Power management system for vehicle

Abstract

A power management system (1) for a vehicle is provided with main contactors (4, 5), a precharge contactor (7), a precharge resistor (8), capacitors (14, 24), and a control device (30). The control device (30) implements pre-charge control and main control. The pre-charge control is a control for increasing the voltage of the capacitors (14, 24) by connecting the pre-charge contactor (7) by receiving the preparation request. The main control is a control that connects the main contactors (4, 5) and cuts off the pre-charge contactor (7) after the voltage of the capacitors (14, 24) reaches the voltage of the battery (2). The control device (30) maintains the connection state of the precharge contactor (7) until the voltage of the capacitors (14, 24) reaches the voltage of the battery (2), even when the preliminary request disappears during the implementation of the precharge control.

Description

Technical Field

[0001] The invention relates to a power management system for a vehicle. Background Art

[0002] In the past, the following technology is known: in a main power supply circuit (main circuit) for supplying power from a vehicle battery to an inverter that generates driving power for a vehicle motor, a smoothing circuit is connected in parallel with the inverter, and a precharge circuit is connected in parallel with the main contactor. The smoothing circuit refers to a circuit equipped with a capacitor, and the precharge circuit refers to a circuit equipped with a precharge contactor and a precharge resistor. By connecting the precharge contactor earlier than the main contactor, the inrush current is reduced, and the protection of the main power supply circuit is improved.

[0003] When the pre-charging contactor is connected, the temperature of the pre-charging resistor rises according to the number of times it is powered on and the power-on time. Therefore, for example, when the main power supply is repeatedly turned on and off in a short period of time, the pre-charging resistor may overheat. Therefore, it is proposed to count the number of times the pre-charging resistor is powered on, and when the number of power-ons within the set time reaches the set number, the pre-charging control (powering on the pre-charging resistor) is interrupted. Through such control, the overheating of the pre-charging resistor can be suppressed (for example, refer to patent document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 4086807

[0007] Technical problem to be solved by the invention

[0008] However, in the control as described above, even if the ignition switch (main power switch) is repeatedly turned on and off due to, for example, a driver's misoperation or carelessness, the pre-charge control will be interrupted due to the increase in the number of power-on times. Therefore, there is a problem that the vehicle's startability is easily lost, and it is difficult to recover from the pre-charge control that is interrupted due to misoperation or carelessness. In addition, the vehicle start mentioned here includes the start when external charging starts and when the air conditioner is turned on, in addition to the start of driving. Summary of the invention

[0009] One of the purposes of this document is to provide a vehicle power management system that is proposed in consideration of the above-mentioned issues and can improve the protection of the main circuit and the starting performance of the vehicle with a simple structure. In addition, without being limited to this purpose, achieving the effects derived from the various structures shown in the "Specific Implementation Method" described later and the effects that cannot be obtained by the previous technology are also included in other purposes of this document.

[0010] Technical means for solving technical problems

[0011] The vehicle power management system of the invention can be implemented as the following disclosed aspects or application examples to solve at least a part of the above-mentioned problems.

[0012] The power management system of the vehicle of the invention has a main contactor, which is installed in a main circuit, and the main circuit is connected to an inverter circuit and a battery that controls the frequency of the power supplied to the motor. In addition, it has a pre-charge contactor and a pre-charge resistor, which are installed in a pre-charge circuit, and the pre-charge circuit is connected in parallel with the main contactor. In addition, it has a capacitor, which is installed in a smoothing circuit, and the smoothing circuit is connected in parallel with the inverter circuit.

[0013] The control device is also provided, and the control device implements pre-charge control and main control, wherein the pre-charge control connects the pre-charge contactor to increase the voltage of the capacitor by receiving a preliminary request indicating a connection request of the main circuit, and the main control connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery. Even if the preliminary request disappears during the implementation of the pre-charge control, the control device maintains the connection state of the pre-charge contactor until the voltage of the capacitor reaches the voltage of the battery.

[0014] Effects of the Invention

[0015] According to the power management system of the vehicle of the invention, even if the preparatory request disappears during the implementation of the pre-charging control, the connection state of the pre-charging contactor is maintained until the pre-charging is completed. Thus, when the pre-charging request is received again during the period until the pre-charging is completed, the main control can be implemented without cutting off the power-on state of the main circuit after the pre-charging is completed. Therefore, the protection of the main circuit and the starting performance of the vehicle can be improved with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a circuit diagram showing the structure of a power management system for a vehicle.

[0017] Figure 2 Graph showing the temporal change of the capacitor voltage based on the precharge control.

[0018] Figure 3 This is a flowchart showing the procedure of the cutoff control.

[0019] Figure 4 This is a flowchart showing the procedure of countdown control.

[0020] Figure 5 This is a flowchart showing the procedure of precharge control.

[0021] Figure 6 This is a flowchart showing the main control procedure.

[0022] Figure 7 This is a flowchart showing the procedure of the main control (modification example).

[0023] Figure 8 This is a flowchart showing the procedure of the first standby control.

[0024] Fig. 9 This is a flowchart showing the procedure of the second standby control.

[0025] Fig.10 This is a flowchart showing the procedure of the second standby control (variation).

[0026] Fig.11 This is a flowchart showing the procedure of the second standby control (variation).

[0027] Fig.12 This is a flowchart showing the procedure of the second standby control (variation).

[0028] Fig.13 This is a flowchart showing the procedure of the second standby control (variation).

[0029] Fig.14 This is a timing chart showing control in the case where the preliminary request disappears during the precharge control and the energization count at the time of completion of the precharge control is ten times.

