JP5450238B2 - Electric vehicle - Google Patents

Description

  The present invention relates to an electric vehicle including an engine and a generator motor as a power generation source of the vehicle.

  In an electric vehicle (so-called hybrid vehicle) provided with an engine and a generator motor (an electric motor capable of selectively performing a power running operation and a power generation operation) as a power generation source for generating propulsion power for the vehicle, the generator motor is used as the vehicle propulsion force. In a situation where the power of the generator is required, power is supplied to the generator motor from the power storage device as its power source, thereby performing a power running operation of the generator motor (operating the generator motor as an electric motor that outputs driving force).

  In situations where the power of the generator motor is not required, the generator operation (regenerative operation) is performed by appropriately operating the generator motor as a generator that outputs electric energy using the output of the engine or the kinetic energy at the time of deceleration of the vehicle. In general, charging or the like of the power storage device is performed by operation.

  For example, Patent Document 1 describes a technique for charging a power storage device while performing a power generation operation (regeneration operation) of a generator motor when a vehicle is decelerated. In this technique, in order to prevent overcharging of the power storage device, the limit value of the charging power of the power storage device is set according to the temperature and remaining capacity of the power storage device. Then, a torque command value of the generator motor (braking torque command value during power generation operation) is set so that the measured value of the charging power of the power storage device does not exceed the limit value, and the generator motor is set according to this torque command value. The operation control is performed.

JP 2005-51847 A

  By the way, since the generator motor that generates power for vehicle propulsion needs to generate a large torque during powering operation, the power storage device that supplies power to the generator motor outputs a high voltage (for example, 100 to 150 V). This is a high-voltage power storage device. In addition, various low-voltage auxiliary electrical components having a lower operating voltage than a generator motor and low-voltage power storage devices that output a low voltage (for example, 12 V) as a power source for these low-voltage auxiliary electrical components The low-voltage power storage device and the low-voltage auxiliary electrical equipment are electrically connected to the high-voltage power storage device via a DC / DC converter so that power can be supplied from the high-voltage power storage device or the generator motor. Connected.

  For example, a state in which power transmission from the engine and the generator motor to the drive wheels of the vehicle is interrupted (for example, the state of the transmission that performs power transmission between the engine and the generator motor and the drive wheels is the parking range. In order to prevent the stored energy of the low-voltage power storage device from being consumed by the low-voltage auxiliary electrical equipment in the neutral range state) In general, the generator motor is driven by the output of the engine, and the generated power is supplied from the generator motor to the low-voltage power storage device or the low-voltage auxiliary electrical equipment via the DC / DC converter. Yes. In this case, for example, the torque command value of the generator motor is set so as to generate the required generated power to supplement the power consumption of the low-voltage auxiliary machine electrical components, and the operation of the generator motor is performed according to the torque command value. By performing the control, it is possible to prevent the storage energy of the low-voltage power storage device from being consumed.

  On the other hand, a high-voltage power storage device such as a lithium ion battery generally has a lower allowable current that can be passed through the high-voltage power storage device in a low-temperature environment. In particular, since the internal resistance of the high-voltage power storage device increases in a low-temperature environment, if the remaining capacity of the high-voltage power storage device is relatively high, if a charging current is passed through the high-voltage power storage device, Even if the current is a relatively small current, the output voltage (inter-terminal voltage) of the high-voltage power storage device may become excessive so as to exceed the allowable upper limit value.

  On the other hand, while the engine is idling as described above and the generator motor is generating power by the output of the engine, for example, the generated power generated by the generator motor is reduced to the power consumption of the low-voltage auxiliary equipment components. If the control is performed so as to match, the high-voltage power storage device can be prevented from being charged.

  However, in a situation where the engine is idling, the engine may be emptied by operating the accelerator pedal by the driver of the vehicle. And in such a case, it became clear by various experiment and examination by this inventor that the following inconvenience arises.

  That is, when the engine is blown away, the engine speed (output shaft rotation speed) increases rapidly, and consequently the rotor speed of the generator motor also increases rapidly. In this case, even if the generated power of the generator motor is controlled to the target power, the rotational speed of the rotor rises rapidly, and therefore the energization control of the generator motor is delayed with respect to the change in the rotational speed. . As a result, the actual power output of the generator motor becomes higher than the target power output, and the surplus power output is charged in the high-voltage power storage device.

  Therefore, particularly when the remaining capacity of the high-voltage power storage device is relatively high in a low-temperature environment and the engine is blown, the high-voltage power storage device is generated by the surplus of the power generation output of the generator motor. Excessive charging, the output voltage of the high-voltage power storage device may exceed the allowable upper limit value, or the high-voltage power storage device may be deteriorated.

  SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and a high-voltage power storage device is used even when an engine is blown up in a situation where a generator motor is generating a power while an engine is idling. An object of the present invention is to provide an electric vehicle that can prevent excessive charging.

In order to achieve the above object, an electric vehicle according to the present invention includes an engine and a generator motor having a rotor that rotates in conjunction with the output shaft of the engine, and the vehicle includes at least one of the engine and the generator motor. A power generation source for generating the propulsion power of the generator, and supplying electric power to the generator motor during powering operation of the generator motor, and electrically charging the generator motor so that the generated power can be charged during power generation operation of the generator motor A high-voltage power storage device connected to the high-voltage power storage device, and a power supply to the low-voltage power storage device electrically connected to the high-voltage power storage device via a DC / DC converter and operating at a voltage lower than the output voltage of the high-voltage power storage device The engine idle state in a state where power transmission from the power generation source to the wheels of the vehicle is cut off as an operating state of the vehicle In the rotating state, while controlling the output torque of the generator motor so that the generated power supplementing at least the power consumption of the low-voltage electric load is generated by the power generation operation of the generator motor driven by the engine, the power generation In an electric vehicle having an idle power generation operation state in which electric power is supplied to the low-voltage power storage device or the low-voltage auxiliary electrical equipment via the DC / DC converter,
In the idle power generation operation state, an emptying detection means for detecting occurrence of an emptying of the engine,
In the idle power generation operation state, it is a predetermined condition that is predetermined as a necessary condition for protecting the high-voltage power storage device, and that the engine idling detection means detects the engine idling. Condition determining means for determining whether or not a predetermined condition including at least the first condition is satisfied;
Generator motor control means for controlling the output torque of the generator motor by limiting the torque command value, which is the command value of the output torque of the generator motor, to zero torque when the judgment result of the condition judging means is affirmative (First invention).

  According to the first aspect of the present invention, when the determination result of the condition determination means is affirmative in the idle power generation operation state, that is, the engine is blown over, and as a result, the generator motor When the generated electric power of the high-voltage power storage device becomes excessive and the output voltage of the high-voltage power storage device tends to increase, the generator motor control means sets the torque command value of the generator motor to zero torque ( The output torque of the generator motor is controlled by restricting the output torque value of the generator motor to a command value “0”. For this reason, in such a situation, the generated power of the generator motor can be quickly set to “0” to prevent an excessive charging current from flowing through the high-voltage power storage device.

  Therefore, according to the first aspect of the present invention, even if the engine is idle while the engine is idling, the high-voltage power storage device is overcharged even if the engine is blown. Can be prevented. As a result, it is possible to prevent the output voltage of the high-voltage power storage device from becoming excessive.

  In the first invention, it is preferable that the predetermined condition further includes a second condition that a detected value of the output voltage of the high-voltage power storage device is higher than a predetermined voltage (second invention).

  According to the second aspect of the present invention, even if the engine is being blown away, the predetermined condition is determined as long as the detected value of the output voltage of the high-voltage power storage device does not become higher than the predetermined voltage. Is not established, and the judgment result of the condition judgment means does not become affirmative. For this reason, when the remaining capacity of the first high-voltage power storage device is relatively low, even if a charging current flows through the high-voltage power storage device, the output voltage of the high-voltage power storage device is not likely to become excessively high. Then, it is possible not to perform the process of forcibly limiting the torque command value of the generator motor to zero torque.

