Charge / discharge control device

Abstract

To provide a charge / discharge control device capable of suppressing a sense of incongruity given to a driver due to different timings of turning off an ignition and turning off a contactor.SOLUTION: A charge / discharge control device includes a high-voltage battery 4 as a main power source, an inverter 3 powered by the high-voltage battery 4 to drive a motor 2, a negative contactor 42 and a positive contactor 43 that disconnect electrical connection between the high-voltage battery 4 and the inverter 3, and a contactor switching control unit 5 that switches between connecting and disconnecting the negative contactor 42 and the positive contactor 43 and switches the negative contactor 42 and the positive contactor 43 to an OFF state at the same time that an ignition switch 51 of a vehicle 1 is turned off.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charge / discharge control device. [Background technology]

[0002] Generally, when a high-voltage battery and a high-voltage device are electrically connected via a contactor, a main contactor that electrically disconnects the high-voltage battery and the high-voltage device, and a pre-charge circuit connected in parallel to the main contactor are provided. This pre-charge circuit is composed of a pre-charge resistor and a pre-charge contactor that are connected in series. In such a circuit, when the ignition switch is turned on, the pre-charge contactor is turned on to start pre-charging, and the main contactor is turned on after pre-charging is completed, thereby suppressing the generation of inrush current.

[0003] Patent Document 1 describes a technology in which, when a stop instruction signal is received from a key switch, if a specified time has not elapsed since the main relay was turned on, the main relay and ground relay are maintained in the on state, thereby enabling the vehicle to be started when necessary while reliably dissipating heat from the inrush limiting resistor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-114974 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in this technology, the main relay and ground relay are maintained in the ON state until heat dissipation from the inrush limiting resistor is complete. Therefore, if the timing of turning off the key switch differs from the timing of turning off the main relay and ground relay, the sound of the main relay and ground relay turning off will be loud, which may cause discomfort to the driver.

[0006] For example, if the key switch is turned on and the main relay is turned on, and then the key switch is turned off before a specified time has elapsed, the main relay and the ground relay will be turned off after the key switch is turned off.

[0007] Therefore, an object of the present invention is to provide a charge / discharge control device that can suppress the sense of discomfort felt by the driver due to the difference between the timing of ignition off and the timing of contactor off. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a charge / discharge control device for a vehicle including a high-voltage battery as a main power source, an inverter that receives power from the high-voltage battery and drives a motor, and a contactor that makes and breaks an electrical connection between the high-voltage battery and the inverter, a precharge circuit connected in parallel with the contactor, for precharging a smoothing capacitor connected in parallel with the inverter when an ignition switch of the vehicle is turned on; A contactor switching control unit is provided for switching between connection and disconnection of the contactor, the precharge circuit includes a precharge resistor that limits a precharge current, and a precharge contactor that is connected in series with the precharge resistor; The contactor switching control unit is When the precharging of the smoothing capacitor is completed, the precharge contactor is turned off, and when the ignition switch is turned on after the precharge contactor is turned off, an overheat protection counter is incremented by 1, and when the overheat protection counter is less than a predetermined value, the contactor is switched to the off state at the same time that the ignition switch is turned off, and when the overheat protection counter becomes equal to or greater than a predetermined value, the contactor is maintained in the on state even if the ignition switch is turned off until a predetermined time has elapsed since the precharge contactor was turned off, and when the predetermined time has elapsed, the overheat protection counter is reset to zero. It is something. Effect of the Invention

[0009] In this way, according to the present invention, it is possible to prevent the driver from feeling uncomfortable due to the difference in timing between ignition-off and contactor-off. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a charge / discharge control device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart showing a procedure of a charge / discharge control process of the charge / discharge control device according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a time chart showing the timing of incrementing and resetting the overheat protection counter by the charge / discharge control process of the charge / discharge control device according to one embodiment of the present invention. [Figure 4]FIG. 4 is a time chart showing a case where the overheat protection counter reaches a predetermined value due to the charge / discharge control process of the charge / discharge control device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A charge / discharge control device according to one embodiment of the present invention is a charge / discharge control device for a vehicle that includes a high-voltage battery as a main power source, an inverter that receives power from the high-voltage battery and drives a motor, and a contactor that disconnects the electrical connection between the high-voltage battery and the inverter, and includes a contactor switching control unit that switches the contactor between connection and disconnection, and the contactor switching control unit is configured to switch the contactor to the off state at the same time that the vehicle's ignition switch is turned off.

