JP2020088918A - Power generation torque control device for rotary electric machine - Google Patents

Abstract

To provide a power generation torque control device for a rotary electric machine capable of making compatible suppression of engine stall and suppression of undershoot of a battery voltage.SOLUTION: A power generation torque control device (14) controls a power generation torque of a rotary electric machine (17) in which a battery (22) is charged by generating power while using a driving torque of an engine (101). The power generation torque control device comprises: a first calculation unit which calculates a command value of the power generation torque; a guard value setting unit which sets an upper limit guard value of the command value on the basis of a response speed of the driving torque and the command value; a second calculation unit which calculates a restriction command value restricting the command value equal to or smaller than the upper limit guard value; and a control unit which controls the power generation torque into the restriction command value.SELECTED DRAWING: Figure 1

Description

The present invention relates to a device for controlling a power generation torque of a rotating electric machine that generates power by using a drive torque of an engine.

Conventionally, in this type of device, there is a device that performs a gradual excitation control that gradually increases an exciting current flowing in a field coil of a rotating electric machine in order to suppress a sudden increase in a power generation torque that acts as a load torque on an engine. (See Patent Document 1). In the device described in Patent Document 1, the excitation duty is set to a predetermined duty value (25%) when the battery voltage falls below the target voltage in the state where the excitation duty is 0%, and then the gradual excitation control is performed. According to the device described in Patent Document 1, it is possible to suppress the undershoot in which the battery voltage drops significantly below the target voltage.

Japanese Patent No. 5430672

However, in the device described in Patent Document 1, if the predetermined duty value is too large, the power generation torque may become excessive and the engine may stall. On the other hand, if the predetermined duty value is too small, the undershoot of the battery voltage cannot be suppressed.

The present invention has been made to solve the above problems, and a main object thereof is to provide a power generation torque control device for a rotary electric machine that can achieve both suppression of engine stall and suppression of undershoot of battery voltage. To do.

The first means for solving the above problems is
A power generation torque control device (14) for controlling the power generation torque of a rotating electric machine (17) for generating power using a drive torque of an engine (101) to charge a battery (22),
A first calculation unit that calculates a command value of the power generation torque;
An upper limit guard value of the command value, a guard value setting unit that sets the response speed of the drive torque and the command value,
A second calculator that calculates a limit command value that limits the command value to the upper limit guard value or less;
A control unit that controls the power generation torque to the limit command value,
Equipped with.

According to the above configuration, the rotating electric machine uses the drive torque of the engine to generate power and charge the battery. Therefore, if the power generation torque of the rotating electric machine is too large with respect to the drive torque of the engine, the engine may stall. On the other hand, when the power generation torque is small and the rate of increase (rate of increase) in increasing the power generation torque is too small, an undershoot may occur in which the battery voltage drops significantly below the target voltage. On the other hand, the power generation torque control device controls the power generation torque of the rotating electric machine.

Specifically, the first calculation unit calculates the command value of the power generation torque. The guard value setting unit sets the upper limit guard value of the command value. The second calculation unit calculates a limit command value that limits the command value to the upper limit guard value or less. Then, the control unit controls the power generation torque to the limit command value. Therefore, the power generation torque can be limited to the upper limit guard value or less.

Here, the upper limit guard value is set based on the response speed of the engine drive torque and the command value of the power generation torque. Therefore, as compared with the case where the response speed of the drive torque is not taken into consideration, it is possible to suppress the upper limit guard value, and thus the power generation torque, from becoming too large with respect to the drive torque. Therefore, even if the command value of the power generation torque sharply increases, engine stall can be suppressed. Further, the command value of the power generation torque is only limited to the upper limit guard value or less, and the increase amount and the increase rate of the command value are not limited until the upper limit guard value is reached. Therefore, the power generation torque can be quickly increased within the range where the engine stall can be suppressed, and the undershoot of the battery voltage can be suppressed.

In the second means, when the command value is limited based on the upper limit guard value, the guard value setting unit increases the upper limit guard value at an increase rate according to the response speed of the drive torque. .. With such a configuration, even if the command value is limited based on the upper limit guard value, it is possible to increase the power generation torque within a range in which engine stall can be suppressed.

In the third means, when the command value is not limited based on the upper limit guard value, the guard value setting unit does not change the command value by a coefficient according to the response speed of the driving torque. The upper limit guard value is set based on the threshold value. With such a configuration, the upper limit guard value can be set in consideration of the response speed of the drive torque by a simple calculation for calculating the moderated value of the command value.

In the fourth means, the guard value setting unit, when the command value is not limited based on the upper limit guard value, does not change the command value by a coefficient according to the response speed of the drive torque. The upper limit guard value is set to a value obtained by adding a predetermined value to the discount value.

