JP2010183767A - Power supply apparatus and method of controlling power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an increase in loss due to a discharging and charging current of a capacitor provided in a power converter even when a motor frequently repeats a powering state and a regenerating state. <P>SOLUTION: Provided is a power supply apparatus wherein when the motor moves from a regenerating state to a powering state, processing is performed to keep an electrical connection between first and second power supplies fixed at a series connection based on the traveling environment and traveling history of the vehicle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power supply device and a control method thereof.

  Conventionally, a power supply device including a plurality of independent power supplies is known. For example, this power supply device supplies power to a motor via an inverter (power conversion device). For example, Patent Document 1 discloses a method for improving system efficiency by lowering an input voltage of an inverter and reducing a switching loss during low output operation of an electric vehicle. Specifically, when the accelerator pedal depression amount, motor output, or brake pedal depression amount is large, a plurality of power supplies are connected in series, and when these values are small, a plurality of power supplies are connected in parallel. .

  In this type of power supply device, when there is a difference between the individual power supply voltages, the power supplies cannot be connected in parallel. Therefore, when the motor is regenerated, a plurality of power supplies are connected in series.

Japanese Patent Laid-Open No. 5-236608

  By the way, for example, in a scene where the accelerator pedal depression amount is small and the motor speed is low, such as in a traffic jam, a state where a plurality of power sources are connected in parallel during a power running state and a plurality of power sources are connected in series during a regenerative state is frequently repeated. Will be. Therefore, there exists a problem that the loss by charging / discharging current will increase with the voltage change of the smoothing capacitor with which an inverter (power converter device) is provided.

  The present invention has been made in view of such circumstances, and its purpose is to increase loss due to the charge / discharge current of the capacitor provided in the power converter even when the motor frequently repeats the power running state and the regenerative state. It is to suppress.

  In order to solve such a problem, according to the present invention, when the transition from the regenerative state to the power running state is performed, the electrical connection states of the first and second power sources are connected in series based on the traveling environment and traveling history of the vehicle. A series fixing process is performed to fix the state as it is.

  According to the present invention, after the transition from the regenerative state to the power running state, the same series connection as the electrical connection state in the regenerative state is maintained as it is by performing the series fixing process. Thereby, the frequency | count of switching with a serial connection and a parallel connection can be reduced. Therefore, a change in the voltage of the capacitor of the inverter is suppressed, heat generation due to the charge / discharge current of the smoothing capacitor can be suppressed, and an increase in loss due to the charge / discharge current can be suppressed.

1 is a configuration diagram schematically showing a power supply device 30 according to a first embodiment and a control system of a motor 10 using the power supply device 30. The block diagram which shows typically the structure of the control unit 40 concerning 1st Embodiment. Explanatory drawing of the electrical connection state of the 1st power supply and 2nd power supply regarding the power supply device 30 concerning 1st Embodiment. The flowchart which shows the control method of the power supply device 30 concerning 1st Embodiment. The flowchart which shows the control method of the power supply device 30 concerning 2nd Embodiment. The flowchart which shows the control method of the power supply device 30 concerning 3rd Embodiment. The flowchart which shows the control method of the power supply device 30 concerning 4th Embodiment. The flowchart which shows the control method of the power supply device 30 concerning 5th Embodiment. The block diagram which shows typically the control system of the motor 10 using the power supply device 30a and the said power supply device 30a concerning 6th Embodiment The block diagram which shows typically the structure of the control unit 40a concerning 6th Embodiment. Explanatory drawing of the electrical connection state of the 1st power supply and 2nd power supply in the power supply device 30a concerning 6th Embodiment

(First embodiment)
FIG. 1 is a configuration diagram schematically showing a power supply device 30 and a control system for a motor 10 using the power supply device 30 according to the first embodiment of the present invention. In the present embodiment, a control system for controlling the motor 10 applied as a drive motor for an electric vehicle will be described. The electric vehicle includes a motor 10, an inverter 20, a power supply device 30, and a control unit 40.

  The motor 10 includes, for example, a plurality of phase windings star-connected around a neutral point (in this embodiment, three phase windings including a U-phase winding, a V-phase winding, and a W-phase winding) Is a three-phase AC synchronous motor. The motor 10 is driven by an interaction between a magnetic field generated by supplying three-phase AC power converted in the inverter 20 to each phase winding and a magnetic field generated by a permanent magnet of the rotor. The rotor of the motor 10 is connected to the input shaft of the automatic transmission.

  The motor 10 can operate as an electric motor by being rotated by receiving power supplied from the power supply device 30 (hereinafter, this operation state is referred to as a “power running state”). On the other hand, when the rotor is rotated by an external force, the motor 10 functions as a generator by generating an electromotive force at both ends of the stator winding (hereinafter, this operation state is referred to as a “regeneration state”). The electric power generated by the motor 10 can charge the power supply device 30. In this specification, the term “motor” is used to mean that both functions of an electric motor and a generator are combined.

  The inverter 20 is PWM-controlled according to an inverter drive signal output from the control unit 40 when the motor 10 is in a power running state, thereby converting DC power supplied from the power supply device 30 into multiphase AC power (this embodiment). Then, it is converted into U-phase AC power, V-phase AC power, and W-phase AC power), and the 3-phase AC power is supplied to each phase winding of the motor 10. Further, the inverter 20 converts the three-phase AC power generated by the motor 10 into DC power when the motor 10 is in a regenerative state. This DC power is stored in the power supply device 30 or a smoothing capacitor C described later.