[0030] Fig.15 This is a timing chart showing control in the case where the preliminary request disappears during the precharge control and the energization count at the time of completion of the precharge control is nine times. DETAILED DESCRIPTION

[0031] The power management system of the vehicle of the invention can be implemented as in the following embodiments. The power management system of this embodiment is applied to electric vehicles equipped with a motor and a battery for driving (for example, electric vehicles, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), etc.). The motor is, for example, an AC electric generator, which has both the function of consuming the power of the battery to drive the rotation of the wheels and the function of generating electricity by utilizing the inertial rotation of the wheels. In addition, a plug-in hybrid electric vehicle refers to a hybrid electric vehicle that can charge the battery externally or supply power to the outside from the battery. The plug-in hybrid electric vehicle is provided with a charging port (inlet) for inserting a charging cable for supplying power from an external charging device, and a socket (outlet) for external power supply.

[0032] (Example)

[0033] [1.Structure]

[0034] Figure 1 1 is a circuit diagram showing the structure of a power management system 1 for a vehicle as an embodiment. The power management system 1 is provided with a main circuit 3 for supplying power from a battery 2 mounted on the vehicle to two motors (a first motor 10 and a second motor 20). The battery 2 is, for example, a secondary battery such as a lithium-ion secondary battery, a nickel-hydrogen battery, or a fuel cell.

[0035] The first motor 10 is, for example, a front motor that drives the front wheels of the vehicle, and the second motor 20 is, for example, a rear motor that drives the rear wheels of the vehicle. In addition, one of the two motors 10 and 20 can be omitted. In addition, in a vehicle where the left and right wheels are controlled by separate motors, for example, the first motor 10 can be used as a right wheel motor, and the second motor 20 can be used as a left wheel motor. In a vehicle where all four wheels are controlled by separate motors, four motors can also be provided.

[0036] A first inverter 11 (front inverter) is connected to the first motor 10, and a second inverter 21 (rear inverter) is connected to the second motor 20. These inverters 11 and 21 are conversion devices that convert the DC power on the battery 2 side and the AC power on the motors 10 and 20 sides. A first inverter circuit 12 involved in DC-AC conversion and a first smoothing circuit 13 for voltage smoothing are provided inside the first inverter 11.

[0037] A plurality of switching elements (e.g., IGBT, MOSFET, etc.) are built into the first inverter circuit 12. Multi-phase AC power is generated from DC power by cutting off and connecting each switching element at a high frequency. The magnitude of the driving torque generated by the first motor 10 can be adjusted by changing the pulse width of the AC voltage output from the first inverter circuit 12. In addition, the first smoothing circuit 13 is a circuit connected in parallel with the first inverter circuit 12.

[0038] The first smoothing circuit 13 is provided with a first capacitor 14 as a storage element. The first capacitor 14 has a function of suppressing the pulsation of the DC voltage output from the battery 2. For example, when the output voltage of the battery 2 temporarily decreases, the voltage of the decrease is supplemented by the charge stored in the first capacitor 14. That is, the temporary change and noise component of the DC voltage introduced from the battery 2 to the first inverter circuit 12 are absorbed by the operation of the first capacitor 14. As a result, the voltage fluctuation input to the first inverter circuit 12 is stabilized, and the AC voltage generated by the first inverter 11 is stabilized.

[0039] The structure of the second inverter 21 is the same as that of the first inverter 11. A second inverter circuit 22 and a second smoothing circuit 23 are provided inside the second inverter 21. The second smoothing circuit 23 is connected in parallel with the second inverter circuit 22. In addition, a second capacitor 24 is installed in the second smoothing circuit 23. The main circuit 3 is connected to the first inverter circuit 12 and the battery 2 for controlling the frequency of the power supplied to the first motor 10, and is connected to the second inverter circuit 22 and the battery 2 for controlling the frequency of the power supplied to the second motor 20.

[0040] A P contactor 4 (positive side contactor) and an N contactor 5 (negative side contactor) are installed in the main circuit 3. They are main contactors for disconnecting the power-on state of the main circuit 3. The P contactor 4 is installed between the inverter circuit 12, 22 and the positive pole of the battery 2, and the N contactor 5 is installed between the inverter circuit 12, 22 and the negative pole of the battery 2. The disconnection and connection states of the P contactor 4 and the N contactor 5 are controlled by the control device 30 described later.

[0041] A precharge circuit 6 is connected in parallel to one of the main contactors 4 and 5. The precharge circuit 6 is a circuit for suppressing an inrush current when the main contactors 4 and 5 are connected. Figure 1 An example is shown in which the precharge circuit 6 is connected in parallel to the P contactor 4. A precharge contactor 7 and a precharge resistor 8 (precharge register) are installed in series in the precharge circuit 6. When the P contactor 4 and the N contactor 5 are connected by the control device 30, the precharge contactor 7 is controlled to be connected before the P contactor 4.

[0042] The control device 30 is a computer (electronic control unit, ECU, Electronic Control Unit) for controlling the disconnection and connection states of the P contactor 4, the N contactor 5, and the pre-charging contactor 7. The control device 30 has a built-in processor (processing device) and a memory (storage device). The content (control program) of the control implemented by the control device 30 is stored in the memory, and the processor reads its content appropriately for execution.

[0043] In addition to the information of the battery voltage and current, the control device 30 also receives the voltage information of the first capacitor 14 and the second capacitor 24. In addition, the control device 30 is connected to a power switch 31 and a brake sensor 32. The power switch 31 is a push-button switch for turning on and off the main power of the vehicle, and the brake sensor 32 is a sensor for detecting the depression of the brake pedal. The control device 30 uses the information related to the operation state of the power switch 31 and the information on the depression of the brake pedal to control the on and off state of the main power of the vehicle.

[0044] The power switch 31 may include a display device (light source, display, etc.) for visually displaying the state of the main power supply of the vehicle. For example, an LED (Light Emitting Diode) that turns off when the main power supply is turned off and turns on when the main power supply is turned on may be installed on the pressing surface of the power switch 31. In addition, the LED may be made to flash when the main power supply is in the process of switching from off to on (when the pre-charging contactor 7 is connected).

