present invention is highly practical.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, item (1) corresponds to claim 1, and the technical feature of item (2) added to claim 1 is claimed in claim 2, claim 1 or claim 2 The technical feature of (7) and (8) is added to claim 3, and the technical feature of (3) is added to any one of claims 1 to 3. Claim 4 corresponds to claim 5 with the technical features of (4) and (6) added to any one of claims 1 to 4.

(1) A vehicle power supply system mounted on a vehicle including an electromagnetic suspension device that is provided between an upper part and an unsprung part and is driven by a set voltage and driven by a set voltage.
A first battery having a nominal voltage higher than the set voltage;
A second battery having a nominal voltage lower than the set voltage;
A power supply permission state provided between the first battery and the electromagnetic motor, wherein the discharge voltage of the first battery is stepped down to the set voltage and power supply to the electromagnetic motor is permitted; and the electromagnetic motor A first converter that selectively realizes a power supply prohibition state that prohibits power supply to the power supply;
A connection / disconnection switch provided between the second battery and the electromagnetic motor, and selectively realizing a connection state in which they are electrically connected and a disconnection state in which they are electrically disconnected;
When the terminal voltage of the electromagnetic motor is equal to or lower than a first threshold voltage higher than the set voltage, the power supply allowable state is realized by the first converter and the disconnected state is realized by the connection / disconnection switcher,
When the terminal voltage of the electromagnetic motor exceeds the first threshold voltage, the vehicle power supply configured to realize a power supply prohibition state by the first converter and a connection state by the connection / disconnection switcher. system.

  To put it plainly, the aspect described in this section is configured such that when an electromagnetic motor of an electromagnetic suspension device (hereinafter, simply referred to as “motor”) requires power, power is supplied from a first battery having a high nominal voltage. When the motor is generating power, the generated power is regenerated to the second battery having a low nominal voltage. When the motor requires power, it is necessary to reliably supply power from the first battery via the first converter. The “first threshold voltage” described in this section is determined from the first battery so that when the motor terminal voltage exceeds the first threshold voltage, the motor is surely generating generated power. It is desirable to set in consideration of fluctuations in the voltage of the power output from the first converter. According to the aspect of this section, it is possible to regenerate efficiently compared with the case where the power generated by the motor is regenerated to the first battery.

  The “connection / disconnection switching device” described in this section may be, for example, a simple relay, switch, etc., and has a function of stepping down the voltage of the electric power generated by the motor as will be described in detail later. There may be. The switching of the state to be realized by the connection / disconnection switching device and the switching of the state to be realized by the first converter include, for example, a sensor capable of detecting the terminal voltage of the motor in the system, the connection / disconnection switching device and the first switching device. A controller that controls the converter may be provided, and the controller may perform the detection based on the detection result of the sensor. In addition, for example, it is possible to switch the state realized by determining that the terminal voltage of the motor is changing by an analog circuit.

  The “electromagnetic suspension device” described in this section includes, for example, an unsprung unit and an unsprung unit capable of relative movement between the unsprung unit and the unsprung unit according to the approach and separation between the unsprung portion and the unsprung portion. And an electromagnetic shock absorber that generates a force for relative movement between the unsprung unit and the unsprung unit on the basis of the force of the electromagnetic motor. Further, for example, an elastic body having one end connected to one of the spring upper part and the spring lower part is provided, and the actuator is disposed between the other end of the elastic body and the other of the spring upper part and the spring lower part. The amount of deformation of the elastic body is changed according to its own operating position by applying the force generated by itself depending on the motor force to the elastic body, and the force is transferred to the spring upper part via the elastic body. It is also possible to make a so-called left and right independent type stabilizer device that acts on the unsprung portion and generates a force in the direction in which they approach and separate.

  Consider a case where the vehicle includes a plurality of electromagnetic suspension devices corresponding to a plurality of wheels. Since the terminals of the electromagnetic motors included in each of the plurality of electromagnetic suspension devices are generally connected in parallel, the terminal voltages of the plurality of motors are equal. In other words, in the aspect of this section, the switching of the state realized by the first converter and the connection / disconnection switching device may be performed by the terminal voltage of any one of the plurality of motors, and they are connected. It may be carried out by the voltage at the other place.

  (2) The vehicle power supply system according to (1), wherein the connection / disconnection switcher includes a second converter having a function of stepping down the voltage of the electric power generated by the electromagnetic motor.

  The electric power generated by the electromagnetic motor included in the electromagnetic suspension device may be very large instantaneously. That is, the voltage of electric power generated by the electromagnetic motor (hereinafter sometimes referred to as “generated voltage”) may be very high. According to the aspect of this section, since the generated power is stepped down and regenerated in the second battery, the load on the second battery can be reduced. It is desirable that the generated voltage is stepped down by the second converter to a voltage lower than the maximum voltage allowed to be applied to the second battery during charging.

  In addition, since the electromagnetic motor generates power by input from the road surface to the lower part of the spring, the generated power fluctuates in a high frequency. Even with such an input, according to the aspect of this section, the voltage output from the second converter can be stabilized, so that the regeneration efficiency to the second battery can be improved.