  The inverter 20 is mainly composed of three switch circuits corresponding to the respective phases of the motor 10. Specifically, the inverter 20 includes a U-phase switch circuit, a V-phase switch circuit, and a V-phase switch circuit between a positive electrode bus on the positive electrode side of the power supply device 30 and a negative electrode bus on the negative electrode side of the power supply device 30. And a W-phase switch circuit. Further, a smoothing capacitor C is connected between the positive electrode bus and the negative electrode bus closer to the power supply device 30 than the switch circuit for each phase.

  The U-phase switch circuit is mainly composed of a pair of switches (arms) connected in series with each other, and the V-phase switch circuit is mainly composed of a pair of switches (arms) connected in series with each other. Has been. In addition, the W-phase switch circuit mainly includes a pair of switches (arms) connected in series. Each switch is mainly composed of a switching element such as an NPN transistor, and a reflux diode is connected in antiparallel between the collector and the emitter of each transistor. The on / off states of these switches are switched according to the inverter drive signal output from the control unit 40.

  The interconnection point of a pair of U-phase switches, the interconnection point of a pair of V-phase switches, and the interconnection point of a pair of W-phase switches each function as an output point for each phase current. ing. A corresponding phase winding of the motor 10 is connected to each output point. The three-phase alternating current generated by the inverter 20 is defined as a U-phase alternating current Iu, a V-phase alternating current Iv, and a W-phase alternating current Iw, respectively. For example, each AC current Iu, Iv, Iw is positive in the direction in which the current flows to the motor 10 side.

  The power supply device 30 is connected to the motor 10 via the inverter 20, and is a power supply device that supplies power to the motor 10 and charges the power generated in the motor 10. The power supply device 30 has a plurality of power supplies (in this embodiment, two power supplies (first and second power supplies)) that each function independently as a DC power supply. For example, a battery such as a nickel metal hydride battery or a lithium ion battery can be used as each power source.

  Further, the power supply device 30 includes a switch circuit that switches an electrical connection state between the first and second power supplies between a series connection and a parallel connection, and the switch circuit mainly includes a single switch SW0 (switching means). It is configured. The single switch SW0 is mainly composed of a switching element such as an NPN transistor, and the transistor has a reflux diode connected in reverse parallel between the collector and the emitter. In the switch circuit, diodes corresponding to the forward direction of the return diode of the single switch SW0 are connected in series to the collector terminal side and the emitter terminal side of the single switch SW0. The on / off state of the single switch SW0 is switched according to the switch drive signal output from the control unit 40.

  Here, the connection point between the single switch SW0 and the diode on the collector terminal side is connected to the positive electrode of the first power supply (power supply voltage Ea), and the connection point between the single switch SW0 and the diode on the emitter terminal side is The negative electrode of the second power supply (power supply voltage Eb) is connected. The other terminal of the diode on the collector terminal side and the positive electrode of the second power source are connected to each other, and this connection end functions as an output end on the positive side of the power supply device 30. The positive output bus is connected to the positive bus of the inverter 20. Further, the other terminal of the diode on the emitter terminal side and the negative electrode of the first power supply are connected to each other, and this connection end functions as the output end on the negative side of the power supply device 30. This negative output side is connected to the negative bus of the inverter 20. A filter reactor L is provided between the inverter 20 and the power supply device 30 in order to suppress an inrush current when the first and second power supplies are switched from the parallel connection to the series connection.

  The control unit 40 is a control unit that controls the motor 10 via the inverter 20 and also a control unit that controls the power supply device 30. As the control unit 40, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. The control unit 40 performs calculations for controlling the inverter 20 and the power supply device 30 in accordance with a control program stored in the ROM. Then, the control unit 40 outputs a control signal calculated by this calculation to the inverter 20 or the power supply device 30.

  FIG. 2 is a block diagram schematically showing the configuration of the control unit 40. The control unit 40 controls the output torque of the motor 10 by controlling each switch constituting the inverter 20. In addition, the control unit 40 sets the electrical connection state of the first and second power sources in the power supply device 30 by controlling the single switch SW <b> 0 that constitutes the power supply device 30.

  Necessary information such as sensor signals is input to the control unit 40 from various sensors. Current sensor 50 detects an alternating current of each phase of motor 10, that is, a U-phase alternating current Iu, a V-phase alternating current Iv, and a W-phase alternating current Iw. The electrical angle detector 51 detects an electrical phase (electrical angle) θ representing the rotor position of the motor 10. Further, the motor speed detection unit 52 detects the rotational angular speed (motor speed) ω of the rotor of the motor 10. For example, the electrical angle detection unit 51 and the motor speed detection unit 52 detect the electrical angle θ and the motor speed ω based on detection results from a rotary position sensor such as an encoder or resolver that detects the rotor position of the motor 10. Further, the torque command value T * calculated in the host device is input to the control unit 40.

  The vehicle speed sensor 53 is a sensor that detects the vehicle speed Vca. The obstacle sensor 54 is an obstacle detection means for detecting an obstacle information (hereinafter referred to as “obstacle information”) Lob that hinders vehicle travel. For example, a laser radar that detects a distance to the object, A millimeter wave radar or the like can be used. The air temperature sensor 55 is air temperature detecting means for detecting the air temperature.

