Motor regeneration control method, motor control circuit, and regeneration control program

Abstract

[Problem] To provide a motor regeneration control method for performing regeneration control without creating a matching map value. [Solution] The present invention provides a regeneration control method for charging a battery by causing a regenerative current to flow through the battery by causing a negative energizing current to flow through a motor. This motor regeneration control method performs control by: setting a target regenerative current value on the basis of the state of the battery; measuring the regenerative current while causing the regenerative current to flow through the battery by causing the negative energizing current to flow through the motor so that a regenerative current value approaches the target regenerative current value; performing feedback control for causing the negative energizing current to flow through the motor so as to fill the difference between the regenerative current value and the target regenerative current value; determining whether the regenerative current value is increasing or decreasing; maintaining the feedback control when it is determined that the regenerative current value is increasing; detecting a maximum regenerative current value on the basis of a history of the regenerative current value when it is determined that the regenerative current value does not reach the target regenerative current value and is decreasing; and adjusting the energizing current to the motor by using the maximum regenerative current value as a target.

Description

Motor regenerative control method, motor control circuit, and regenerative control program

[0001] The present invention relates to a motor regenerative control method, a motor control circuit, and a regenerative control program.

[0002] Conventional motor regenerative control is performed by commanding the energization current value of the motor based on the motor rotation speed and the regenerative target current value by an adaptation map value. Related techniques are disclosed in Patent Document 1.

[0003] In order to create the above adaptation map value, it is necessary to perform a large amount of measurements using a motor bench. Moreover, motor bench measurements are required for the number of map grids, and in addition, a plurality of map measurements corresponding to battery voltage fluctuations are required. Thus, a lot of time and effort are required to create a large amount of adaptation map values.

[0004] Therefore, a method for performing motor regenerative control without creating an adaptation map value is required.

[0005] Japanese Patent Application Laid-Open No. 10-014010

[0006] Various aspects of the present invention aim to provide a motor regenerative control method, a motor control circuit motor, and a regenerative control program capable of performing regenerative control without creating an adaptation map value.

[0007] The following describes various aspects of the present invention.

[0008] [1] A regenerative control method in which a positive torque is generated in a motor by flowing a positive current from a battery to the motor, and then a regenerative current is flowed from the motor to the battery by flowing a negative current to the motor to charge the battery, wherein a target regenerative current value is set based on the state of the battery, the regenerative current is measured while a regenerative current is flowing to the battery by flowing a negative current to the motor to approach the target regenerative current value, feedback control is performed to flow a negative current to the motor to bridge the difference between the measured regenerative current value and the target regenerative current value, it is determined whether the measured regenerative current value is increasing or decreasing, and if it is determined that the measured regenerative current value is increasing, the feedback control is maintained. A motor regeneration control method characterized in that, if it is determined that the measured regenerative current value has not reached the target regenerative current value and the measured regenerative current value has decreased, the maximum value of the regenerative current is detected based on the history of the measured regenerative current value, and the current supplied to the motor is adjusted and controlled with the maximum value of the regenerative current as the target.

[0009] According to the motor regeneration control method described in [1] above in one aspect of the present invention, a negative current is supplied to the motor to approach a target regenerative current value. The regenerative current is measured while a regenerative current is supplied to the battery, and feedback control is performed to supply a negative current to the motor to bridge the difference between the measured regenerative current value and the target regenerative current value. It is determined whether the measured regenerative current value is increasing or decreasing. If it is determined to be increasing, the feedback control is maintained. If it is determined to be decreasing, the maximum regenerative current value is detected based on the history of measured regenerative current values, and the current supplied to the motor is adjusted and controlled with this maximum regenerative current as the target. Therefore, it is not necessary to create a compatible map value when performing motor regeneration control. This reduces the time and effort required to create a large number of compatible map values.

[0010] [2] A motor regeneration control method characterized in that the regenerative current is measured continuously or intermittently in the manner described in [1] above.

[0011] [3] A motor regeneration control method characterized in that, in [1] or [2] above, when determining whether the measured regenerative current value has increased or decreased, the measured regenerative current value is compared with a previously measured regenerative current value, and if it has increased by a predetermined value or more, it is determined that the measured regenerative current value has increased, and if it has decreased by a predetermined value or more, it is determined that the measured regenerative current value has decreased.

[0012] [4] A motor regenerative control method characterized in that, in [1] or [2] above, the feedback control is PI control.

[0013] [5] The motor regeneration control method in the above [1] or [2], characterized in that the motor regeneration control method is a control method that does not use a compatible map value.