According to the above configuration, in the third means, the upper limit guard value is set to a value obtained by adding a predetermined value to the smoothed value. For this reason, the upper limit guard value is likely to shift to a state larger by a predetermined value than the command value, and it is possible to make it difficult for the command value to be limited by the upper limit guard value when the command value is changed to a larger value. Therefore, it is possible to improve the responsiveness of the power generation torque, and thus the responsiveness of the power generation amount.

Further, like the fifth means, the guard value setting unit determines the change rate of the upper limit guard value to be the response speed of the drive torque when the command value is not limited based on the upper limit guard value. It is also possible to adopt a configuration in which the rate of change is limited to the rate of change according to Also with such a configuration, the upper limit guard value can be set in consideration of the response speed of the drive torque.

In a sixth means, the guard value setting unit sets the drive torque until the upper limit guard value becomes equal to or larger than a value obtained by adding a predetermined value to the command value after the command value becomes equal to or larger than the upper limit guard value. The upper limit guard value is increased at a rate of increase according to the response speed of.

According to the above configuration, after the command value of the power generation torque becomes equal to or higher than the upper limit guard value, the upper limit guard value is increased until the upper limit guard value becomes equal to or higher than a value obtained by adding a predetermined value to the command value. For this reason, the upper limit guard value is likely to shift to a state larger by a predetermined value than the command value, and it is possible to make it difficult for the command value to be limited by the upper limit guard value when the command value is changed to a larger value. Therefore, it is possible to improve the responsiveness of the power generation torque, and thus the responsiveness of the power generation amount. Further, the upper limit guard value is increased at an increase rate according to the response speed of the drive torque. Therefore, the engine stall can be suppressed and the upper limit guard value can be swiftly changed to a state larger than the command value by a predetermined value.

Specifically, as in the seventh means, in the engine in which the drive torque is controlled so that the rotation speed of the engine becomes a predetermined idle rotation speed when the engine is in the idle operation state, The first to fifth means can be applied.

In the eighth means, the guard value setting unit receives the increase rate from an external device that controls the drive torque. With such a configuration, the external device that controls the drive torque of the engine appropriately sets the increase rate according to the response speed of the drive torque, and the upper limit guard value can be increased at the increase rate. Therefore, it is possible to quickly increase the upper limit guard value while suppressing engine stall.

In a ninth means, the guard value setting unit receives the coefficient from an external device that controls the drive torque. With this configuration, an external device that controls the drive torque of the engine sets the coefficient according to the response speed of the drive torque appropriately according to the specifications of the engine, etc. An upper guard value can be set for the value. Therefore, the upper limit guard value can be appropriately set in order to achieve both suppression of engine stall and suppression of undershoot of battery voltage.

The circuit diagram which shows the structure of a vehicle-mounted rotary electric machine system. The time chart which shows the control mode of a comparative example. The flowchart which shows the procedure of power generation control. 4 is a flowchart showing a procedure for calculating a torque command value in FIG. 3. 4 is a flowchart showing a procedure of guard determination in FIG. 4 is a flowchart showing a procedure of guard processing of FIG. 3. The time chart which shows the control aspect at the time of target voltage fall. The time chart which shows the control mode at the time of electric load reduction. The time chart which shows the control mode at the time of electric load increase.

Hereinafter, an embodiment embodied as a rotating electrical machine system mounted on a vehicle will be described with reference to the drawings.

As shown in FIG. 1, the vehicle-mounted rotary electric machine system 100 includes a rotary electric machine unit 10, an engine ECU (Electronic Control Unit) 20, a battery 22, a second capacitor 23, an electric load 24, and the like. The rotary electric machine unit 10 includes a rotary electric machine 17, an inverter 13, a rotary electric machine ECU 14, and the like. The rotary electric machine unit 10 is a generator with a motor function (power running function), and is configured as an electromechanical integrated ISG (Integrated Starter Generator). The rotary electric machine 17 includes X, Y and Z phase windings 11X, 11Y, 11Z as three-phase armature windings, a field winding 12, a rotational position sensor 18, and current sensors 19X, 19Y. The battery 22 is, for example, a Pb battery that outputs a voltage of 12V. It should be noted that as the battery 22, a battery that outputs 12V as a battery different from the Pb battery, a battery that outputs a voltage other than 12V, or the like can be adopted.

The X, Y and Z phase windings 11X, 11Y and 11Z are wound around a stator core (not shown) to form a stator. In the present embodiment, the first ends of the X, Y and Z phase windings 11X, 11Y and 11Z are connected to each other at a neutral point. That is, the rotary electric machine unit 10 is Y-connected.