  Furthermore, the control unit 40 can acquire information Iinfo held by the navigation system 56 as necessary. The navigation system 56 is a device that presents map information and route information around its own location, and includes a map database, position detection means for detecting the current position, information reception means for receiving information from an external system, and various arithmetic processes. The processing means to perform is comprised mainly. The map database is a database that holds road information for navigation. The road information in this map database is referred to by processing means as necessary. The road information is information in which position information or the like is associated with the road on which the host vehicle is traveling. Through this road information, the curvature of the road, the gradient of the road, the width of the road, and the like can be grasped. The road information also includes information on facilities existing around the road. The position detection means detects the current position of the vehicle based on information output from, for example, a GPS receiver, an orientation sensor, and a vehicle speed sensor. The information receiving means receives traffic information (for example, traffic jam information) such as VICS information from the external infrastructure. The processing means performs various processes necessary for current position display and route guidance, and also performs various processes in response to requests from the control unit 40, whereby the information held by itself is stored as information related to the driving environment (hereinafter referred to as the travel environment). It can be output to the control unit 40 as Iinfo) (referred to as “environmental information”). In other words, the navigation system 56 functions as a travel environment detection unit that detects the travel environment of the vehicle for the control unit 40.

  The control unit 40 includes a torque control unit 41, a current control unit 42, a power supply control unit 43, and a memory 44 when this is viewed functionally. Among these functional elements, the torque control unit 41 and the current control unit 42 mainly serve as a control unit of the motor 10, and the power control unit 43 and the memory 44 mainly include the power supply device 30. It functions as a control means.

  The torque control unit 41 calculates a d-axis current command value Id * and a q-axis current command value Iq *, which are current command values for vector control, based on the torque command value T * and the motor speed ω. Specifically, the torque control unit 41 uses the d-axis and q-axis current command values for the motor 10 to output a torque that matches the torque command value T * based on the torque command value T * and the motor speed ω. Id * and Iq * are respectively calculated. The calculated d-axis and q-axis current command values Id * and Iq * are output to the current control unit 42. The torque control unit 41 holds a map describing the correspondence between each parameter of the torque command value T * and the motor speed ω and the d-axis and q-axis current command values Id * and Iq *. By referencing, d-axis and q-axis current command values Id * and Iq * are calculated. A map describing this correspondence is acquired in advance through experiments and simulations.

  Here, the dq axis coordinate system is an orthogonal coordinate system including a d axis and a q axis that rotate at an electrical rotation speed that is an integral multiple of the mechanical rotation speed of the motor 10. In the motor 10 which is a three-phase synchronous motor, the dq axis coordinate system rotates in synchronization with the motor rotation. With the dq axis coordinate system, the current supplied to the stator winding of the motor 10 is divided into a field component current (d axis current) and a torque component current (q axis current) and is displayed as a vector.

  The current control unit 42 generates an inverter based on the d-axis and q-axis current command values Id * and Iq * output from the torque control unit 41, the electrical angle θ, and the AC currents Iu, Iv, and Iw of each phase. The drive signal Sdinv is output. Specifically, the current control unit 42 performs coordinate conversion of the three-phase alternating currents Iu, Iv, and Iw into d-axis and q-axis currents that are actual currents of the d-axis and the q-axis, based on the electrical angle θ. . The current control unit 42 uses a control law such as PI control or PID control so that the deviation between the d-axis and q-axis currents and the d-axis and q-axis current command values Id * and Iq * becomes small. The axis and q-axis voltage command values are calculated respectively.

  The current control unit 42 performs coordinate conversion of the d-axis and q-axis voltage command values into the voltage command values of each phase based on the electrical angle θ. The current control unit 42 generates an inverter drive signal Sdinv for driving the inverter 20 based on a comparison between the voltage level of the carrier and the voltage command value of each phase. The generated inverter drive signal Sdinv is output to the inverter 20, and the on / off state of each switch (specifically, the switching element) is controlled according to the inverter drive signal Sdinv.

  The power supply control unit 43 is a single unit in the power supply device 30 based on the motor speed ω, the vehicle speed Vca, the obstacle information Lob, the temperature Temp, the environment information Iinfo, and a travel history stored in the memory 44 described later. A switch drive signal Sdsw0 for driving the switch SW0 is generated. The power supply control unit 43 switches the electrical connection state of the first power supply and the second power supply between the serial connection and the parallel connection in response to switching of the on / off state of the single switch SW0 controlled through the switch drive signal Sdsw0. Further, the power supply control unit 43 determines switching between the regenerative state and the power running state based on the motor speed ω. In addition to the motor speed ω, the power supply control unit 43 sets the regeneration state based on any one of the torque of the motor 10, the AC currents Iu, Iv, and Iw of each phase in the motor 10, or a combination thereof. Switching to the power running state may be determined.

  The memory (storage means) 44 stores the traveling state of the motor 10 as a traveling history. In the present embodiment, the memory 44 stores a state history of the regenerative state and the power running state of the motor 10 that drives the vehicle as a travel history.

  FIG. 3 is an explanatory diagram of an electrical connection state of the first power supply and the second power supply in the power supply device 30 according to the present embodiment. When power is supplied by connecting the first power source and the second power source in series when the motor 10 is in a power running state, the power source control unit 43 controls the single switch SW0 to be in an on state (see FIG. 4A). . When the motor 10 is in the power running state, when the first power source and the second power source are connected in parallel to supply power, the power source control unit 43 controls the single switch SW0 to be in the off state. In this case, the current from the first power supply or the second power supply to the motor 10 flows through the diodes connected to both sides of the single switch SW0. On the other hand, when the motor 10 is in the regenerative state, the power supply control unit 43 controls the single switch SW0 to be turned off in order to charge the power by connecting the first power supply and the second power supply in series. In this case, the electric power from the motor 10 flows through the return diode in the single switch SW0, and a current flows through the first and second power supplies.

  FIG. 4 is a flowchart illustrating a method for controlling the power supply device 30 according to the first embodiment of the present invention. The process shown in this flowchart shows the procedure for setting the electrical connection state of the first power supply and the second power supply of the power supply device 30. When the vehicle starts running, that is, when the vehicle speed Vca becomes greater than zero. This is executed by the control unit 40 (specifically, the power control unit 43).

