JP2019004544A - Control system - Google Patents

Abstract

To provide a control system capable of reducing power consumption of a power storage device, which is required for a rise in the temperature of the power storage device.SOLUTION: A control apparatus 10 makes a first DDC 20 perform a step-down operation and makes a second DDC 30 perform a step-up operation, so as to circulate an electric current through a loop circuit including each of high-voltage lines HL1, HL3 and HL5, the first DDC 20 and the second DDC 30, and each of sub-wiring SL1 and sub-wiring SL2. Additionally, a control system 100 comprises a heat transfer part that transfers heat, generated by at least one of the first DDC 20 and the second DDC 30 by the step-down and step-up operations performed by the control apparatus 10, to a high-voltage battery 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control system including a first DC / DC converter that performs a step-down operation and a second DC / DC converter that performs a step-up operation.

  The power storage device has a characteristic that the terminal voltage changes depending on the temperature. Therefore, in order to stabilize the terminal voltage of the power storage device, it is necessary to manage the temperature of the power storage device. In Patent Document 1, a heater driven by electric power supplied from a DC / DC converter is provided, and the temperature of the power storage device is managed by the heat generated by the heater.

Japanese Patent Laid-Open No. 2006-157647

  When a heater is used for temperature management of the power storage device, the power of the power storage device is consumed as the heater generates heat. In this case, there is a concern that the decrease in the remaining capacity of the power storage device is accelerated.

  SUMMARY An advantage of some aspects of the invention is that it provides a control system that can reduce the power consumption of a power storage device required for increasing the temperature of the power storage device.

  In order to solve the above problems, a first invention is a first DC / DC converter that performs a step-down operation, a second DC / DC converter that performs a step-up operation, an input side of the first DC / DC converter, and the second DC / DC A control system comprising: a main wiring that connects an output side of a converter and a main power storage device; and a sub wiring that connects an output side of the first DC / DC converter and an input side of the second DC / DC converter. In the first invention, the first DC / DC converter is stepped down to circulate current through a loop circuit including the main wiring, the first DC / DC converter, the second DC / DC converter, and the sub wiring, and A temperature rise control unit for boosting the second DC / DC converter, and heat generated by at least one of the first DC / DC converter and the second DC / DC converter by the step-down operation and the step-up operation of the temperature rise control unit And a heat transfer section that transmits the heat to the main power storage device.

  When power conversion is performed by the first and second DC / DC converters, part of the power is converted into thermal energy in the first and second DC / DC converters. Therefore, it is conceivable to use the converted thermal energy for raising the temperature of the main power storage device. Therefore, the first invention includes a temperature rise control unit and a heat transfer unit. By the step-down operation and the step-up operation of the temperature increase control unit, a current flows through the loop circuit, and heat for increasing the temperature of the main power storage device is generated by the first DC / DC converter and the second DC / DC converter. The heat transfer unit transfers heat generated in at least one of the first DC / DC converter and the second DC / DC converter to the main power storage device. Thereby, the heat generated by the power conversion can be effectively used, and the power consumption of the power storage device required for increasing the temperature of the power storage device can be reduced.

  In a second aspect of the invention, the temperature increase control unit includes the first DC / DC required for raising the temperature of the main power storage device to the target temperature based on a deviation between the temperature of the main power storage device and the target temperature. A command value setting unit for setting a first output current command value that is an output current command value of the DC converter and a second output current command value that is an output current command value of the second DC / DC converter; The output current of the DC converter is controlled to the first output current command value, and the output current of the second DC / DC converter is controlled to the second output current command value.

  In the above configuration, since the output currents of the first and second DC / DC converters are controlled based on the amount of temperature increase required to raise the current temperature of the main power storage device to the target temperature, unnecessary thermal energy Can be prevented. As a result, an increase in power consumption during the temperature raising operation of the main power storage device can be suppressed.

  In a third invention, a power source when a sub power storage device is connected to the sub-wiring and the step-down operation and the step-up operation are performed by the temperature increase control unit based on the voltage state of the main power storage device A selection unit that selects either the main power storage device or the sub power storage device, and the command value setting unit selects the main power source selected by the selection unit as a power source for circulating current in the loop circuit. A first output voltage command value that is an output voltage command value of the first DC / DC converter, the first output current command value, and an output of the second DC / DC converter so as to be either a power storage device or the sub power storage device The second output voltage command value and the second output current command value, which are voltage command values, are set, and the temperature raising control unit controls the output current of the first DC / DC converter to the first output current command value. The And controlling the output voltage of the first DC / DC converter to the first output voltage command value, controlling the output current of the second DC / DC converter to the second output current command value, and the second DC / DC converter. Is controlled to the second output voltage command value.

  In the above configuration, either the main power storage device or the sub power storage device can be used as a power source for circulating current through the loop circuit in accordance with the voltage state of the main power storage device. Therefore, for example, when the voltage between the terminals of the main power storage device is small, the sub power storage device may be used as a power source, and the temperature raising operation can be stably continued.

  In a fourth aspect of the invention, the command value setting unit sets the first output voltage command value to be larger than the terminal voltage of the sub power storage device when the main power storage device is selected by the selection unit. The second output voltage command value is set to be smaller than the terminal voltage of the main power storage device.

  Specifically, when the main power storage device is used as a power source, as in the fourth invention, the output voltage command values of the first and second DC / DC converters and the terminal voltages of the main power storage device and the sub power storage device What is necessary is just to define the relationship.