The field winding 12 is wound around field poles (not shown) that are arranged opposite to each other on the inner peripheral side of the stator core to form a rotor. By passing an exciting current through the field winding 12, the field pole is magnetized. An alternating voltage is output from each phase winding 11X, 11Y, 11Z by the rotating magnetic field generated when the field pole is magnetized. In the present embodiment, the rotor rotates by obtaining rotational power from the crankshaft of the engine 101 (the body of the vehicle-mounted engine is schematically shown in FIG. 1). The rotational position sensor 18 detects the rotational position of the field winding 12. The rotational position sensor 18 is composed of a resolver, a Hall element and the like. The crankshaft of the engine 101 and the rotor of the rotary electric machine 17 are connected by a belt. The engine 101 is, for example, an engine that uses gasoline as a fuel, and generates a driving force by burning the fuel. The engine 101 is not limited to a gasoline engine, but may be a diesel engine that uses light oil as a fuel or an engine that uses another fuel.

The inverter 13 (corresponding to a power conversion circuit) converts the AC voltage (AC power) output from each phase winding 11X, 11Y, 11Z into a DC voltage (DC power). Further, the inverter 13 converts a DC voltage input from the battery 22 into an AC voltage and outputs the AC voltage to the phase windings 11X, 11Y, 11Z. The inverter 13 (corresponding to a rectifier circuit) is a bridge circuit having the same number of upper and lower arms as the number of phases of the armature winding. Specifically, the inverter 13 includes an X-phase module 13X, a Y-phase module 13Y, and a Z-phase module 13Z, and constitutes a three-phase full-wave rectifier circuit. The AC voltage generated by the rotating electric machine 17 is converted into a DC voltage by the inverter 13 and supplied to the battery 22 to charge the battery 22. That is, the rotary electric machine 17 uses the drive torque of the engine 101 to generate power and charge the battery 22. Further, the inverter 13 constitutes a drive circuit that drives the rotating electric machine 17 by adjusting the AC voltage supplied to each phase winding 11X, 11Y, 11Z of the rotating electric machine 17. The current sensor 19X detects the current flowing through the X-phase winding, and the current sensor 19Y detects the current flowing through the Y-phase winding.

Each of the X, Y, Z phase modules 13X, 13Y, 13Z includes an upper arm switch Sp and a lower arm switch Sn. That is, the switches Sp and Sn (corresponding to switching elements) are bridge-connected. In this embodiment, voltage-controlled semiconductor switching elements are used as the switches Sp and Sn, and specifically, N-channel MOSFETs are used. An upper arm diode Dp is connected in antiparallel (parallel) to the upper arm switch Sp, and a lower arm diode Dn is connected in antiparallel (parallel) to the lower arm switch Sn. In this embodiment, the body diodes of the switches Sp and Sn are used as the diodes Dp and Dn. The diodes Dp and Dn are not limited to body diodes and may be diodes that are separate parts from the switches Sp and Sn, for example.

The second end of the X phase winding 11X is connected to the X terminal PX of the X phase module 13X. A low potential side terminal (source) of the upper arm switch Sp and a high potential side terminal (drain) of the lower arm switch Sn are connected to the X terminal PX. The B terminal (corresponding to an output terminal) of the rotary electric machine unit 10 is connected to the drain of the upper arm switch Sp, and the source of the lower arm switch Sn is connected to the grounded portion (ground GND) via the E terminal of the rotary electric machine unit 10. ) Is connected to the body of the engine 101. The B terminal is a terminal connected to the positive electrode of the battery 22, and is formed in a detachable connector shape.

The second end of the Y-phase winding 11Y is connected to the Y terminal PY of the Y-phase module 13Y. A connection point between the upper arm switch Sp and the lower arm switch Sn is connected to the Y terminal PY. The B terminal is connected to the drain of the upper arm switch Sp, and the body of the engine 101 as the ground GND is connected to the source of the lower arm switch Sn via the E terminal.

The second end of the Z-phase winding 11Z is connected to the Z terminal PZ of the Z-phase module 13Z. The connection point of the upper arm switch Sp and the lower arm switch Sn is connected to the Z terminal PZ. The B terminal is connected to the drain of the upper arm switch Sp, and the body of the engine 101 as the ground GND is connected to the source of the lower arm switch Sn via the E terminal.

The first capacitor 15 and the Zener diode 16 are connected in parallel to the series connection body of the switches Sp and Sn that form the phase modules 13X, 13Y, and 13Z, respectively. A voltage sensor 41 (corresponding to a voltage detection unit) that detects a voltage between the high-voltage side connection point P1 and the low-voltage side connection point P2 of the inverter 13 is provided. The battery voltage detected by the voltage sensor 41 is output to the rotary electric machine ECU 14.

The rotary electric machine ECU 14 (corresponding to a power generation torque control device of the rotary electric machine) is configured as a microcomputer including a CPU, a ROM, a RAM, an input/output interface and the like. The rotating electrical machine ECU 14 adjusts an exciting current flowing through the field winding 12 by an IC regulator (not shown) therein. As a result, the power generation torque of the rotary electric machine unit 10, and consequently the power generation voltage (voltage at the B terminal) is controlled. Further, the rotary electric machine ECU 14 controls the inverter 13 to drive the rotary electric machine 17 after the vehicle starts traveling to assist the driving force of the engine 101. The rotary electric machine 17 is capable of imparting rotation to the crankshaft when the engine 101 is started when it receives a command to start the engine 101 from the engine ECU 20, and has a function as a starter. The rotary electric machine ECU 14 is connected to an engine ECU 20 which is a control device outside the rotary electric machine unit 10 via an L terminal which is a communication terminal and a communication line.