[0014] According to the motor regeneration control method described in [5] above in one aspect of the present invention, since this control method does not use a compatible map value when performing motor regeneration control, there is no need to create a compatible map value, and as a result, a great deal of time and effort can be saved in creating a large number of compatible map values.

[0015] [6] A motor control circuit that generates positive torque in a motor by supplying a positive current from a battery to the motor through an inverter circuit, and then charges the battery by supplying a negative current from the battery to the motor through the inverter circuit, wherein the motor control circuit includes: an inverter drive control unit that drives and controls the inverter circuit; a power supply current measurement unit that sets a target regenerative current value based on the state of the battery and supplies a negative current to the motor to approach the target regenerative current value, thereby measuring the regenerative current while supplying a regenerative current to the battery; a motor current supply command unit that determines a current supply command value for supplying a negative current to the motor to bridge the difference between the regenerative current value measured by the power supply current measurement unit and the target regenerative current value, and inputs the current supply command value to the inverter drive control unit; and a determination unit that determines whether the regenerative current value measured by the power supply current measurement unit is increasing or decreasing. If the determination unit determines that the regenerative current value measured by the power supply current measurement unit is increasing, the motor energizing current command unit continues to control the motor to supply a negative current to bridge the gap between the regenerative current value measured by the power supply current measurement unit and the target regenerative current value. If the determination unit determines that the regenerative current value measured by the power supply current measurement unit is decreasing and has not reached the target regenerative current value, the power supply current measurement unit detects the maximum regenerative current value based on the history of the measured regenerative current value, the motor energizing current command unit determines an energizing current command value that adjusts the energizing current supplied to the motor to target the maximum regenerative current value, and inputs the energizing current command value to the inverter drive control unit.

[0016] According to the motor control circuit of [6] above in one aspect of the present invention, the motor current command unit determines a current command value for supplying a negative current to the motor in order to bridge the difference between the regenerative current value measured by the power supply current measurement unit and the target regenerative current value, and the motor current command unit inputs this current command value to the inverter drive control unit, and the determination unit determines whether the regenerative current value measured by the power supply current measurement unit has increased or decreased, and if the determination unit determines that the regenerative current value measured by the power supply current measurement unit has decreased because it could not reach the target regenerative current value, the power supply current measurement unit detects the maximum regenerative current value based on the history of measured regenerative current values, and the motor current command unit determines a current command value that adjusts the current supplied to the motor with the maximum regenerative current value as the target, and inputs this current command value to the inverter drive control unit.Therefore, it is not necessary to create a compatible map value when performing motor regeneration control.This reduces the amount of time and effort required to create a large number of compatible map values.

[0017] [7] A program that implements regenerative control in which a positive torque is generated in the motor by flowing a positive current from the battery to the motor, and then a regenerative current is flowed from the motor to the battery by flowing a negative current to the motor to charge the battery, the program includes: a function to set a target regenerative current value based on the state of the battery (a); a function to measure the regenerative current while flowing a regenerative current to the battery by flowing a negative current to the motor to approach the target regenerative current value (b); a function to perform feedback control by flowing a negative current to the motor to bridge the difference between the measured regenerative current value and the target regenerative current value (c); a function to determine whether the measured regenerative current value is increasing or decreasing (d); and a function to maintain the feedback control if it is determined that the measured regenerative current value is increasing (e). A motor regenerative control program characterized by having the following function (f): If the measured regenerative current value is determined to be decreasing without reaching the target regenerative current value, the program detects the maximum regenerative current value based on the history of the measured regenerative current value and controls the current supplied to the motor by adjusting it to target the maximum regenerative current value.

[0018] According to various aspects of the present invention, it is possible to provide a motor regeneration control method, a motor control circuit motor, and a regeneration control program that can perform regenerative control without creating a compatible map value.

[0019] This figure illustrates the relationship between motor energizing current and regenerative current for illustrating a motor regenerative control method according to one aspect of the present invention. This figure illustrates the relationship between motor energizing current and regenerative current for illustrating a motor regenerative control method according to one aspect of the present invention. This figure illustrates the configuration of a motor control circuit according to one aspect of the present invention. This figure illustrates a timing chart of an example of feedback control (PI control and novel control) in motor control according to one aspect of the present invention. This figure illustrates the current flow during acceleration (powering) and deceleration (regeneration) of a motor according to one aspect of the present invention.

[0020] Embodiments of the present invention will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be interpreted as being limited to the descriptions of the embodiments shown below.

