JP2011073622A - Drive control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain temporary torque increase of a motor for traveling, with a further simple structure. <P>SOLUTION: The drive control device for hybrid vehicle includes: a generator (2) which generates power by driving force of an engine 1; a battery 3 storing the power generated by the generator (2); a motor 4 for traveling which receives power supplied from at least one of the generator (2) and the battery 3 to drive the vehicle; and a power generation control means 23 which calculates a required current value of the motor 4 for traveling based on a driving condition, and controls the engine 1 and the generator to generate power according to the calculated required current value. The power generation control means 23 performs generation increase control, when a predetermined level or more of acceleration is requested, to cause the generator (2) to generate a current value Ig1 larger than the required current value Im1 of the motor 4 for traveling by a predetermined amount, and charge the battery 3 with a surplus current Is that is the difference between them, through the inverter 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention drives an vehicle by receiving power from at least one of the engine, a generator that generates electric power using the driving force of the engine, a battery capable of storing electric power generated by the generator, and the generator and the battery. A driving motor, an inverter provided between the generator and battery and the driving motor, driving state determination means for determining a driving state of the vehicle, and a driving state determined by the driving state determination means. The present invention relates to a drive control device for a hybrid vehicle, comprising: a power generation control means for controlling the engine and the generator so as to generate a required current value of the traveling motor based on the calculated current value and generating electric power according to the calculated required current value .

  Conventionally, as shown in Patent Document 1 below, a hybrid including an engine, a motor generator for cranking the engine, a battery capable of storing electric power to be supplied to the motor generator, and an inverter for voltage conversion In a vehicle, when a booster unit is provided between the battery and the inverter and the engine is cranked, the power from the battery is first boosted by the booster unit and then supplied to the motor generator through the inverter. It has been broken.

JP 2006-194133 A

  The hybrid vehicle disclosed in Patent Document 1 has an advantage that cranking can be smoothly performed using the electric power boosted by the booster circuit when cranking an engine that requires a relatively large amount of electric power.

  In addition, if the electric power boosted by the booster circuit as described above is supplied to, for example, a traveling motor for driving the vehicle, the torque of the traveling motor can be temporarily increased. It is also possible to cope with required driving conditions (for example, when suddenly accelerating or traveling suddenly uphill).

  However, it is not so often that high torque as described above is required during traveling, and the frequency with which the booster circuit is actually used is considered to be low. Therefore, it is not a good idea to use a dedicated booster circuit for such a low request frequency in terms of cost effectiveness. Of course, if the capacity of the battery is increased, it is not necessary to use a booster circuit, but this time the problem is that the cost of the battery is increased and the occupied space is also increased.

  The present invention has been made in view of the above circumstances, and provides a drive control device for a hybrid vehicle capable of realizing a temporary torque increase of a traveling motor with a simpler configuration. Objective.

  In order to solve the above-described problems, the present invention provides an engine, a generator that generates electric power using the driving force of the engine, a battery that can store electric power generated by the generator, and at least one of the generator and the battery. A driving motor for receiving power from the vehicle to drive the vehicle, an inverter provided between the generator and the battery and the driving motor, driving state determination means for determining the driving state of the vehicle, driving Power generation control means for calculating the required current value of the traveling motor based on the driving state determined by the state determination means and controlling the engine and the generator so as to generate electric power according to the calculated required current value; When the driving state determination means determines that there is a request for acceleration of a predetermined level or higher, the power generation control system is provided. The means executes a power generation amount increase control for causing the generator to generate a current value that is a predetermined amount larger than the required current value of the traveling motor and charging the battery with a surplus current consisting of the difference through the inverter. (Claim 1).

  According to the present invention, since a current larger than the required current value of the traveling motor is supplied from the generator and the generated surplus current is charged to the battery, the boosted amount generated by the surplus current flowing through the resistance element is reduced. By adding to the terminal voltage of the inverter, the torque of the traveling motor can be temporarily increased. In addition, since the surplus current only needs to be used for charging the battery, for example, unlike a case where a dedicated booster circuit is provided to increase the terminal voltage of the inverter, the torque of the traveling motor can be increased with a simpler and lower cost configuration. There is an advantage that it can be planned.

  In the present invention, preferably, a bypass line with a resistor provided in parallel with the power transmission line between the inverter and the battery is provided, and in the power generation amount increase control, the surplus current is supplied to the bypass line. The battery is charged through (Claim 2).

  According to this configuration, the terminal voltage of the inverter can be effectively boosted even with a small surplus current, and there is an advantage that the torque of the traveling motor can be increased without imposing a large burden on the battery.

  In the above configuration, more preferably, the power transmission line includes a main relay, and the bypass line is closed before the main relay when the vehicle is started, and the smoothing capacitor in the inverter is provided. A precharge relay for precharging, and the main relay is opened and the precharge relay is closed during the power generation increase control.