[0045] [2. Control]

[0046] The control device 30 of the present embodiment implements the shutoff control, the precharge control, the main control, the first standby control, and the second standby control. These controls are implemented exclusively.

[0047] The cut-off control is, for example, a control implemented when the main power supply of the vehicle is cut off, and is a control that maintains all contactors (P contactor 4, N contactor 5, pre-charge contactor 7) in a cut-off state. Even during the implementation of the cut-off control, the control device 30 is connected to the power of a low-voltage battery not shown. During the implementation of the cut-off control, when a preliminary request described later is received (when a preliminary request exists), the pre-charge control is implemented. In addition, the cut-off control can also be implemented in the determination of the pre-charge number X described later, when the pre-charge number X is less than the specified number.

[0048] The preparatory request is a signal or flag indicating that the occupant or an electronic control device other than the control device 30 requests "setting the main circuit 3 to a connected state". For example, when the power switch 31 is pressed while the brake pedal is depressed, the driver intends to turn on the main power of the vehicle and complete the preparation for driving the vehicle (requesting to turn on the main power of the vehicle), so the control device 30 determines that the "preparatory request (main circuit 3 connection request) (main circuit 3 connection request exists)" is received. In addition, when a charging gun for external charging is inserted into the inlet of the on-board charger (external charging is requested), when the air conditioner is operated when the main power of the vehicle is cut off (pre-air conditioning is instructed via wireless communication, when the scheduled time for pre-air conditioning is reached), the control device 30 also determines that the "preparatory request (main circuit 3 connection request) (main circuit 3 connection request exists)" is received and implements pre-charging control. The specific determination conditions for the presence or absence of the connection request of the main circuit 3 can apply known conditions.

[0049] The pre-charge control is a control to increase the voltage of the first capacitor 14 and the second capacitor 24 by maintaining the state of disconnecting the P contactor 4 and connecting the N contactor 5 and the pre-charge contactor 7 (control to charge the first capacitor 14 and the second capacitor 24). When the voltage of these capacitors 14 and 24 reaches the battery voltage, it is judged that the pre-charge is completed and the pre-charge control is ended, and the main control is implemented instead. In addition, even if the pre-charge requirement disappears during the implementation of the pre-charge control (before the pre-charge is completed), the pre-charge control will not be interrupted. That is, until the capacitor voltage reaches the battery voltage, the connection state of the pre-charge contactor 7 is maintained.

[0050] Figure 2 It is a graph showing the relationship between the battery voltage and the capacitor voltage during pre-charge control. When the pre-charge contactor 7 is connected at time A, the pre-charge of the capacitors 14 and 24 begins. As a result, the voltage of each capacitor rises and gradually approaches the battery voltage. Time B is the moment when the capacitor voltage reaches the battery voltage (the moment when the capacitor voltage becomes approximately equal to the battery voltage, and the difference between the capacitor voltage and the battery voltage becomes less than a specified small value). At the moment when the capacitor voltage of the two capacitors 14 and 24 reaches the battery voltage, the pre-charge of the capacitors 14 and 24 is completed.

[0051] During pre-charging control, when the pre-charging contactor 7 is connected and the power supply to the pre-charging resistor 8 is confirmed, the control device 30 performs an operation of adding 1 (increment) to the value of the pre-charging number X. The pre-charging number X is a variable that represents the number of times the pre-charging resistor 8 is powered (or the number of successful connections of the pre-charging contactor 7) within the most recent prescribed period (for example, about 50 to 300 seconds) based on the current time. When implementing controls other than pre-charging control, the value of the pre-charging number X is reduced by 1 (decremented) every time the above-mentioned prescribed period is performed. Therefore, the value of the pre-charging number X increases in the case where the power supply to the pre-charging resistor 8 is repeatedly disconnected and connected in a short period of time, and then slowly decreases after a long time. In addition, for example, in the case where the power supply to the pre-charging resistor 8 is disconnected and connected at a low frequency of about once within a prescribed period, it hardly increases.

[0052] The value of the precharge number X roughly corresponds to the temperature of the precharge resistor 8 and the precharge contactor 7. For example, the larger the value of the precharge number X, the higher the possibility that the temperature of the precharge resistor 8 and the precharge contactor 7 will become high, and the smaller the value of the precharge number X, the higher the possibility that the temperature of the precharge resistor 8 and the precharge contactor 7 will become low. The above-mentioned prescribed period is set by considering, for example, the ease of heat generation (temperature rise rate) of the precharge resistor 8 and the precharge contactor 7 when energized, the ease of heat cooling (temperature drop rate) when not energized, and heat capacity.

[0053] In this embodiment, only when a pre-charge request is received at the time of pre-charge completion, the main control is transferred from the pre-charge control. On the other hand, when there is no pre-charge request at the time of pre-charge completion (that is, when the pre-charge request disappears during the implementation of the pre-charge control, and the capacitor voltage reaches the battery voltage), the number of energization times of the pre-charge resistor 8 (pre-charge number X) is determined, and any one of the first standby control, the second standby control, and the cut-off control is implemented according to the pre-charge number X.

[0054] The main control is a control that maintains the state in which the pre-charging contactor 7 is disconnected, connects the P contactor 4 and the N contactor 5, and supplies power to the inverters 11 and 21. The state in which the main control is implemented is equivalent to the state in which the main circuit 3 is connected (for example, the state in which the preparation for the vehicle to travel is completed), and is a state in which the preparatory requirement is achieved. Therefore, as long as the preparatory requirement exists, the main control is continued. Another invention is that when the preparatory requirement disappears during the implementation of the main control, any one of the first standby control, the second standby control, and the cut-off control is implemented. At this time, any one of the first standby control, the second standby control, and the cut-off control can be selected in consideration of the number of pre-charging times X.