  In the second invention, it is preferable that the predetermined voltage related to the second condition has a hysteresis characteristic. That is, the predetermined voltage includes a first predetermined voltage and a second predetermined voltage that is lower than the first predetermined voltage, and the condition determination means determines that the detected value of the output voltage of the high-voltage power storage device is the first voltage. The second condition is satisfied when the voltage rises from a voltage lower than a predetermined voltage to a voltage higher than the first predetermined voltage. After the satisfaction, the detected value of the output voltage of the high-voltage power storage device is greater than the second predetermined voltage. It is preferable to determine that the state where the second condition is satisfied continues until the voltage decreases to a lower voltage (third invention).

  According to the third aspect of the invention, even if the output voltage of the high-voltage power storage device may fluctuate in the vicinity of the first predetermined voltage due to a disturbance or the like, the determination result of the condition determination unit frequently changes. You can prevent it from happening. Therefore, the stability of the control of the generated power of the generator motor can be improved.

  In the second or third aspect of the invention, the predetermined condition includes the first condition and the second condition, and a third condition that a detected value of the temperature of the high-voltage power storage device is lower than a predetermined temperature. Preferably, the high-voltage power storage device includes a fourth condition that a detected value of the remaining capacity is larger than a predetermined value (fourth invention).

  According to the fourth invention, when the detected value of the temperature of the high-voltage power storage device is higher than the predetermined temperature, or when the detected value of the remaining capacity of the high-voltage power storage device is larger than a predetermined value. The judgment result of the condition judgment means becomes negative. Here, when the temperature of the high-voltage power storage device is relatively high, or when the remaining capacity of the high-voltage power storage device is relatively low, the high-voltage power storage device can be used even if a charging current is passed through the high-voltage power storage device. The output voltage of the device is not likely to be excessive. Therefore, according to the fourth aspect of the present invention, even in such a situation, it is possible to prevent the process of forcibly limiting the torque command value of the generator motor to zero torque. In other words, it is possible to limit the situation where the process of forcibly limiting the torque command value of the generator motor to zero torque is limited to the necessary limit.

  In the fourth aspect of the invention, the predetermined temperature related to the third condition or the predetermined value related to the fourth condition may have a hysteresis characteristic in the same manner as the predetermined voltage related to the second condition. Also good.

  In the first to fourth aspects of the invention, when the generator motor control unit changes from a positive state to a negative state in the idle power generation operation state, The generator motor is set such that the torque command value of the generator motor is gradually changed to a torque command value for causing the generator motor to generate power to supplement at least the power consumption of the low-voltage electric load. It is preferable to control the output torque (5th invention).

  According to the fifth aspect of the present invention, when the determination result of the condition determination unit changes from a positive state to a negative state, the generated power of the generator motor can be prevented from increasing rapidly. For this reason, it is possible to prevent the occurrence of a situation in which excessive charging current flows transiently in the high-voltage power storage device.

  In the fourth aspect of the invention, wherein the predetermined condition includes the third condition, the DC / DC converter outputs the low-pressure system when the determination result of the condition determination means is positive in the idle power generation operation state. It is preferable to further comprise DC / DC converter control means for controlling the output voltage of the DC / DC converter so as to cut off the flow of current to the power storage device or the low-voltage auxiliary machine electrical equipment (sixth invention).

  According to the sixth aspect of the invention, in a situation where the third condition is satisfied, that is, in a situation where the temperature of the high-voltage power storage device is low, the judgment result of the condition judgment means becomes affirmative, and the torque command value of the generator motor is When processing for forcibly limiting to zero torque is performed, in addition to the charging current not flowing to the high-voltage power storage device, DC is transferred from the high-voltage power storage device to the low-voltage power storage device or the low-voltage auxiliary electrical equipment. The flow of the discharge current through the / DC converter is interrupted. For this reason, it is possible to prevent the high-voltage power storage device from being energized in a low-temperature environment, and as a result, it is possible to prevent the deterioration of the high-voltage power storage device from being accelerated.

  In this sixth aspect of the invention, the generator motor control means, when the judgment result of the condition judgment means is changed from a positive state to a negative state in the idle power generation operation state, Control the output torque of the generator motor while setting the command value to gradually change to the torque command value for causing the generator motor to generate power to supplement at least the power consumption of the low-voltage electric load The DC / DC converter control means outputs the output of the DC / DC converter when the judgment result of the condition judgment means changes from a positive state to a negative state in the idle power generation operation state. The voltage is gradually changed from the DC / DC converter to a voltage at which a current can flow to the low-voltage power storage device or the low-voltage auxiliary electrical equipment. It is preferable to control the output voltage of the DC / DC converter (seventh aspect).

  According to the seventh aspect of the invention, when the judgment result of the condition judgment unit changes from a positive state to a negative state, the generated power of the generator motor increases rapidly or from the high-voltage power storage device. It is possible to prevent a discharge current from flowing to the low-voltage power storage device or the low-voltage auxiliary electrical equipment through a DC / DC converter in a transient manner. Therefore, it is possible to prevent a situation in which excessive charging current or discharging current flows transiently in the high-voltage power storage device in a low temperature environment. As a result, it is possible to more reliably prevent the deterioration of the high-voltage power storage device from proceeding at an early stage.

The figure which shows the outline of the whole structure of the electric vehicle in embodiment of this invention. The flowchart which shows the process performed with battery ECU shown in FIG. The flowchart which shows the process performed with battery ECU shown in FIG. The flowchart which shows the process of STEP11 of FIG. The flowchart which shows the process performed with battery ECU shown in FIG. The flowchart which shows the process performed with battery ECU shown in FIG. The timing chart which shows the example of the action | operation in embodiment.

  An embodiment of the present invention will be described below with reference to FIGS.

  First, with reference to FIG. 1, the outline of the whole structure of the electric vehicle of this embodiment is demonstrated. As shown in the figure, the electric vehicle 1 of the present embodiment is a parallel hybrid vehicle, and includes an engine 3 and a generator motor 4 as a power generation source 2 that generates propulsion power for the vehicle 1. A power generation source 2 is provided.

  The engine 3 is, for example, an internal combustion engine. The generator motor 4 is an electric motor capable of selectively performing a power running operation and a power generation operation, for example, a permanent magnet type synchronous motor (DC brushless motor).

  A rotor (not shown) of the generator motor 4 is coaxially mounted on the output shaft (crank shaft) 3a of the engine 3, and the rotor of the generator motor 4 rotates integrally with the output shaft 3a. . Note that the rotor of the electric motor 2 is connected to the output shaft 3a of the engine 3 via a power transmission mechanism such as a speed reducer so that the rotor and the output shaft of the engine 3 rotate in conjunction with each other. Good.

  As described above, the output shaft 3a of the engine 3 on which the rotor of the generator motor 4 is mounted (and thus the rotor of the generator motor 4) is connected to the vehicle via the transmission 5 constituted by CVT and the differential gear mechanism 6. 1 drive wheels 7, 7. As a result, the power generated by the power generation source 2 from one or both of the engine 3 and the generator motor 4 is transmitted to the drive wheels 7 and 7 via the transmission 5 and the differential gear mechanism 6. Traveling is performed.

  In this case, the transmission 5 is operated between the power generation source 2 and the drive wheels 7 and 7 in a state in which a shift lever (not shown) for operating the operation state of the vehicle 1 by the driver is operated in the parking range or the neutral range. It is comprised so that the power transmission between may be interrupted | blocked.