  According to this configuration, it is possible to charge the surplus current to the battery using an existing system for precharging without providing a dedicated bypass line, and it is possible to easily and effectively realize the torque increase of the traveling motor. There is an advantage.

  In the above-described configuration, more preferably, it includes temperature detection means for detecting the temperature of the resistor of the bypass line, and the power generation control means is configured such that when the temperature of the resistor detected by the temperature detection means becomes a predetermined value or more, Execution of the power generation increase control is prohibited (claim 4).

  According to this configuration, there is an advantage that the traveling motor can be temporarily increased in torque while reliably preventing damage due to excessive temperature rise of the resistor.

  In the present invention, preferably, the power generation control means sets the surplus current charged to the battery to be larger as the charge amount of the battery is lower in the power generation amount increase control (Claim 5).

  According to this configuration, it is possible to increase the torque of the traveling motor during power generation increase control to the same level regardless of the charge amount of the battery, and to stably generate a high torque according to the acceleration request. There is an advantage that you can.

  In the present invention, the power generation control means may execute or prohibit the power generation amount increase control in accordance with a temperature state of the battery.

  Note that “according to the temperature state of the battery” means depending on the state quantity directly or indirectly related to the temperature of the battery. For example, the detection value of the battery temperature or generated from the inside of the battery It is conceivable that the power generation amount increase control is executed or prohibited depending on the concentration of the gas to be generated.

  According to this configuration, for example, even when a surplus current is charged using a normal power transmission line without using a bypass line with a resistor, the battery is properly protected from excessive temperature rise while traveling There is an advantage that the torque of the motor can be temporarily increased.

  The power generation control means may limit the duration of the power generation increase control to a predetermined time, and set the predetermined time shorter as the surplus current charged in the battery increases. 7).

  There is an advantage that proper protection of the battery can be achieved by timer control without requiring any means for detecting the temperature state of the battery.

  As described above, according to the hybrid vehicle drive control device of the present invention, the temporary torque increase of the travel motor can be realized with a simpler configuration.

1 is a plan view showing an overall configuration of a drive control apparatus for a hybrid vehicle according to an embodiment of the present invention. It is a block diagram which shows the control system of the said drive control apparatus. It is a circuit diagram of a generator, a battery, a motor for driving, and an inverter. It is a figure which shows the output characteristic of a motor for driving | running | working. FIG. 4 is a diagram corresponding to FIG. FIG. 4 is a view corresponding to FIG. 3 showing a current flow during normal control. It is a figure which shows the output characteristic at the time of the normal time of the motor for driving | running | working, and the output characteristic at the time of power generation amount increase control. It is a flowchart which shows the specific content of electric power generation amount increase control. It is a figure which shows the output characteristic of the motor for driving | running | working read during the process of the flowchart of FIG. It is a figure which shows the state change of each part when control based on the flowchart of FIG. 8 is performed.

  FIG. 1 is a plan view showing the overall configuration of a drive control apparatus for a hybrid vehicle according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a control system of the apparatus. The hybrid vehicle drive control device shown in these drawings includes an engine 1 provided as a power source for power generation, and a generator 2 that generates power by obtaining driving force from the engine 1 (corresponding to the generator according to the present invention). And a battery 3 capable of storing electric power generated by the generator 2 and a power source for traveling, and for driving to drive the drive wheels 9 by receiving power supply from at least one of the generator 2 and the battery 3 An inverter 5 that converts an input / output current between the motor 4, the generator 2, the battery 3, and the traveling motor 4 from alternating current to direct current or vice versa, and a controller 20 that comprehensively controls these components. ing. As is clear from the above configuration, the hybrid vehicle of the present embodiment uses a so-called series type hybrid in which the engine 1 is exclusively used as a power source for power generation and the drive wheels 9 are driven only by the traveling motor 4. It is a vehicle.

  The traveling motor 4 is connected to a differential device 7 disposed in an intermediate portion of the drive shaft 8, and the driving force of the traveling motor 5 is transmitted via the differential device 7 and the drive shaft 8. It is transmitted to a pair of left and right drive wheels 9 attached to both ends of the drive shaft 8. In the hybrid vehicle of the present embodiment, two of the four wheels provided on the front, rear, left, and right are drive wheels 9, and the remaining wheels are driven wheels 10.

  The generator 2 receives a supply of electric power from the battery 3 through the inverter 5 when the engine 1 is started, and thereby functions as a starter for forcibly rotating the crankshaft of the engine 1 and starting the engine 1. It has both functions as an alternator that generates power by obtaining driving force from the crankshaft.