[0055] The first standby control is a control implemented when the pre-charge number X is more than the specified number (for example, 10 times) in the determination of the pre-charge number X. In the first standby control, the P contactor 4 and the N contactor 5 are connected, the pre-charge contactor 7 is disconnected, and the connection state of the P contactor 4 and the N contactor 5 is maintained until the pre-charge number X becomes less than the specified number. That is, the first standby control is to delay the disconnection of the power-on state (maintain the state of the main contactors 4 and 5 connected and cool the pre-charge resistor 8) in the case of receiving a preparatory request again after the start of the first standby control, so as to be able to immediately return to the main control. After the pre-charge number X becomes less than the specified number, the disconnection control can be implemented, and the second standby control can also be implemented. In addition, when the pre-charge request is received again during the implementation of the first standby control, the main control is implemented.

[0056] The second standby control is a control implemented when the pre-charging number X is less than a predetermined number (e.g., 1 to 9 times) in the determination of the pre-charging number X. In the second standby control, the connection state of the N contactor 5 and the connection state of the P contactor 4 or the pre-charging contactor 7 are maintained until the predetermined standby time has passed. In other words, the connection state of the main contactors 4 and 5 is maintained, or the connection state of the N contactor 5 and the pre-charging contactor 7 is maintained until the standby time has passed.

[0057] The standby time determined here is a time that can be set arbitrarily (for example, several seconds to tens of seconds) without depending on the above-mentioned prescribed period. That is, the second standby control is a control that further delays the disconnection of the power-on state (maintains the power-on state to prevent the possibility of receiving a preparatory request again). In addition, when a preparatory request is received again during the implementation of the second standby control, the main control is implemented. In addition, when the second standby control can be substantially omitted, the disconnection control can also be implemented just after confirming that there is no preparatory request.

[0058] As a method for delaying the disconnection of the power-on state in the second standby control, the following three methods can be listed. The first method is to set the P contactor 4 and the N contactor 5 to be turned on, and to set them to be disconnected after the standby time. According to this method, the pre-charging contactor 7 can be cooled and the disconnection of the power-on state can be delayed. The second method is to set the pre-charging contactor 7 and the N contactor 5 to be turned on, and to set them to be disconnected after the standby time. According to this method, the consumption and deterioration of the P contactor 4 can be suppressed and the disconnection of the power-on state can be delayed.

[0059] The third method is a method of initially setting the pre-charge contactor 7 and the N contactor 5 to be turned on, then setting the P contactor 4 and the N contactor 5 to be turned on, and then setting them to be turned off after the standby time is added up. This method is a combination of the first method and the second method. Here, the time when the pre-charge contactor 7 and the N contactor 5 are initially turned on is used as the first standby time, and the time when the P contactor 4 and the N contactor 5 are then turned on is used as the second standby time. Each time is set so that their total is equal to the standby time.

[0060] [3. Flowchart]

[0061] Figure 3 This is a flowchart showing the procedure of the cutoff control.

[0062] In step A1, the P contactor 4, the N contactor 5, and the pre-charge contactor 7 are all disconnected. At this time, if any of the contactors 4, 5, and 7 are connected, the connected state is switched to the disconnected state. In addition, when all the contactors 4, 5, and 7 have been disconnected, the disconnected state is maintained. In addition, there may be a delay in the timing of disconnecting each contactor 4, 5, and 7.

[0063] Next, in step A2, it is determined whether there is a preparatory request. Here, if it is determined that there is a preparatory request, the cut-off control is terminated and the pre-charge control is started. On the other hand, if it is determined in step A2 that there is no preparatory request, the process proceeds to step A3 and the countdown control is executed. The countdown control is a sub-process for timing the above-mentioned prescribed period and subtracting (decreasing) the number of pre-charges X. After the countdown control is executed, the cut-off control in the control cycle ends. In the next control cycle, the cut-off control is continued and step A1 is executed again.

[0064] Figure 4 It is a flowchart showing the sequence of countdown control (sub-process). In this sub-process, an operation is performed to reduce the value of the pre-charge number X by 1 every time a specified period has passed. The variable Z in the process is a variable used to measure the specified period, and its initial value is 0. In this process, the time when the value of the variable Z is counted to 100 (the sub-process is executed 100 times) is equivalent to the time of the specified period. In addition, the count value of the variable Z can be a variable value corresponding to the pre-charge number X. That is, the specified period for reducing the value of the pre-charge number X one by one can be given as a function of the pre-charge number X.

[0065] In step B1, determine whether the number of pre-charge times X is greater than 1. If this condition is met, proceed to step B2. On the other hand, if the condition of step B1 is not met (if the number of pre-charge times X is 0), skip steps B2 to B5 and end the sub-routine. In step B2, perform an operation of adding 1 (increment) to the value of variable Z. Then, in step B3, determine whether the value of variable Z is 100. If this condition is met, proceed to step B4 and perform an operation of subtracting 1 (decrement) from the value of the number of pre-charge times X. In addition, in step B5, the value of variable Z is reset to 0. If the condition of step B3 is not met, skip steps B4 to B5 and end the sub-routine.

[0066] Figure 5 This is a flowchart showing the procedure of precharge control.

[0067] In step C1, the P contactor 4 is set to be disconnected, and the N contactor 5 and the pre-charge contactor 7 are set to be connected. Then in step C2, it is determined whether the pre-charge resistor 8 is energized. Until this condition is met, step C1 is repeated. When the condition of step C2 is met, step C3 is entered, and 1 is added to the value of the pre-charge number X.