  The above is the outline of the mechanical overall configuration of the electric vehicle 1 of the present embodiment.

  Next, an electrical configuration for controlling the operation of the electric vehicle 1 according to the present embodiment will be described.

  The vehicle 1 includes a high-voltage battery 10 as a high-voltage power storage device that stores electrical energy necessary for powering operation of the generator motor 4, and a low-voltage auxiliary machine that includes an air conditioner, an acoustic device, a lighting device, and a navigation device. A low-voltage battery 11 is mounted as a low-voltage power storage device that stores electrical energy for operation of the electrical component 12.

  The high voltage battery 10 and the low voltage battery 11 are both rechargeable secondary batteries. In this case, the high-voltage battery 10 is a battery whose output voltage (voltage between the positive terminal and the negative terminal of the high-voltage battery 10) is a high voltage (for example, 100 to 150 V), and is configured by, for example, a lithium ion battery. The low-voltage battery 11 is a battery whose output voltage (voltage between the positive terminal and the negative terminal of the low-voltage battery 11) is lower than that of the high-voltage battery 10 (for example, 12V), and is composed of, for example, a lead storage battery. The

  The high-voltage battery 10 is electrically connected to an armature winding (not shown) of the generator motor 4 via a power drive unit 13 (hereinafter referred to as PDU 13) which is a motor drive circuit including an inverter circuit and the like not shown. Connected. Then, by controlling ON / OFF of the switching element of the inverter circuit of the PDU 13, power is supplied from the high-voltage battery 10 to the generator motor 4 during powering operation of the generator motor 4, and power generation operation of the generator motor 4 is also performed. Sometimes, it is possible to charge the high-voltage battery 10 with the power generation output of the generator motor 4.

  In this embodiment, an electric fuel pump 14 for supplying fuel to the engine 3 is provided, and the high-voltage battery 10 is further connected to the electric fuel pump 14 via an inverter circuit 15. Electrically connected. Electric power for the operation is supplied from the high-voltage battery 10 to the fuel pump 14 via the inverter circuit 15. However, the operating power of the fuel pump 14 may be supplied to the fuel pump 14 from a power source different from the high-voltage battery 10.

  The low-voltage system battery 11 is electrically connected to the low-voltage system auxiliary equipment 12 and also via a DC / DC converter 16 that converts a high voltage on the high-voltage system battery 10 side to a low voltage on the low-voltage system battery 11 side. The high voltage battery 10 and the PDU 13 are connected. As a result, power is supplied from the high voltage system battery 10 to the low voltage system auxiliary equipment 12 or the low voltage system battery 11 via the DC / DC converter 16 (power for operating the low voltage system auxiliary equipment 12 or charging power of the low voltage system battery 11). ) Or the power generated during the power generation operation of the generator motor 4 is supplied from the generator motor 4 to the low-voltage auxiliary electrical equipment 12 or the low-voltage battery 11 via the PDU 13 and the DC / DC converter 16. It is possible.

  In the present embodiment, the high-voltage power storage device and the low-voltage power storage device are both configured by secondary batteries, but both or one of them may be configured by a high-capacity capacitor, or A capacitor and a secondary potential may be combined.

  The vehicle 1 further includes an engine ECU 21, which is a control circuit unit responsible for operation control of the engine 3 (specifically, throttle valve opening control, fuel injection control, ignition control, etc. of the engine 3), and a generator motor 3. Control of the motor ECU 22 which is a control circuit unit responsible for operation control, the charge state of the high voltage system battery 10 and the low voltage system battery 11, battery ECU 23, setting processing of target values of output torque of the engine 3 and the generator motor 4, etc. A vehicle integrated ECU 24 which is a control circuit unit to be performed is mounted. The ECUs 21 to 24 are circuit units including a CPU, an RM, a ROM, and the like, and can exchange various data with each other via the bus line 25.

  The engine ECU 21 is given a target value (hereinafter referred to as a target engine torque), an operation mode, and the like of the output torque of the engine 3 from the vehicle overall ECU 24, and the rotational speed NE (of the output shaft 3a of the engine 3 from an appropriate sensor). Rotation speed) and detection data such as the intake pipe internal pressure PB of the engine 3 are given. The engine ECU 21 performs throttle valve opening control, fuel injection control, and ignition control based on these input data.

  For example, the engine ECU 21 determines the target opening of the throttle valve of the engine 3 according to the target engine torque, and the fuel injection amount of the engine 3 according to the detected value of the rotational speed NE and the detected value of the intake pipe internal pressure PB. And the ignition timing, and the operation control of the engine 3 is performed according to the determined target opening, fuel injection amount, and ignition timing.

  Further, for example, in the operation mode in which the engine 3 is to be idled, the throttle valve opening, the fuel injection amount, and the ignition timing are controlled so that the engine 3 is idled.

  The motor ECU 22 is given a torque command value (hereinafter referred to as a reference sign Tr_c) which is a target value of the output torque of the generator motor 3 from the vehicle overall ECU 24, and the rotor of the generator motor 4 from an appropriate sensor. Detection data such as the rotation angle θm of the rotor, the rotational speed (rotational speed) ωm of the rotor, the energization current Im of the armature winding, and the like. The motor EC22 controls the energization current of the armature winding via the PDU 13 based on these input data.

  For example, the motor ECU 22 sequentially determines the instantaneous target value of the energization current Im of the armature winding according to the torque command value Tr_c and the detected values of the rotation angle θm and the rotation speed ωm of the rotor, and energizes the target value. The energization current Im is feedback-controlled via the PDU 13 so as to follow the detected value of the current Im.

  In the present embodiment, the torque command value Tr_c of the generator motor 4 is a torque command value (drive torque command value) at the time of power running operation of the generator motor 4 as a positive value, and a torque command value ( The braking torque command value) is a negative value.

  The battery ECU 23 receives detection data of the output voltage Vb_H, energization current (charge / discharge current) Ib_H, and temperature Tb_H of the high-voltage battery 10 from appropriate sensors, as well as the output voltage Vb_L and energization current of the low-voltage battery 11. Detection data of Ib_L and the supply current I_L to the low-voltage auxiliary electrical equipment 12 is given. Then, the battery ECU 23 executes processing such as detecting (estimating) the remaining capacities of the high-voltage battery 10 and the low-voltage battery 11 based on these data.

  For example, the battery ECU 23 sequentially calculates the integrated discharge charge amount of the high-voltage battery 10 by integrating the detected value of the energization current Ib_H of the high-voltage battery 10 from the fully charged state of the high-voltage battery 10, and this integrated discharge. The remaining capacity SOC_H of the high-voltage battery 10 is sequentially estimated by subtracting the amount from the capacity of the high-voltage battery 10 in the fully charged state (capacity expressed in the charge amount dimension).

  Alternatively, the battery ECU 23 integrates the power detection value calculated as the product of the detection value of the energization current Ib_H of the high voltage battery 10 and the detection value of the output voltage Vb_H from the fully charged state of the high voltage battery 10. By sequentially calculating the accumulated discharge energy amount of the high-voltage battery 10 and subtracting this accumulated discharge energy amount from the capacity of the high-voltage battery 10 in the fully charged state (capacity expressed in the dimension of energy), the high-voltage battery 10 Are sequentially estimated.

  In these cases, the energization current Ib_H of the high-voltage battery 10 is a positive value when the current is in the discharging direction, and is a negative value when the current is in the charging direction.

  Further, the battery ECU 23 performs, for example, a low voltage system by a process similar to that of the high voltage battery 10 based on the detected value of the conduction current Ib_L of the low voltage battery 11 or the detected values of the conduction current Ib_L and the output voltage Vb_L. The remaining capacity SOC_L of the battery 11 is estimated sequentially.