The engine ECU 20 (corresponding to an external device) is configured as a microcomputer including a CPU, ROM, RAM, an input/output interface, etc., and controls the operating state of the engine 101. The engine ECU 20 feedback-controls the rotation speed of the engine 101 to the target idle rotation speed (predetermined idle rotation speed) by controlling the driving torque of the engine 101 when the engine 101 is in the idle operation state. Further, the engine ECU 20 automatically stops the engine 101 when a predetermined automatic stop condition is satisfied, and automatically restarts the engine 101 when a predetermined automatic restart condition is satisfied. The engine ECU 20 calculates the target voltage of the battery 22. For example, the engine ECU 20 lowers the target voltage when the engine 101 is started or when the vehicle equipped with the engine 101 is accelerated (when the engine 101 is accelerated), and increases the target voltage when the battery voltage decreases. The engine ECU 20 transmits the target voltage of the battery 22 to the rotary electric machine ECU 14.

Further, the engine ECU 20 calculates an increase rate limit (upper limit increase rate) of an upper limit guard value, which will be described later, according to the response speed of the drive torque of the engine 101, and transmits it to the rotary electric machine ECU 14. The power generation torque response speed of the rotating electric machine 17 is higher than the drive torque response speed of the engine 101. The increase rate limit is set to the maximum increase rate (maximum increase rate) of the drive torque of the engine 101. The engine ECU 20 calculates a smoothing coefficient (corresponding to a coefficient) when deciding a torque command value, which will be described later, in the calculation of the upper limit guard value, and transmits it to the rotary electric machine ECU 14. The smoothing coefficient is set so that the rate of change of the smoothed value of the torque command value becomes the maximum rate of change of the drive torque of the engine 101 (maximum rate of change). The rotary electric machine ECU 14 and the engine ECU 20 perform bidirectional communication (for example, serial communication using the LIN protocol) to exchange information with each other.

Based on the serial communication signal transmitted from the engine ECU 20, the rotary electric machine ECU 14 outputs a powering command that is a command for powering the rotary electric machine 17, a power generation command that is a command for generating power by the rotary electric machine 17, and a neutral that is neither of them. The command and the required torque required for the rotating electric machine 17 (power running torque, power generation torque, braking torque) are grasped. Then, the rotary electric machine ECU 14 controls the PWM voltage applied to the field winding 12 and the on/off states of the switches Sp and Sn so that the rotary electric machine 17 generates the required torque. Specifically, the rotary electric machine ECU 14 calculates the rotational speed of the field winding 12 (that is, the rotary electric machine 17) based on the rotational position of the field winding 12 detected by the rotational position sensor 18. The rotary electric machine ECU 14 turns on and off the PWM voltage applied to the field winding 12 based on the X-phase and Y-phase currents detected by the current sensors 19X and 19Y, the rotation position and the rotation speed of the field winding 12. The ON/OFF phase and ON/OFF period (duty etc.) of each switch Sp, Sn are controlled by (duty etc.) and PWM control.

Further, the rotating electrical machine ECU 14 (corresponding to the first calculating unit), based on the target voltage of the battery 22 received from the engine ECU 20 during power generation by the rotating electrical machine 17, generates a command value for power generation torque (hereinafter, “torque command value”). Is calculated). The rotary electric machine ECU 14 (corresponding to a guard value setting unit) sets the upper limit guard value of the torque command value based on the response speed of the drive torque of the engine 101 and the torque command value. At that time, the rotary electric machine ECU 14 receives the increase rate limit of the upper limit guard value and the smoothing coefficient from the engine ECU 20. The rotating electrical machine ECU 14 (corresponding to the second calculating unit) calculates the torque command value after guard (corresponding to the limit command value) in which the torque command value is guarded (limited) to the upper limit guard value or less. The rotary electric machine ECU 14 (corresponding to a control unit) controls the power generation torque to the torque command value after guard.

The engine ECU 20 and the positive terminal of the battery 22 are connected to the B terminal via the relay 21. The body of the engine 101 as the ground GND is connected to the negative terminal of the battery 22. The second capacitor 23 and the electric load 24 are connected to the B terminal. The electric load 24 includes an electric load such as an electronically controlled brake system of a vehicle or an electric power steering system whose operating voltage is a predetermined voltage or higher. The operating voltage is a voltage at which the electric load can exhibit the specified performance, such as a guaranteed voltage or a rated voltage of the electric load. The electric load 24 may include an air conditioner, an in-vehicle audio system, a head lamp, and the like. The relay 21 is turned on by turning on the ignition switch.