(3) The vehicle power supply system is
Even if the terminal voltage of the electromagnetic motor exceeds the first threshold voltage, if the charge state of the second battery is higher than a set threshold state, the disconnected state is realized by the connection / disconnection switcher. The vehicle power supply system according to (1) or (2), configured to

  The aspect described in this section can be an aspect that realizes a state in which the second battery and the motor are disconnected based on an index related to the state of charge of the second battery. By setting the threshold state to a state in which the second battery is nearly fully charged, it is possible to prohibit regeneration to the second battery and prevent overcharge of the second battery. In addition, as an index regarding the state of charge of the second battery, for example, a charge amount, a residual electric energy amount, a ratio of the remaining energy amount based on the charge capacity, or the like can be employed. Further, the charge amount of the battery (remaining electric energy amount) and the discharge voltage of the battery are related to each other, and it is considered that the charge amount of the battery is relatively large when the discharge voltage of the battery is relatively high. That is, the discharge voltage of the battery can also be adopted as an index related to the charge state of the second battery.

  (4) The vehicle power supply system according to any one of (1) to (3), wherein the vehicle power supply system includes a charging device that charges the second battery.

  The configuration of the “charging device” described in this section is not particularly limited. For example, it may be configured to charge the second battery from the first battery, which will be described in detail later, and may be a generator that generates power by the driving force of the engine mounted on the vehicle or the rotational force of the wheels. May be. According to the aspect of this section, since the second battery can be charged by the charging device even in a situation where the amount of power regenerated to the second battery by the electromagnetic motor is small, the remaining energy amount of the second battery It is possible to suppress or prevent the decrease.

(5) The charging device is
A fourth converter is provided between the first battery and the second battery for charging from the first battery and has a function of stepping down the discharge voltage of the first battery. The vehicle power supply system according to Item.

  The mode described in this section is a mode in which the configuration of the charging device is embodied, and can be considered as a mode in which the charging device is configured by the first battery and the third converter. According to the aspect of this section, since the second battery can be reliably charged using the first battery having a large capacity, it is possible to prevent the remaining energy amount of the second battery from being reduced.

(6) The vehicle power supply system is
The vehicle power supply system according to (4) or (5), wherein the second battery is not charged by the charging device when the connection state is realized by the connection / disconnection switcher. .

  According to the aspect described in this section, the current from the charging device to the second battery and the current from the motor to the second battery are prevented from interfering with each other, that is, the current is between the charging device and the motor. It can be prevented from flowing. Moreover, since the aspect of this term gives priority to the regeneration from the motor, when the charging device charges the second battery from the first battery, the power consumption due to the charging of the second battery of the first battery is reduced. Is possible.

  (7) The vehicle according to any one of (1) to (6), wherein the vehicle power supply system includes a generated power consumption device that consumes at least a part of the power generated by the electromagnetic motor. Power system.

(8) The vehicle power supply system is
The vehicle power supply system according to (7), wherein the generated power consumption device is configured to operate on condition that a terminal voltage of the motor exceeds a second threshold voltage higher than the first threshold voltage.

  According to the aspects described in the above two items, at least a part of the generated power can be consumed by the generated power consumption device, so that the burden on the second battery and the second converter can be reduced. The greater the power generated by the electromagnetic motor, the greater the burden on the second battery. Further, when the connection / disconnection switching device is the second converter described above, the burden on the converter increases. The electromagnetic motor may momentarily generate very large electric power, and in such a case, the burden on the second battery or the second converter becomes more prominent. In view of that, the latter aspect is an aspect in which conditions for operating the generated power consumption device are set, and when the power generated by the motor is not large, all of the generated power is regenerated in the second battery, When very large electric power is generated by the motor, the generated electric power consuming device consumes a part of the generated voltage and regenerates the remaining electric power to the second battery. According to the latter aspect, it is possible to efficiently regenerate the generated power while protecting the second battery and the second converter.

  By the way, the second battery and the motor are disconnected if the above-described aspect of disconnecting the second battery and the motor when the state of charge of the second battery exceeds the threshold state and the aspect of this section are combined. Even in this case, it is possible to suppress an increase in the voltage in the circuit by consuming the generated power by the generated power consumption device as compared with the case where the generated voltage consumption device is not provided.

  The structure of the “generated power consumption device” described in this section is not particularly limited, and various structures that have already been studied can be employed. Specifically, for example, it can have the same structure as a so-called dynamic brake including a resistor. The location where the generated power consumption device is disposed is not particularly limited. For example, when the connection / disconnection switching device is the second converter, from the viewpoint of reducing the burden on the second converter, Among the two batteries, it is desirable to be provided on the motor side from the second battery.

  (9) The vehicle power supply system according to any one of (1) to (8), wherein the first battery supplies electric power to a vehicle driving motor that applies driving force to the vehicle.

  The aspect described in this section is an aspect in which the use of the electric energy of the first battery is limited, and the vehicle power supply system according to the aspect of this section constitutes a part of a power supply system of a hybrid vehicle or an electric vehicle. It has become.

  (10) Any of the items (1) to (9), wherein the second battery supplies electric power to an electric load portion of a vehicle excluding those in which the first battery supplies electric power. The power supply system for vehicles as described in one.

  The mode described in this section is a mode in which the use of the electric energy of the second battery is limited, and the second battery is operated by a relatively small electric power such as electric components such as lamps and audios. This is a mode in which power is supplied.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do. Moreover, it is also possible to constitute the modification of the following Example using the technical matter described in the description of each item of [Aspect of the Invention].