[0012] As a result, the charge / discharge control device according to one embodiment of the present invention can suppress the sense of discomfort felt by the driver due to the difference in timing between ignition-off and contactor-off. EXAMPLES

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a charge / discharge control device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] In FIG. 1, a vehicle 1 equipped with a charge / discharge control device according to an embodiment of the present invention includes a motor 2, an inverter 3, a high-voltage battery 4, and a contactor switching control unit 5.

[0015] The motor 2 is, for example, a synchronous motor equipped with a rotor in which multiple permanent magnets are embedded and a stator around which a stator coil is wound. When three-phase AC power is applied to the stator coil, a rotating magnetic field is generated in the stator of the motor 2, and the rotor rotates due to this rotating magnetic field, generating a driving force.

[0016] In addition, the motor 2 is driven so that the rotational resistance during power generation is utilized for braking the vehicle 1. This allows the motor 2 to have a function of generating power through regeneration. In this manner, the motor 2 also functions as a generator, and is capable of generating power for charging the high-voltage battery 4.

[0017] The inverter 3 supplies three-phase AC power to the motor 2. The inverter 3 also converts the three-phase AC power generated by the motor 2 into DC power to charge the high-voltage battery 4.

[0018] A smoothing capacitor 31 is connected between the positive and negative electrodes of the input terminals that connect the inverter 3 and the high-voltage battery 4. The smoothing capacitor 31 smoothes the voltage of the DC power generated between the positive and negative electrodes.

[0019] The high-voltage battery 4 is, for example, a nickel storage battery or a lithium storage battery, and is configured by connecting a plurality of cells in series. The high-voltage battery 4 supplies power to the motor 2 via the inverter 3.

[0020] The high-voltage battery 4 is housed in, for example, a sealed battery pack 41. The battery pack 41 is disposed, for example, outside the passenger compartment under the body of the vehicle 1. The battery pack 41 is provided with a temperature sensor 47 that detects the temperature inside the battery pack 41. The temperature sensor 47 is connected to the contactor switching control unit 5.

[0021] A negative electrode side contactor 42 is provided on the negative electrode side between the inverter 3 and the high voltage battery 4. A positive electrode side contactor 43 is provided on the positive electrode side between the inverter 3 and the high voltage battery 4. A pre-charge circuit 44 in which a pre-charge contactor 45 and a pre-charge resistor 46 are connected in series is connected to the positive electrode side contactor 43 in parallel with the positive electrode side contactor 43.

[0022] Depending on the control of the contactor switching control unit 5, the negative side contactor 42 and the positive side contactor 43 are configured to take either an on state in which the inverter 3 and the high-voltage battery 4 are electrically connected, or an off state in which the inverter 3 and the high-voltage battery 4 are electrically disconnected.

[0023] Depending on the control of the contactor switching control unit 5, the pre-charge contactor 45 is configured to take either an on state in which the pre-charge resistor 46 is connected in parallel to the positive side contactor 43, or an off state in which the pre-charge resistor 46 is electrically disconnected from the positive side contactor 43.

[0024] For example, the precharge contactor 45 is controlled to be in the ON state before the motor 2 starts to operate, and to be in the OFF state after the positive contactor 43 is in the ON state.

[0025] The negative contactor 42, the positive contactor 43 and the pre-charge contactor 45 are disposed in, for example, the battery pack 41.

[0026] The contactor switching control unit 5 is configured by a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input port, and an output port.