[0021] (First Embodiment) Figure 1 is a diagram illustrating the relationship between motor energizing current and regenerative current for illustrating a motor regenerative control method according to one aspect of the present invention. Figure 2 is a diagram illustrating the relationship between motor energizing current and regenerative current for illustrating a motor regenerative control method according to one aspect of the present invention. Figure 3 is a diagram illustrating the configuration of a motor control circuit according to one aspect of the present invention.

[0022] This section describes a motor regeneration control method in which a positive torque is generated in the motor 12 by supplying a positive current from the battery 11 shown in Figure 3, and then a negative current is supplied to the motor 12, causing a regenerative current to flow from the motor 12 to the battery 11 and charge the battery 11.

[0023] First, a target regenerative current value is set based on the state of the battery 11, or based on the state of both the battery 11 and the motor 12. The target regenerative current value is set by the target regenerative current setting unit. This target regenerative current setting unit is included in the motor energizing current command unit 15 of the mapless regenerative control shown in Figure 3. Note that the target regenerative current value may be, for example, several tens of amperes.

[0024] Next, the regenerative current is measured while a negative current is supplied to the battery 11 by applying a current in the negative direction to the motor 12 to approach the target regenerative current value. This regenerative current value is measured by the power supply current measurement unit 16 shown in Figure 3, and this measured regenerative current value data is sent to the motor current command unit 15 of the MAPless regenerative control. Note that the measurement of the regenerative current may be continuous or intermittent.

[0025] Next, feedback control is performed to supply a negative current to the motor 12 in order to bridge the difference between the regenerative current value measured by the power supply current measurement unit 16 and the target regenerative current value. For example, PI control (proportional-integral control) may be used for this feedback control.

[0026] Next, it is determined whether the regenerative current value measured by the power supply current measurement unit 16 has increased or decreased. This determination is performed by the determination unit. This determination unit is located within the motor energization current command unit 15 of the mapless regenerative control shown in Figure 3.

[0027] Furthermore, when the determination unit determines whether the measured regenerative current value has increased or decreased, it is preferable to compare the measured regenerative current value with the regenerative current value measured previously, and if it has increased by a predetermined value or more, it is determined that the regenerative current value has increased, and if it has decreased by a predetermined value or more, it is determined that the regenerative current value has decreased (see Figures 2(A) to (C)).

[0028] If the determination unit determines that the regenerative current value is increasing, it maintains the feedback control. In other words, as shown in Figure 2(A), the feedback control is used to bring the regenerative current value closer to the target regenerative current value. Also, as shown in Figure 2(B), if it is determined that the regenerative current value is decreasing and has not reached the target regenerative current value, the maximum regenerative current value is detected based on the history of the regenerative current value, and the current supplied to the motor 12 is adjusted and controlled with the maximum regenerative current value as the target (see Figure 2(C)). In other words, if it is determined (detected) that the regenerative current value is decreasing, the motor current is controlled in the positive direction, aiming to maximize the regenerative current value. The detection unit for detecting the maximum regenerative current value is included in the motor current command unit 15 of the mapless regenerative control.

[0029] The motor regeneration control method described above is preferably a control method that does not use a compatible map value.

[0030] According to this embodiment, since the control method does not use adaptive map values ​​when performing motor regeneration control, there is no need to create adaptive map values, and as a result, a great deal of time and effort can be saved in creating a large number of adaptive map values.

[0031] Figure 4 is a timing chart of an example of feedback control (PI control and novel control) in motor control according to one aspect of the present invention. Figure 5 is a diagram showing the current flow during acceleration (powering) and deceleration (regeneration) of a motor according to one aspect of the present invention.

[0032] The motor regeneration control and feedback control (FB control) described above are performed when the vehicle speed is reduced as shown in Figure 4, when the throttle is closed, and at that time the regeneration start signal is set to ON.

[0033] Furthermore, when the vehicle speed is accelerating (powering) as shown in Figure 4, the current discharged from the battery flows to the motor through the inverter, as shown in Figure 5. Also, when the vehicle speed is decelerating (regenerative braking) as shown in Figure 4, current flows from the motor to the battery through the inverter and charges it.