  The traveling motor 4 is composed of, for example, a three-phase AC synchronous motor, and is driven by electric power supplied from at least one of the generator 2 and the battery 3 via the inverter 5 during the power running operation of the vehicle. Is transmitted to the drive wheel 9 via the differential device 7 and the drive shaft 8, while at the time of regenerative operation such as when decelerating or traveling downhill, power is obtained from the drive shaft 8 to generate power. Electric power is stored in the battery 3 via the inverter 5.

  The inverter 5 includes a first inverter 5A and a second inverter 5B. When the generator 2 operates as a starter, the first inverter 5A converts a direct current from the battery 3 into an alternating current and supplies the alternating current to the generator 2, while when the generator 2 operates as an alternator, The alternating current generated by the generator 2 is converted into a direct current and supplied to the second inverter 5B or the battery 3.

  The second inverter 5B converts a direct current generated by the generator 2 and converted into a direct current by the first inverter 5A or a direct current supplied from the battery 3 into an alternating current during power running of the vehicle. While the subsequent alternating current is supplied to the traveling motor 4, the alternating current from the traveling motor 4 is converted into a direct current and supplied to the battery 3 during the regenerative operation of the vehicle.

  FIG. 3 is a circuit diagram of the generator 2, the battery 3, the traveling motor 4, and the inverter 5. As shown in the figure, the battery 3 and the inverter 5 are connected to each other via a power transmission line 13, and a main relay 14 is provided in the power transmission line 13. And according to ON / OFF of this main relay 14, the said power transmission line 13 is interrupted | blocked or opened.

  Between the battery 3 and the inverter 5, a bypass line 15 is provided in parallel with the power transmission line 13. The bypass line 15 includes a resistor 16 and a precharge relay 17 and has a function of limiting a current flowing into the inverter 5 when the vehicle is started.

  That is, when the vehicle is started, the electric charge of the smoothing capacitor 12 provided in the inverter 5 is zero and the impedance is low, so the main relay 14 is immediately closed (ON) in this state and the power transmission line 13 is opened. If it does, a large current will flow into the said smoothing capacitor 12 instantly, and the smoothing capacitor 12 etc. may be damaged. Therefore, when the vehicle is started, the smoothing capacitor 17 is not connected through the power transmission line 13 but the bypass line 15 by closing (ON) the precharge relay 17 before the main relay 14 (see the state of FIG. 5 described later). An electric current is supplied to 12. At this time, the current flowing into the smoothing capacitor 12 is limited by the impedance (resistor R) of the resistor 16 provided in the bypass line 15, and the smoothing capacitor 12 is gradually charged (precharge).

  Then, as described above, a certain amount of electric charge is charged in the smoothing capacitor 12 through the bypass line 15, and then the main relay 14 is closed (ON), and then the precharge relay 17 is opened (OFF). Thereby, since the transmission line 13 is opened after the impedance of the smoothing capacitor 12 rises to some extent, a large current does not flow into the smoothing capacitor 12 instantaneously, and damage or the like is prevented.

  FIG. 4 is a diagram showing output characteristics of the traveling motor 4. As shown in the figure, the maximum value of the torque T obtained from the traveling motor 4 gradually decreases when the motor rotation speed N exceeds a predetermined value Nt. The torque T is lowered because the field weakening control is executed in the range of the rotational speed N> Nt. The field weakening control is control for reducing the induced voltage Va by shifting the phase of the sine wave of the current that drives the traveling motor 4.

  That is, when the traveling motor 4 rotates, as shown in FIG. 3, an induced voltage Va corresponding to the rotational speed N is generated. While the induced voltage Va is smaller than the terminal voltage Vdc of the inverter 5, A current Im flows from the inverter 5 side to the traveling motor 4 due to the potential difference. However, when the motor rotation speed N further increases from this state and reaches the predetermined value Nt in FIG. 4, the induced voltage Va becomes substantially equal to the terminal voltage Vdc of the inverter 5, and the current Im flows to the traveling motor 4. It becomes difficult.

  Therefore, if the field weakening control is executed and the induced voltage Va is forcibly lowered before the current Im stops flowing, the inverter 5 and the traveling motor 4 can be connected even in a region higher than the predetermined value Nt. A potential difference can be generated in the travel motor 4 and the traveling motor 4 can be driven to a higher speed. However, since the field weakening control is a control for shifting the phase of the sine wave of the drive current, when this control is executed, the efficiency of the traveling motor 4 decreases and the torque T decreases. This is why the torque T decreases in the range of the rotational speed N> Nt. Hereinafter, the predetermined value Nt that is a threshold value for executing the field weakening control is referred to as a field weakening threshold value Nt.