[0068] In step C4, it is determined whether the capacitor voltage reaches the battery voltage. Step C4 is repeated until the condition is met. Here, for example, even if the preparatory request disappears before the capacitor voltage reaches the battery voltage, the connection state of the pre-charge contactor 7 is maintained until the capacitor voltage reaches the battery voltage. When the condition of step C4 is met, step C5 is entered.

[0069] In step C5, it is determined whether there is a preliminary request. Here, in the case of a preliminary request, the pre-charge control is terminated and the main control is started. On the other hand, in the case of no preliminary request, step C6 is entered. In step C6, it is determined whether the value of the pre-charge number X is greater than 10 (above the prescribed number of times). If this condition is met, the pre-charge control is terminated and the first standby control is started. In addition, if this condition is not met, the pre-charge control is terminated and the cut-off control or the second standby control is started.

[0070] Figure 6 , Figure 7 This is a flowchart showing the main control procedure. Figure 6 This is a flowchart for the case where the cutoff control is started immediately when the preparatory request disappears during the implementation of the main control. Figure 7 A control as a modified example is shown. Figure 7 This is a flowchart for the case where the first standby control and the second standby control are executed according to the value of the precharge count X when the preliminary request disappears during the execution of the main control.

[0071] exist Figure 6 In step D1, the P contactor 4 and the N contactor 5 are set to be turned on, and the pre-charging contactor 7 is set to be cut off. In addition, in step D2, countdown control is performed. Then in step D3, it is determined whether there is a preparatory request. Here, if there is a preparatory request, the main control in this control cycle is ended. In the next control cycle, the main control is continued and step D1 is performed again. On the other hand, if there is no preparatory request, the main control is ended and the cut-off control is started.

[0072] Figure 7 Steps E1 to E3 and Figure 6 The steps D1 to D3 are roughly the same. In step E3, if there is no preparatory request, the process proceeds to step E4 to determine whether the value of the pre-charge times X is greater than 10 (above the prescribed times). If this condition is met, the main control is terminated and the first standby control is started. In addition, if this condition is not met, the main control is terminated and the cut-off control or the second standby control is started.

[0073] Figure 8It is a flowchart showing the sequence of the first standby control. The first standby control is implemented at least when there is no preliminary request and the value of the pre-charge number X is greater than 10 (more than the specified number of times). In step F1, the P contactor 4 and the N contactor 5 are set to be on, and the pre-charge contactor 7 is set to be disconnected. In addition, in step F2, countdown control is performed. Then in step F3, it is determined whether there is a preliminary request. Here, in the case of a preliminary request, the first standby control is ended and the main control is started. At this time, the value of the pre-charge number X and the value of the variable Z are directly inherited. Therefore, in the main control, the countdown control is also continued.

[0074] In step F3, if there is no preparatory request, the process proceeds to step F4 to determine whether the value of the pre-charge times X is greater than 10 (or greater than the specified times). If this condition is met, the first standby control in the control cycle is terminated. In the next control cycle, the first standby control is continued and step F1 is executed again. On the other hand, if the condition of step F4 is not met, the first standby control is terminated and the cut-off control or the second standby control is started.

[0075] Figures 9 to 13 2 is a flowchart showing the procedure of the second standby control. The second standby control is performed when at least there is no preliminary request and the value of the pre-charging number X is less than 10 (less than a predetermined number, 1 to 9 times). Fig. 9 , Fig.10 This is a flow chart for maintaining the connection state of the P contactor 4 and the N contactor 5. Fig.11 , Fig.12 This is a flowchart when the connection state between the N contactor 5 and the pre-charging contactor 7 is maintained. Fig.13 This is a flowchart in the case where the N contactor 5 and the pre-charging contactor 7 are connected first, and then the P contactor 4 and the N contactor 5 are connected.

[0076] exist Fig. 9 In step G1, the P contactor 4 and the N contactor 5 are set to be turned on, and the pre-charging contactor 7 is set to be cut off. In addition, in step G2, countdown control is performed. Then in step G3, it is determined whether there is a preparatory request. Here, in the case of a preparatory request, the second standby control is ended and the main control is started. At this time, the value of the pre-charging number X and the value of the variable Z are directly inherited. Therefore, in the main control, the countdown control is also continued. On the other hand, in step G3, in the case of no preparatory request, the second standby control is ended and the cut-off control is started.

[0077] Fig.10 Steps H1 to H3 and Fig. 9The steps G1 to G3 are substantially the same. In the case where there is no preparatory request in step H3, the process proceeds to step H4 to determine whether the standby time has passed since the start of the second standby control. Here, if the standby time has passed, the second standby control is terminated and the cut-off control is started. On the other hand, if the standby time has not passed, the process proceeds to step H2. Thus, as long as no preparatory request is received, the second standby control is continued until the standby time has passed.

[0078] exist Fig.11 In step J1, the N contactor 5 and the pre-charge contactor 7 are set to be turned on, and the P contactor 4 is set to be cut off. In addition, in step J2, countdown control is performed. Then in step J3, it is determined whether there is a preparatory request. Here, in the case of a preparatory request, the second standby control is ended and the main control is started. On the other hand, in step J3, in the case of no preparatory request, the second standby control is ended and the cut-off control is started.

[0079] Fig.12 Steps K1 to K3 and Fig.11 The steps J1 to J3 of the second standby control are substantially the same. In the case where there is no preparatory request in step K3, the process proceeds to step K4 to determine whether the standby time has passed since the start of the second standby control. Here, if the standby time has passed, the second standby control is terminated and the cut-off control is started. On the other hand, if the standby time has not passed, the process proceeds to step K2. Thus, as long as no preparatory request is received, the second standby control is continued until the standby time has passed.