  Supplementally, various methods are known for estimating the remaining capacity of the battery, and the remaining capacity of the high-voltage battery 10 and the low-voltage battery 11 is estimated by other known methods other than the above-described method. You may make it carry out using.

  Further, the battery ECU 23 calculates the product of the detected value of the output voltage Vb_L of the low voltage system battery 11 (the power supply voltage of the low voltage system auxiliary equipment 12) and the detected value of the supply current I_L to the low voltage system auxiliary equipment 12 By doing so, the power consumption of the low-voltage auxiliary electrical equipment 12 is sequentially detected (estimated).

  In the present embodiment, the battery ECU 23 includes, as one function thereof, a battery protection control processing unit 23a that executes a control process related to the present invention. The battery protection control processing unit 23a performs a control process (hereinafter referred to as an upper limit voltage protection control process) for preventing the output voltage Vb_H of the high voltage battery 10 from exceeding a predetermined allowable upper limit voltage under a required condition. It is something to execute. In this upper limit voltage protection control process, the battery protection control processing unit 23a executes a process of appropriately determining parameters used by the vehicle overall ECU 24 to determine the torque command value Tr_c of the generator motor 4. In the present embodiment, the parameter includes an allowable upper limit value and an allowable lower limit value of the torque command value Tr_c.

  The battery ECU 23 can also cut off the energization from the high voltage system side to the low voltage system side by controlling the DC / DC converter 16.

  The vehicle control ECU 24 receives, from appropriate sensors, a depression amount AP of an accelerator pedal (not shown) of the vehicle 1 (hereinafter referred to as an accelerator operation amount AP), a vehicle speed Vcar, and an operation position SP (hereinafter referred to as a shift lever) of the transmission 5. Detection value such as shift position SP) is given. Further, the vehicle overall ECU 24 receives from the battery ECU 23 a detected value (estimated value) of the remaining capacity SOC_H of the high-voltage battery 10, a detected value of the temperature Tb_H, a detected value (estimated value) of the remaining capacity SOC_L of the low-voltage battery 11, The detection value (estimated value) of the power consumption of the low-voltage auxiliary electrical equipment 12 and the above parameters are also input. Based on these input data, the vehicle overall ECU 24 determines the operation mode of the engine 3, the target engine torque of the engine 3, and the torque command value Tr_c of the generator motor 4, and the operation mode of the engine 3 and the target engine The torque is output to the engine ECU 21 and the torque command value Tr_c of the generator motor 4 is output to the motor ECU 22.

  For example, when the vehicle 1 is traveling, the vehicle supervising ECU 24 sets a total target torque that should be generated by the power generation source 2 in accordance with the detected values of the accelerator operation amount AP and the vehicle speed Vcar. The target engine torque of the engine 3 and the torque command value Tr_c (> 0) of the generator motor 4 are determined according to the remaining capacity SOC_H of the system battery 10.

  Further, for example, when the engine 3 is idling while the vehicle 1 is parked or stopped, the vehicle overall ECU 24 prevents the stored energy of the low voltage system battery 11 from being consumed by the low voltage system auxiliary equipment 12. At a target generated power that can supply at least the power consumption of the low-voltage auxiliary electrical equipment 12 to the low-voltage battery 11 or the low-voltage auxiliary electrical equipment 12 (generated power greater than the power consumption of the low-voltage auxiliary electrical equipment 12) The target engine torque of the engine 3 and the torque command value Tr_c (<0) of the generator motor 4 are determined so as to perform the power generation operation of the generator motor 4. Thus, the operation state of the vehicle 1 that performs the power generation operation of the generator motor 4 while performing the idle operation of the engine 3 is an operation state corresponding to the idle power generation operation state in the present invention.

  In the vehicle 1 of the present embodiment, in this idle power generation operation state, the vehicle overall ECU 24 also sets a target value for the charging power of the high-voltage battery 10 according to the detected values of the remaining capacity SOC_H and the temperature Tb_H of the high-voltage battery 10. To do. Then, the target engine torque of the engine 3 is generated so that the target generated power corresponding to the sum of the target value of the charging power and the detected value of the power consumption of the low-voltage auxiliary electric machine 12 is generated by the power generation operation of the generator motor 4. And the torque command value Tr_c (<0) of the generator motor 4 is determined. In this case, the torque command value Tr_c is calculated from the target generated power and the detected value of the rotational speed ωm of the rotor of the generator motor 4.

  In the idle power generation operation state, the vehicle overall ECU 24 limits the torque command value Tr_c to be determined according to parameters determined by the battery protection control processing unit 23a of the battery ECU 23 as described later under specific conditions. .

  Further, in the idle power generation operation state, the vehicle overall ECU 24 uses the detected value of the shift position SP of the transmission 5 and the detected value of the accelerator operation amount AP as data used by the battery ECU 23 to execute processing to be described later. Output to the battery ECU 23.

  Next, the operation of the electric vehicle 1 in this embodiment, particularly the operation related to the present invention will be described below.

  In the idle power generation operation state, the battery ECU 23 sequentially executes the processing shown in the flowchart of FIG. 2 at a predetermined calculation processing cycle. This process satisfies a necessary condition for executing the upper limit voltage protection control process by the battery protection control processing unit 23a with respect to the state of the high-voltage battery 10 (specifically, states of SOC_H, Vb_H, and Tb_H). This is a process for determining whether or not there is.

  In the present embodiment, as a necessary condition for executing the upper limit voltage protection control process (a necessary condition regarding the state of the high voltage battery 10), the temperature Tb_H of the high voltage battery 10 is lower than a predetermined set temperature (high voltage). Temperature condition that the temperature Tb_H of the battery 10 is low), the remaining capacity condition that the remaining capacity SOC_H is larger than the predetermined set SOC (the remaining capacity SOC_H of the high-voltage battery 10 is high), and the output voltage Vb_H is predetermined. And a voltage condition of higher than the set voltage.

  Here, the internal resistance of the high-voltage battery 10 tends to increase in an environment where the temperature Tb_H is low (for example, −35 ° C. or lower). For this reason, when a charging current is applied to the high-voltage battery 10, the output voltage of the high-voltage battery 10 is likely to increase even if the charging current is very small. Therefore, in particular, when the temperature Tb_H of the high-voltage battery 10 is low and the remaining capacity SOC_H of the high-voltage battery 10 is relatively high (when the capacity is close to the fully charged state), the high-voltage battery 10 Even if the charging current of the battery 10 is very small, the output voltage Vb_H of the high-voltage battery 10 may become an excessive voltage that exceeds the allowable upper limit voltage.

  Therefore, in the present embodiment, the temperature condition, remaining capacity condition, and voltage condition are used as necessary conditions for executing the upper limit voltage protection control process.

  Hereinafter, the processing of FIG. 2 will be described. In STEP 1, the battery ECU 23 determines whether or not the detected value of the temperature Tb_H of the high-voltage battery 10 is lower than a predetermined set temperature (whether the above temperature condition is satisfied). Judging. The set temperature is, for example, −30 ° C.

  In FIG. 2, the determination process of STEP1 is simplified and described, but in the present embodiment, the set temperature used in the determination process actually has a hysteresis characteristic. That is, the set temperature is composed of the first set temperature and the second set temperature slightly higher than this, and when the detected value of Tb_H is lowered to the first set temperature, the determination result of STEP 1 becomes positive. . Then, in a state where the detected value of Tb_H is kept below the second set temperature, the determination result of STEP1 is maintained positively. Further, when the detected value of Tb_H rises to a temperature higher than the second set temperature, the determination result of STEP1 becomes negative.