  Similarly, as shown in FIG. 4, the output characteristics of the traveling motor 4 change according to the charge amount SOC of the battery 3. That is, as the charge amount SOC of the battery 3 increases, the terminal voltage Vdc (FIG. 3) of the inverter 5 increases, and the traveling motor 4 can be driven to a higher rotation side. On the contrary, when the charge amount SOC of the battery 3 is low, the traveling motor 4 can be driven only in a lower rotational range than when the charge amount SOC is high. As described above, the output characteristics of the traveling motor 4 expand or contract in the direction of the rotation speed (horizontal axis) according to the charge amount SOC of the battery 3. In response to this, the value of the field weakening threshold Nt also varies.

  Returning to FIG. 2 again, the function of the controller 20 will be described. The controller 20 is a control device including a conventionally known CPU, ROM, RAM, and the like, and is electrically connected to various sensors provided in each part of the vehicle as shown in FIG. Specifically, the controller 20 includes a vehicle speed sensor 30 that detects the traveling speed (vehicle speed) of the vehicle, an accelerator opening sensor 31 that detects an opening ACC of an accelerator pedal (not shown) that is depressed by the driver, A motor rotational speed sensor 32 for detecting the rotational speed N of the output shaft of the traveling motor 4; a voltage sensor 33 for detecting the terminal voltage Vb of the battery 3; a current sensor 34 for detecting the charge / discharge current Ib of the battery 3; A temperature sensor 35 for detecting the temperature Tr of the resistor 16 (FIG. 3) between the battery 3 and the inverter 5 is connected to each other, and various control information detected by each of the sensors 30 to 35 is stored in the controller. 20 is input as an electrical signal.

  The controller 20 performs various calculations based on input information from the sensors 30 to 35, and comprehensively controls the operations of the engine 1, the generator 2, the traveling motor 4, the inverter 5, and the like based on the results. To control.

  Next, more specific functions of the controller 20 will be described. The controller 20 includes a storage unit 21, an operation state determination unit 22, and a power generation control unit 23 as functional elements.

  The storage means 21 stores various programs and data related to vehicle control. For example, the storage means 21 stores output characteristic data of the traveling motor 4 as shown in FIG. 4 for each value of the charge amount SOC of the battery 3.

  The driving state determination means 22 acquires the accelerator opening degree ACC detected by the accelerator opening degree sensor 31 and the rotational speed N of the traveling motor 4 detected by the motor rotational speed sensor 32, respectively, and based on the values. Various determinations regarding the driving state of the vehicle are made.

  The power generation control unit 23 calculates a required current value of the traveling motor 4 based on the driving state determined by the driving state determination unit 22, and generates power corresponding to the calculated required current value. The engine 1 and the generator 2 are controlled.

  In particular, when the operating state determining means 22 determines that the rotational speed N of the traveling motor 4 exceeds the field weakening threshold Nt in FIG. 4 and the accelerator opening degree ACC is fully open, the power generation control is performed. As shown in FIG. 5, the means 23 causes the generator 2 to generate a current value Ig1 larger than the required current value Im1 of the traveling motor 4 by a predetermined amount, and the surplus current Is consisting of the difference (Ig1-Im1) is The battery 3 is charged via the inverter 5. Hereinafter, such control is referred to as power generation amount increase control.

  During execution of the power generation increase control as described above, between the inverter 5 and the battery 3, the main relay 14 is opened (OFF), the power transmission line 13 is shut off, and the precharge relay 17 is closed (ON). ) And the bypass line 15 is opened. Then, the surplus current Is flows into the battery 3 through the bypass line 15, and a voltage (R × Is) generated by energization of the resistor 16 is generated in the bypass line 15. Further, since the battery 3 has an internal resistance r, a voltage (r × Is) due to the internal resistance r is also generated.

  As described above, when the surplus current Is flows into the battery 3 and a voltage ((R + r) × Is) is generated due to the resistance R of the resistor 16 of the bypass line 15 or the internal resistance r of the battery 3, the terminal of the inverter 5 The voltage Vdc (the voltage between the contacts PQ in FIG. 5) increases by the voltage ((R + r) × Is) due to the resistance. As described above, when the terminal voltage Vdc of the inverter 5 rises, the traveling motor 4 can be driven to a higher rotational side. Therefore, the output characteristics of the traveling motor 4 are as shown in FIG. Changes to a characteristic (output characteristic B) as indicated by a dashed line.

  As described above, by executing the power generation amount increase control that causes the generator 2 to generate the current value Ig1 (= Im1 + Is) larger than the required current value Im1 of the traveling motor 4, the output characteristics of the traveling motor 4 are shown in FIG. 7 is changed to the characteristics shown by the one-dot chain line, and a high torque can be exhibited even in a high rotation range. Hereinafter, the output characteristic (one-dot chain line) of the traveling motor 4 when the power generation amount increase control is executed is referred to as an output characteristic B, and the output characteristic of the traveling motor 4 during normal time when the power generation amount increase control is not performed ( A solid line or a broken line) is an output characteristic A.