[0027] The ROM of the contactor switching control unit 5 stores various control constants, various maps, and the like, as well as a program for causing the computer unit to function as the contactor switching control unit 5. That is, the computer unit functions as the contactor switching control unit 5 by the CPU executing the program stored in the ROM.

[0028] In addition to the temperature sensor 47 described above, various sensors including an ignition switch 51 and an outside air temperature sensor 52 are connected to the input port of the contactor switching control unit 5.

[0029] The ignition switch 51 detects whether or not the system of the vehicle 1 has been started, and transmits the detection result to the contactor switching control unit 5. The ignition switch 51 is switched between an ON state for starting the system of the vehicle 1, and an OFF state for stopping the system of the vehicle 1, and transmits the state to the contactor switching control unit 5. The outside air temperature sensor 52 detects the temperature of the outside air around the vehicle 1.

[0030] On the other hand, various control targets including the negative contactor 42, the positive contactor 43, and the precharge contactor 45 described above are connected to the output port of the contactor switching control unit 5.

[0031] In this embodiment, the contactor switching control unit 5 switches the negative contactor 42 and the positive contactor 43 to the OFF state at the same time that the ignition switch 51 is turned to the OFF state.

[0032] The contactor switching control unit 5 increments the overheat protection counter by adding 1 when the precharge contactor 45 is turned off and then the ignition switch 51 is turned on.

[0033] When the overheat protection counter is less than a predetermined value, the contactor switching control unit 5 turns the ignition switch 51 to the OFF state and simultaneously switches the negative contactor 42 and the positive contactor 43 to the OFF state.

[0034] When the overheat protection counter reaches or exceeds a predetermined value, the contactor switching control unit 5 maintains the negative side contactor 42 and the positive side contactor 43 in the on state until a predetermined time has elapsed since the precharge contactor 45 was turned off, even if the ignition switch 51 is turned off.

[0035] When a predetermined time has elapsed since the pre-charge contactor 45 was turned off, the contactor switching control unit 5 resets the overheat protection counter to zero.

[0036] The contactor switching control unit 5 may stop incrementing the overheat protection counter until a predetermined time has elapsed since the overheat protection counter reaches or exceeds a predetermined value and the precharge contactor 45 is turned off.

[0037] The contactor switching control unit 5 may increment the overheat protection counter when the ignition switch 51 is turned on within a predetermined time after the precharge contactor 45 is turned off.

[0038] The lower the temperature inside the battery pack 41, the shorter the predetermined time period the contactor switching control unit 5 sets. The contactor switching control unit 5 shortens the predetermined time as the outside air temperature decreases.

[0039] The predetermined time for incrementing the overheat protection counter and the predetermined time for maintaining the negative contactor 42 and the positive contactor 43 in the ON state may be different in length.

[0040] The charge / discharge control process performed by the charge / discharge control device according to this embodiment configured as above will be described with reference to Fig. 2. The charge / discharge control process described below is started when the ignition switch 51 is turned on.

[0041] In step S1, the contactor switching control unit 5 determines whether or not the overheat protection counter is equal to or greater than a predetermined value.

[0042] If it is determined that the overheat protection counter is equal to or greater than the predetermined value, the contactor switching control unit 5 ends the charge / discharge control process. If it is determined that the overheat protection counter is not equal to or greater than the predetermined value, the contactor switching control unit 5 executes the process of step S2.

[0043] In step S2, the contactor switching control unit 5 determines whether or not a predetermined time has elapsed since the pre-charge contactor 45 was turned off the previous time.

[0044] If it is determined that the predetermined time has elapsed since the previous turning-off of the pre-charge contactor 45, the contactor switching control unit 5 executes the process of step S4. If it is determined that the predetermined time has not elapsed since the previous turning-off of the pre-charge contactor 45, the contactor switching control unit 5 executes the process of step S3.

[0045] In step S3, the contactor switching control unit 5 increments the overheat protection counter. After executing the process of step S3, the contactor switching control unit 5 executes the process of step S5.