<Configuration of vehicle equipped with power supply system for vehicle>
i) Configuration of Hybrid System FIG. 1 schematically shows a vehicle equipped with a vehicle power supply system 10 which is an embodiment of the claimable invention. This vehicle is a hybrid vehicle. That is, this vehicle is equipped with a hybrid system that includes both the engine 12 and the vehicle driving motor 14 for applying driving force to the vehicle. A power distribution mechanism 16 is provided between the engine 12 and the vehicle drive motor 14. The engine 12 is connected to the power distribution mechanism 16 via a generator 18, and the vehicle drive motor 14 is connected to the power distribution mechanism 16. It is connected. The power distribution mechanism 16 changes whether to transmit both the driving force of the engine 12 and the driving force of the vehicle driving motor 14 or to transmit only one of them. It is transmitted to the front wheels 22FR and 22FL via the speed reduction mechanism 20 and the like. In addition, FR and FL attached | subjected to the wheel 22 are subscripts which show a wheel position as shown in the figure, and it is necessary to clarify which of four wheels corresponds also in the following description. In some cases, FL, FR, RL, and RR may be added to those corresponding to the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively.

  In the hybrid system, various controls are performed by the hybrid electronic control unit 30 (hereinafter, also referred to as “hybrid ECU 30”). The hybrid ECU 30 is connected to inverters 32 and 34 corresponding to the vehicle drive motor 14 and the generator 18. The hybrid ECU 30 controls the inverters 32 and 34 to control the driving force. The inverters 32 and 34 are connected to a vehicle power supply system 10 described in detail later, and electric power is supplied to the vehicle drive motor 14 from the power supply system 10.

ii) Configuration of Suspension Device The vehicle includes four independent suspension type electromagnetic suspension devices 40 corresponding to the front, rear, left and right wheels 22, respectively. As shown in FIG. 2, these suspension devices 40 are provided between a suspension lower arm 42 that holds the wheel 22 and forms a part of the unsprung portion, and a mount portion 44 that is provided on the vehicle body and forms a portion of the unsprung portion. These are arranged so as to connect them. The suspension device 40 includes an electromagnetic actuator 46 and a coil spring 48 as a suspension spring, and these are integrated.

  The actuator 46 includes a screw rod 50 as a male screw portion in which a thread groove is formed, and a ball screw mechanism configured to include a nut 52 as a female screw portion that holds the bearing ball and is screwed with the screw rod 50; An electromagnetic motor 54 (hereinafter sometimes simply referred to as “motor 54”) as a power source and a casing 56 that houses the motor 54 are provided. The casing 56 rotatably holds the screw rod 50 and is connected to the mount portion 44 via a vibration isolating rubber 58 at the outer peripheral portion. The motor 54 has a hollow motor shaft 60, and a screw rod 50 is fixed to the motor shaft 60 at the upper end through the inside thereof. That is, the motor 54 gives a rotational force to the screw rod 50.

  The actuator 46 includes a cylinder 74 that includes an outer tube 70 and an inner tube 72 that is fitted into the outer tube 70 and protrudes upward from the upper end portion thereof. The outer tube 70 is connected to the lower arm 42 via a mounting bush 76 provided at the lower end portion thereof, and the inner tube 72 is fixed to the casing 56 at the upper end portion with the threaded rod 50 inserted therethrough. . A nut support cylinder 78 is erected on the inner bottom portion of the inner tube 72, and the nut 52 is fixed to the inner end of the inner tube 72 in a state of being screwed with the screw rod 50.

  Further, the actuator 46 has a cover tube 80, and the cover tube 80 is connected to the lower surface side of the mount portion 44 through the anti-vibration rubber 82 at the upper end portion with the cylinder 74 inserted. ing. A flange portion 84 (functioning as an upper retainer) is formed at the upper end portion of the cover tube 80, and the flange portion 84 and an annular lower retainer 86 provided on the outer peripheral surface of the outer tube 70. Thus, the coil spring 48 as a suspension spring is supported in a sandwiched state.

  Due to the structure as described above, the actuator 46 includes the screw rod 50, the motor 54, the casing 56, the inner tube 72, the cover tube 80, and the like, the unsprung unit connected to the mount portion 44, the nut 52, and the inner tube. 70, including a nut support cylinder 78 and the like, and a structure having an unsprung unit connected to the lower arm 42. The relative rotation is impossible, and the approaching and separating operation between the sprung part and the sprung part is performed. The structure is movable in the axial direction, in other words, can be expanded and contracted.

  In the actuator 46, when the sprung portion and the unsprung portion are moved toward and away from each other, the sprung unit and the unsprung unit can move relative to each other in the axial direction, that is, the screw rod 50 and the nut 52 are moved in the axial direction. The relative movement is enabled, and the screw rod 50 rotates with respect to the nut 52 with the relative movement. Thereby, the motor shaft 60 also rotates. The motor 54 can apply a rotational torque to the screw rod 50, and the rotational torque can generate a resistance force in a direction that prevents the relative rotation between the screw rod 50 and the nut 52. Is possible. By causing this resistance force to act as a damping force for the relative movement between the unsprung unit and the unsprung unit, and thus a damping force for the approaching and separating operation between the unsprung portion and the unsprung portion, the actuator 46 can be used as a so-called shock absorber. As a function. The actuator 46 is also capable of generating a propulsive force for the relative motion between the sprung portion and the unsprung portion, and executes control based on the so-called skyhook damper theory, pseudo groundhook theory, and the like. Is possible.