  Here, as described above, the output characteristic A in the normal state changes according to the charge amount SOC of the battery 3, and therefore, in FIG. 7, different output characteristics A are set depending on the charge amount SOC. In the figure, output characteristics when the charge amount SOC is 30, 40, 50, and 60% are illustrated. On the other hand, the output characteristic B during the power generation amount increase control is constant regardless of the charge amount SOC of the battery 3. Therefore, when the output characteristic of the traveling motor 4 is changed from A to B, the width of the change becomes larger as the original charge amount SOC is lower. For this reason, when the power generation amount increase control is executed, the current increase width (that is, the surplus current Is) is set larger as the charge amount SOC of the battery 3 is lower. The output characteristics A and B as described above are stored in the storage unit 21 as a map.

  In FIG. 7, with respect to the normal output characteristic A, when the maximum value of the charge amount SOC of the battery 3 is 60% and the charge amount SOC exceeds 60%, the power generation as described above is performed. The amount increase control (switching to the output characteristic B) is not executed. This is because the power generation amount increase control for charging the battery 3 with the surplus current Is cannot be performed unless a certain amount of free capacity exists in the battery 3.

  Next, specific contents of the control performed by the controller 20 regarding the power generation increase control will be described with reference to the flowchart of FIG. When the processing shown in this flowchart is started, the operation state determination means 22 of the controller 20 detects each sensor from the accelerator opening sensor 31, the motor rotation speed sensor 32, the voltage sensor 33, the current sensor 34, and the temperature sensor 35. As values, control for reading the accelerator opening ACC, the rotational speed N of the traveling motor 4, the terminal voltage Vb of the battery 3, the current Ib, and the temperature Tr of the resistor 16 is executed (step S1).

  Next, the operation state determination means 22 of the controller 20 executes control for calculating the charge amount SOC of the battery 3 based on the voltage Vb and current Ib of the battery 3 read in step S1 (step S2).

  Next, the operating state determination means 22 of the controller 20 reads out the output characteristic A of the normal traveling motor 4 that matches the SOC from the charge amount SOC calculated in step S2 from the map of FIG. Then, control is performed to read the output characteristic B when the power generation amount increase control (control in step S9 described later) is performed (step S3). For example, if the charge amount SOC = 60%, the data of the solid line is read from the data of the plurality of output characteristics A shown in FIG. 7, and the data of the output characteristic B shown by the one-dot chain line is also read. FIG. 9 shows the output characteristics A and B read in step S3.

  Next, the operation state determination means 22 of the controller 20 determines that the rotational speed N of the traveling motor 4 is higher than the field weakening threshold Nt in FIG. 9, the accelerator opening ACC is higher than the full open determination threshold ACCmax, 3 is executed to determine whether or not all three conditions of the charge amount SOC of 3 are 60% or less are satisfied (step S4).

  Specifically, it is determined whether or not the rotational speed N of the traveling motor 4 read in step S1 is higher than the field weakening threshold Nt of the output characteristic A (FIG. 9) specified in step 3 above. If YES in this step, it is determined whether or not the accelerator opening degree ACC read in step S1 is higher than a threshold value (full open determination threshold value) ACCmax indicating that the accelerator pedal is fully open. If YES, it is determined whether or not the charge amount SOC of the battery 3 calculated in step S2 is 60% or less.

  When it is determined YES in step S4, that is, when it is confirmed that all the conditions of the motor rotation speed N> Nt, the accelerator opening ACC> ACCmax, and the charge amount SOC ≦ 60% are satisfied, the controller 20 The operation state determination means 22 executes control for determining whether or not the temperature Tr of the resistor 16 read in step S1 is less than a predetermined threshold value Tr1 (step S5).

  When it is determined YES in step S5 and it is confirmed that the temperature Tr <Tr1 of the resistor 16 is satisfied, the power generation control unit 23 of the controller 20 outputs the output characteristic B in the power generation amount increase control shown in FIG. Based on the above, the control for calculating the required torque of the traveling motor 4 is executed (step S6). In this step S6, since the motor rotational speed N> Nt and the accelerator opening degree ACC> ACCmax (fully open), the required torque is calculated at the point B1 in FIG. Torque.

  When the required torque is calculated as described above, the power generation control means 23 of the controller 20 executes a control for calculating the required current value Im1 of the traveling motor 4 based on the calculated required torque (step). S7).

  Next, as shown in FIG. 5, the power generation control means 23 of the controller 20 closes (ON) the precharge relay 17 of the bypass line 15 and opens (OFF) the main relay 14 of the power transmission line 13. Thus, the control for opening the bypass line 15 and blocking the power transmission line 13 is executed (step S8).