  First, in step 10 (S10), the power supply control unit 43 acquires traffic jam information and the current position from the navigation system 56 as environment information Iinfo, and determines whether or not the vehicle is currently traveling in a traffic jam section. If an affirmative determination is made in step 10, that is, if the vehicle is traveling in a traffic jam section, the process proceeds to step 11 (S11). On the other hand, if a negative determination is made in step 10, that is, if the vehicle is not traveling in a traffic jam section, the process proceeds to step 14 (S14).

  In step 11, the power supply control unit 43 sets the determination number Jvth based on the temperature Tem. The determination number Jvth is a determination value for determining whether or not switching between the power running state and the regenerative state is frequently performed, and whether or not the determination number Jvth corresponds to a scene for performing a serial fixing process described later. Determine whether. This determination number Jvth is a value that is variably set according to the temperature Tem in order to take into account the margin to the upper limit temperature of the smoothing capacitor C. Specifically, the number of times Jvth is smaller as the temperature Temp is higher. It is set to be a value. The power supply control unit 43 holds a map or an arithmetic expression that defines the correspondence between the temperature Tem and the number of determinations Jvth, and sets the determination number Jvth according to the temperature Tem using the map or the arithmetic expression. .

  In step 12, the power supply control unit 43 refers to the memory 44, extracts a travel history from the present to a predetermined time before (for example, 10 minutes before), and switches between the regenerative state and the power running state in the extracted section. Is calculated as the switching frequency Jvcon. Then, the power supply control unit 43 determines whether or not the calculated switching number Jvcon is equal to or greater than the determination number Jvth (for example, 30 times). If an affirmative determination is made in step 12, that is, if the switching count Jvcon is greater than or equal to the determination count Jvth (Jvcon ≧ Jvth), the process proceeds to step 13 (S13). On the other hand, if a negative determination is made in step 12, that is, if the switching number Jvcon is smaller than the determination number Jvth (Jvcon <Jvth), the process proceeds to step 14.

  In step 13, the power supply control unit 43 sets the electrical connection state of the first power supply and the second power supply to series connection. Specifically, when the motor 10 is in a power running state, the power supply control unit 43 controls the single switch SW0 to be in an on state (see FIG. 3A), while when the motor 10 is in a regenerative state, the single switch SW0. Is turned off (see FIG. 3B).

  In step 14, the power supply control unit 43 determines whether or not the vehicle speed Vca is equal to or less than the speed determination value Vcath. In the power running state of the motor 10, in a high-speed scene, the supply voltage to the motor 10 is higher when the first power supply and the second power supply are connected in series than in parallel connection, which corresponds to an increase in motor torque and output. This is preferable. Therefore, in step 14, it is determined whether or not the low-speed scene is based on the vehicle speed Vca, that is, whether or not the first power supply and the second power supply should not be connected in series. . As the speed determination value Vcath, a vehicle speed Vca for determining whether it is better to select a series connection or a parallel connection in a powering state is set in advance through experiments and simulations.

  If an affirmative determination is made in step 14, that is, if the vehicle speed Vca is equal to or less than the speed determination value Vcath (Vca ≦ Vcath), the process proceeds to step 15 (S15). On the other hand, if a negative determination is made in step 14, that is, if the vehicle speed Vca is greater than the speed determination value Vcath (Vca> Vcath), the process proceeds to step 13.

  In step 15, the power supply control unit 43 determines whether or not it is currently in a power running state. If a negative determination is made in step 15, that is, if it is in a regenerative state, the process proceeds to step 13. On the other hand, if an affirmative determination is made in step 15, that is, if the vehicle is in a power running state, the process proceeds to step 16 (S16). In step 16, the power supply control unit 43 controls the single switch SW <b> 0 to the off state in order to set the electrical connection state of the first power supply and the second power supply to parallel connection (see FIG. 3B). ).

  In step 17 (S17), the power supply controller 43 determines whether or not the vehicle speed Vca is zero. If the determination in step 17 is affirmative, that is, if the vehicle speed Vca is zero (Vca = 0), the routine is exited. On the other hand, if a negative determination is made in step 17, that is, if the vehicle speed Vca is not zero (Vca ≠ 0), the process returns to step 10 again.

  Hereinafter, the control concept of the power supply control unit 43 embodied by the series of control processes described above will be described. For example, when traveling in a traffic jam section, the vehicle may frequently repeat acceleration and deceleration, and in this case, the power running state and the regenerative state are alternately repeated in a low-speed scene. In the power running state, basically, the state of the motor 10, specifically, the electrical connection state is set to one of serial connection and parallel connection according to the vehicle speed Vca. Therefore, when the low speed scene shifts from the regenerative state to the power running state, the electrical connection state is switched from the series connection in the regenerative state to the parallel connection in the power running state. Similarly, when the low speed scene shifts from the power running state to the regenerative state, the electrical connection state is switched from the parallel connection in the power running state to the series connection in the regenerative state.

  When the series connection and the parallel connection are repeated corresponding to the repetition of the power running state and the regenerative state, the smoothing capacitor C of the inverter 20 is charged in the regenerative state, and the smoothing capacitor C is discharged in the power running state. Thus, when the connection between the series connection and the parallel connection is switched, the charging / discharging current for changing the smoothing capacitor C of the inverter 20 to the series voltage / parallel voltage is between the capacitor C and the power supply device 30. Flowing. Therefore, a loss is generated by the internal resistance and heat is generated by the internal resistance.