  The four suspension devices 40 are controlled by an actuator 46 by a suspension electronic control unit 90 (hereinafter also referred to as “suspension ECU 90”). The suspension ECU 90 is connected to four inverters 92 that are provided corresponding to the motors 54 included in the actuators 46 and that function as drive circuits for the corresponding motors 54. The suspension ECU 90 controls the actuator force generated by the actuator 46 by controlling the four inverters 92. The four inverters 92 are connected to a vehicle power supply system 10 to be described later, and power is supplied from the power supply system 10 to the motors 54 of the actuators 46.

  As shown in FIG. 3, the motor 54 of each actuator 46 is a three-phase DC brushless motor in which coils are star-connected (Y-connected), and is controlled by the inverter 92 described above. The inverter 92 is a general one as shown in FIG. 3, and a switching element pair composed of a switching element on the high side (high potential side) and a switching element on the low side (low potential side) of a power source is connected to a motor. There are 3 pairs corresponding to the U phase, V phase, and W phase, which are 54 three phases. The inverter 92 includes a switching element control circuit 94 that opens and closes the switching element.

The inverter 92 adjusts the current flowing through the motor 54, that is, the energization current of the motor 54, regardless of whether it is a supply current from the power supply system 10 or a generated current that depends on the electromotive force. It is structured to control the motor force. That is, the motor 54 can generate not only the motor force depending on the supply current but also the motor force depending on the electromotive force. When receiving power supply from the power supply system 10, the motor 54 is driven at a constant voltage at a set voltage E _D (for example, 46V). Incidentally, the energization current is adjusted by each inverter 92 changing the ratio (duty ratio) between the pulse on time and the pulse off time by PWM (Pulse Width Modulation).

iii) Configuration of Vehicle Power Supply System Next, the vehicle power supply system 10 according to the claimable invention that supplies power to the hybrid system and the suspension device 40 described above and other electric devices and devices that are operated by the power installed in the vehicle. Details will be described with reference to FIG. 3 in addition to FIG. As shown in FIG. 1, the power supply system 10 includes a hybrid battery 100 (hereinafter also referred to as “HV battery”) that is a first battery, and the HV battery 100 includes a vehicle drive of the hybrid system. The motor 14 is connected via the inverter 32 described above. That is, the vehicle drive motor 14 is configured to be capable of receiving a supply of electric power from the HV battery 30 and applying a driving force to the front wheels 22FR and 22FL. Incidentally, HV battery 30 is one in which the motor 54 of the suspension device 40 is a set are driven voltage E _D higher than the nominal voltage E _N1 (e.g., 288 V).

Further, the motors 54 of the four suspension devices 40 are also connected to the HV battery 100. Specifically, inverters 92 corresponding to the four motors 54 are connected to the HV battery 100 via the DC-DC converter 102. The DC-DC converter 102 includes a noise filter unit 104, a DC-AC conversion unit 106 that is a transistor-bridge circuit, a transformer 108, a rectification unit 110, a smoothing unit 112, and a converter control circuit 114. is configured, as well as down the discharge voltage of the HV battery 100 to the set voltage E _D, by so no current through DC-AC conversion unit, it is possible to avoid outputting electrical energy . That is, the DC-DC converter 102, and a state that allows to supply power to the motor 54 steps down the discharge voltage of the HV battery 100 to the set voltage E _D, first selectively implement a state that does not permit Since it functions as a converter, the DC-DC converter 102 is hereinafter referred to as a first converter 102.

Further, the power supply system 10 includes an auxiliary battery 120 that is a second battery that supplies electric power to the auxiliary machines 116 such as lamps and audios that are electric loads of the vehicle. The auxiliary battery 120 has a nominal voltage E _N2 (for example, 12V) lower than a set voltage E _D at which the motor 54 of the suspension device 40 is driven. An inverter 92 corresponding to the four motors 54 is connected to the auxiliary battery 120 via a DC-DC converter 122. The DC-DC converter 122 is configured in the same manner as the first converter, and the voltage of the electric power generated by the motor 54 is charged to be slightly higher than the nominal voltage _EN2 of the auxiliary battery 120. It is possible to step down to a working voltage V _C (for example, 14 V). In addition, since the DC-DC converter 122 can prevent the current from flowing through the DC-AC converter included in the DC-DC converter 122, the motor 54 and the auxiliary battery 120 are electrically connected to each other. It is possible to switch between the disconnected state. That is, the DC-DC converter 122 functions as a connection / disconnection switcher, and is a second converter having a function of stepping down the voltage of the electric power generated by the motor 54. Therefore, in the following description, the DC-DC converter 122 is referred to as the second converter 122.

Further, in the power supply system 10, a third converter 130 is provided between the HV battery 100 and the auxiliary battery 120. The third converter 130 is provided for charging the auxiliary battery 120 from the HV battery 100 or for supplementing the power supply from the auxiliary battery 120 to the auxiliary machine 116, and discharging the HV battery 100. This is a DC-DC converter that steps down the voltage to the charging voltage V _C.

In addition, a resistor 136 is switched between a position where the first converter 102 and the second converter 122 are connected to the motor 54, and switching between a state where current flows through the resistor 136 and a state where current does not flow through the resistor 136 is performed. A power consumption circuit 140 (a so-called dynamic brake) configured to include the element 138 is disposed. In the power consumption circuit 140, the voltage between the high potential side and the low potential side of the power consumption circuit 140 (equal to the terminal voltage E _M of the motor 54) exceeds a second threshold voltage E ₂ described in detail later. In this case, the switching element 138 is turned on, and a current flows through the resistor 136 so that power is consumed.