  In a fifth aspect, the command value setting unit sets the first output voltage command value to be smaller than a terminal voltage of the sub power storage device when the sub power storage device is selected by the selection unit. The second output voltage command value is set to be larger than the terminal voltage of the main power storage device.

  Specifically, when the sub power storage device is used as a power source, as in the fifth invention, the output voltages of the first and second DC / DC converters and the terminal voltages of the main power storage device and the sub power storage device are You may decide.

  In a sixth aspect of the invention, the temperature increase control unit includes the first DC / DC required to raise the temperature of the main power storage device to a predetermined temperature based on a deviation between the temperature of the main power storage device and its target temperature. A command value setting unit that sets a first output current command value that is an output current command value of the converter and a second output current command value that is an output current command value of the second DC / DC converter, and the second DC / DC The output current of the converter is controlled to the second output current command value.

  In the above configuration, the temperature of the main power storage device can be brought close to the target temperature only by adjusting the second output current command value. Therefore, the control related to the temperature raising operation can be simplified, and the processing load of the control device can be reduced.

The block diagram of the control system which concerns on 1st Embodiment. The figure explaining the arrangement | positioning relationship of each part in a power supply unit. The figure explaining the relationship between the discharge capacity and temperature of a high voltage battery. The figure explaining the loop circuit which concerns on this embodiment. The flowchart explaining the temperature rising process which a control apparatus implements. The graph showing the correspondence of temperature rise amount ATR and required electric energy NAP. The flowchart explaining the temperature rising process which concerns on 2nd Embodiment. The flowchart explaining the process which the control apparatus which concerns on 3rd Embodiment implements. The figure explaining the electric current which flows through a power supply unit. The block diagram of the control system which concerns on 4th Embodiment. The flowchart explaining the process which the control apparatus which concerns on 4th Embodiment implements.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a control system 100 according to the first embodiment. The control system 100 is mounted on a vehicle. The vehicle on which the control system 100 is mounted is, for example, a hybrid vehicle that includes an engine that is an internal combustion engine and a motor for traveling as a traveling power source.

  The control system 100 includes a power supply unit 40, an inverter 51, a motor 11, a device group 60, and an auxiliary battery 61. In the control system 100, power is supplied from the power supply unit 40 to the inverter 51, the device group 60, and the auxiliary battery 61 that are power supply targets.

  The power supply unit 40 includes a high voltage battery 50, first to sixth high voltage lines HL1 to HL6, first and second sub wirings SL1 and SL2, a first DC / DC converter 20, and a second DC / DC converter 30. Mainly prepared. The high voltage battery 50 corresponds to the main power storage device.

  The high voltage battery 50 functions as a main power source in the control system 100. In this embodiment, the high voltage battery 50 is an assembled battery in which cells of a plurality of lithium ion storage batteries are combined. The high voltage battery 50 generates the first terminal voltage Vb1 of 200V to 400V, for example. Further, the high voltage battery 50 includes a monitoring unit that detects a remaining capacity (SOC).

  The first high voltage line HL1 is connected to the plus terminal of the high voltage battery 50, and the second high voltage line HL2 is connected to the minus terminal. In the first and second high voltage lines HL 1 and HL 2, the side opposite to the side connected to the high voltage battery 50 is connected to the inverter 51.

  A relay 53 is provided in the first high-voltage line HL1. By controlling the relay 53 in the closed state, a closed circuit that connects the high-voltage battery 50 and the inverter 51 is formed, and a current flows through the closed circuit. Thereby, electric power transmission between the high voltage battery 50 and the inverter 51 is enabled.

  The first and second DC / DC converters 20 and 30 are connected to the high voltage battery 50 through the first to sixth high voltage lines HL1 to HL6. Hereinafter, the first DC / DC converter 20 is referred to as a first DDC 20, and the second DC / DC converter 30 is referred to as a second DDC 30.

  The first DDC 20 is a unidirectional step-down converter. In the present embodiment, the first DDC 20 is an insulating conversion device in which a primary side circuit and a secondary side circuit are connected via a transformer. The first input terminal Ti1 of the first DDC 20 is connected to the first high voltage line HL1 through the third high voltage line HL3, and the second input terminal Ti2 is connected to the second high voltage line HL2 through the fourth high voltage line HL4. Further, the first output terminal To1 of the first DDC 20 is connected to the first sub-line SL1, and the second output terminal To2 is connected to the second sub-line SL2. In the present embodiment, the first and second input terminals Ti1 and Ti2 correspond to the input side of the first DDC 20, and the first and second output terminals To1 and To2 correspond to the output side.

  The first DDC 20 includes a plurality of semiconductor switches. The first terminal voltage Vb1 supplied from the high voltage battery 50 is input to the first input terminal Ti1 and the second input terminal Ti2. By switching on / off of each semiconductor switch, the first terminal voltage Vb1 is stepped down and output from the first output terminal To1 and the second output terminal To2. Thereby, the electric power of the high voltage battery 50 is supplied to at least one of the equipment group 60 and the auxiliary battery 61 via the first DDC 20.

  The third high voltage line HL3 is connected to the first high voltage line HL1 on the high voltage battery 50 side with respect to the relay 53. Therefore, even when the relay 53 is controlled to be in the open state, a current can be passed through the closed circuit that connects the high voltage battery 50 and the first DDC 20.

  The first DDC 20 is provided with a first current sensor 21 that detects a current flowing through the first DDC 20. For example, the first current sensor 21 is connected to the primary side circuit of the first DDC 20. The control device 10 constituting the control system 100 can estimate the output current output from the first DDC 20 based on the current detected by the first current sensor 21 and the turns ratio of the transformer of the first DDC 20. Hereinafter, the output current of the first DDC 20 is referred to as a first output current Ic1r.