  In this regard, according to the present embodiment, as shown in the determination process in step 11 described above, the first and second states are based on the traveling environment and the traveling history of the vehicle when shifting from the regenerative state to the powering state. A series fixing process is performed in which the electrical connection state of the power source is fixed while being connected in series. Specifically, the serial fixing process is performed on the condition that the traveling in the traffic jam section is detected and it is determined that the switching between the power running state and the regenerative state is repeatedly performed. Originally, since the state of the motor 10, specifically, the electrical connection state is determined based on the vehicle speed Vca, in the low speed scene (vehicle speed Vca ≦ Vcath), the parallel connection is made after the transition from the regenerative state to the power running state. However, the direct connection is maintained by the series fixing process. As a result, even when the switching between the power running state and the regenerative state is repeatedly performed during the series fixing process, the switching between the series connection and the parallel connection is not performed, and the charging / discharging of the smoothing capacitor C accompanied by the voltage change is performed. The temperature rise and loss of the smoothing capacitor C can be suppressed.

  In particular, in an electric vehicle, a torque command value frequently repeats a power running state and a regenerative state at a low speed during traveling in a traffic jam section. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

  In the present embodiment, when the series fixing process is executed, the maintenance state of the serial connection is canceled when the curve section is exited or when the switching frequency Jvcon becomes smaller than the determination frequency Jvth. However, the series fixing process may be terminated on the condition that the reference time that is variably set according to the temperature Tem is used as a condition from the timing when the series fixing process is started. In this case, it is preferable that the reference time is set to be shorter as the temperature Tem is lower. In this case, it is possible to reduce the time for performing the series fixing process on the first and second power supplies, and thus it is possible to select parallel connection. When parallel connection is set in a low-speed scene, the inverter 20 can be driven with a low voltage, so that efficient driving is possible and the smoothing capacitor C can be downsized. Note that this method can be similarly applied to embodiments described later.

(Second Embodiment)
FIG. 5 is a flowchart showing a method for controlling the power supply device 30 according to the second embodiment of the present invention. The difference between the power supply device 30 of the present embodiment and the first embodiment described above is the control method of the power supply device 30. Note that the overall system configuration including the power supply device 30 is the same as that of the first embodiment, and the following description will focus on differences in the control method.

  The process shown in the flowchart of FIG. 5 shows a procedure for setting the electrical connection state of the first power source and the second power source of the power supply device 30. When the vehicle starts running, that is, the vehicle speed Vca is less than zero. When it becomes larger, it is executed by the control unit 40 (specifically, the power supply control unit 43).

  First, in step 20 (S20), the power supply control unit 43 acquires road information and position information around the vehicle from the navigation system 56 as environment information Iinfo. Then, the power supply control unit 43 determines whether or not the vehicle is currently traveling in a curve section, specifically, a section where there are a plurality of curves (for example, ten curves) having a curvature equal to or greater than a specified value. To do. The prescribed curvature value for determining the curve section is set assuming a small curve that the vehicle frequently repeats acceleration and deceleration when traveling in the curve section.

  If an affirmative determination is made in step 20, that is, if the vehicle is currently traveling in a curve section, the process proceeds to step 21 (S21). On the other hand, if a negative determination is made in step 20, that is, if the vehicle is not currently traveling in the curve section, the process proceeds to step 24 (S24).

  Note that the processing from step 21 to step 27 (S27) corresponds to the processing from step 11 to step 17 shown in the first embodiment, and detailed description thereof is omitted. However, in the determination process of step 22 (S22), the extraction section for extracting the travel history and the number of determinations Jvth may be different from those at the time of traveling in the traffic jam section in consideration of the characteristics of the travel in the curve section. it can.

  As described above, according to the present embodiment, in a curve section where a plurality of small curves exist, the vehicle may frequently repeat acceleration / deceleration. In this case, the power running state and the regenerative state are alternately repeated in the low-speed scene. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

(Third embodiment)
FIG. 6 is a flowchart showing a method for controlling the power supply device 30 according to the third embodiment of the present invention. The difference between the power supply device 30 of the present embodiment and the first embodiment described above is the control method of the power supply device 30. Note that the overall system configuration including the power supply device 30 is the same as that of the first embodiment, and the following description will focus on differences in the control method.

  The process shown in the flowchart of FIG. 5 shows a procedure for setting the electrical connection state of the first power source and the second power source of the power supply device 30. When the vehicle starts running, that is, the vehicle speed Vca is less than zero. When it becomes larger, it is executed by the control unit 40 (specifically, the power supply control unit 43).

  First, in step 30 (S30), the power supply control unit 43 acquires road information and position information around the vehicle from the navigation system 56 as environment information Iinfo. Then, the power supply control unit 43 determines whether or not the vehicle is currently traveling on a slope section, specifically, a section where there are a plurality of slopes (for example, 10 slopes) having a gradient equal to or greater than a specified value. judge. The specified slope value for determining the slope section is set assuming a large slope such that the vehicle frequently repeats acceleration / deceleration when traveling on the slope section.

  If an affirmative determination is made in step 30, that is, if the vehicle is currently traveling on a slope section, the process proceeds to step 31 (S31). On the other hand, if a negative determination is made in step 30, that is, if the vehicle is not currently traveling on the slope section, the process proceeds to step 34 (S34).

  Note that the processing from step 31 to step 37 (S37) corresponds to the processing from step 11 to step 17 shown in the first embodiment, and a detailed description thereof will be omitted. However, in the determination process of step 32 (S32), the extraction section for extracting the travel history and the number of times of determination Jvth may be different from those during travel in a congested section in consideration of the characteristics of the travel in the slope section. it can.