  If the determination result in STEP 1 is affirmative (when the temperature Tb_H is low), the battery ECU 23 determines in STEP 2 whether the detected value of the remaining capacity SOC_H of the high-voltage battery 10 is higher than a predetermined set SOC. It is determined whether or not (whether or not the remaining capacity condition is satisfied). The set SOC is, for example, 80% of the remaining capacity when the remaining capacity of the high voltage battery 10 in the fully charged state is 100%.

  In FIG. 2, the determination process of STEP 2 is described in a simplified manner. However, in the present embodiment, actually, the set SOC used in the determination process has a hysteresis characteristic similar to the set temperature in STEP 1. It is supposed to have. That is, the set SOC includes a first set SOC and a second set SOC that is slightly lower than the first set SOC. When the detected value of SOC_H exceeds the first set SOC, the determination result of STEP2 becomes affirmative. . After that, in a state where the detected value of SOC_H is maintained at the second set SOC or higher, the determination result of STEP2 is positively maintained. Further, when SOC_H decreases to a remaining capacity lower than the second set SOC, the determination result of STEP2 becomes negative.

  When the determination result of STEP2 is affirmative (when the remaining capacity SOC_H is high), the battery ECU 23 determines that the detected value of the output voltage Vb_H of the high voltage battery 10 exceeds the predetermined first set voltage VbH1 in STEP3. Is determined (whether the voltage condition is satisfied). The first set voltage VbH1 is a voltage that is slightly lower than the allowable upper limit voltage of the output voltage Vb_H of the high-voltage battery 10, for example.

  If the determination result in STEP 3 is affirmative, the battery ECU 23 determines whether or not the voltage condition is satisfied in STEP 4 as a voltage condition establishment flag that is a flag indicating “1” or “0”, respectively. Is set to “1”. Further, the battery ECU 23 determines whether or not the necessary conditions for executing the upper limit voltage protection control process (necessary conditions relating to the state of the high voltage battery 10) are satisfied in STEP5. The value of the upper limit voltage protection control region flag Fs, which is a flag indicated by “0”, is set to “1”, and the processing of FIG.

  On the other hand, if the determination result in STEP 3 is negative, the battery ECU 23 determines whether or not the current voltage condition flag value is “1” (whether or not the voltage condition has already been established). Judge at.

  If the determination result in STEP 6 is affirmative, the battery ECU 23 determines that the output voltage Vb_H of the high-voltage battery 10 is lower than a predetermined second set voltage VbH2 that is slightly smaller than the first set voltage VbH1. It is determined in STEP 7 whether or not it has decreased.

  If the determination result in STEP 7 is negative, the battery ECU 23 executes the process in STEP 5 while maintaining the value of the voltage condition establishment flag at “1”, and the value of the upper limit voltage protection control region flag Fs. Is set to “1”.

  Further, when the determination result of any one of STEPs 1, 2, and 6 is negative, or when the determination result of STEP 7 is positive, the battery ECU 23 sets the value of the voltage condition establishment flag in STEP 8. Initialize or reset to “0”. Further, the battery ECU 23 sets the value of the upper limit voltage protection control region flag Fs to “0” in STEP 9 and ends the process of FIG.

  Accordingly, like the set temperature related to the temperature condition and the set SOC related to the remaining capacity condition, the predetermined set voltage related to the voltage condition also has a hysteresis characteristic, and the set voltage is the first set voltage VbH1 and the second set voltage. And a set voltage VbH2 (<VbH1).

  After executing the process of the flowchart of FIG. 2 as described above (or in parallel with the process of the flowchart of FIG. 2), the battery ECU 23 sequentially executes the process shown in the flowchart of FIG. 3 at a predetermined calculation processing cycle. This process is a process for determining whether or not all necessary conditions for executing the upper limit voltage protection control process by the battery protection control processing unit 23a are satisfied, including the conditions relating to the operating state of the engine 3. .

  In the present embodiment, the necessary condition regarding the operation state of the engine 3 for executing the upper limit voltage protection control process is a condition that the engine 3 is being blown.

  Here, in the idling power generation operation state, when the driver of the vehicle 1 depresses the accelerator pedal so as to make the engine 3 run open, the rotational speed NE of the output shaft 3a of the engine 3 rapidly increases. . As a result, the rotational speed ωm of the rotor of the generator motor 4 also rapidly increases. Further, in the idle power generation operation state, the vehicle overall ECU 24 can supply the low-voltage battery 11 or the low-voltage auxiliary electrical equipment 12 with the power consumed by the low-voltage auxiliary electrical equipment 12 as described above. The target engine torque of the engine 3 and the torque command value Tr_c of the generator motor 4 are determined so that the generator motor 4 performs the power generation operation with the generated power.

  In this case, the generated power of the generator motor 4 is approximately proportional to the product of the rotor rotational speed ωm and the output torque of the generator motor 4, so that the actual generated power of the generator motor 4 is maintained at the target generated power. For this purpose, it is necessary to decrease the magnitude of the torque command value Tr_c as the rotor rotational speed ωm of the generator motor 4 increases.

  However, since the increase in the rotational speed NE of the engine 3 and the rotational speed ωm of the rotor of the generator motor 4 at the time when the engine 3 is blown away is abrupt, the generator motor 4 does not respond to the increase in the rotational speed ωm. Delay in control of output torque occurs. This is determined corresponding to the detected value of the rotational speed ωm of the rotor of the generator motor 4 when the engine 3 is idling, causing a rapid increase in the rotational speed NE of the engine 3 and the rotational speed ωm of the rotor of the generator motor 4. At the time when the energization current of the armature winding of the generator motor 4 is controlled according to the torque command value Tr_c, the actual rotational speed ωm of the rotor of the generator motor 4 is used to determine the torque command value Tr_c. This is because it is higher than the detected value of the rotational speed ωm of the rotor of the generator motor 4 used.

  As a result, when the engine 3 is vacated, the actual generated power of the generator motor 4 tends to be larger than the original target generated power. In such a case, the actual generated power of the generator motor 4 becomes excessive with respect to the power consumption of the low-voltage auxiliary electrical equipment 12, and the surplus generated power is charged in the high-voltage battery 10. It may be done.

  Therefore, in the present embodiment, as a necessary condition for executing the upper limit voltage protection control process, in addition to the temperature condition, the remaining capacity condition and the voltage condition regarding the state of the high-voltage battery 10, Include the condition that the test is being performed.

  Hereinafter, the process of FIG. 3 will be described. In STEP 11, the battery ECU 23 executes an empty determination process in which it is determined whether or not the engine 3 is empty.

  In this case, the detected value of the rotational speed NE of the engine 3, the detected value of the shift position SP of the transmission 5, and the detected value of the accelerator operation amount AP are sequentially given to the battery ECU 23 from the engine ECU 21 or the vehicle integrated ECU 24. . Then, in the above-described empty determination process, the battery ECU 23 executes the process shown in the flowchart of FIG. 4 based on these detected values.

  In the following, the process of FIG. 4 will be described. The battery ECU 23 determines in STEP 11-1 whether the detected value of the shift position is the neutral range “N” or the parking range “P”.

  When the determination result in STEP 11-1 is positive, the battery ECU 23 determines that the amount of change (time change rate) per unit time of the detected value of the accelerator operation amount AP is a predetermined threshold value ΔAPX (> 0). It is determined in STEP 11-2 whether or not the acceleration pedal is larger than that, that is, whether or not the accelerator pedal is quickly depressed.

  If the determination result in STEP 11-2 is affirmative, the battery ECU 23 determines whether or not the engine 3 is being idled in STEP 11-3 with the values “1” and “0”, respectively. 4 is set to “1”, and the processing of the flowchart of FIG. 4 is terminated.