  The second DDC 30 is a bidirectional buck-boost converter. In the present embodiment, the second DDC 30 is an insulating conversion device in which a primary side circuit and a secondary side circuit are connected via a transformer. The second DDC 30 includes a plurality of semiconductor switches, and performs a step-down operation or a step-up operation on the input voltage by switching each semiconductor switch on and off.

  The first terminal TA of the second DDC 30 is connected to the first high voltage line HL1 through the fifth high voltage line HL5. The second terminal TB is connected to the second high voltage line HL2 through the sixth high voltage line HL6. The third terminal TC is connected to the first output terminal To1 via the first sub-wiring SL1, and the fourth terminal TD is connected to the second output terminal To2 via the second sub-wiring SL2.

  The step-down operation will be described. The second DDC 30 steps down the first terminal voltage Vb1 supplied through the first and second terminals TA and TB and outputs it from the third and fourth terminals TC and TD. The boosting operation will be described. The second DDC 30 boosts the voltage supplied through the third and fourth terminals TC and TD and outputs the boosted voltage from the first and second terminals TA and TB. In the present embodiment, the third and fourth terminals TC and TD correspond to the input side of the second DDC 30, and the first and second terminals TA and TB correspond to the output side.

  The fifth high voltage line HL5 is connected to the first high voltage line HL1 on the inverter 51 side of the relay 53. Therefore, when the relay 53 is in the closed state, a current can be passed through the closed circuit including the high voltage battery 50, the first DDC 20, and the second DDC 30. On the other hand, when the relay 53 is opened, a closed circuit including the high voltage battery 50 and the second DDC 30 is not formed.

  The second DDC 30 is provided with a second current sensor 31 that detects a current flowing through the second DDC 30. For example, the second current sensor 31 is connected to the primary side circuit of the second DDC 30. The control device 10 can estimate the output current output from the second DDC 30 based on the current detected by the second current sensor 31 and the turns ratio of the transformer of the second DDC 30. Hereinafter, the output current of the second DDC 30 is referred to as a second output current Ic2r.

  FIG. 2 is a diagram for explaining an arrangement relationship of each part in the power supply unit 40. The power supply unit 40 further includes a housing 41 and a fan 42. FIG. 2 is a diagram showing the inside of the housing 41. Further, the flow of air in the housing 41 is indicated by broken arrows.

  Inside the housing 41, the high-voltage battery 50, the first DDC 20, the second DDC 30, and the fan 42 are arranged in this order. The air blown from the fan 42 flows to the high voltage battery 50 after passing through the first and second DDCs 20 and 30. Then, the air flows from the opening 43 of the housing 41 to the outside of the power supply unit 40. At this time, the heat generated in the first and second DDCs 20 and 30 is transmitted to the high voltage battery 50 by the air blown from the fan 42. Therefore, in this embodiment, the housing | casing 41, the fan 42, and the opening 43 correspond to a heat transfer part.

  Returning to FIG. 1, the first and second sub wirings SL <b> 1 and SL <b> 2 are connected to a device group 60 supplied with power through the sub wirings SL <b> 1 and SL <b> 2 and an auxiliary battery 61 corresponding to the sub power storage device. A plus terminal of the device group 60 is connected to the first sub-wiring SL1. Further, the minus terminal of the device group 60 is connected to the second sub-wiring SL2. The device group 60 is, for example, an audio device, a navigation device, a power slide door, a power back door, and a meter.

  The auxiliary terminal of the auxiliary battery 61 is connected to the first sub-wiring SL1, and the negative terminal is connected to the second sub-wiring SL2. Therefore, at least one of the output voltages V1r and V2r of the first and second DDCs 20 and 30 and the second terminal voltage Vb2 that is the terminal voltage of the auxiliary battery 61 is applied to the first and second sub-wirings SL1 and SL2. The

  In the present embodiment, the storage capacity of the auxiliary battery 61 is smaller than the storage capacity of the high voltage battery 50. Further, the second terminal voltage Vb <b> 2 of the auxiliary battery 61 is lower than the first terminal voltage Vb <b> 1 of the high voltage battery 50. The second terminal voltage Vb2 of the auxiliary battery 61 is, for example, 12V.

  The inverter 51 converts a DC voltage supplied from the high voltage battery 50 into an AC voltage and supplies the AC voltage to the motor 11. A smoothing capacitor 52 is connected in parallel to the inverter 51 between the first high-voltage line HL1 and the second high-voltage line HL2. The output side of the inverter 51 is connected to the motor 11.

  The motor 11 is a motor for driving the vehicle and is driven by an AC voltage from the inverter 51. The motor 11 has a function of generating regenerative power using the kinetic energy of the vehicle while the vehicle is running. The inverter 51 has a rectifying function for rectifying an alternating current into a direct current. The inverter 51 rectifies the alternating current output from the motor 11 by regenerative power generation into a direct current during braking of the vehicle. The rectified direct current is supplied to the high voltage battery 50 through the high voltage lines HL1, HL2, whereby the high voltage battery 50 is charged.

  The control system 100 includes a control device 10. The control device 10 calculates a command torque necessary for driving the motor 11 according to the accelerator operation amount of the user. The control device 10 controls the inverter 51 so as to control the torque of the motor 11 to the command torque.