FIG. 2 shows a control mode of the comparative example. The power generation torque control device of the comparative example gradually controls the excitation current flowing through the field winding 12 of the rotary electric machine 17 in order to suppress a rapid increase in the power generation torque that acts as a load torque on the engine 101. It is carried out. In FIG. 2, the engine 101 is in an idle operation state, and the drive torque of the engine 101 is controlled, so that the rotation speed of the engine 101 is feedback-controlled to the target idle rotation speed.

Before time t11, the rotation speed of the engine 101 is controlled to the target idle rotation speed, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electric machine 17, and the actual power generation torque are It is constant. At time t11, the target voltage of the battery 22 decreases, and the torque command value of the rotary electric machine 17 decreases to 0. As a result, the actual torque of the engine 101 and the battery voltage decrease, and the battery voltage falls below the target voltage of the battery 22 at time t12. Therefore, the torque command value rises and the exciting current flowing through the field winding 12 is increased. However, since the gradual excitation control for gradually increasing the exciting current flowing through the field winding 12 is performed, the torque command value and the actual power generation torque are only gradually increased, and the battery voltage drops significantly below the target voltage. Shoot occurs. After that, at time t13, the battery voltage matches the target voltage, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electric machine 17, and the actual power generation torque become constant.

In the present embodiment, in order to achieve both suppression of engine stall and suppression of undershoot of battery voltage, the power generation control shown in FIG. 3 and each processing shown in FIGS. These series of processes are repeatedly executed by the rotary electric machine ECU 14 at a predetermined cycle.

As shown in FIG. 3, first, a torque command value for the rotary electric machine 17 is calculated based on the target voltage of the battery 22 and the battery voltage (S10). Subsequently, it is determined whether the torque command value is in the guard state where the guard value is equal to or less than the upper limit guard value, or the guard is released and the guard is released (S20). Subsequently, guard processing is performed to guard the torque command value with the upper limit guard value (S30). After that, this series of processing is temporarily terminated (END). The process of S10 corresponds to the process of the first calculator.

FIG. 4 is a flowchart showing details of the torque command value calculation processing of S10 of FIG. This series of processing is executed by the rotary electric machine ECU 14.

First, the deviation between the target voltage and the battery voltage is calculated (S101). Specifically, the target voltage is received from the engine ECU 20, and the deviation is calculated by subtracting the battery voltage detected by the voltage sensor 41 from the target voltage.

Then, the calculated deviation is multiplied by the proportional coefficient KP to calculate the proportional term (S102). Further, the deviation integrated value is calculated by adding the calculated deviation to the previous value of the deviation integrated value (S103). The calculated integrated deviation value is multiplied by the integration coefficient KI to calculate the integral term (S104). The deviation integrated value is saved as the previous value of the deviation integrated value (S105).

Then, the torque command value is calculated by adding the calculated proportional term and integral term (S106). The torque command value is saved as the previous value of the torque command value (S107). Then, this series of processing is ended (END).

FIG. 5 is a flowchart showing details of the guard determination in S20 of FIG. This series of processing is executed by the rotary electric machine ECU 14.

First, it is determined whether or not the guard state of the torque command value is the guard release (S201). The guard state is set by the process of S203 or S205 described later, and the initial state is guard release.

In the determination of S201, when it is determined that the guard state of the torque command value is the guard release (S201: YES), it is determined whether the torque command value is the upper limit guard value or more (S202). The upper limit guard value is set in the process of S302 or S305 of FIG. 6 described later. When it is determined in this determination that the torque command value is equal to or greater than the upper limit guard value (S202: YES), the guard state is set to guard (S203). On the other hand, if it is determined in this determination that the torque command value is not greater than or equal to the upper limit guard value (S202: NO), the current guard state is maintained. After these processes, this series of processes is ended (END).

In addition, in the determination of S201, when it is determined that the guard state of the torque command value is not the guard release (S201: NO), it is determined whether the value obtained by subtracting the torque command value from the upper limit guard value is the offset value or more ( S204). The offset value (corresponding to a predetermined value) is set to the maximum value in the range in which engine stall can be suppressed even if the torque command value sharply increases by the offset value. In this determination, if it is determined that the value obtained by subtracting the torque command value from the upper limit guard value is equal to or greater than the offset value (S204: YES), the guard state is set to guard release (S205). On the other hand, in this determination, when it is determined that the value obtained by subtracting the torque command value from the upper limit guard value is not greater than or equal to the offset value (S204: NO), the current guard state is maintained. After these processes, this series of processes is ended (END).

FIG. 6 is a flowchart showing details of the guard processing of S30 of FIG. This series of processing is executed by the rotary electric machine ECU 14.