[0080] Fig.13 Steps L1 to L3 and Fig.12 Steps K1 to K3 are roughly the same. If there is no preparatory request in step L3, the process proceeds to step L4 to determine whether the first standby time has passed since the start of the second standby control. Here, if the first standby time has not passed, the process proceeds to step L2 and the state of step L1 is maintained. In addition, if the first standby time has passed, the process proceeds to step L5.

[0081] In step L5, the P contactor 4 and the N contactor 5 are set to be turned on, and the pre-charging contactor 7 is set to be cut off. In addition, in step L6, countdown control is performed. Then in step L7, it is determined whether there is a preparatory request. Here, when there is a preparatory request, the second standby control is ended and the main control is started. On the other hand, in step L7, if there is no preparatory request, step L8 is entered to determine whether the second standby time has passed since the state of step L5 was reached. In other words, in step L8, it is determined whether the standby time (the total time of the first standby time and the second standby time) has passed since the start of the second standby control. If the condition of step L8 is met, the second standby control is ended and the cut-off control is started. On the other hand, if the condition of step L8 is not met, step L6 is entered. Thus, as long as no preparatory request is received, the second standby control is continued.

[0082] [4. Function]

[0083] Fig.14 1 is a timing chart showing a control state when the preliminary request disappears during the precharge control. Here, an example is shown in which the number of precharges X is 10 when the precharge control is completed.

[0084] Before time t1, the cut-off control is implemented, and the high voltage sequence (power-on state of the main circuit 3) is "none". At time t1, for example, when the driver of the vehicle steps on the brake pedal and presses the power switch 31, a preparatory request is generated. Upon receiving the preparatory request, the control device 30 ends the cut-off control and starts the pre-charge control. As a result, the high voltage sequence becomes "pre-charge (implementation state of pre-charge control)".

[0085] On the other hand, at time t2, when the driver mistakenly removes his foot from the brake pedal, the preparatory request disappears. However, the control device 30 does not interrupt the pre-charge control, but maintains the connection state of the pre-charge contactor 7 until the capacitor voltage reaches the battery voltage. Therefore, when the power supply to the pre-charge resistor 8 is confirmed at time t3, and when the pre-charge number X is added at time t4, the connection state of the pre-charge contactor 7 is maintained. In addition, assuming that the pre-charge control is interrupted just after the pre-charge request disappears, the control may be cut off before the time when the pre-charge number X is added (time t4), so that the value of the pre-charge number X may become incorrect. For such a problem, in this embodiment, since the pre-charge control will not be interrupted, the calculation of the value of the pre-charge number X becomes correct.

[0086] When the capacitor voltage reaches the battery voltage at time t5 and the charging of the capacitors 14 and 24 is completed, the value of the pre-charge number X corresponding to the number of times the pre-charge resistor 8 is energized is determined. Here, if the pre-charge number X is 10 times (above the specified number of times), the control device 30 implements the first standby control instead of the pre-charge control. As a result, the high voltage sequence after time t5 becomes "main (implementation state of main control)". In addition, assuming that the pre-charge control is interrupted just after the preliminary request disappears, the moment when the value of the pre-charge number X is added (time t4) may coincide with the moment when the cut-off control is started. In this case, it is a preferred state to prohibit the energization of the main circuit 3 until the pre-charge number X becomes less than the specified number, and the vehicle's startability is greatly lost. For such a problem, in this embodiment, the first standby control is implemented after the pre-charge control, thereby eliminating the issues related to the startability.

[0087] Afterwards, when the value of the pre-charge times X is reduced from 10 to 9 at time t6, the control device 30 implements, for example, a cut-off control instead of the first standby control. Even if a preparatory request is generated after time t6, since the value of the pre-charge times X is already less than the prescribed number of times, it is not necessary to prohibit the power supply to the main circuit 3, and good starting performance can be obtained. In addition, since the charging of the capacitors 14 and 24 is completed at time t5, even if the pre-charge control is implemented again after time t6, the pre-charge is completed in a very short time. In this sense, the protection of the power supply circuit and the starting performance of the vehicle are also greatly improved. In addition, after time t6, the second standby control can be implemented instead of the cut-off control.

[0088] Fig.15 t5 is a timing diagram showing the control state when the pre-charge request disappears during the pre-charge control. Here, an example is shown in which the number of pre-charges X is 9 when the pre-charge control is completed. The control content before time t5 is the same as Fig.14 When the capacitor voltage reaches the battery voltage at time t5, the value of the pre-charge number X is determined. Here, if the pre-charge number X is 9 times (less than the specified number), the control device 30 implements the second standby control instead of the pre-charge control.

[0089] As the high voltage sequence at time t5 to t8 in the second standby control, three sequences are illustrated. The solid line and the case where the P contactor 4 and the N contactor 5 are set to be turned on ( Fig. 9 , Fig.10 The dotted line corresponds to the case where the pre-charge contactor 7 and the N contactor 5 are set to be turned on ( Fig.11 , Fig.12 In addition, the single-dot chain line corresponds to the case where the pre-charge contactor 7 and the N contactor 5 are first turned on, and then the P contactor 4 and the N contactor 5 are turned on ( Fig.13The standby time of the second standby control corresponds to the time from time t5 to time t8. In addition, the first standby time corresponds to the time from time t5 to time t7, and the second standby time corresponds to the time from time t7 to time t8.

[0090] In this way, by implementing the second standby control, the starting performance when a new preparatory request is generated is greatly improved. For example, if the high voltage sequence is maintained as "main", there is no need to implement pre-charge control for the new preparatory request, and the cooling of the pre-charge resistor 8 can also be expected. On the other hand, if the high voltage sequence is maintained as "pre-charge", the number of times the P contactor 4 is driven can be suppressed, and the pre-charge control can be completed in a very short time, thereby further improving the protection of the power circuit and the starting performance of the vehicle.