  Moreover, the control apparatus 10 sets the duty command value which determines the ON period in 1 switching period of a semiconductor switch so that the 1st, 2nd DDC20,30 may be operated. Of the duty command values, the one that operates the semiconductor switch of the first DDC 20 is the first duty command value Duty1, and the one that operates the semiconductor switch of the second DDC 30 is the second duty command value.

  The control device 10 sets the first duty command value Duty1 to control the first output current Ic1r to the first output current command value Ic1 *. Further, the second duty command value Duty2 is set to control the second output current Ic2r to the second output current command value Ic2 *.

  In the present embodiment, the control device 10 that drives the inverter 51 and the semiconductor switches of the first and second DDCs 20 and 30 is described as one device, but the present invention is not limited to this. For example, it is good also as a structure provided separately with the control apparatus which controls the inverter 51, and the control apparatus which drives the semiconductor switch of 1st, 2nd DDC20,30.

  The control system 100 includes a first voltage sensor 54, a second voltage sensor 55, and a temperature sensor 56. The first voltage sensor 54 is connected in parallel to the plus terminal and the minus terminal of the high voltage battery 50 and detects the first terminal voltage Vb1. The second voltage sensor 55 is connected in parallel to the plus terminal and the minus terminal of the auxiliary battery 61 and detects the second terminal voltage Vb2. The temperature sensor 56 detects the temperature of the high-voltage battery 50 as the battery temperature Tbat.

  Next, the principle of this embodiment will be described. FIG. 3 is a diagram illustrating the relationship between the first terminal voltage Vb1 of the high-voltage battery 50 and the battery temperature Tbat. FIG. 3 is a graph in which the horizontal axis is the battery temperature Tbat and the vertical axis is the first terminal voltage Vb1.

  The high voltage battery 50 has a voltage characteristic in which the first terminal voltage Vb1 depends on the battery temperature Tbat. This voltage characteristic is a characteristic that the first terminal voltage Vb1 decreases as the battery temperature Tbat decreases. Therefore, in order to stabilize the first terminal voltage Vb1, it is necessary to manage the high voltage battery 50 at a reference temperature (for example, 0 degrees) or more. However, when the temperature of the high-voltage battery 50 is increased using a heater that uses the high-voltage battery 50 as a power source, there is a concern that the remaining capacity of the high-voltage battery 50 may be accelerated due to the power consumption of the heater.

  Here, the first and second DDCs 20 and 30 have a loss during power conversion, and a part of the power becomes thermal energy. Therefore, it can be considered that this thermal energy is used for raising the temperature of the high-voltage battery 50. At this time, if the amount of heat energy radiated by the first and second DDCs 20 and 30 can be controlled, the power consumption required for the temperature raising process can be reduced as compared with the case where the amount of heat energy is not controlled.

  Therefore, the control device 10 forms a loop circuit in which a current circulates between the first DDC 20 and the second DDC 20, 30. A temperature raising process for raising the temperature is performed. FIG. 4 is a diagram illustrating the loop circuit according to the present embodiment. In FIG. 4, a part of the configuration of the power supply unit 40 is omitted for convenience.

  In FIG. 4, a loop circuit is formed by a current path that connects the first, third, and fifth high-voltage lines HL1, HL3, and HL5, the first DDC 20, the first sub-wiring SL1, and the second DDC 30. In this loop circuit, the first DDC 20 steps down the first terminal voltage Vb1 from the high voltage battery 50 and outputs it to the first sub-wiring SL1. The second DDC 30 boosts the output voltage V1r from the first DDC 20 and outputs the boosted voltage to the fifth high-voltage line HL5. Therefore, current continues to flow through the loop circuit. The first, third, and fifth high-voltage lines HL1, HL3, and HL5 correspond to the main wiring, and the first sub wiring SL1 corresponds to the sub wiring.

  Further, the control device 10 controls the first output current Ic1r of the first DDC 20 and the second output current Ic2r of the second DDC 30 according to the battery temperature Tbat, so that the heat released from the first and second DDCs 20 and 30. Control energy (calorific value). Therefore, compared with the case where the amount of current flowing through the loop circuit is not controlled, the power consumption required for the temperature raising process is reduced, and the decrease in the remaining capacity SOC of the high-voltage battery 50 can be suppressed.

  Next, the temperature increasing process performed by the control device 10 will be described with reference to FIG. The process illustrated in FIG. 5 is repeatedly performed by the control device 10 at a predetermined cycle.

  In step S11, the battery temperature Tbat which is the temperature of the high voltage battery 50 is acquired. In step S12, based on the battery temperature Tbat, it is determined whether the conditions for performing the temperature increase process are satisfied. For example, if the battery temperature Tbat is lower than the reference temperature Tref, it is determined that the conditions for executing the temperature increase process are satisfied.

  If it is determined that the conditions for executing the temperature raising process are not satisfied, the process proceeds to step S14. In step S <b> 14, a power supply process for supplying power from the high voltage battery 50 to the auxiliary battery 61 and the device group 60 via the first and second DDCs 20 and 30 is performed. In this power supply process, the first DDC 20 and the second DDC 30 are stepped down to supply power to the auxiliary battery 61 and the device group 60.

  If it is determined that the execution condition for the temperature raising process is satisfied, the process proceeds to step S13. In steps S13 to S18, a temperature raising process for raising the temperature of the high-voltage battery 50 by the heat generated by the first and second DDCs 20 and 30 is performed. Steps S13 to S18 correspond to a temperature increase control unit.