  Next, the power generation control means 23 of the controller 20 should generate the current value Ig1 (= Im1 + Is) obtained by adding the surplus current Is to the required current value Im1 of the traveling motor 4 calculated in step S7 by the generator 2. It sets as an electric current value, and controls the drive of the engine 1 and the generator 2 according to this (step S9). At this time, the drive motor 4 is controlled so that its drive current coincides with the required current value Im1. Thereby, surplus current Is generated as a difference flows into battery 3 and voltage (R + r) × Is generated by resistance R of resistor 16 and internal resistance r of battery 3 is added to terminal voltage Vdc of inverter 5. The output characteristic of the traveling motor 4 changes to the output characteristic B in FIG. As described above, the surplus current Is for boosting the terminal voltage Vdc of the inverter has a low charge SOC of the battery 3 and a large difference between the normal output characteristic A and the boosted output characteristic B. It is set so large.

  Next, when it is determined NO in step S4 or step S5, that is, at least one of motor rotation speed N> Nt, accelerator opening degree ACC> ACCmax, charge amount SOC ≦ 60%, resistor temperature Tr <Tr1 A control operation when the condition is not satisfied will be described. In this case, the power generation control means 23 of the controller 20 executes control for calculating the required torque of the traveling motor 4 based on the normal output characteristic A shown in FIG. 9 (step S10). For example, if the determination in step S4 is YES and the determination in step S5 is NO, the motor rotational speed N> Nt and the accelerator opening ACC> ACCmax (fully open) at the time of step S10. When the required torque is calculated in light of this condition in the normal output characteristic A, the required torque is the torque at point A1 in FIG.

  When the required torque is calculated as described above, the power generation control unit 23 of the controller 20 executes control for calculating the required current value Im2 of the traveling motor 4 based on the calculated required torque (step). S11).

  Next, as shown in FIG. 3, the power generation control means 23 of the controller 20 opens (OFF) the precharge relay 17 of the bypass line 15 and closes (ON) the main relay 14 of the power transmission line 13. Thus, the control for blocking the bypass line 15 and opening the power transmission line 13 is executed (step S12).

  Next, the power generation control means 23 of the controller 20 sets the required current value Im2 of the traveling motor 4 calculated in step S11 as the current value Ig2 to be generated by the generator 2, and according to this, the engine 1 and The drive of the generator 2 is controlled (step S13). At this time, the driving motor 4 is controlled so that its drive current matches the required current value Im2. As a result, as shown in FIG. 6, the current value Ig <b> 2 generated by the generator 2 is supplied as it is to the traveling motor 4 as the required current value Im <b> 2 of the traveling motor 4, and no surplus current flows through the battery 3. .

  Next, the state change of each part when the control based on the flowchart as described above is executed will be described based on a specific example shown in FIG. In FIG. 10, when the accelerator opening is fully opened at time t1, before and after that, the required current value Im of the traveling motor 4, the generated current value Ig of the generator 2, and the charging / discharging current value Ib of the battery 3 are shown. , And how the temperature Tr of the resistor 16 changes with time. As conditions other than those shown in the figure, it is assumed that the motor rotation speed N> the field weakening threshold Nt, and the charge amount SOC of the battery 3 ≦ 60%.

  In the example of FIG. 10, the temperature Tr of the resistor 16 is lower than the threshold value Tr1 at the time t1 when the accelerator opening degree ACC is fully opened ((c) in FIG. 10). In this case, since YES is determined in step S5 in FIG. 8, the processing of the motor 4 for traveling based on the output characteristic B in FIG. 9 (output characteristic at the time of power generation increase control) is performed by the processing in subsequent steps S6 to S9. A required torque is calculated, and a required current value Im1 corresponding to the torque is set (FIG. 10B). Similarly, as shown in FIG. 10B, a value obtained by adding the surplus current Is to the required current value Im1 is set as the generated current value Ig1 of the generator 2.

  At this time, since the actual increase in the generated current value Ig1 has a response delay, the generated current value Ig1 coincides with the required current value Im1 for the first time at a time t2 when a predetermined time elapses from the time t1. During this period (interval between time points t1 and t2), only the generated current value Ig1 of the generator 2 is insufficient for the driving current of the traveling motor 4, and the shortage is covered by the discharge from the battery 3.

  When a further time elapses from the time point t2, the generated current value Ig1 of the generator 2 exceeds the required current value Im1 of the traveling motor 4, and the surplus current Is is sent to charge the battery 3 (time points t2 to t2). t3).