[0046] In step S4, the contactor switching control unit 5 resets the overheat protection counter. After executing the process of step S4, the contactor switching control unit 5 executes the process of step S5.

[0047] In step S5, the contactor switching control unit 5 turns on the pre-charge contactor 45 and turns on the negative electrode side contactor 42. After executing the process of step S5, the contactor switching control unit 5 executes the process of step S6.

[0048] In step S6, the contactor switching control unit 5 determines whether or not the precharge is completed.

[0049] If it is determined that the pre-charging is completed, the contactor switching control unit 5 executes the process of step S7. If it is determined that the pre-charging is not completed, the contactor switching control unit 5 executes the process of step S6.

[0050] In step S7, the contactor switching control unit 5 turns on the positive electrode side contactor 43. After executing the process of step S7, the contactor switching control unit 5 executes the process of step S8.

[0051] In step S8, the contactor switching control unit 5 turns off the pre-charge contactor 45. After executing the process of step S8, the contactor switching control unit 5 executes the process of step S9.

[0052] In step S9, the contactor switching control unit 5 determines whether the overheat protection counter is equal to or greater than a predetermined value.

[0053] If it is determined that the overheat protection counter is equal to or greater than the predetermined value, the contactor switching control unit 5 executes the process of step S12. If it is determined that the overheat protection counter is not equal to or greater than the predetermined value, the contactor switching control unit 5 executes the process of step S10.

[0054] In step S10, the contactor switching control unit 5 determines whether the ignition switch 51 is turned off.

[0055] If it is determined that the ignition switch 51 is turned off, the contactor switching control unit 5 executes the process of step S11. If it is determined that the ignition switch 51 is not turned off, the contactor switching control unit 5 executes the process of step S10.

[0056] In step S11, the contactor switching control unit 5 turns off the positive contactor 43 and turns off the negative contactor 42. After executing the process of step S11, the contactor switching control unit 5 ends the charge / discharge control process.

[0057] In step S12, the contactor switching control unit 5 determines whether or not a predetermined time has elapsed.

[0058] If it is determined that the predetermined time has elapsed, the contactor switching control unit 5 executes the process of step S13. If it is determined that the predetermined time has not elapsed, the contactor switching control unit 5 executes the process of step S12.

[0059] In step S13, the contactor switching control unit 5 determines whether the ignition switch 51 is in the OFF state.

[0060] If it is determined that the ignition switch 51 is in the OFF state, the contactor switching control unit 5 executes the process of step S11. If it is determined that the ignition switch 51 is not in the OFF state, the contactor switching control unit 5 ends the charge / discharge control process.

[0061] Such an operation based on the combustion stabilization process will be described with reference to FIGS. 3 is a timing chart showing the timing of incrementing and resetting the overheat protection counter, where the predetermined time is T [s].

[0062] At time t1, when the ignition switch 51 is turned on, the pre-charge contactor 45 and the negative electrode side contactor 42 are turned on, and pre-charging is started.

[0063] When the pre-charge is completed, the positive contactor 43 is turned on, and at time t2, the pre-charge contactor 45 is turned off and clocking of a predetermined time period is started.

[0064] At time t3, when the ignition switch 51 is turned on after a time T1 shorter than the predetermined time T has elapsed, the precharge contactor 45 and the negative contactor 42 are turned on, and the overheat protection counter is incremented by one.

[0065] When the pre-charge is completed, the positive contactor 43 is turned on, and at time t4, the pre-charge contactor 45 is turned off and clocking of a predetermined time is started.

[0066] At time t5, when the ignition switch 51 is turned on after a time T1 shorter than the predetermined time T has elapsed, the precharge contactor 45 and the negative contactor 42 are turned on, and the overheat protection counter is incremented by one.

[0067] When the pre-charge is completed, the positive contactor 43 is turned on, and at time t6, the pre-charge contactor 45 is turned off and clocking of a predetermined time period is started.