[0091] [5. Effect]

[0092] (1) The above-mentioned vehicle power management system 1 includes main contactors 4 and 5 installed in a main circuit 3 connected to an inverter circuit 12 and 22 for controlling the frequency of power supplied to motors 10 and 20 and a battery 2. In addition, the power management system 1 includes a pre-charge contactor 7 and a pre-charge resistor 8 installed in a pre-charge circuit 6 connected in parallel with the main contactor 4, and capacitors 14 and 24 installed in smoothing circuits 13 and 23 connected in parallel with the inverter circuits 12 and 22.

[0093] In addition, the power management system 1 includes a control device 30, which implements pre-charge control and main control, wherein the pre-charge control connects the pre-charge contactor 7 to increase the voltage of the capacitors 14 and 24 by receiving a preliminary request, and the main control connects the main contactors 4 and 5 and disconnects the pre-charge contactor 7 after the voltage of the capacitors 14 and 24 reaches the voltage of the battery 2. Even if the preliminary request disappears during the implementation of the pre-charge control, the control device 30 maintains the connection state of the pre-charge contactor 7 until the voltage of the capacitors 14 and 24 reaches the voltage of the battery 2.

[0094] According to the above structure, even if the preparatory requirement disappears during the implementation of the pre-charging control, the connection state of the pre-charging contactor 7 is maintained until the pre-charging is completed. Thus, in the case where the preparatory requirement is received again during the period until the pre-charging is completed, the main control can be implemented without setting the power-on state of the main circuit 3 to be cut off after the pre-charging is completed. In particular, in the case where the disappearance of the preparatory requirement is caused by the driver's misoperation or carelessness, the pre-charging control will not be interrupted and is therefore easy to recover. Therefore, the protection of the main circuit 3 (power supply circuit) and the starting performance of the vehicle can be improved by a simple structure.

[0095] In addition, when the preparatory request disappears during the implementation of the pre-charging control, even if the preparatory request is not received again until the pre-charging is completed and the energization state of the main circuit 3 is cut off, the time required for the subsequent pre-charging control (the time required to increase the capacitor voltage) can be shortened. Therefore, the protection of the main circuit 3 and the startability of the vehicle can be improved with a simple structure.

[0096] (2) In the above-mentioned power management system 1, the pre-charging number X (number of power-on times) is determined before the pre-charging is about to be completed. That is, when the preparatory requirement disappears during the implementation of the pre-charging control and the voltage of the capacitors 14 and 24 reaches the voltage of the battery 2, the control device 30 determines the number of power-on times of the pre-charging resistor 8 within the most recent specified period in the past based on the current moment. When the number of power-on times is more than the specified number (for example, 10 times), the first standby control is implemented. The first standby control is a control that connects the main contactors 4 and 5 and disconnects the pre-charging contactor 7 to maintain the connection state of the main contactors 4 and 5.

[0097] Thus, when the number of pre-charging times X is large, by delaying the disconnection of the energized state in the main circuit 3 and disconnecting the pre-charging contactor 7, the pre-charging resistor 8 can be cooled while maintaining the energized state of the main circuit 3. Therefore, the protection of the pre-charging resistor 8 can be improved, and the starting performance of the vehicle can be improved.

[0098] (3) The control device 30 described above can implement cut-off control when the number of times the pre-charging resistor 8 is energized is less than a specified number of times (for example, 1 to 9 times). Cut-off control is a control that cuts off the main contactors 4, 5 and the pre-charging contactor 7. By implementing the cut-off control, the operating time of the main contactors 4, 5 and the pre-charging contactor 7 can be shortened, and consumption and degradation can be suppressed. In addition, waste of power of the battery 2 can be prevented. Moreover, when a preliminary request is received again, the pre-charging control can be implemented immediately, which can improve the protection of the main circuit 3 and the starting performance of the vehicle.

[0099] (4) The control device 30 described above can implement the second standby control when the number of times the pre-charge resistor 8 is energized is less than a specified number of times (for example, 1 to 9 times). The second standby control is a control to maintain the connection state of the main contactor 4, 5 or the pre-charge contactor 7 until the standby time has passed. In other words, it is a control to maintain the high voltage sequence as "main" or "pre-charge". By implementing the second standby control, there is no need to implement the pre-charge control again when a new preparatory request is generated, so the starting performance of the vehicle can be greatly improved.

[0100] (5) In the above-mentioned second standby control, the main contactors 4 and 5 may be kept connected to each other. Fig.15The main contactors 4 and 5 are disconnected when the standby time has passed (the solid line of time t5 to t8 in FIG). In this way, if the main contactors 4 and 5 are kept connected just after the pre-charge control, when a new preparatory request is generated after time t5, there is no need to change the high voltage sequence or implement the pre-charge control. Therefore, the starting performance of the vehicle can be greatly improved. In addition, the pre-charge resistor 8 can be cooled during the second standby control.

[0101] (6) In the above-mentioned second standby control, the pre-charging contactor 7 may be kept connected to the standby state. Fig.15 The pre-charging contactor 7 is disconnected when the standby time has passed (the dashed line at time t5 to t8 in FIG). In this way, if the connection state of the pre-charging contactor 7 is maintained just after the pre-charging control is performed, at least the number of times the P contactor 4 is driven can be suppressed, and the consumption and degradation of the P contactor 4 can be suppressed. In addition, the pre-charging control can be completed in a very short time, which can greatly improve the protection of the main circuit 3 and the starting performance of the vehicle.

[0102] (7) In the above-mentioned second standby control, the pre-charging contactor 7 can be kept connected during the initial first standby time, and the pre-charging contactor 7 can be disconnected during the subsequent second standby time while the main contactors 4 and 5 are kept connected ( Fig.15 By such control, the startability of the vehicle can be greatly improved, the consumption and degradation of the P contactor 4 can be suppressed to some extent, and the cooling of the pre-charging resistor 8 can be promoted.