First, it is determined whether the guard state of the torque command value is guard (S301). In this determination, when it is determined that the guard state of the torque command value is in the guard state (S301: YES), the upper limit guard value is set to a value obtained by adding the rising rate limit to the previous value of the upper limit guard value (S302). .. The increase rate limit is received from the engine ECU 20. The increase rate limit is set to the maximum increase rate (maximum increase rate) of the drive torque of the engine 101.

Then, it is determined whether the torque command value is equal to or more than the upper limit guard value (S303). In this determination, when it is determined that the torque command value is equal to or greater than the upper limit guard value (S303: YES), the upper limit guard value is set as the torque command value after guard (S304). On the other hand, when it is determined that the torque command value is not greater than or equal to the upper limit guard value (S303: NO), the torque command value is set as the guarded torque command value (S306). After these processes, this series of processes is ended (END).

When it is determined that the guard state of the torque command value is not in the guard state (S301: NO), the upper limit guard value is set to a value obtained by adding the torque command value with the smoothing coefficient and the offset value. (S305). Specifically, the upper limit guard value=torque command value (previous value)+{torque command value−torque command value (previous value)}/smoothing coefficient+offset value. The smoothing coefficient is received from the engine ECU 20. The smoothing coefficient is set so that the rate of change of the smoothed value of the torque command value becomes the maximum rate of change of the drive torque of the engine 101 (maximum rate of change). As described above, the offset value (corresponding to the predetermined value) is set to the maximum value in the range in which engine stall can be suppressed even if the torque command value sharply increases by the offset value. Then, the process proceeds to S306.

The processing of S301, S302, and S305 corresponds to the processing as the guard value setting unit, and the processing of S304 and S306 corresponds to the processing as the second calculation unit.

FIG. 7 shows a control mode when the target voltage drops in this embodiment. The power generation torque control device of the present embodiment does not perform the gradual excitation control that gradually increases the excitation current flowing in the field winding 12 of the rotary electric machine 17, but performs the control described in FIGS. In FIG. 7, the engine 101 is in the idle operation state, and the drive torque of the engine 101 is controlled, so that the rotation speed of the engine 101 is feedback-controlled to the target idle rotation speed. It should be noted that the drawing shows the case where the torque command value of the rotary electric machine 17 has decreased, and the effect of the offset value is omitted for convenience because the effect of the offset value is small.

Before time t21, the rotation speed of the engine 101 is controlled to the target idle rotation speed, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electric machine 17, the actual power generation torque, and the upper limit. The guard value is constant. At time t21, the target voltage of the battery 22 decreases, and the torque command value of the rotary electric machine 17 decreases to 0. As a result, the actual torque of the engine 101 and the battery voltage decrease. At this time, the upper limit guard value is set to a value obtained by adding a value obtained by smoothing the torque command value with a smoothing coefficient and the offset value. Therefore, the upper limit guard value falls behind the torque command value.

At time t22, the battery voltage falls below the target voltage and the torque command value rises. At this time, the increase amount and the increase rate of the torque command value are not limited until the torque command value reaches the upper limit guard value. Therefore, the actual power generation torque rises more quickly than in the comparative example of FIG. 2, and the undershoot of the battery voltage is suppressed. When the torque command value reaches the upper limit guard value, the torque command value is guarded below the upper limit guard value, and the guard state is set to guard. While guarding, the upper limit guard value is set to a value obtained by adding the rising rate limit to the previous value of the upper limit guard value. Therefore, the upper limit guard value and the torque command value increase at the increase rate limit, and the actual power generation torque reaches the upper limit guard value later than these. After that, at time t23, the battery voltage matches the target voltage, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electric machine 17, the actual power generation torque, and the upper limit guard value are constant. Become.

FIG. 8 shows a control mode when the electric load is reduced in the present embodiment. The power generation torque control device of the present embodiment does not perform the gradual excitation control that gradually increases the excitation current flowing in the field winding 12 of the rotary electric machine 17, but performs the control described in FIGS. In FIG. 8, the engine 101 is in the idle operation state, and the drive torque of the engine 101 is controlled, so that the rotation speed of the engine 101 is feedback-controlled to the target idle rotation speed. It should be noted that the drawing shows the case where the torque command value of the rotary electric machine 17 has decreased, and the effect of the offset value is omitted for convenience because the effect of the offset value is small.

Before time t31, the rotation speed of the engine 101 is controlled to the target idle rotation speed, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electrical machine 17, the actual power generation torque, and the upper limit. The guard value is constant. At time t31, the electric load of the vehicle decreases, and the torque command value of the rotary electric machine 17 decreases to 0. As a result, the actual torque of the engine 101 decreases and the battery voltage increases. At this time, the upper limit guard value is set to a value obtained by adding a value obtained by smoothing the torque command value with a smoothing coefficient and the offset value. Therefore, the upper limit guard value falls behind the torque command value. After that, the battery voltage decreases as the amount of power generation by the rotating electric machine 17 decreases.