  In the vehicle power supply system 10, the power supply electronic control unit 150 (hereinafter, also referred to as “power supply ECU 150”) monitors the charge states of the two batteries 100, 120, supplies power from them, or charges them. Control, that is, control of the three converters 102, 122, and 130 is performed. Specifically, the power supply ECU 150 is connected to a converter control circuit 114 included in each of the three converters 102, 122, and 130, and outputs a command regarding whether or not to output electric energy, and electric energy. In this case, a command or the like for making the voltage at the output terminal constant is transmitted from power supply ECU 150 to converter control circuit 114.

iv) Sensor mounted on vehicle As shown in FIG. 1, the vehicle includes four on-spring vertical acceleration sensors that detect the vertical acceleration (vertical acceleration) of each mount portion 24 of the vehicle body corresponding to each wheel 12. [Gzs] 160, four unsprung vertical acceleration sensors [Gzg] 162 for detecting the vertical acceleration of each wheel 12, and a voltmeter [E _M ] 164 for measuring the terminal voltage of the motor 54 as shown in FIG. A voltmeter [E _B2 ] 166 for measuring the terminal voltage of the auxiliary battery 120, a thermistor [T] 168 for measuring the temperature of the resistor 136 included in the power consumption circuit 140, and the like are provided. The sprung vertical acceleration sensor 160, the unsprung vertical acceleration sensor 162, and the thermistor 168 are connected to the suspension ECU 190, and the two voltmeters 164 and 166 are connected to the power supply ECU 150. The suspension ECU 90 and the power supply ECU 150 perform control based on signals from these sensors. Incidentally, the character [] is a symbol used when the above-mentioned switch, sensor, etc. are shown in the drawing. The suspension ECU 90 and the power supply ECU 150 store a control program, various data, and the like.

<Control in a vehicle equipped with a vehicle power supply system>
i) Basic Control of Suspension Device The suspension ECU 90 can control each of the four suspension devices 40 independently. In each of the suspension devices 40, the actuator force of the actuator 46 is independently controlled, and control for damping the vibration of the vehicle body and the wheel 22, that is, the sprung vibration and the unsprung vibration is executed. In the control, so as to generate the actuator force magnitude corresponding to the speed of vibration to attenuate the vibration of the vehicle body and the wheel 22, the target actuator force F ^* is determined. In other words, the control is based on both the control based on the so-called skyhook damper theory and the control based on the pseudo groundhook damper theory. Specifically, the vertical movement speed of the vehicle mount unit 44 obtained from the spring vertical acceleration sensor 160 detected by the spring vertical acceleration sensor 160 provided on the vehicle mount 44, so-called absolute sprung speed Vs. Based on the vertical movement speed of the wheel 22 obtained from the unsprung longitudinal acceleration detected by the unsprung longitudinal acceleration sensor 162 provided on the lower arm 42, the so-called unsprung absolute speed Vg, the target actuator is The force F ^* is calculated.
F ^* = Cs · Vs−Cg · Vg
Here, Cs is a sprung mass damping gain for generating a damping force according to the vertical operating speed of the mount 44 of the vehicle body, and Cg is a damping corresponding to the vertical operating speed of the wheel 22. It is an unsprung vibration suppression gain for generating force. That is, Cs and Cg can be considered as damping coefficients for so-called sprung and unsprung absolute vibrations.

The inverter 92 performs operation control of the motor 54 for generating the target actuator force F ^* determined as described above. More specifically, a target duty ratio is determined based on the target actuator force F ^* determined as described above, and a command based on the duty ratio is transmitted to the inverter 92. Under the appropriate duty ratio, the inverter 92 controls the opening and closing of the switching element included in the inverter 92 by the switching element control circuit 94 to operate the motor 54 so as to generate the target actuator force F ^* . That is, the actuator force generated by the actuator 46 is controlled by controlling the operation of the motor 54.

  As described above, the actuator 46 relies on the force of the motor 54 to generate a force relative to the relative movement between the unsprung unit and the unsprung unit, and the approach and separation between the unsprung portion and the unsprung portion. Power for movement is given. The actuator force is applied not only as a resistance force against the relative movement between the sprung unit and the unsprung unit, but also as a propulsive force.

  The torque generated by the motor 54 and the actuator force are in a proportional relationship, and the relative operation between the unsprung unit and the unsprung unit matches the approach / separation operation between the unsprung portion and the unsprung portion. Can think. FIG. 4 shows the short circuit characteristics of the motor 54 with the torque or actuator force on the vertical axis and the speed of the relative motion or the rotational speed of the motor 54 on the horizontal axis. The first quadrant in the figure is a region in which the sprung portion and the sprung portion move in the rebound direction, and the actuator force acts in the rebound direction. Similarly, the second quadrant has a rebound direction in the rebound direction. The region where the actuator force acts, the third quadrant is the region where the actuator force in the bound direction acts on the motion in the bound direction, and the fourth quadrant is the region where the actuator force in the bound direction acts on the motion in the rebound direction It is. That is, the first and third quadrants are areas where the actuator force acts as a propulsive force, and the second and fourth quadrants are areas where the actuator force acts as a resistance force. The short-circuit characteristic line shown in the figure is a line indicating the force generated by the motor 54 based on the electromotive force when the energization terminals of the motor 54 are short-circuited.