  As described above, according to the present embodiment, in a slope section where a plurality of slopes with a large slope exist, the vehicle may frequently repeat acceleration / deceleration. In this case, the power running state and the regenerative state are alternately repeated in a low-speed scene. It is. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

(Fourth embodiment)
FIG. 7 is a flowchart illustrating a method for controlling the power supply device 30 according to the fourth embodiment of the present invention. The difference between the power supply device 30 of the present embodiment and the first embodiment described above is the control method of the power supply device 30. Note that the overall system configuration including the power supply device 30 is the same as that of the first embodiment, and the following description will focus on differences in the control method.

  The process shown in the flowchart of FIG. 5 shows a procedure for setting the electrical connection state of the first power source and the second power source of the power supply device 30. When the vehicle starts running, that is, the vehicle speed Vca is less than zero. When it becomes larger, it is executed by the control unit 40 (specifically, the power supply control unit 43). In the present embodiment, the memory 44 of the control unit 40 stores an obstacle detection history from the obstacle information Lob detected by the obstacle sensor 54 instead of the state history of the regeneration state and the power running state. Is done.

  First, in step 40 (S40), the power supply control unit 43 acquires road information and position information around the vehicle from the navigation system 56 as environment information Iinfo. Then, the power supply control unit 43 determines whether or not the vehicle is currently traveling in the prescribed facility area. The specified facility is set as a facility such as a parking lot where it is assumed that the vehicle frequently repeats acceleration and deceleration due to the influence of an obstacle or the like when traveling in the facility.

  If an affirmative determination is made in step 40, that is, if the vehicle is currently traveling in the facility area, the process proceeds to step 41 (S41). On the other hand, if a negative determination is made in step 40, that is, if the vehicle is not currently traveling in the facility area, the process proceeds to step 44 (S44).

  In step 41, the power supply control unit 43 sets the number of times Joth based on the temperature Temp as shown in the processing of step 11 in the first embodiment.

  In step 42, the power supply control unit 43 extracts a travel history from the present to a predetermined time before (for example, 5 minutes before) in the memory 44, and calculates the number of obstacle detections in the extracted section. Then, the power supply control unit 43 determines whether or not the calculated number of detections Jocon is equal to or greater than the determination number Joth (for example, 5 times). If an affirmative determination is made in step 42, that is, if the detection count Jocon is equal to or greater than the determination count Joth (Jocon ≧ Joth), the routine proceeds to step 43 (S43). On the other hand, if a negative determination is made in step 42, that is, if the detection count Jocon is smaller than the determination count Joth (Jocon <Joth), the process proceeds to step 44.

  Note that the processing from step 43 to step 47 (S47) corresponds to the processing from step 13 to step 17 shown in the first embodiment, and a detailed description thereof will be omitted.

  Thus, according to the present embodiment, the vehicle may frequently repeat acceleration / deceleration due to obstacles (parked vehicles, facility structures, etc.) in a traveling environment within a prescribed facility area such as a parking lot. In this case, the power running state and the regenerative state are alternately repeated in the low-speed scene. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

(Fifth embodiment)
FIG. 8 is a flowchart illustrating a method for controlling the power supply device 30 according to the fifth embodiment of the present invention. The power supply device 30 of the present embodiment is different from the above-described fourth embodiment in the control method of the power supply device 30. Note that the overall system configuration including the power supply device 30 is the same as that of the fourth embodiment, and the description below will focus on the differences in the control method.

  The process shown in the flowchart of FIG. 5 shows a procedure for setting the electrical connection state of the first power source and the second power source of the power supply device 30. When the vehicle starts running, that is, the vehicle speed Vca is less than zero. When it becomes larger, it is executed by the control unit 40 (specifically, the power supply control unit 43).

  First, in step 50 (S50), the power supply control unit 43 acquires road information and position information around the vehicle from the navigation system 56 as environment information Iinfo. Then, the power supply control unit 43 determines whether or not the current vehicle is traveling on a narrow road, specifically, a road having a width equal to or less than a specified value such as a mountain road. The width regulation value for determining a narrow road is set on the assumption that the vehicle will frequently repeat acceleration / deceleration due to the influence of the obstacle or its width when traveling on the road. .

  If an affirmative determination is made in step 50, that is, if the vehicle is traveling on a narrow road, the process proceeds to step 51 (S51). On the other hand, if a negative determination is made in step 50, that is, if the vehicle is not currently traveling on a narrow road, the process proceeds to step 54 (S54).

  Note that the processing from step 51 to step 57 (S57) corresponds to the processing from step 41 to step 47 shown in the fourth embodiment, and a detailed description thereof will be omitted. However, in the determination process of step 52 (S52), the extraction section for extracting the travel history and the number of determinations Joth are made different from those during travel in the facility area in consideration of the characteristics of the travel on the narrow road. be able to.

  As described above, according to this embodiment, in a traveling environment such as a narrow road, the vehicle may frequently repeat acceleration / deceleration due to the narrowness of the obstacle and the road itself. In this case, the power running state and the regeneration are performed in the low-speed scene. The state is repeated alternately. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

(Sixth embodiment)
FIG. 9 is a configuration diagram schematically showing a power supply device 30a and a control system for the motor 10 using the power supply device 30a according to the sixth embodiment of the present invention. The system configuration of this embodiment is different from that of the first embodiment in that a power supply device 30a and a control unit 40a are provided instead of the power supply device 30 and the control unit 40 shown in the first embodiment. Therefore, in the present embodiment, description will be made focusing on the power supply device 30a and the control unit 40a, which are different from the first embodiment. Moreover, about the structure which is common in 1st Embodiment, the overlapping description is abbreviate | omitted by quoting a code | symbol.