At time t32, the battery voltage falls below the target voltage and the torque command value rises. At this time, the increase amount and the increase rate of the torque command value are not limited until the torque command value reaches the upper limit guard value. Therefore, the actual power generation torque rises more quickly than in the comparative example of FIG. 2, and the undershoot of the battery voltage is suppressed. The subsequent steps are the same as in FIG. 7.

FIG. 9 shows a control mode when the electric load is increased in this embodiment. The power generation torque control device of the present embodiment does not perform the gradual excitation control that gradually increases the excitation current flowing in the field winding 12 of the rotary electric machine 17, but performs the control described in FIGS. In FIG. 9, the engine 101 is in the idle operation state, and the drive torque of the engine 101 is controlled, so that the rotation speed of the engine 101 is feedback-controlled to the target idle rotation speed. In the figure, the effect of the offset value is not omitted.

Before time t41, the rotation speed of the engine 101 is controlled to the target idle rotation speed, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electric machine 17, the actual power generation torque, and the upper limit. The guard value is constant. Here, the upper limit guard value is set to a value obtained by adding an offset value to a value obtained by smoothing the torque command value with a smoothing coefficient. At time t41, the electric load of the vehicle increases and the torque command value of the rotary electric machine 17 increases. As a result, the actual torque of the engine 101 increases and the battery voltage decreases. At this time, since the torque command value rises faster than the upper limit guard value, the torque command value reaches the upper limit guard value. That is, when the torque command value increases, the torque command value can be quickly increased by the offset value. Then, the torque command value is guarded below the upper limit guard value, and the guard state is set to guard.

After that, during the guard, the upper limit guard value is set to a value obtained by adding the rising rate limit to the previous value of the upper limit guard value. Therefore, the upper limit guard value and the torque command value rise at the rising rate limit, and the actual power generation torque rises behind them. After that, at time t42, the battery voltage matches the target voltage, and the actual torque of the engine 101, the target voltage of the battery 22, the battery voltage, the torque command value of the rotating electrical machine 17, and the actual power generation torque become constant. The upper limit guard value rises at the rate of rise limit until it becomes a value obtained by adding the offset value to the value obtained by rounding the torque command value with the smoothing coefficient. After that, the upper limit guard value is set to a value obtained by adding the offset value to the value obtained by smoothing the torque command value with the smoothing coefficient.

The embodiment described in detail above has the following advantages.

・Power generation torque is controlled to the torque command value after guard. Therefore, the power generation torque can be limited to the upper limit guard value or less. Here, the upper limit guard value is set based on the response speed of the drive torque of the engine 101 and the torque command value. Therefore, as compared with the case where the response speed of the drive torque is not taken into consideration, it is possible to suppress the upper limit guard value, and thus the power generation torque, from becoming too large with respect to the drive torque. Therefore, even if the torque command value suddenly rises, engine stall can be suppressed. Further, the torque command value is only limited to the upper limit guard value or less, and the increase amount and the increase rate of the torque command value are not limited until the upper limit guard value is reached. Therefore, the power generation torque can be quickly increased within the range where the engine stall can be suppressed, and the undershoot of the battery voltage can be suppressed.

When the torque command value is limited based on the upper limit guard value, the rotary electric machine ECU 14 increases the upper limit guard value at the increase rate limit according to the response speed of the drive torque. With such a configuration, even when the torque command value is limited based on the upper limit guard value, the power generation torque can be increased within a range in which engine stall can be suppressed.

When the torque command value is not limited based on the upper limit guard value, the rotating electrical machine ECU 14 makes the upper limit guard based on the smoothed value of the torque command value with the smoothing coefficient according to the response speed of the driving torque. Set the value. With such a configuration, the upper limit guard value can be set in consideration of the response speed of the drive torque by a simple calculation for calculating the smoothed value of the torque command value.

・The upper limit guard value is set to the value obtained by adding the offset value to the above smoothed value. Therefore, the upper limit guard value easily shifts to a state where the offset value is larger than the torque command value, and it is possible to make it difficult for the torque command value to be limited by the upper limit guard value when the torque command value is changed to a larger value. .. Therefore, it is possible to improve the responsiveness of the power generation torque, and thus the responsiveness of the power generation amount.

After the torque command value exceeds the upper limit guard value, the upper limit guard value is increased until the upper limit guard value becomes equal to or larger than the torque command value plus the offset value. Therefore, the upper limit guard value is likely to shift to a state in which it is larger than the torque command value by the offset value, and it may be difficult for the torque command value to be limited by the upper limit guard value at the beginning when the torque command value is changed to a larger value. it can. Therefore, it is possible to improve the responsiveness of the power generation torque, and thus the responsiveness of the power generation amount. Further, the upper limit guard value is increased at the rate of increase limit according to the response speed of the drive torque. Therefore, while suppressing engine stall, the upper limit guard value can be quickly shifted to a state in which the offset value is larger than the torque command value.