  When the surplus current Is is charged in the battery 3 as described above, the temperature Tr of the resistor 16 gradually increases as shown in the section from time t2 to t3 in FIG. When the temperature Tr reaches the threshold value Tr1 at time t3, the determination in step S5 in FIG. 8 is NO, and the processing in steps S10 to S13 thereafter results in the output characteristic A (normal output characteristic) in FIG. The required torque of the traveling motor 4 is calculated, and the required current value Im2 corresponding to the torque is set (FIG. 10B). Similarly, as shown in FIG. 10B, a current value that coincides with the required current value Im2 is set as the generated current value Ig2 of the generator 2. Thereby, after the time point t3, the current flowing through the battery 3 becomes zero, and the temperature Tr of the resistor 16 starts to decrease.

  As described above, in the hybrid vehicle drive control device of the present embodiment, when it is determined that a predetermined condition such as the accelerator opening ACC being fully open is satisfied (YES in steps S4 and S5 in FIG. 5). In this case, the generator 2 generates a current value Ig1 larger than the required current value Im1 of the traveling motor 4 by a predetermined amount, and the battery 3 is charged with the surplus current Is consisting of the difference via the inverter 5. Since the amount increase control (step S9) is executed, there is an advantage that the temporary torque increase of the traveling motor 4 can be realized with a simpler configuration.

  That is, in the above embodiment, since the generator 2 supplies the generated current value Ig1 larger than the required current value Im1 of the traveling motor 4 and charges the generated surplus current Is to the battery 3, the surplus current Is is a resistance. By adding the boosted voltage generated by flowing through the elements (in the above embodiment, the boosted voltage (R + r) × Is due to the resistance R of the resistor 16 and the internal resistance r) to the terminal voltage Vdc of the inverter 5, Torque can be increased temporarily. In addition, since the surplus current Is only needs to be used for charging the battery 3, for example, unlike the case where a dedicated booster circuit is provided to increase the terminal voltage Vdc of the inverter 5, the traveling motor can be configured with a simpler and lower cost. There is an advantage that a torque increase of 4 can be achieved.

  In the embodiment, the bypass line 15 with the resistor 16 is provided between the inverter 5 and the battery 3, and the surplus current Is is charged to the battery 3 through the bypass line 15 in the power generation increase control. As a result, the terminal voltage Vdc of the inverter 5 can be effectively boosted even with a small surplus current Is, and there is an advantage that the torque of the traveling motor 4 can be increased without imposing a heavy burden on the battery 3.

  For example, it is possible to charge the battery 3 with the surplus current Is through the power transmission line 13 between the inverter 5 and the battery 3 instead of the bypass line 15. Only r × Is due to the internal resistance r of the battery 3 is obtained. Therefore, if the same boosting effect is to be obtained, it is necessary to increase the surplus current Is, and the burden on the battery 3 increases.

  On the other hand, in the above embodiment, since the surplus current Is is charged in the battery 3 through the bypass line 15 with the resistor 16, the surplus current Is can be reduced, and the burden on the battery 3 can be effectively reduced. it can.

  In particular, in the above embodiment, since the surplus current Is is charged to the battery 3 through the bypass line 15 used when the smoothing capacitor 12 in the inverter 5 is precharged, it is possible to precharge without providing a dedicated bypass line. The surplus current Is can be charged into the battery 3 using the existing system for charging, and there is an advantage that the torque increase of the traveling motor 4 can be realized easily and effectively.

  Further, in the above embodiment, when the temperature Tr of the resistor 16 detected by the temperature sensor 35 is equal to or higher than the predetermined threshold value Tr1 (NO in step S5 in FIG. 8), the generated current value of the generator 2 is set. The power generation amount increase control is prohibited from being executed by lowering it to the same value (Ig2) as the required current value Im2 of the traveling motor 4. According to such a configuration, if the power generation amount increase control is executed frequently or for a long time and the temperature of the resistor 16 rises considerably, the power generation amount increase control is prohibited until the temperature of the resistor 16 decreases. Therefore, there is an advantage that the torque of the traveling motor 4 can be temporarily increased while reliably preventing the resistor 16 from being damaged due to an excessive temperature rise.

  Further, in the above-described embodiment, during the power generation amount increase control, as the charge amount SOC of the battery 3 is lower, the surplus current Is charged to the battery 3 is set to be larger. Regardless of the value, the torque of the traveling motor 4 during the power generation increase control can be increased to the same level, and a high torque according to the acceleration request (accelerator opening ACC) can be stably generated. There is an advantage.

  In the above embodiment, the bypass line 15 with the resistor 16 is provided between the inverter 5 and the battery 3, and the surplus current Is is charged to the battery 3 through the bypass line 15 in the power generation increase control. However, as described above, the surplus current Is may be charged through the power transmission line 13 between the inverter 5 and the battery 3. In this case, in order to prevent an excessive burden on the battery 3, it is desirable to detect the temperature state of the battery 3 and execute or prohibit the power generation amount increase control according to the result.