  Similarly to the power supply device 30 of the first embodiment, the power supply device 30a is connected to the motor 10 via the inverter 20, supplies power to the motor 10, and charges power generated by the motor 10. It is a power supply device. The power supply device 30a has a plurality of power supplies (in this embodiment, two power supplies (first and second power supplies)) that each function independently as a DC power supply.

  The power supply device 30a includes a switch circuit that switches an electrical connection state between the first and second power supplies between a series connection and a parallel connection. The switch circuit includes first to third switches SW1 to SW3. (Switching means) is mainly used. The first to third switches SW1 to SW3 are connected in series according to the order of the first switch SW1, the second switch SW1, and the third switch SW3. Each of the switches SW1 to SW3 is mainly composed of a switching element such as an NPN transistor, and each of the transistors has a reflux diode connected in reverse parallel between the collector and the emitter. The on / off states of the switches SW1 to SW3 are switched according to the switch drive signal output from the control unit 40a.

  Here, in the switch circuit, the connection point between the first switch SW1 and the second switch SW2 is connected to the positive electrode of the first power supply (power supply voltage Ea), and the second switch SW2 and the third switch SW3. Is connected to the negative electrode of the second power supply (power supply voltage Eb). The collector terminal of the first switch SW1 and the positive electrode of the second power source are connected to each other, and this connection end functions as an output end on the positive side of the power supply device 30a. The positive output bus is connected to the positive bus of the inverter 20. The emitter terminal of the third switch SW3 and the negative electrode of the first power supply are connected to each other, and this connection end functions as an output end on the negative side of the power supply device 30a. This negative output side is connected to the negative bus of the inverter 20.

  FIG. 10 is a block diagram schematically showing the configuration of the control unit 40a according to the third embodiment of the present invention. The control unit 40 a includes a torque control unit 41, a current control unit 42, a power supply control unit 43 a, and a memory 44. The torque control unit 41, the current control unit 42, and the memory 44 have the same functions as those in the first embodiment.

  The power supply control unit 43a starts from the first in the power supply device 30a based on the motor speed ω, the vehicle speed Vca, the obstacle information Lob, the temperature Temp, the environment information Iinfo, and the travel history stored in the memory 44. Switch drive signals Sdsw1 to Sdsw3 for driving the third switches SW1 to SW3 are generated. The power supply control unit 43b connects the electrical connection states of the first power supply and the second power supply in series or in parallel according to switching of the on / off states of the switches SW1 to SW3 controlled through the switch drive signals Sdsw1 to Sdsw3. Switch with.

  FIG. 11 is an explanatory diagram of an electrical connection state of the first power supply and the second power supply in the power supply device 30a. When the motor 10 is in the power running state and the first power source and the second power source are connected in series to supply power, the power source control unit 43a turns off the first and third switches SW1 and SW3, The switch SW2 is controlled to be in an ON state (see (a) in the figure). When the motor 10 is in the power running state, when the first power source and the second power source are connected in parallel to supply power, the power source control unit 43a controls the second switch SW2 to be in an off state. Here, when the first power supply voltage Ea and the second power supply voltage Eb are substantially equal, the first and third switches SW1 and SW3 are controlled to be in the ON state, respectively, and the first power supply voltage Ea and the second power supply voltage Ea When the power supply voltage Eb is not equal to each other, the current is controlled to be in the off state in order to suppress the current from flowing from the high potential side to the low potential side (see FIG. 5B). In this case, the current from the first power supply or the second power supply to the motor 10 flows through the return diodes in the first and third switches SW1 and SW3, respectively. On the other hand, when the motor 10 is in the regenerative state, the power supply control unit 43a turns off the first to third switches SW1 to SW3 in order to charge the power by connecting the first power supply and the second power supply in series. Control is performed (see FIG. 2C). In this case, the electric power from the motor 10 flows through the return diode in the second switch SW2, and a current flows through the first and second power supplies.

  In such a configuration, the control unit 40a (specifically, the power supply control unit 43a) is configured so that the first power supply and the second power supply of the power supply device 30a are similar to the control method of the power supply device 30 described in each of the above-described embodiments. The electrical connection state of the power source can be set. In this case, in the processing of Steps 13, 23, 33, 43, and 53 shown in each embodiment, the power supply control unit 43a determines the electrical connection state of the first power supply and the second power supply. Set to series connection. Specifically, when the motor 10 is in a power running state, the power supply control unit 43a controls the second switch SW2 to an on state and controls the first and third switches SW1 and SW3 to an off state (FIG. 11 (a)). On the other hand, when the motor 10 is in the regenerative state, the power supply control unit 43a controls the first to third switches SW1 to SW3 to the off state (see FIG. 11C).

  Further, in the processing of steps 16, 26, 36, 46, and 56 shown in each embodiment, the power supply control unit 43a sets the electrical connection state of the first power supply and the second power supply to parallel connection. Specifically, the power supply control unit 43a monitors the voltage Ea of the first power supply and the voltage Eb of the second power supply with a voltage sensor (not shown), and then the voltage Ea of the first power supply and the second power supply. When the voltage Eb corresponds to the second switch SW2, the second switch SW2 is controlled to be in an OFF state, and the first and third switches SW1 and SW3 are controlled to be in an ON state (see FIG. 11B). . On the other hand, when the voltage Ea of the first power supply does not correspond to the voltage Eb of the second power supply, the power supply control unit 43a controls the first to third switches SW1 to SW3 to be in an off state ( (Refer FIG.11 (b)).