  If the determination result in STEP 11-2 is negative, whether or not the value of the empty flag Fe is “1”, that is, the state after the empty flag has already started. Whether or not is determined in STEP 11-4. When the determination result is affirmative, the battery ECU 23 further determines that the amount of change (time change rate) per unit time of the detected value of the rotational speed NE of the engine 3 is greater than a predetermined threshold value ΔNEX (<0). It is determined in STEP 11-5 whether the engine speed NE of the engine 3 is rapidly decreasing. Note that the determination in STEP 11-5 may be made using the detected value of the rotational speed ωm of the rotor of the generator motor 4 instead of the rotational speed NE of the engine 3.

  If the determination result in STEP 11-5 is negative, the battery ECU assumes that the engine 3 continues to be exhausted, executes the processing in STEP 11-3, and The value of the flag Fe is set to “1”.

  On the other hand, if the determination result of either STEP 11-1 or STEP 11-4 is negative or the determination result of STEP 11-5 is positive, the battery ECU 23 performs the engine emptying. In step 11-6, the empty flag Fe is initialized or reset to “0”, and the process of the flowchart of FIG. 4 is terminated.

  In the present embodiment, when the detected value of the accelerator operation amount AP increases rapidly when the detected value of the shift position SP is in the neutral range “N” or the parking range “P”, Until the detected value of the rotational speed NE of the engine 3 quickly decreases, it is determined that the engine 3 is being emptied (the value of the vacancy flag Fe is set to “1”). ).

  Returning to the description of FIG. 3, after the battery ECU 23 has executed the step 12 in the above-described step, it is determined in step 12 whether or not the value of the step flag Fe is “1”. Determine whether.

  If the determination result in STEP 12 is affirmative (when the engine 3 is being vacated), the battery ECU 23 determines in STEP 13 that the value of the upper limit voltage protection control region flag Fs is “ It is determined whether or not 1 ″.

  When the determination result in STEP 13 is affirmative (when the temperature condition, the remaining capacity condition, and the voltage condition regarding the state of the high-voltage battery 10 are satisfied), the battery ECU 23 determines in STEP 14 that the battery All necessary conditions for executing the upper limit voltage protection control process by the protection control processing unit 23a (temperature condition regarding the state of the high voltage battery 10, the remaining capacity condition and the voltage condition, and the condition regarding the operation state of the engine 3) are satisfied. The upper limit voltage protection control execution flag Fc, which is a flag indicating whether the value is “1” or “0”, is set to “1”, and the processing in FIG. 3 ends.

  If the determination result of either STEP 12 or STEP 13 is negative, the battery ECU 23 initializes or resets the upper limit voltage protection control execution flag Fc to “0” in STEP 15 and performs the processing of FIG. finish.

  2 and 3 described above, in this embodiment, the temperature condition, the remaining capacity condition and the voltage condition regarding the state of the high-voltage battery 10 are satisfied, and the engine 3 is blown. If the condition regarding the operating state of the engine 3 is established, the necessary condition for executing the upper limit voltage protection control process is established.

  The battery protection control processing unit 23a of the battery ECU 23 sequentially executes the processing shown in the flowchart of FIG. 5 at a predetermined arithmetic processing cycle.

  That is, the battery protection control processing unit 23a first determines in STEP21 whether or not the value of the upper limit voltage protection control execution flag Fc is “1”. If the determination result is affirmative, the processes of STEP22 to STEP24 are executed as the upper limit voltage protection control process, and the process of FIG.

  Specifically, in STEPs 22 and 23, the battery protection control processing unit 23a includes a torque command upper limit value that is an upper limit value of the torque command value Tr_c of the generator motor 4 and a torque command lower limit value that is a lower limit value of the torque command value Tr_c. Are set to 0 [N · m], respectively. In the present embodiment, the driving torque of the generator motor 4 during the power running operation is a positive value, and the braking torque (regenerative torque) during the power generation operation is a negative value. The upper limit value of the magnitude of the drive torque during the power running operation is meant, and the torque command lower limit value means the upper limit value of the magnitude of the braking torque (regenerative torque) during the power generation operation of the generator motor 4.

  Thus, setting the torque command upper limit value and the torque command lower limit value to 0 [N · m] means that the power running operation and the power generation operation of the generator motor 4 are not performed, and the output torque of the generator motor 4 is always set to 0 [ N · m].

  Further, the battery protection control processing unit 23a determines whether or not the operation of the DC / DC converter 16 should be stopped in Step 24, DC / DC stop flag Fdc which is a flag indicating values “1” and “0”, respectively. Is set to “1”.

  On the other hand, when the determination result in STEP 21 is negative, the battery protection control processing unit 23a executes the processes in STEP 25 to STEP 27 and ends the process in FIG.

  Specifically, in STEP 25, the battery protection control processing unit 23a increases the torque command upper limit value by a predetermined amount DTQD (> 0) from the current value (value determined in the previous calculation processing cycle) (> Update to 0). However, in this case, if the value obtained by adding the predetermined amount DTQD to the current value of the torque command upper limit value exceeds a predetermined maximum value (> 0), the torque command upper limit value is set to the maximum value. The The maximum value corresponds to an allowable limit value of the magnitude of the output torque (drive torque) during the power running operation of the generator motor 4.

  In STEP 26, the battery protection control processing unit 23a reduces the torque command upper limit value to a value (<0) obtained by reducing the current value (value determined in the previous calculation processing cycle) by a predetermined amount DTQR (> 0). Update. However, in this case, if the value obtained by subtracting the predetermined amount DTQR from the current value of the torque command upper limit value falls below a predetermined minimum value (<0), the torque command upper limit value is set to the minimum value. The The minimum value corresponds to an allowable limit value of the magnitude of the output torque (braking torque) during the generator operation of the generator motor 4.

  Further, the battery protection control processing unit 23 a initializes or resets the value of the DC / DC stop flag Fdc to “0” in STEP 27.

  Further, the battery protection control processing unit 23a performs predetermined processing (processing for controlling the output voltage of the DC / DC converter 16) shown in the flowchart of FIG. 6 in accordance with the DC / DC stop flag Fdc set as described above. Are sequentially executed in the arithmetic processing cycle.

  That is, the battery protection control processing unit 23a determines whether or not the value of the DC / DC stop flag Fdc is “1” in STEP31.

  In the present embodiment, the value of the DC / DC stop flag Fdc is “1” or “0”, depending on whether the value of the upper limit voltage protection control execution flag Fc is “1” or “0”. Since it is set to “1” or “0”, determining whether the value of the DC / DC stop flag Fdc is “1” means that the value of the upper limit voltage protection control execution flag Fc is “ This is equivalent to determining whether or not 1 ″.

  If the determination result in STEP 31 is affirmative, the battery protection control processing unit 23 a determines the command voltage of the output voltage of the DC / DC converter 16 in STEP 32 when the power generation operation of the generator motor 4 is stopped. The power generation stop command value is set as a command voltage in advance. The power generation stop command value is a command value for stopping the operation of the DC / DC converter 16 (cutting off the power supply from the high pressure system to the low pressure system).

  If the determination result in STEP 31 is negative, the battery protection control processing unit 23a determines the command voltage of the output voltage of the DC / DC converter 16 in STEP 33 as the current value (in the previous calculation processing cycle). Value) is increased by a predetermined amount DVDC (> 0). However, in this case, a value obtained by adding a predetermined amount DVDC to the current value of the command voltage of the output voltage of the DC / DC converter 16 is a target value of the output voltage of the DC / DC converter 16 determined by the battery ECU 23 through higher processing. If the value exceeds the target value determined by the battery ECU 23 according to the remaining capacity SOC_H of the high-voltage battery 10 in the situation where the value of the upper limit voltage protection control execution flag Fc is “0”, the target value Is set as the command voltage of the output voltage of the DC / DC converter 16.

  5 and 6 described above is a process executed by the battery protection control processing unit 23a.