  For example, if the temperature of the battery 3 is directly detected and the temperature is equal to or higher than a predetermined value, the power generation amount increase control may be prohibited. Further, when the battery 3 becomes high temperature, the concentration of gas generated from the internal electrolyte etc. increases, so that when the concentration of this gas exceeds a predetermined value, the power generation amount increase control is prohibited. Also good. As a result, it is possible to temporarily increase the torque of the traveling motor 4 while appropriately protecting the battery 3.

  In addition, when the relationship between the value of the surplus current Is and the amount of temperature rise caused by charging the surplus current Is to the battery 3 is known in advance, the charging time of the surplus current Is (power generation amount) The duration of the increase control) may be limited to a time set according to the value of the surplus current Is.

  For example, in the case of FIG. 10, the temperature Tr of the resistor 16 reaches the upper limit temperature (threshold value) Tr1 at a time point t3 when a predetermined time has elapsed from a time point t2 at which the battery 3 starts to be charged with the surplus current Is. At this time, the time (t2 to t3) required to reach the upper limit temperature Tr1 should be shorter as the surplus current Is is larger. Therefore, the time until the upper limit temperature Tr1 is reached (time limit) is checked in advance in relation to the surplus current Is, and the duration time is controlled to be within the limit in the power generation increase control. By doing so, it is possible to easily protect the bypass line 15 without directly measuring the temperature of the resistor 16.

  This is the same when the surplus current Is is charged through the power transmission line 13 instead of the bypass line 15. In this case, by investigating the relationship between the time until the temperature of the battery 3 reaches the upper limit value and the surplus current Is, the temperature of the battery 3 can be controlled by timer control without directly measuring the temperature of the battery 3. Appropriate protection can be achieved.

  In the above embodiment, the power generation amount increase control for generating the surplus current Is and charging the battery 3 is executed when the condition including that the accelerator opening ACC is fully open (ACC> ACCmax) is satisfied. However, the power generation amount increase control may be performed as long as the accelerator opening is equal to or higher than a predetermined high value (for example, about 80%). May be executed.

1 Engine 2 Generator (generator)
DESCRIPTION OF SYMBOLS 3 Battery 4 Driving motor 5 Inverter 12 Smoothing capacitor 13 Power transmission line 14 Main relay 15 Bypass line 16 Resistor 17 Precharge relay 22 Operating state determination means 23 Power generation control means 35 Temperature sensor (temperature detection means)
Is surplus current Tr (resistor) temperature

Claims (7)

An engine, a generator that generates electric power using the driving force of the engine, a battery that can store electric power generated by the generator, and a travel motor that drives the vehicle by receiving electric power from at least one of the generator and the battery An inverter provided between the generator / battery and the driving motor, driving state determination means for determining a driving state of the vehicle, and the driving condition based on the driving state determined by the driving state determination means A drive control device for a hybrid vehicle, comprising a power generation control means for controlling the engine and the generator so as to calculate a required current value of the motor and generate electric power according to the calculated required current value,
When it is determined by the operating state determining means that there is an acceleration request above a predetermined level, the power generation control means causes the generator to generate a current value that is a predetermined amount larger than the required current value of the traveling motor, and A drive control device for a hybrid vehicle, which executes power generation amount increase control for charging the battery with a surplus current consisting of a difference through the inverter. The drive control apparatus for a hybrid vehicle according to claim 1,
A bypass line with a resistor provided in parallel to the power transmission line between the inverter and the battery,
In the power generation increase control, the surplus current is charged to the battery through the bypass line. The drive control apparatus for a hybrid vehicle according to claim 2,
The power transmission line has a main relay,
The bypass line includes the resistor and a precharge relay that is closed before the main relay at the start of the vehicle and precharges the smoothing capacitor in the inverter.
In the power generation increase control, the main relay is opened and the precharge relay is closed. In the hybrid vehicle drive control device according to claim 2 or 3,
Temperature detecting means for detecting the temperature of the resistor of the bypass line,
The drive control device for a hybrid vehicle, wherein the power generation control unit prohibits execution of the power generation amount increase control when the temperature of the resistor detected by the temperature detection unit becomes equal to or higher than a predetermined value. In the hybrid vehicle drive control device according to any one of claims 1 to 4,
The power generation control means sets the surplus current charged in the battery to be larger as the charge amount of the battery is lower during the power generation amount increase control. The drive control apparatus for a hybrid vehicle according to claim 1,
The drive control device for a hybrid vehicle, wherein the power generation control means executes or prohibits the power generation amount increase control in accordance with a temperature state of the battery. The drive control apparatus for a hybrid vehicle according to claim 1,
The power generation control means limits the duration of the power generation amount increase control to a predetermined time, and sets the predetermined time to be shorter as the surplus current charged in the battery is larger. .

Images