-The rotary electric machine ECU 14 receives the rate of increase from the engine ECU 20 that controls the drive torque. With this configuration, the engine ECU 20 that controls the drive torque of the engine 101 appropriately sets the increase rate limit according to the response speed of the drive torque, and the increase guard limit can be increased by the increase rate limit. Therefore, it is possible to quickly increase the upper limit guard value while suppressing engine stall.

The rotary electric machine ECU 14 receives the moderating coefficient from the engine ECU 20 that controls the drive torque. With this configuration, the engine ECU 20 that controls the drive torque of the engine 101 appropriately sets the moderating coefficient according to the response speed of the drive torque according to the specifications of the engine 101 and the like, and the torque command value is smoothed. The upper limit guard value can be set to the smoothed value that is simulated by a coefficient. Therefore, the upper limit guard value can be appropriately set in order to achieve both suppression of engine stall and suppression of undershoot of battery voltage.

The above embodiment can be modified and implemented as follows. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted.

The increase rate limit (the increase rate upper limit value) may be set to a value slightly smaller than the maximum increase rate (maximum increase rate) of the drive torque of the engine 101.

The smoothing coefficient may be set such that the rate of change of the smoothed value of the torque command value is slightly smaller than the maximum rate of change of the drive torque of the engine 101 (maximum rate of change).

The smoothing coefficient and the increase rate limit may be stored in the rotary electric machine ECU 14 in advance.

When the torque command value is not limited based on the upper limit guard value, the rotating electrical machine ECU 14 (corresponding to the guard value setting unit) changes the rate of change of the upper limit guard value according to the response speed of the drive torque of the engine 101. It is also possible to employ a configuration in which the rate of change (rate of change limit) or less is limited. Also with such a configuration, the upper limit guard value can be set in consideration of the response speed of the drive torque of the engine 101. The change rate limit (change rate upper limit value) may be set to the maximum change rate (maximum change speed) of the drive torque of the engine 101, or may be set to a value slightly smaller than the maximum change rate. The rate-of-change limit may be received from the engine ECU 20 or may be stored in the rotary electric machine ECU 14 in advance.

The offset value may be omitted by setting the offset value (corresponding to a predetermined value) to 0.

As the rotating electric machine 17, an alternator (generator) or an MG (Motor Generator) that generates a torque that can drive the vehicle can be adopted.

The power generation control described above may be executed not only in the idle operation state of the engine 101 but also during cruise control in which the engine ECU 20 controls the vehicle to run at a constant speed.

14... Rotating electric machine ECU, 17... Rotating electric machine, 22... Battery, 101... Engine.

Claims (9)

A power generation torque control device (14) for controlling the power generation torque of a rotating electric machine (17) for generating power using a drive torque of an engine (101) to charge a battery (22),
A first calculation unit that calculates a command value of the power generation torque;
An upper limit guard value of the command value, a guard value setting unit that sets the response speed of the drive torque and the command value,
A second calculator that calculates a limit command value that limits the command value to the upper limit guard value or less;
A control unit that controls the power generation torque to the limit command value,
A power generation torque control device for a rotating electric machine, comprising: The guard value setting unit increases the upper limit guard value at a rate of increase according to a response speed of the drive torque when the command value is limited based on the upper limit guard value. Generator torque control device for rotating electric machine. The guard value setting unit, when the command value is not limited based on the upper limit guard value, the command value based on a smoothed value by a coefficient according to the response speed of the drive torque. The power generation torque control device for a rotating electric machine according to claim 1, wherein an upper limit guard value is set. The guard value setting unit, when the command value is not limited based on the upper limit guard value, the command value is a predetermined value to the moderation value that is a coefficient accelerating the response value of the drive torque. The power generation torque control device for a rotating electric machine according to claim 3, wherein the upper limit guard value is set to an added value. The guard value setting unit, when the command value is not limited based on the upper limit guard value, limits the change rate of the upper limit guard value to a change rate or less according to the response speed of the drive torque, The power generation torque control device for a rotating electric machine according to claim 1. The guard value setting unit responds to the response speed of the drive torque until the upper limit guard value becomes equal to or larger than a value obtained by adding a predetermined value to the command value after the command value becomes equal to or larger than the upper limit guard value. The power generation torque control device for a rotary electric machine according to claim 1, wherein the upper limit guard value is increased at a rate of increase. The rotary electric machine according to claim 1, wherein the drive torque is controlled so that the rotation speed of the engine becomes a predetermined idle rotation speed when the engine is in an idle operation state. Power generation torque control device. The power generation torque control device for a rotary electric machine according to claim 2 or 6, wherein the guard value setting unit receives the increase rate from an external device (20) that controls the drive torque. The power generation torque control device for a rotating electric machine according to claim 3 or 4, wherein the guard value setting unit receives the coefficient from an external device that controls the drive torque.

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