  The torque command upper limit value and the torque command lower limit value determined by the battery protection control processing unit 23a through the process of the flowchart of FIG. 5 are sequentially given from the battery ECU 23 to the vehicle integrated ECU 24. At this time, the vehicle overall ECU 24 sets the torque command value Tr_c determined in accordance with the accelerator operation amount AP, the vehicle speed Vcar, the detected value of the remaining capacity SOC_H of the high-voltage battery 10 between the torque command upper limit value and the torque command lower limit value. After being limited to the value, it is output to the motor ECU 22.

  In this case, the situation where the upper limit voltage protection control execution flag Fc is set to “1”, that is, the temperature condition, remaining capacity condition and voltage condition regarding the state of the high voltage battery 10 are satisfied, and the engine 3 is empty. In the situation where the overshooting is being performed, both the torque command upper limit value and the torque command lower limit value are “0”, so that the torque command value Tr_c given to the motor ECU 22 is always “0” (of the generator motor 4 The command value is set so that the output torque is zero torque). Therefore, the motor ECU 22 performs control so that the energization current of the armature winding of the generator motor 4 is maintained at “0”. For this reason, the power generation operation of the generator motor 4 is stopped, and a situation in which a charging current flows through the high voltage battery 10 is prevented from occurring.

  For example, when the charging current does not flow to the high voltage battery 10, the output voltage Vb_H of the high voltage battery 10 decreases to a voltage equal to or lower than the second set voltage VbH 2, or the engine 3 is blown away. When the upper limit voltage protection control execution flag Fc is changed from “1” to “0”, both the torque command upper limit value and the torque command lower limit value gradually return to the original allowable limit value. Therefore, the torque command value Tr_c is gradually changed to the original torque command value Tr_c (the torque command value Tr_c for performing the power generation operation of the generator motor 4 with the generated power that can supplement the power consumption of the low-voltage auxiliary electrical equipment 12). For this reason, the power generated by the generator motor 4 is prevented from rapidly increasing, and a situation in which excessive charging current flows again to the high-voltage battery 10 is prevented. .

  Further, the battery ECU 23 controls the output voltage of the DC / DC converter 16 in accordance with the command voltage of the output voltage of the DC / DC converter 16 determined by the battery protection control processing unit 23a by the process of the flowchart of FIG.

  In this case, in a situation where the upper limit voltage protection control execution flag Fc is set to “1”, the command voltage of the output voltage of the DC / DC converter 16 is set to the power generation stop time command value. The operation of the DC converter 16 is stopped, and current is prevented from flowing from the high-voltage system battery 10 to the low-voltage system battery 11 or the low-voltage system auxiliary equipment 12 via the DC / DC converter 16. Therefore, in a low temperature environment where the temperature Tb_H of the high voltage battery 10 is lower than the set temperature, not only the charging current but also the discharge current does not flow through the high voltage battery 10, The deterioration is prevented from progressing at an early stage.

  When the upper limit voltage protection control execution flag Fc is changed from “1” to “0”, the command voltage of the output voltage of the DC / DC converter 16 gradually returns to the original target value. Since both the torque command upper limit value and the torque command lower limit value gradually return to the original allowable limit value, it is possible to prevent a situation in which the discharge current of the high-voltage battery 10 increases rapidly. The

  FIG. 7 shows the engine speed NE, the accelerator operation amount AP, the idling flag Fe, the upper limit voltage protection control execution flag Fc, the output voltage Vb_H of the high-voltage battery 10, and the torque command value Tr_c in the idle power generation operation state. It is a timing chart which shows the example of a time-dependent change.

  In the example shown in FIG. 7, the engine 3 is emptied during a period from time t1 to time t4 in the idle power generation operation state in which the temperature condition and the remaining capacity condition regarding the state of the high-voltage battery 10 are satisfied. An example in the case where an erasure is performed is shown.

  As shown in the figure, when the accelerator pedal is depressed at time t1 and the accelerator operation amount AP increases rapidly, the empty flag Fe is set to “1”. Further, the rotational speed NE of the engine 3 increases from time t1. As the rotational speed NE increases, the actual generated power of the generator motor 4 becomes larger than the original target generated power for replenishing the power consumed by the low-voltage auxiliary machine electrical equipment 12, thereby causing the high-voltage battery 10. Thus, the charging current flows, and as a result, the output voltage Vb_H of the high voltage battery 10 increases.

  When the output voltage Vb_H of the high-voltage battery 10 rises to the first set voltage VbH1 (time t2 in FIG. 7), the upper limit voltage protection control region flag Fs is set to “1” by the process shown in FIG. Therefore, the upper limit voltage protection control execution flag Fc is set to “1” by the processing shown in FIG.

  For this reason, the torque command upper limit value and the torque command lower limit value are set to “0” by the processing of FIG. 5, so that the torque command value Tr_c given to the motor ECU 22 becomes “0” as shown in FIG. As a result, the electric power generated by the generator motor 4 becomes “0”, so that no charging current flows through the high-voltage battery 10. As a result, the output voltage Vb_H of the high voltage battery 10 decreases as shown in FIG.

  When the output voltage Vb_H decreases to a voltage equal to or lower than the second set voltage VbH2, the voltage condition is not satisfied (and the upper limit voltage protection control region flag Fs is reset to “0” by the processing of FIG. 2). The upper limit voltage protection control execution flag Fc is reset to “0” (time t3 in FIG. 7).

  For this reason, the torque command upper limit value and the torque command lower limit value are gradually returned to the original allowable limit values by the processing of FIG. 5, and the torque command value Tr_c given to the motor ECU 22 is as shown in FIG. The magnitude gradually increases on the braking torque side (negative side).

  At this time, the generated electric power of the generator motor 4 gradually increases, so that the charging current of the high voltage battery 10 does not increase suddenly. As a result, the output voltage Vb_H of the high voltage battery 10 does not increase. There will be no sudden increase.

  After that, when the engine 3 is eliminated at time t4, the output voltage Vb_H of the high-voltage battery 10 is stabilized at a substantially constant voltage.

  As described above, according to the present embodiment, when the temperature condition and the remaining capacity condition are satisfied, that is, when a charging current is passed through the high voltage battery 10, the output voltage Vb_H of the high voltage battery 10 is allowed. In a situation where the upper limit value may be exceeded, the engine 3 is idled in the idle power generation operation state, and as a result, the detected value of the output voltage Vb_H of the high voltage battery 10 is the first set voltage. When the voltage rises to a voltage exceeding Vb_H (that is, when the voltage condition and the condition that the engine 3 is blown off are satisfied in addition to the temperature condition and the remaining capacity condition), the generator motor 4 The torque command value Tr_c is forcibly set to “0”.

  As a result, even if the engine speed NE and the rotor rotational speed ωm of the generator motor 4 suddenly increase due to the engine 3 being blown away, the generated power of the generator motor 4 becomes “0”, and the high-voltage battery 10 can be reliably prevented from flowing a charging current. As a result, it is possible to prevent the output voltage Vb_H of the high-voltage battery 10 from further rising and prevent the situation where the output voltage Vb_H exceeds the allowable upper limit.

  In the present embodiment, in addition to the temperature condition and the remaining capacity condition, the torque command of the generator motor 4 is set in a situation where the voltage condition and the condition that the engine 3 is being blown are established. In addition to forcing the value Tr_c to “0”, the output voltage of the DC / DC converter 16 is prevented from flowing current from the high voltage system battery 10 to the low voltage system battery 11 or the low voltage system auxiliary equipment 12. Be controlled. As a result, it is possible to prevent current from flowing through the high-voltage battery 10 as much as possible in a low-temperature environment where the temperature condition is satisfied, and to prevent deterioration of the high-voltage battery 10 from proceeding at an early stage. it can.