  In step S13, based on the battery temperature Tbat acquired in step S11, a temperature increase amount ATR required to raise the battery temperature Tbat to the target temperature Ttag is calculated. In the present embodiment, the target temperature Ttag is set to the reference temperature Tref. The temperature increase amount ATR is calculated by subtracting the battery temperature Tbat acquired in step S11 from the target temperature Ttag. For this reason, when the battery temperature Tbat is the reference temperature Tref, the temperature increase amount ATR becomes zero.

  In step S15, based on the calculated temperature increase amount ATR, a required power amount NAP [Wh] indicating the amount of power required to increase the battery temperature Tbat by the temperature increase amount ATR is calculated. FIG. 6 is a graph showing a correspondence relationship between the temperature increase amount ATR and the required power amount NAP as an example. In the graph of FIG. 6, the horizontal axis is the temperature increase amount ATR, and the vertical axis is the required power amount NAP. As the temperature increase amount ATR increases, the thermal energy necessary to raise the temperature of the high-voltage battery 50 increases, so that the required power amount NAP increases. The relationship between the temperature rise amount ATR and the required power amount NAP is preferably determined in consideration of the heat transfer efficiency when heat is transferred through air, the material of the high-voltage battery 50, and the like.

  For example, the map information shown in FIG. 6 may be recorded in a memory as a storage unit of the control device 10, and the required power amount NAP corresponding to the temperature increase amount ATR may be calculated based on the recorded map information.

  In step S16, the required power amount NAP calculated in step S15 is allocated to the first DDC 20 and the second DDC 30, respectively. Hereinafter, the required power amount allocated to the first DDC 20 is referred to as a first allocation amount NA1, and the required power amount allocated to the second DDC 30 is referred to as a second allocation amount NA2. The first distribution amount NA1 and the second distribution amount NA2 can be set to different values. For example, the first DDC 20 and the second DDC 30 can be made different according to the magnitude of the rated current. Specifically, when the rated current of the first DDC 20 is smaller than the rated current of the second DDC 30, the first allocation amount NA1 can be made smaller than the second allocation amount NA2.

  In step S17, the first and second output current command values Ic1 * and Ic2 * of the first and second DDCs 20 and 30 are set according to the first and second distribution amounts NA1 and NA2 calculated in step S16. Specifically, the first output current command value Ic1 * is set larger as the first allocation amount NA1 is larger, and the second output current command value Ic2 * is set larger as the second allocation amount NA2 is larger. For example, map information that defines the relationship between the first and second distribution amounts NA1 and NA2 and the first and second output current command values Ic1 * and Ic2 * is recorded in a memory as a storage unit of the control device 10. . Then, the first and second output current command values Ic2 * corresponding to the first and second distribution amounts NA1 and NA2 may be calculated based on the recorded map information. Step S17 corresponds to a command value setting unit.

  In step S18, the first duty command value Duty1 of the first DDC 20 and the second duty command value Duty2 of the second DDC 30 are set according to the first and second output current command values Ic1 * and Ic2 * set in step S17. . When the first duty command value Duty1 is set in step S18, the first DDC 20 performs a step-down operation in the direction from the first and second input terminals Ti1 and Ti2 to the first and second output terminals To1 and To2. In addition, when the second duty command value Duty2 is set in step S18, the second DDC 30 performs the boosting operation in the direction from the third and fourth terminals TC and TD to the first and second terminals TA and TB.

  Therefore, the high voltage battery 50 is heated to the target temperature Ttag due to heat generated from the first and second DDCs 20 and 30. When the process of step S18 is finished, the process of FIG. 5 is once finished.

  According to this embodiment described above, the following effects are obtained.

  The control device 10 performs a step-down operation on the first DDC 20 and a step-up operation on the second DDC 30, thereby forming a loop circuit in which current circulates between the first DDC 20 and the second DDC 30. Then, by adjusting the output currents of the first and second DDCs 20 and 30 based on the temperature rise amount ATR, the heat generation amounts of the first and second DDCs 20 and 30 are controlled. Thereby, the heat generated by the power conversion of the first and second DDCs 20 and 30 can be effectively used, and the power consumption required for the temperature rise of the own device in the high voltage battery 50 can be reduced.

  The control device 10 controls the output currents Ic1r and Ic2r of the first and second DDCs 20 and 30 based on the temperature increase amount ATR for bringing the battery temperature Tbat close to the target temperature. Therefore, unnecessary increase in thermal energy can be prevented. As a result, it is possible to suppress an increase in power consumption during the temperature raising process of the high voltage battery 50.

(Second Embodiment)
In the second embodiment, a description will be given focusing on a configuration different from the first embodiment. In addition, since the location which attached | subjected the same code | symbol shows the same content as 1st Embodiment, the description is not repeated.

  In the present embodiment, the rated current of the first DDC 20 is smaller than the rated current of the second DDC 30. For this reason, the first distribution amount NA1 is made smaller than the second distribution amount NA2. Further, the control device 10 adjusts the required power amount NAP by controlling the output current Ic2r of the second DDC 30 having a large rated current without changing the output current Ic1r of the first DDC 20 having a small rated current.

  With reference to FIG. 7, the temperature raising process performed by the control device 10 will be described. The process shown in FIG. 7 is repeatedly performed by the control apparatus 10 with a predetermined period.

  In step S19, the first distribution amount NA1 is set to a predetermined fixed value. In step S19, the second distribution amount NA2 is set based on the temperature increase amount ATR calculated in step S13. Specifically, the second distribution amount NA2 is set to be larger as the temperature increase amount ATR is larger (as the battery temperature Tbat is lower than the target temperature Ttag).