  In the areas [A], [B], [D], and [E] in FIG. 4, the actuator force is generated while the motor 54 is supplied with power from the power supply system 10. On the other hand, in the area [C], [F], that is, the hatched area, the electric power based on the electromotive force is generated by the motor 54, and the actuator force depending on the generated electric power is generated. Become.

ii) Control of Power Supply System for Vehicle In the power supply system 10, the charge / discharge states of the two batteries 100, 120 are controlled by controlling the three converters 102, 122, 130. When the motor 54 of the suspension device 40 requires supply power, the power supply system 10 reduces the discharge voltage from the HV battery 100 to the set voltage E _D by the first converter 102 as described above. Then, electric power is supplied to the motor 54. On the other hand, when the motor 54 is generating electric power, the power supply system 10 regenerates the generated electric power to the auxiliary battery 120 whose nominal voltage E _N2 is lower than the set voltage E _M.

Based on terminal voltage E _{M of} motor 54 measured by voltmeter 164 (hereinafter sometimes referred to as “motor terminal voltage E _M ”), power supply ECU 150 determines whether motor 54 is receiving supply power or generates power. It is judged whether it is in a state. Specifically, when the motor terminal voltage E _M is equal to or lower than a first threshold voltage E ₁ (for example, 48 V) that is slightly higher than the set voltage E _D , the motor 54 is supplied with power. If the motor terminal voltage E _M exceeds the first threshold voltage E ₁ , it is determined that the power is being generated. When motor terminal voltage E _M is equal to or lower than first threshold voltage E ₁ , power supply ECU 150 sets first converter 102 to the ON state, which is a state for outputting electric energy, and does not output second converter 122 for electric energy. The state is the OFF state. On the other hand, when the motor terminal voltage E _M exceeds the first threshold voltage E ₁ is the first converter 102 and disconnects the motor 54 and the HV battery as OFF state, by the second converter 122 to the ON state The electric power generated by the motor 54 is regenerated to the auxiliary battery 120 via the second converter 122.

However, the electric power generated by the motor 54 may be very large. In such a case, the voltage applied to the second converter 122 is very large, and the burden on the second converter 122 is also large. Therefore, in the power supply system 10, when the second threshold voltage E ₂ (for example, 55 V), which is higher than the first threshold voltage E ₁ , is exceeded, the power consumption circuit 140 causes the power consumption circuit 140 to generate power generated by the motor 54. A part of the electric power is consumed, and the remaining electric power is regenerated to the auxiliary battery 120 via the second converter 122. That is, the power consumption circuit 140 functions as a generated power consumption device. Incidentally, in the power supply system 10, the switching element 138 included in the power consumption circuit 140 is switched on and off by an analog circuit. It may be configured as such.

  Note that, when the motor 54 is supplied with power from the HV battery 100, naturally, power is not regenerated from the motor 54 to the auxiliary battery 120, so that the auxiliary battery 120 is assisted, that is, In order to supplement the power supply from the auxiliary battery 120 to the auxiliary machine 116 or to charge the auxiliary battery 120, the third converter is turned on to charge the auxiliary battery 120 from the HV battery 100. ing. Therefore, the power supply system 10 includes the HV battery 100 and the third converter 130, and includes a charging device that charges the auxiliary battery 120 as the second battery.

Further, the power supply system 10 determines the voltage at the time of discharging the auxiliary battery 120 from the terminal voltage of the auxiliary battery 120 detected by the voltmeter 166 (hereinafter may be referred to as “auxiliary battery discharge voltage E _B2 ”). And the charging state of the auxiliary battery 120 is monitored based on the auxiliary battery discharge voltage E _B2 . It can be seen that the discharge voltage of the battery and the charge amount (remaining electric energy amount) are related to each other, and that the charge amount of the auxiliary battery 120 increases as the auxiliary battery discharge voltage E _B2 increases. Therefore, in the power supply system 10, when the auxiliary battery discharge voltage E _B2 exceeds the battery threshold voltage E ₀ (for example, 13.5 V), it is determined that the battery is almost fully charged. In this case, even if the motor 54 is in the power generation state, the second converter 122 is turned off, and regeneration of the power generated by the motor 54 to the auxiliary battery 120 is prohibited. When motor 54 is supplied with power, third converter 130 is turned off, and charging from HV battery 100 to auxiliary battery 120 is prohibited.

iii) Control of Suspension Device Relying on Status of Power Supply System The suspension ECU 90 is configured to change the control of the suspension device 40 according to the status where the vehicle power supply system 10 is placed. More specifically, when the temperature of the power consumption circuit 140, specifically, the temperature of the resistor 136 measured by the thermistor 168 exceeds the set temperature T ₀ , the burden on the power consumption circuit 140 is increased. Therefore, the control of the suspension device 40 is changed to control that increases power consumption compared to normal control, in other words, control that makes the motor 54 difficult to generate power. Specifically, as shown in the energy contour diagram of FIG. 5, the sprung mass damping gain Cs and the unsprung vibration damping gain Cg in the normal control take into consideration both the ride comfort of the vehicle and the grounding property of the wheels. whereas uses the value Cs _0, Cg ₀ which is set Te, when the temperature of the power circuit 140 rises, using conventional control value greater than Cs _1, Cg ₁ as the gain thereof both Thus, the force for damping the vibration, that is, the target actuator force F ^* is determined. Therefore, when the temperature rises, the control is changed to focus on the vibration control performance of both the sprung portion and the unsprung portion, and the generated power of the motor 54 is reduced, so that the load on the power consumption circuit 140 is reduced. It becomes.