[0068] At time t7, the predetermined time T has elapsed and the overheat protection counter is reset to zero. Even if the ignition switch 51 is turned on after a time T2 longer than the predetermined time T has elapsed, the overheat protection counter is not incremented.

[0069] 4 is a time chart showing the case where the overheat protection counter reaches a predetermined value. Here again, the predetermined time is T [s].

[0070] At time t11, when the ignition switch 51 is turned on after a time T1 shorter than the predetermined time T has elapsed since the pre-charge contactor 45 was turned off, the pre-charge contactor 45 and the negative contactor 42 are turned on, and the overheat protection counter is incremented by 1. At this time, the overheat protection counter becomes a predetermined value.

[0071] When the pre-charge is completed, the positive contactor 43 is turned on, the pre-charge contactor 45 is turned off, and the clocking of a predetermined time is started.

[0072] At time t12, the ignition switch 51 is turned off, but because the predetermined time has not elapsed, the positive contactor 43 and the negative contactor 42 are maintained in the on state. After that, even if the ignition switch 51 is turned on, the predetermined time has not elapsed and the positive contactor 43 and the negative contactor 42 are in the on state, so the pre-charge contactor 45 is not turned on.

[0073] At time t13, when a predetermined time T has elapsed, the overheat protection counter is reset to zero.

[0074] Thereafter, at time t14, when the ignition switch 51 is turned off, since the predetermined time has elapsed, the positive side contactor 43 and the negative side contactor 42 are turned off, and when the ignition switch 51 is turned on at a time T3 that is longer than the predetermined time T since the pre-charge contactor 45 was turned off, the pre-charge contactor 45 and the negative side contactor 42 are turned on, and the overheat protection counter is not incremented.

[0075] In this manner, in this embodiment, the contactor switching control unit 5 switches the negative contactor 42 and the positive contactor 43 to the OFF state at the same time that the ignition switch 51 is turned to the OFF state.

[0076] As a result, the timing of turning off the ignition switch 51 coincides with the timing of the off operation sound of the negative contactor 42 and the positive contactor 43, so that the driver can recognize that the off operation sound is caused by the operation of the ignition switch 51. Therefore, it is possible to prevent the driver from feeling uncomfortable due to the timing of the off operation sound being separated from the timing of the driver's vehicle operation.

[0077] In addition, when the pre-charge contactor 45 is turned off and then the ignition switch 51 is turned on, the contactor switching control unit 5 adds 1 to the overheat protection counter. When the overheat protection counter is less than a predetermined value, the ignition switch 51 is turned off and at the same time the negative side contactor 42 and the positive side contactor 43 are switched off. When the overheat protection counter becomes equal to or greater than the predetermined value, the negative side contactor 42 and the positive side contactor 43 are maintained in the on state even if the ignition switch 51 is turned off until a predetermined time has elapsed since the pre-charge contactor 45 was turned off.

[0078] As a result, when the number of times the pre-charge contactor 45 is turned on is less than a predetermined value, the timing when the ignition switch 51 is turned off coincides with the timing at which the negative contactor 42 and the positive contactor 43 make an off operation sound, and when the number of times the pre-charge contactor 45 is turned on reaches or exceeds a predetermined value, the pre-charge contactor 45 is not turned on for a predetermined time. This makes it possible to prevent the pre-charge resistor 46 from overheating excessively, while preventing the timing at which the off operation sound is made from deviating from the timing at which the driver operates the vehicle, thereby preventing the driver from feeling uncomfortable.

[0079] In addition, the contactor switching control unit 5 increments an overheat protection counter when the ignition switch 51 is turned on within a predetermined time after the precharge contactor 45 is turned off, and resets the overheat protection counter to zero when the predetermined time has elapsed.