  In step S20, a first output current command value Ic1 * is set according to the first distribution amount NA1. Further, the second output current command value Ic2 * is set according to the second distribution amount NA2. It progresses to step S18 after the process of step S20.

  According to the present embodiment, the second output current command value Ic2 * is set smaller as the temperature increase amount ATR calculated in step S13 approaches zero.

  According to this embodiment described above, the following effects are obtained.

  The control device 10 brings the temperature of the high-voltage battery 50 close to the target temperature Ttag only by adjusting the second output current command value Ic2 *. Therefore, the control related to the temperature raising operation can be simplified, and the processing load on the control device 10 can be reduced. Further, the first output current Ic1r of the first DDC 20 having a small rated current is made constant, and the output current Ic2r of the second DDC 30 having a large rated current is controlled. It is possible to prevent the first output current Ic1r from exceeding the rated current.

(Third embodiment)
In the third embodiment, a description will be given focusing on the configuration different from the first embodiment. In addition, since the location which attached | subjected the same code | symbol shows the same content as 1st Embodiment, the description is not repeated.

  When the high voltage battery 50 is used as a power source in the temperature raising process, it may be assumed that the temperature raising process cannot be stably continued if the remaining capacity SOC of the high voltage battery 50 is low. In particular, when the remaining capacity SOC of the high voltage battery 50 is in the vicinity of the remaining capacity indicating a predetermined overdischarge state, the remaining capacity SOC of the high voltage battery 50 may be in an overdischarge state due to the temperature raising process. In this case, the high voltage battery 50 is deteriorated, which is not desirable.

  Therefore, in the present embodiment, the control device 10 is configured to switch the power source for the temperature raising process to either the high voltage battery 50 or the auxiliary battery 61 in accordance with the remaining capacity SOC of the high voltage battery 50.

  FIG. 8 is a flowchart for describing processing performed by the control device 10 according to the second embodiment. The process shown in FIG. 8 is repeatedly performed by the control apparatus 10 with a predetermined period.

  After setting the first and second output current command values Ic1 * and Ic2 * in step S17, the process proceeds to step S30. In step S30, the remaining capacity SOC of the high voltage battery 50 is acquired. In the present embodiment, the remaining capacity SOC is acquired from the battery monitoring unit provided in the high voltage battery 50.

  In step S31, based on the remaining capacity SOC acquired in step S30, which of the high voltage battery 50 and the auxiliary battery 61 is to be used as the power source in the temperature raising process is selected. In the present embodiment, the power source is selected by comparing the remaining capacity SOC with the battery threshold Thb. Specifically, when the remaining capacity SOC is equal to or greater than the battery threshold Thb, the high voltage battery 50 is selected as the power source, and when the remaining capacity SOC is less than the battery threshold Thb, the auxiliary battery 61 is used as the power source. To do. The battery threshold Thb is a value indicating the remaining capacity when the high voltage battery 50 is overdischarged. Step S31 corresponds to the selection unit.

  When the high voltage battery 50 is selected as the power source, the process proceeds to step S32. In step S32, the outputs of the first DDC 20 and the second DDC 30 are set so that the power source of the current circulating in the loop circuit is the high voltage battery 50 and the auxiliary battery 61 is not the power source of the current circulating in the loop circuit. . Specifically, a first output voltage command value V1 * that is a command value for the output voltage of the first DDC 20 and a second output voltage command value V2 * that is a command value for the output voltage of the second DDC 30 during the boosting operation are set. To do. In the present embodiment, the first output voltage command value V1 * is set to a value larger than the second terminal voltage Vb2, and the second output voltage command value V2 * is set to a value smaller than the first terminal voltage Vb1.

  If the auxiliary battery 61 is selected as the power source, the process proceeds to step S33. In step S33, the first and second output voltage command values V1 *, V1 *, and the power source of the current circulating in the loop circuit are the auxiliary battery 61, and the high-voltage battery 50 is not the power source of the current circulating in the loop circuit. Set V2 *. In the present embodiment, the first output voltage command value V1 * is set to a value smaller than the second terminal voltage Vb2, and the second output voltage command value V2 * is set to a value larger than the first terminal voltage Vb1.

  In step S34, based on the first and second output current command values Ic1 * and Ic2 * set in step S17 and the first and second output voltage command values V1 * and V2 * set in step S32 or step S33. Thus, the first and second duty command values Duty1 and Duty2 are set. Specifically, the first duty command value Duty1 is set so that the output power of the first DDC 20 is a product of the first output current command value Ic1 * and the first output voltage command value V1 *. Further, the second duty command value Duty2 is set so that the output power of the second DDC 30 is a product of the second output current command value Ic2 * and the second output voltage command value V2 *.

  For example, map information that defines the relationship among the first output current command value Ic1 *, the first output voltage command value V1 *, and the first duty command value Duty1 is recorded in a memory as a storage unit of the control device 10. . In addition, map information that defines the relationship among the second output current command value Ic2 *, the second output voltage command value V2 *, and the second duty command value Duty2 is recorded in a memory as a storage unit of the control device 10. . The first and second output current command values Ic1 * and Ic2 * and the first and second output voltage command values V1 * and V2 * based on the recorded map information. What is necessary is just to acquire 2 duty command value Duty1, Duty2.