When the hybrid system stops the engine 12 and applies a driving force to the vehicle only by the vehicle driving motor 14 (hereinafter sometimes referred to as “EV mode traveling”), the suspension ECU 90 It is determined that the power supplied from the battery 100 to the vehicle drive motor 14 is increased, and the control of the suspension device 40 is changed to a control in which the generated power is increased as compared with the normal control. Specifically, as shown in the energy contour diagram of FIG. 5, the target actuator force F is obtained by using values Cs ₂ and Cg ₂ smaller than normal control for the sprung mass damping gain Cs and the unsprung mass damping gain Cg. ^* is determined. Therefore, during EV mode traveling, the control is changed to focus on the power generation amount, and the power supplied from the HV battery 100 to the motor 54 is reduced.

<Control program>
Control of the vehicle power supply system 10 described above is performed by executing a power supply control program whose flowchart is shown in FIG. The actuator 46 is controlled by repeatedly executing the actuator control program shown in the flowchart of FIG. 7 by the suspension ECU 90 at short time intervals while the ignition switch is in the ON state. The control flow will be briefly described below with reference to the flowchart shown in the drawing. The actuator control program is executed for each of the actuators 46 of the suspension device 40 provided on each of the four wheels 22. In the following description, processing by this program for one actuator 46 will be described in consideration of simplification of description.

i) Power Supply Control Program In the power supply control program executed by the power supply ECU 150, first, the motor 54 measured by the voltmeter 1164 in step 1 (hereinafter abbreviated as “S1”, the same applies to other steps). It is determined whether the terminal voltage E _M is equal to or lower than the first threshold voltage E ₁ . When the motor terminal voltage E _M is equal to or lower than the first threshold voltage E ₁ , a state in which power is supplied from the HV battery 100 to the motor 54 is realized at S2 or lower. Specifically, first, the first converter 102 is turned on in S2, and the second converter 122 is turned off in S3. Next, in S4, it is determined whether or not the discharge voltage E _B2 of the auxiliary battery 120 is equal to or lower than the threshold voltage E ₀ . If the auxiliary battery discharge voltage E _B2 is the threshold voltage E ₀ or less, in S5, the third converter 130 is turned ON, the electric energy is transmitted to the auxiliary battery 120 from the HV battery 100. When the auxiliary battery discharge voltage E _B2 exceeds the threshold voltage E ₀ , the auxiliary battery 120 is almost fully charged, so that electric energy is not sent from the HV battery 100 to the auxiliary battery 120. In S6, the third converter 130 is turned off.

When the motor terminal voltage E _M exceeds the first threshold voltage E ₁ at S1, the first converter 102 is turned off at S7, and the motor 54 and the HV battery 100 are disconnected. Then, in S9, it is determined whether or not auxiliary battery discharge voltage E _B2 is equal to or lower than threshold voltage E ₀ . When auxiliary battery discharge voltage E _B2 is equal to or lower than threshold voltage E ₀ , second converter 122 is turned on in S10, and a state in which the generated power of motor 54 is regenerated to auxiliary battery 120 is realized. . When auxiliary battery discharge voltage E _B2 exceeds threshold voltage E ₀ , auxiliary battery 120 is in a fully charged state, so second converter 122 is turned off in S11 so that regeneration is not performed. The Incidentally, the auxiliary battery discharge voltage E _B2 regardless of whether the threshold voltage E ₀ or less, the third converter 130 is adapted to be OFF state.

Incidentally, when the terminal voltage E _M of the motor 54 is larger than the second threshold voltage E ₂ , the power consumption circuit 140 is turned on, and part or all of the generated power of the motor 54 is consumed. .

ii) Actuator control program In the actuator control program executed in the suspension ECU 90, first, in S21 and 22, the sprung absolute velocity Vs and the unsprung absolute value are obtained from the detection results of the sprung vertical acceleration sensor 160 and the unsprung vertical acceleration sensor 162. The speed Vg is acquired. Then, in S23, whether with whether or not the temperature T of the power consuming circuit 140 detects the set temperature T ₀ or more is determined by the thermistor 168, in S24, the vehicle is driven only by the power by the hybrid system (Whether or not the vehicle is traveling in the EV mode) is determined. When the temperature T is lower than the set temperature T ₀ and the vehicle is not traveling in the EV mode, normal control is executed in S25 and subsequent steps. Specifically, in S25, the sprung mass damping gain Cs and the unsprung mass damping gain Cg are determined to be Cs ₀ and Cg ₀ , respectively. In S26, the target actuator force F ^* is determined by the method described above. In S27, the duty ratio for controlling the motor 54 is determined based on the target actuator force F ^*, and the duty ratio is determined. Is sent to the inverter 92.

In S23, Cs ₁ when the temperature T is determined to be the set temperature T ₀ or more, sprung vibration suppression gain Cs, unsprung vibration suppression gain Cg is a large value compared to the normal control, is determined in cg _1, electric power generated by the power consumption of the suspension device 40 is larger motor 54 is reduced, the burden of power consumption circuit 140 can be reduced. Further, in S24, if it is determined that the traveling in the EV mode, the sprung vibration suppression gain Cs, unsprung vibration suppression gain Cg is, Cs _2, Cg is a small value as compared to the normal control is determined to be _2, the power generation amount of the motor 54 is increased, the electric power supplied from the HV battery 100 to the motor 54 is reduced.