  Thus, according to the present embodiment, the electrical connection state between the first power source and the second power source can be switched by the three switches SW1 to SW3. As a result, the torque command value frequently repeats the power running state and the regenerative state at a low speed. According to the configuration and the control method of the present embodiment, even when such a power running state and a regenerative state are repeated, the first and second power sources are fixed in series connection, thereby being connected in series and parallel. The number of times of switching can be reduced. Thereby, while being able to suppress the heat_generation | fever by the charging / discharging current of the smoothing capacitor C, the increase in the loss by charging / discharging current can be suppressed. As a result, the travel distance per charge of the electric vehicle can be extended, and the life of the capacitor C can be extended.

  The power supply apparatus and the control method thereof according to the embodiment of the present invention have been described above, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the number of power supplies constituting the power supply device may be three or more. Moreover, the determination method of the serial fixing process shown in each embodiment described above can be determined in combination with each other.

DESCRIPTION OF SYMBOLS 10 ... Motor 20 ... Inverter 30 ... Power supply device 40 ... Control unit 41 ... Torque control part 42 ... Current control part 43 ... Power supply control part 44 ... Memory 50 ... Current sensor 51 ... Electric angle detection part 52 ... Motor speed detection part 53 ... Vehicle speed sensor 54 ... Obstacle sensor 55 ... Air temperature sensor 56 ... Navigation system

Claims (9)

A plurality of power supplies connected to the motor via a power converter;
A switch circuit having switching means for switching an electrical connection state between the plurality of power supplies between a series connection and a parallel connection;
By controlling the switching means, when the motor is in a regenerative state, the electrical connection state is set in series connection, and when the motor is in a power running state, the electrical connection is based on the state of the motor. Control means for setting the state to one of serial connection and parallel connection;
Driving environment detection means for detecting the driving environment of the vehicle;
Storage means for storing the traveling state by the motor as a traveling history,
The control unit is configured to change the electrical connection state according to a travel history stored in the storage unit and a travel environment of the vehicle detected by the travel environment detection unit when transitioning from the regenerative state to the power running state. A power supply device is characterized in that a series fixing process is performed to fix the cables in series connection. The storage means stores a state history of the motor regeneration state and power running state as the travel history,
The traveling environment detection means detects whether the vehicle is traveling in a traffic jam section,
The control means, on the condition that the travel environment detection means has detected the travel of the traffic jam section, and has determined that the switching between the power running state and the regenerative state has been repeatedly performed with reference to the storage means, The power supply device according to claim 1, wherein a series fixing process is performed. The storage means stores the state history of the motor regeneration state and power running state as the travel history,
The traveling environment detecting means detects whether the vehicle is traveling in a curve section where a plurality of curves having a curvature equal to or greater than a specified value exists,
On the condition that the control means has detected that the traveling environment detection means has detected the traveling of the curve section, and that the switching between the power running state and the regenerative state has been repeatedly performed with reference to the storage means, The power supply device according to claim 1, wherein a series fixing process is performed. The storage means stores a state history of the motor regeneration state and power running state as the travel history,
The traveling environment detecting means detects whether or not the vehicle travels on a slope section where a plurality of slopes having a slope equal to or greater than a specified value exists.
The control means, on the condition that the traveling environment detection means has detected that the traveling of the slope section has been detected, and that the switching between the power running state and the regenerative state has been repeatedly performed with reference to the storage means, The power supply device according to claim 1, wherein a series fixing process is performed. It further has an obstacle detection means for detecting an obstacle that hinders driving of the vehicle,
The traveling environment detection means detects whether the vehicle is traveling within a prescribed facility area,
The storage means stores an obstacle detection history by the obstacle detection means,
The control means is fixed in series on the condition that the traveling environment detection means has detected that traveling within a prescribed facility area has been detected and that the obstacle detection has been repeated with reference to the storage means. The power supply device according to claim 1 which performs processing. It further has an obstacle detection means for detecting an obstacle that hinders driving of the vehicle,
The traveling environment detection means detects whether the vehicle is traveling on a narrow road that is a width road having a specified value or less,
The storage means stores an obstacle detection history by the obstacle detection means,
The control means performs the serial fixing process on the condition that the traveling environment detection means has detected that the traveling on the narrow road has been detected and that the obstacle detection has been repeated with reference to the storage means. The power supply device according to claim 1 to be performed. It further has an air temperature detecting means for detecting the air temperature,
7. The control unit according to claim 1, wherein the control unit sets a reference time based on the temperature detected by the temperature detection unit, and terminates the series fixing process when the reference time elapses. The power supply device described in the section. The switch circuit includes a switch having a switching element and a diode connected in reverse parallel to the switching element, and two diodes that are arranged in the center and connected in series to the terminals of the switch. And
The connection point between the switch and one diode is connected to the positive electrode of the first power supply, and the connection point between the switch and the other diode is connected to the negative electrode of the second power supply,
2. The one diode has the other terminal connected to the positive electrode of the second power supply, and the other diode has the other terminal connected to the negative electrode of the first power supply. The power supply apparatus described in any one of 7 to 7. In a control method of a power supply device having a plurality of power supplies connected to a motor via a power converter, and capable of switching an electrical connection state between the plurality of power supplies between a serial connection and a parallel connection,
In the regenerative state of the motor, a first step of setting the electrical connection state to series connection;
In the case of the power running state of the motor, a second step of setting the electrical connection state to one of serial connection and parallel connection based on the state of the motor;
A third step of detecting a traveling environment of the vehicle;
And a fourth step of storing the running state by the motor as a running history,
The second step is a series in which the electrical connection state is fixed in a serial connection state according to the traveling history and the detected traveling environment of the vehicle at the time of transition from the regenerative state to the power running state. A method for controlling a power supply apparatus, comprising a step of performing a fixing process.

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