[0103] [6. Others]

[0104] The above-mentioned embodiments are merely examples and are not intended to exclude the application of various modifications and technologies not explicitly stated in the present embodiments. The various structures of the present embodiments can be implemented in various modifications within the scope of their main purpose. In addition, the various structures of the present embodiments can be selected as needed, or can be appropriately combined.

[0105] For example, in the above-mentioned embodiment, the circuit structure in which the pre-charging circuit 6 is connected in parallel with the P contactor 4 is illustrated, but the pre-charging circuit 6 may be connected in parallel with the N contactor 5, or the pre-charging circuit 6 may be provided for each of the plurality of main contactors. In addition, the main contactor for disconnecting and connecting the circuit on the second motor 20 side may be provided separately from the main contactor for disconnecting and connecting the circuit on the first motor 10 side. By implementing the control of maintaining the connection state of the pre-charging contactor 7 until the capacitor voltage reaches the battery voltage when the preparatory requirement disappears during the implementation of the pre-charging control regardless of the specific circuit structure, the same effect as the above-mentioned embodiment can be achieved.

[0106] In addition, in the above-mentioned embodiment, an example is given of a control structure in which the pre-charging number X is determined before the pre-charging is about to be completed, and the first standby control is implemented when the number of power-on times is more than the specified number. However, the first standby control can be omitted. Similarly, the second standby control can also be omitted. By continuing the pre-charging control even when the preparatory requirement disappears at least during the implementation of the pre-charging control, the protection of the power supply circuit (main circuit 3) and the startability of the vehicle can be improved.

[0107] In addition, in the above-mentioned embodiment, the pre-charging control is implemented when a request for the vehicle's main power supply to be turned on is received, but the pre-charging control may be implemented when a request for the main circuit 3 to be connected is received, such as when a charging gun for external charging is inserted into the inlet of the on-board charger. Alternatively, the pre-charging control may be implemented when a request for the main circuit 3 to be connected is received in order to operate the air conditioner when the vehicle's main power supply is turned off.

[0108] Possibility of industrial application

[0109] The present invention can be utilized in the manufacturing industry of a power management system applied to a vehicle, and can also be utilized in the manufacturing industry of a vehicle equipped with the power management system.

[0110] Explanation of symbols

[0111] 1 Power Management System

[0112] 2 Batteries

[0113] 3 Main circuit

[0114] 4P contactor (main contactor)

[0115] 5N contactor (main contactor)

[0116] 6 Pre-charge circuit

[0117] 7 Pre-charging contactor

[0118] 8 Pre-charge resistor

[0119] 10 First Motor

[0120] 11 First Inverter

[0121] 12. First inverter circuit

[0122] 13. First smoothing circuit

[0123] 14 First capacitor

[0124] 20 Second motor

[0125] 21 Second inverter

[0126] 22 Second inverter circuit

[0127] 23 Second smoothing circuit

[0128] 24 Second capacitor

[0129] 30 Control device

[0130] 31 Power switch

[0131] 32 Brake sensor

[0132] X pre-charge times (power-on times).

Claims

1. A power management system for a vehicle, characterized in that: have: a main contactor mounted on a main circuit connected to an inverter circuit and a battery for controlling the frequency of electric power supplied to the motor; A pre-charging contactor and a pre-charging resistor, the pre-charging contactor and the pre-charging resistor are installed in a pre-charging circuit, and the pre-charging circuit is connected in parallel with respect to the main contactor; a capacitor mounted on a smoothing circuit connected in parallel with the inverter circuit; as well as a control device that implements pre-charge control and main control, wherein the pre-charge control connects the pre-charge contactor to increase the voltage of the capacitor by receiving a preliminary request indicating a connection request of the main circuit, and the main control connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery, Even when the preliminary request disappears during the execution of the pre-charge control, the control device maintains the connection state of the pre-charge contactor until the voltage of the capacitor reaches the voltage of the battery.

2. The vehicle power management system according to claim 1, characterized in that: When the preliminary request disappears during the implementation of the pre-charge control and the voltage of the capacitor reaches the voltage of the battery, the control device determines the number of times the pre-charge resistor is energized within a prescribed period in the most recent past based on the current time. When the number of power-ons is greater than a specified number, the control device implements a first standby control, which connects the main contactor and disconnects the pre-charging contactor, and maintains the connection state of the main contactor until the number of power-ons in the most recent specified period in the past based on the current moment is less than the specified number.

3. The vehicle power management system according to claim 2, characterized in that: When determining the number of power-on times, the control device When the number of energizations is less than the predetermined number of times, a cutoff control is performed to cut off the main contactor and the pre-charging contactor.

4. The vehicle power management system according to claim 2, characterized in that: When determining the number of power-on times, the control device When the number of energizations is less than the predetermined number of times, a second standby control is implemented, the second standby control maintaining the connection state of the main contactor or the pre-charging contactor until a standby time elapses.

5. The vehicle power management system according to claim 4, characterized in that: When performing the second standby control, the control device stands by while maintaining the connected state of the main contactor, and disconnects the main contactor when the standby time has elapsed.

6. The vehicle power management system according to claim 4, characterized in that: The control device stands by while maintaining the connection state of the pre-charging contactor when performing the second standby control, and disconnects the pre-charging contactor when the standby time has elapsed.

7. The vehicle power management system according to claim 4, characterized in that: The standby time is equal to the sum of the first standby time and the second standby time, When performing the second standby control, the control device stands by while maintaining the connection state of the pre-charging contactor, disconnects the pre-charging contactor and connects the main contactor when the first standby time has passed, and then disconnects the main contactor when the second standby time has passed.

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