<Effect of vehicle power supply system>
The vehicle power supply system 10 applies power generated by an electromagnetic motor 54 included in the electromagnetic suspension device 40 to an HV battery 100 having a nominal voltage _EN1 higher than a set voltage E _D for driving the electromagnetic motor 54. without regeneration, it is configured to regenerated to auxiliary battery 120 that is a setting voltage E lower nominal voltage than the _{D EN2,} are the efficient regeneration possible. Further, the power supply system 10 includes a power consumption circuit 140 as a generated power consuming device capable of consuming at least a part of the generated power of the electromagnetic motor 54, and when the generated power of the electromagnetic motor 54 becomes very large. The generated power is consumed by the power consumption circuit 140 to relieve the load on the auxiliary battery 120 and the second converter 122 which is a connection / disconnection switcher, and the remaining generated power is regenerated in the auxiliary battery 120. It is possible.

It is the schematic which shows the whole structure of the vehicle carrying the vehicle power supply system which is an Example of claimable invention. It is front sectional drawing which shows the electromagnetic suspension apparatus shown in FIG. It is a circuit diagram of the power supply system for vehicles shown in FIG. 3 is a graph for explaining the relationship between the actuator force of the actuator shown in FIG. 2, the supply of electric power to the electromagnetic motor included in the actuator, and the regeneration of electric power from the electromagnetic motor. It is a figure which shows the relationship between the unsprung damping gain used for control of the actuator shown in FIG. 2, and an unsprung damping gain. It is a flowchart showing the power supply control program performed by the power supply electronic control unit shown in FIG. It is a flowchart showing the actuator control program performed by the suspension electronic control unit shown in FIG.

Explanation of symbols

10: Vehicle power supply system 12: Engine [ENG] 14: Motor for motor drive [MO] 22: Wheel 30: Hybrid electronic control unit [Hybrid ECU] 32, 34: Inverter 40: Electromagnetic suspension device 42: Lower arm (spring) (Lower part) 44: mount part (spring upper part) 46: actuator 48: coil spring (suspension spring) 54: electromagnetic motor 90: suspension electronic control unit [suspension ECU] 92: inverter 100: hybrid battery (first battery) [HV BAT 102: First converter [CONV1] 104: Noise filter unit 106: DC-AC conversion unit 108: Transformer 110: Rectification unit 112: Smoothing filter unit 114: Converter control circuit 120: Auxiliary equipment (Second battery) 122: second converter [CONV2] 130: third converter (charging device) [CONV3] 136: resistor 138: switching element 140: power consumption circuit (generated power consumption device) 150: power supply electronic control Unit [power supply ECU] 164: Voltmeter [E _M ] 166: Voltmeter [E _B2 ] 168: Thermistor [T]

E _D : Setting voltage (46V) E _N1 : Nominal voltage of the first battery (288V) E _N2 : Nominal voltage of the second battery (12V) V _C : Voltage for charging (14V) E _M : Terminal voltage E of the electromagnetic motor _1: the first threshold voltage (48V) E _2: second threshold voltage (55V) E _B2: auxiliary discharge voltage of the battery E _0: battery threshold voltage (13.5V) Vs: sprung absolute speed Vg: unsprung absolute speed Cs: Sprung damping gain Cg: Unsprung damping gain F ^* : Target actuator force

Claims (5)

A vehicle power supply system mounted on a vehicle including an electromagnetic suspension device that is provided between an upper spring portion and an unspring portion and is driven by a set voltage and driven by a set voltage,
A first battery having a nominal voltage higher than the set voltage;
A second battery having a nominal voltage lower than the set voltage;
A power supply permission state provided between the first battery and the electromagnetic motor, wherein the discharge voltage of the first battery is stepped down to the set voltage and power supply to the electromagnetic motor is permitted; and the electromagnetic motor A first converter that selectively realizes a power supply prohibition state that prohibits power supply to the power supply;
A connection / disconnection switch provided between the second battery and the electromagnetic motor, and selectively realizing a connection state in which they are electrically connected and a disconnection state in which they are electrically disconnected;
When the terminal voltage of the electromagnetic motor is equal to or lower than a first threshold voltage higher than the set voltage, a power supply allowable state is realized by the first converter and a disconnected state is realized by the connection / disconnection switcher,
When the terminal voltage of the electromagnetic motor exceeds the first threshold voltage, the vehicle power supply configured to realize a power supply prohibition state by the first converter and a connection state by the connection / disconnection switcher. system. The connection / disconnection switcher is
The vehicular power supply system according to claim 1, comprising a second converter having a function of stepping down a voltage of electric power generated by the electromagnetic motor. The vehicle power supply system is
A generated power consumption device that consumes at least part of the power generated by the electromagnetic motor;
3. The vehicle power supply according to claim 1, wherein the generated power consumption device is configured to operate on condition that a terminal voltage of the motor exceeds a second threshold voltage higher than the first threshold voltage. 4. system. The vehicle power supply system is
Even if the terminal voltage of the electromagnetic motor exceeds the first threshold voltage, if the charge state of the second battery is higher than a set threshold state, the disconnected state is realized by the connection / disconnection switcher. The vehicular power supply system according to any one of claims 1 to 3, wherein the vehicular power supply system is configured to.   When the vehicle power supply system includes a charging device that charges the second battery, and the connection state is realized by the connection / disconnection switcher, the charging device does not charge the second battery. The vehicular power supply system according to any one of claims 1 to 4, which is configured.

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