  Here, the correspondence between the present embodiment and the present invention will be supplemented.

  In the present embodiment, the emptying detection means in the present invention is realized by the processing of STEP11 in FIG. 3 (emptyness determination processing). Moreover, the condition judging means in the present invention is realized by the processing shown in the flowcharts of FIGS. In this case, in the present embodiment, the predetermined condition in the present invention is that the temperature Tb_H of the high-voltage battery 10 is lower than a predetermined set temperature, and the remaining capacity that the remaining capacity SOC_H is larger than the predetermined set SOC. The condition, the voltage condition that the output voltage Vb_H is higher than the predetermined set voltage, and the engine 3 are being emptied (in STEP 11 it is determined that the vacancy is being performed). It is composed of the conditions. The temperature condition, the remaining capacity condition, the voltage condition, and the condition that the idling is performed correspond to the third condition, the fourth condition, the second condition, and the first condition in the present invention, respectively.

  Further, the generator motor control means in the present invention is realized by the processing of the flowchart of FIG. 5 (specifically, the processing of STEPs 21, 22, 23, 25, and 26) and the processing of the vehicle overall ECU 24 and the motor ECU 22.

  Further, the steps 24 and 27 in the process of the flowchart of FIG. 5 and the process of the flowchart of FIG. 6 realize the DC / DC converter control means in the present invention.

  In the embodiment described above, only when the temperature condition, remaining capacity condition, and voltage condition related to the state of the high-voltage battery 10 and the condition that the engine 3 is blown are satisfied. The upper limit voltage protection control process (specifically, the processes of STEPs 22, 23, and 32) is executed, but only when the condition that the engine 3 is blown is satisfied, or The upper limit voltage protection control process (specifically, the processes of STEPs 22, 23, and 32) is executed when the voltage condition and the condition that the engine 3 is blown are satisfied. May be. Even in this case, it is possible to prevent the output voltage Vb_H of the high voltage battery 10 from exceeding the allowable upper limit value when the engine 3 is idle, including the case where the temperature condition and the remaining capacity condition are satisfied.

  In the above embodiment, in the upper limit voltage protection control process, the process of limiting the output voltage of the DC / DC converter 16 (the process of STEP 32) is performed. However, in a situation where a discharge current flows through the high-voltage battery 10. Since the output voltage Vb_H of the high-voltage battery 10 decreases, the output voltage Vb_H of the high-voltage battery 10 does not exceed the allowable upper limit value. Therefore, in order to prevent the output voltage Vb_H of the high-voltage battery 10 from exceeding the allowable upper limit value, the process of limiting the output voltage of the DC / DC converter 16 (the process of STEP 32) may be omitted.

  Further, in the present embodiment, the processing shown in the flowcharts of FIGS. 2 to 6 is executed by the battery ECU 23, but some processing may be executed by another ECU such as the vehicle integrated ECU 24. For example, the processing in FIGS. 3 to 5 may be executed by the vehicle overall ECU 24, or the processing in FIG. 4 may be executed by the engine ECU 21.

  The electric vehicle according to the present embodiment is a so-called parallel type hybrid vehicle, but may be a series type hybrid vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Electric vehicle, 2 ... Power generation source, 3 ... Engine, 4 ... Generator motor, 7 ... Drive wheel, 10 ... High voltage system battery (high voltage system power storage device), 11 ... Low voltage system battery (low voltage system power storage device), 12 DESCRIPTION OF SYMBOLS ... Low voltage | pressure system auxiliary equipment, 16 ... DC / DC converter, 22 ... Motor ECU (generator motor control means), 24 ... Vehicle control ECU (generator motor control means), STEP11 ... Emptying detection means, STEP1-9 , 12-15 ... Condition judging means, STEPs 21, 22, 23, 25, 26 ... Generator motor control means, STEPs 24, 27, 31 to 33 ... DC / DC converter control means.

Claims (7)

A power generation source that includes an engine and a generator motor having a rotor that rotates in conjunction with the output shaft of the engine, and that generates propulsion power for a vehicle by at least one of the engine and the generator motor, and the generator motor A high-voltage power storage device that is electrically connected to the generator motor so that power can be supplied to the generator motor during powering operation of the generator motor and the generated power can be charged during power generation operation of the generator motor; And a low-voltage power storage device that is electrically connected to the low-voltage power load that operates at a voltage lower than the output voltage of the high-voltage power storage device. In the idle operation state of the engine in a state where power transmission from the power generation source to the wheels of the vehicle is interrupted, at least the low-voltage electric load While controlling the output torque of the generator motor so that the generated power supplementing the power consumption is generated by the power generation operation of the generator motor driven by the engine, the generated power is passed through the DC / DC converter. In an electric vehicle having an idle power generation operation state to be supplied to a low-voltage power storage device or the low-voltage auxiliary machine electrical component,
In the idle power generation operation state, an emptying detection means for detecting occurrence of an emptying of the engine,
In the idle power generation operation state, it is a predetermined condition that is predetermined as a necessary condition for protecting the high-voltage power storage device, and that the engine idling detection means detects the engine idling. Condition determining means for determining whether or not a predetermined condition including at least the first condition is satisfied;
Generator motor control means for controlling the output torque of the generator motor by limiting the torque command value, which is the command value of the output torque of the generator motor, to zero torque when the judgment result of the condition judging means is affirmative An electric vehicle comprising: The electric vehicle according to claim 1,
The predetermined condition further includes a second condition that a detected value of an output voltage of the high-voltage power storage device is higher than a predetermined voltage. The electric vehicle according to claim 2,
The predetermined voltage includes a first predetermined voltage and a second predetermined voltage that is lower than the first predetermined voltage, and the condition determination means determines that the detected value of the output voltage of the high-voltage power storage device is the first predetermined voltage. The second condition is satisfied when the voltage rises from a lower voltage to a voltage higher than the first predetermined voltage, and after the satisfaction, the detected value of the output voltage of the high-voltage power storage device is lower than the second predetermined voltage It is determined that the second condition is maintained until the voltage drops to a voltage. In the electric vehicle according to claim 2 or 3,
The predetermined condition includes the first condition and the second condition, a third condition that a detected value of the temperature of the high-voltage power storage device is lower than a predetermined temperature, and a detected value of the remaining capacity of the high-voltage power storage device. An electric vehicle comprising: a fourth condition that is greater than a predetermined value. In the electric vehicle according to any one of claims 1 to 4,
The generator motor control means, at the idle power generation operation state, when the judgment result of the condition judgment means changes from a positive state to a negative state, at least the torque command value of the generator motor The output torque of the generator motor is controlled while setting the generated power to supplement the power consumption of the low-voltage electric load to be gradually changed to the torque command value for generating the generator motor. Electric vehicle. The electric vehicle according to claim 4, wherein
In the idling power generation operation state, when the determination result of the condition determination means is affirmative, the current is prevented from flowing from the DC / DC converter to the low-voltage power storage device or the low-voltage auxiliary electrical equipment. An electric vehicle further comprising DC / DC converter control means for controlling an output voltage of the DC / DC converter. The electric vehicle according to claim 6, wherein
The generator motor control means, at the idle power generation operation state, when the judgment result of the condition judgment means changes from a positive state to a negative state, at least the torque command value of the generator motor Controlling the output torque of the generator motor while setting to gradually change the generated power supplementing the power consumption of the low-voltage electric load to the torque command value for generating the generator motor,
The DC / DC converter control means changes the output voltage of the DC / DC converter when the judgment result of the condition judgment means changes from a positive state to a negative state in the idle power generation operation state. An electric vehicle characterized by controlling an output voltage of the DC / DC converter so as to gradually change from the DC / DC converter to a voltage at which a current can flow to the low-voltage power storage device or the low-voltage auxiliary electrical equipment. .