[0080] When the pre-charge contactor 45 is repeatedly turned on and off in a short period of time, there is a risk that the pre-charge resistor 46 will become even more excessively overheated, so the pre-charge contactor 45 is not turned on for a predetermined period of time. This makes it possible to prevent the pre-charge resistor 46 from becoming excessively overheated, while also preventing the timing of the off operation sound from deviating from the timing of the driver's vehicle operation, thereby preventing the driver from feeling uncomfortable.

[0081] Moreover, the lower the temperature inside the battery pack 41, the shorter the predetermined time period the contactor switching control unit 5 sets.

[0082] The lower the temperature inside the battery pack 41, the easier it is for the pre-charge resistor 46 to cool, and therefore the predetermined time required for the pre-charge resistor 46 to cool can be shortened. This increases the frequency with which the timing of the ignition switch 51 being turned off coincides with the timing at which the negative contactor 42 and the positive contactor 43 make their off operation sounds.

[0083] Moreover, the lower the outside air temperature, the shorter the predetermined time period the contactor switching control unit 5 sets. The battery pack 41 in which the negative contactor 42, the positive contactor 43, the pre-charge contactor 45, and the pre-charge resistor 46 are arranged is a sealed battery pack that is cooled by heat exchange with the outside, and is installed outside the passenger compartment under the vehicle body. Therefore, the lower the outside air temperature, the cooler the battery pack 41 is, and the time required for the pre-charge resistor 46 to cool can be shortened. This increases the frequency with which the timing of the ignition switch 51 being turned off coincides with the timing of the off-operation sounds of the negative contactor 42 and the positive contactor 43 being generated.

[0084] In this embodiment, an example has been described in which the contactor switching control unit 5 performs various judgments and calculations based on various sensor information, but this is not limited to the above. The vehicle 1 may be provided with a communication unit capable of communicating with an external device such as an external server, and various judgments and calculations may be performed by the external device based on the detection information of the various sensors transmitted from the communication unit. The judgment results and calculation results may be received by the communication unit, and various controls may be performed using the received judgment results and calculation results.

[0085] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made thereto without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0086] 1 vehicle 2 Motors 3 Inverter 4 High Voltage Battery 5 Contactor switching control section 31 Smoothing capacitor 41 Battery pack 42 Negative contactor (contactor) 43 Positive contactor (contactor) 44 Precharge Circuit 45 Precharge Contactor 46 Precharge resistor 47 Temperature Sensor 51 Ignition switch 52 Outside air temperature sensor

Claims

1. A high-voltage battery as the main power source; an inverter that receives power from the high-voltage battery and drives a motor; A charge / discharge control device for a vehicle comprising: a contactor that disconnects an electrical connection between the high-voltage battery and the inverter, a precharge circuit connected in parallel with the contactor, for precharging a smoothing capacitor connected in parallel with the inverter when an ignition switch of the vehicle is turned on; a contactor switching control unit that switches between connecting and disconnecting the contactor, the precharge circuit includes a precharge resistor that limits a precharge current, and a precharge contactor that is connected in series with the precharge resistor; the contactor switching control unit turns the precharge contactor off when precharging of the smoothing capacitor is completed, and adds one to an overheat protection counter when the ignition switch is turned on after the precharge contactor is turned off, and when the overheat protection counter is less than a predetermined value, switches the contactor to the off state at the same time as the ignition switch is turned off, and when the overheat protection counter becomes equal to or greater than the predetermined value, maintains the contactor in the on state even if the ignition switch is turned off until a predetermined time has elapsed since the precharge contactor was turned off, and resets the overheat protection counter to zero when the predetermined time has elapsed.

2. the contactor and the precharge circuit are disposed in a battery pack in which the high voltage battery is housed; The charge / discharge control device according to claim 1 , wherein the contactor switching control unit shortens the predetermined time period as the temperature inside the battery pack decreases.

3. The charge / discharge control device according to claim 2 , wherein the battery pack is disposed outside a passenger compartment of the vehicle.

4. The charge / discharge control device according to claim 3 , wherein the contactor switching control unit shortens the predetermined time period as the outside air temperature decreases.

Images