  FIG. 9 is a diagram for explaining the current flowing in the power supply unit 40 in the temperature raising process. FIG. 9A shows a loop circuit when the high voltage battery 50 is used as a power source. The first output voltage V1r of the first DDC 20 becomes higher than the second terminal voltage Vb2 of the auxiliary battery 61 by the first output voltage command value V1 * set in step S32. For this reason, the current from the auxiliary battery 61 does not flow through the first sub-wiring SL1.

  Due to the second output voltage command value V2 * set in step S32, the second output voltage V2r of the second DDC 30 becomes smaller than the first terminal voltage Vb1 of the high-voltage battery 50. Therefore, the output current of the second DDC 30 does not flow into the plus terminal side of the high voltage battery 50 but flows into the input side of the first DDC 20. Further, the current from the high voltage battery 50 flows into the input side of the first DDC 20 via the first and third high voltage lines HL1 and HL3.

  FIG. 9B shows a loop circuit when the auxiliary battery 61 is used as a power source. Due to the first output voltage command value V1 * set in step S33, the first output voltage V1r of the first DDC 20 becomes smaller than the second terminal voltage Vb2 of the auxiliary battery 61. Therefore, the output current of the first DDC 20 does not flow into the auxiliary battery 61 but flows into the input side of the second DDC 30 during the boosting operation. In addition, current from the auxiliary battery 61 flows into the input side of the second DDC 30 via the first sub-wiring SL1.

  Due to the second output voltage command value V2 * set in step S33, the second output voltage V2r of the second DDC 30 becomes larger than the first terminal voltage Vb1 of the high-voltage battery 50. Therefore, the current from the high voltage battery 50 does not flow into the input side of the first DDC 20 via the first and third high voltage lines HL1 and HL3. Further, the output current from the second DDC 30 flows into the input side of the first DDC 20 via the first, third, and fifth high-voltage lines HL1, HL3, and HL5.

  Therefore, the high voltage battery 50 is heated to the target temperature Ttag due to heat generated from the first and second DDCs 20 and 30. Returning to FIG. 8, when the process of step S34 is completed, the process shown in FIG. 8 is temporarily ended.

  According to this embodiment described above, the following effects are obtained.

  -The control apparatus 10 selects either the high voltage battery 50 or the auxiliary battery 61 as a power source at the time of the temperature increasing process according to the remaining capacity SOC of the high voltage battery 50. Therefore, either the high voltage battery 50 or the auxiliary battery 61 can be selected and the temperature raising operation can be continued. Further, when the remaining capacity SOC of the high voltage battery 50 is small, the auxiliary battery 61 is used as a power source for flowing a current to the loop circuit, thereby preventing the high voltage battery 50 from being deteriorated due to overdischarge.

(Modification of the third embodiment)
Instead of the remaining capacity SOC of the high-voltage battery 50, the first terminal voltage Vb1 of the high-voltage battery 50 may be used to select either the high-voltage battery 50 or the auxiliary battery 61 as a power source during the temperature raising process. . In this case, when the first terminal voltage Vb1 is equal to or higher than a predetermined voltage threshold, the high voltage battery 50 is selected as the power source during the temperature raising process. Further, when the first terminal voltage Vb1 is less than the voltage threshold, the auxiliary battery 61 is selected as a power source during the temperature raising process.

  Either the high voltage battery 50 or the auxiliary battery 61 may be selected as a power source using the terminal voltages Vb1 and Vb2 of both the high voltage battery 50 and the auxiliary battery 61.

  When the control device 10 can acquire the remaining capacity SOC of the auxiliary battery 61, the remaining capacity SOC of the high voltage battery 50 and the auxiliary battery 61 is used to power either the high voltage battery 50 or the auxiliary battery 61. It may be selected as a source. In this case, for example, in step S31, the higher remaining capacity SOC may be used as the power source in the temperature raising process.

(Fourth embodiment)
In the fourth embodiment, a description will be given focusing on a configuration different from the first embodiment. In addition, since the location which attached | subjected the same code | symbol shows the same content as 1st Embodiment, the description is not repeated.

  In the fourth embodiment, the control device 10 controls the first and second output currents Ic1r and Ic2r based on the predetermined required power amount NAP during the temperature raising process.

  FIG. 10 shows a control system 100 according to the fourth embodiment. The power supply unit 40 includes a heater 70. The heater 70 is disposed near the high voltage battery 50. The heater 70 is connected to the first sub wiring SL1. Therefore, the electric power from the high voltage battery 50 is supplied to the heater 70 via the first sub-wiring SL1. In the present embodiment, the control system 100 does not include the temperature sensor 56.

  Next, the temperature increasing process performed by the control device 10 in the fourth embodiment will be described with reference to FIG. The process shown in FIG. 11 is repeatedly performed by the control apparatus 10 with a predetermined period.

  In step S40, predetermined first and second distribution amounts NA1 and NA2 for the first and second DDCs 20 and 30 are acquired. In step S41, the first and second output current command values Ic1 * and Ic2 * of the first and second DDCs 20 and 30 are set based on the first and second allocation amounts NA1 and NA2 acquired in step S40. . In step S41, the temperature raising time indicating the time of the temperature raising process by the first and second DDCs 20 and 30 is set.

  In step S18, the first and second duty command values Duty1 and Duty2 are set based on the first and second allocation amounts NA1 and NA2 set in step S41.

  It progresses to step S42 after the process of step S18. In step S42, the elapse of the temperature raising time set in step S41 is counted. In step S43, the count time counted in step S41 is compared with the time set as the temperature raising time. If the count time has not passed the temperature rising time, the process of FIG. 11 is once ended.

  On the other hand, if the count time has passed the temperature raising time in step S43, the process proceeds to step S44. In step S44, the operation of the heater 70 is started to raise the temperature of the high-voltage battery 50. In the present embodiment, open control for operating the heater 70 for a predetermined time is performed.

  In the present embodiment, the temperature of the high-voltage battery 50 is increased by the heat generated from the first and second DDCs 20 and 30. Therefore, the time required for the heater 70 to raise the temperature of the high-voltage battery 50 to the target temperature Ttag can be shortened compared to the case where the temperature raising process is not performed. As a result, the time for operating the heater 70 can be shortened, and the power consumption of the heater 70 can be reduced.

(Other embodiments)
The power supply unit 40 may include the first to sixth high voltage lines HL1 to HL6, the first and second sub wirings SL1 and SL2, the first DDC 20, and the second DDC 30, excluding the high voltage battery 50. In this case, the power supply unit 40 is connected to the high voltage battery 50 so that the power from the high voltage battery 50 is supplied.

  In the first to fourth embodiments described above, only the heat generated by the first DDC 20 may be used for raising the temperature of the high-voltage battery 50.

  Instead of using either the high voltage battery 50 or the auxiliary battery 61 as a power source, both the high voltage battery 50 and the auxiliary battery 61 may be used as power sources. In this case, the first output voltage command value V1 * may be set to a value smaller than the second terminal voltage Vb2, and the second output voltage command value V2 * may be set to a value smaller than the first terminal voltage Vb1.

  In the first to third embodiments described above, the control system 100 may include a heater. Even in this case, since the high voltage battery 50 is heated by the temperature increasing process of the first and second DDCs 20 and 30, the power consumption of the heater 70 required to raise the high voltage battery 50 to the target temperature Ttag is reduced. can do.

  The heat transfer unit may transmit heat generated in at least one of the first and second DDCs 20 and 30 to the high voltage battery 50. For example, a member as a heat transfer unit is interposed between the first and second DDCs 20 and 30 and the high voltage battery 50. Then, the high-voltage battery 50 is heated by heat transferred from the first and second DDCs 20 and 30 to the member.

  DESCRIPTION OF SYMBOLS 10 ... Control apparatus, 20 ... 1st DC / DC converter, 30 ... 2nd DC / DC converter, 41 ... Housing | casing, 42 ... Fan, 43 ... Opening, 50 ... High voltage battery, 100 ... Control system.

Claims (6)

A first DC / DC converter (20) for performing step-down operation;
A second DC / DC converter (30) for performing a boost operation;
Main wires (HL1, HL3, HL5) connecting the input side of the first DC / DC converter, the output side of the second DC / DC converter, and the main power storage device (50);
In a control system (100) comprising: a sub-wiring (SL1) that connects an output side of the first DC / DC converter and an input side of the second DC / DC converter;
The first DC / DC converter is stepped down to circulate current through a loop circuit including the main wiring, the first DC / DC converter, the second DC / DC converter, and the sub wiring, and the second DC / DC converter A temperature rise control unit (10) for boosting operation of
Heat transfer units (41, 42, 43) that transmit heat generated to at least one of the first DC / DC converter and the second DC / DC converter to the main power storage device by the step-down operation and the step-up operation of the temperature increase control unit. And a control system comprising: The temperature rise control unit
A first output current that is an output current command value of the first DC / DC converter required to raise the temperature of the main power storage device to the target temperature based on a deviation between the temperature of the main power storage device and the target temperature A command value setting unit that sets a command value and a second output current command value that is an output current command value of the second DC / DC converter;
2. The control system according to claim 1, wherein an output current of the first DC / DC converter is controlled to the first output current command value, and an output current of the second DC / DC converter is controlled to the second output current command value. A sub power storage device (61) is connected to the sub wiring,
A selection unit that selects either the main power storage device or the sub power storage device as a power source when the step-down operation and the step-up operation are performed by the temperature increase control unit based on the voltage state of the main power storage device,
The command value setting unit includes the first DC / DC converter such that a power source for circulating current through the loop circuit is either the main power storage device or the sub power storage device selected by the selection unit. A first output voltage command value that is an output voltage command value, the first output current command value, a second output voltage command value that is an output voltage command value of the second DC / DC converter, and the second output current command value are set. And
The temperature raising control unit controls the output current of the first DC / DC converter to the first output current command value, and controls the output voltage of the first DC / DC converter to the first output voltage command value; 3. The control system according to claim 2, wherein an output current of the second DC / DC converter is controlled to the second output current command value, and an output voltage of the second DC / DC converter is controlled to the second output voltage command value. .   The command value setting unit sets the first output voltage command value to be larger than a terminal voltage of the sub power storage device when the main power storage device is selected by the selection unit, and the second The control system according to claim 3, wherein an output voltage command value is set to be smaller than a terminal voltage of the main power storage device.   The command value setting unit sets the first output voltage command value to be smaller than a terminal voltage of the sub power storage device when the sub power storage device is selected by the selection unit, and the second The control system according to claim 3 or 4, wherein an output voltage command value is set to be larger than a terminal voltage of the main power storage device. The temperature rise control unit
A first output current command that is an output current command value of the first DC / DC converter required to raise the temperature of the main power storage device to a predetermined temperature based on a deviation between the temperature of the main power storage device and its target temperature. A command value setting unit for setting a value and a second output current command value that is an output current command value of the second DC / DC converter,
The control system according to claim 1, wherein an output current of the second DC / DC converter is controlled to the second output current command value.

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