[0034] According to this embodiment, by supplying a negative current to the motor 12 to approach a target regenerative current value, the regenerative current is measured while regenerative current is supplied to the battery 11. Feedback control is performed to supply a negative current to the motor 12 to bridge the difference between the measured regenerative current value and the target regenerative current value. It is determined whether the measured regenerative current value is increasing or decreasing. If it is determined to be increasing, the feedback control is maintained. If it is determined to be decreasing, the maximum regenerative current value is detected based on the history of measured regenerative current values, and the current supplied to the motor 12 is adjusted and controlled with this maximum regenerative current value as the target. As a result, the regenerative current value can be brought closer to the target regenerative current value in real time, and the regenerative current can be brought closer to maximizing. Furthermore, there is no need to create a calibration map value when performing motor regeneration control. This reduces the time and effort required to create a large number of calibration map values.

[0035] (Second Embodiment) A motor control circuit according to one aspect of the present invention will be described with reference to Figures 1 to 3.

[0036] The motor control circuit shown in Figure 3 is a circuit that generates positive torque in the motor 12 by supplying a positive current from the battery 11 to the motor 12 through the inverter circuit 13 (see Figure 5), and then supplies a negative current from the battery 11 to the motor 12 through the inverter circuit 13 (see Figure 5), thereby supplying a regenerative current from the motor 12 to the battery 11 and charging the battery 11.

[0037] The motor control circuit includes an inverter drive control unit 14 that drives and controls the inverter circuit 13. It also has a target regenerative current setting unit that sets a target regenerative current value based on the state of the battery 11, or based on the state of the battery 11 and the state of the motor 12, and this target regenerative current setting unit is included in the motor energizing current command unit 15 of the mapless regenerative control shown in Figure 3.

[0038] To approach the target regenerative current value set by the target regenerative current setting unit, a negative current is supplied to the motor 12 under the control of the inverter drive control unit 14. As a result, the regenerative current is supplied to the battery 11 while the power supply current measurement unit 16 measures the regenerative current. Furthermore, while a negative current is supplied to the motor 12, the motor current supply detection unit 21 detects the current value of the motor 12, and this current value data is transmitted to the inverter drive control unit 14 and the motor current supply command unit 15 of the mapless regenerative control.

[0039] In the motor energization current command unit 15, a current command value is determined to supply a negative current to the motor 12 in order to bridge the difference between the regenerative current value measured by the power supply current measurement unit 16 and the target regenerative current value, and this current command value is input to the inverter drive control unit 14. The inverter drive control unit 14 then drives the inverter circuit 13 to supply a negative current to the motor 12 based on the current command value (see Figure 2(A)).

[0040] A determination unit within the motor energizing current command unit 15 of the mapless regenerative control determines whether the regenerative current value measured by the power supply current measurement unit 16 is increasing or decreasing. If this determination unit determines that the regenerative current value measured by the power supply current measurement unit 16 is increasing, the motor energizing current command unit 15 continues to control the motor 12 to supply negative current to bridge the difference between the regenerative current value measured by the power supply current measurement unit 16 and the target regenerative current value (see Figure 2(A)).

[0041] Furthermore, if the determination unit determines that the regenerative current value measured by the power supply current measurement unit 16 has not reached the target regenerative current value and the regenerative current value is decreasing, the power supply current measurement unit 16 detects the maximum regenerative current value based on the history of the regenerative current value, and the data of the maximum regenerative current value is input to the motor energizing current command unit 15. The power supply current measurement unit 16 has a storage unit that stores the history of the regenerative current value. The motor energizing current command unit 15 then determines an energizing current command value that adjusts the energizing current supplied to the motor 12 with the maximum regenerative current value as the target, and inputs this energizing current command value to the inverter drive control unit 14. For example, the inverter drive control unit 14 controls the motor energizing current in the positive direction, aiming to maximize the regenerative current value.

[0042] According to the present embodiment, as shown in FIG. 2(A), in order to fill the difference between the regenerative current value measured by the power supply current measurement unit 16 and the target regenerative current value, the motor energization current command unit 15 determines an energization current command value for flowing a negative-direction energization current through the motor 12, inputs the energization current command value to the inverter drive control unit 14 by the motor energization current command unit 15, determines whether the regenerative current value measured by the power supply current measurement unit 16 is increasing or decreasing by the determination unit, and when it is determined by the determination unit that the regenerative current value measured by the power supply current measurement unit 16 has decreased without reaching the target regenerative current value, in the power supply current measurement unit 16, the maximum regenerative current value is detected based on the history of the measured regenerative current value, and in the motor energization current command unit 15, an energization current command value obtained by adjusting the energization current flowing through the motor 12 with the maximum regenerative current value as the target is determined, and the energization current command value is input to the inverter drive control unit 14. For this reason, it is not necessary to create an adaptation map value when performing motor regenerative control, and thereby, a lot of time and labor for creating a large number of adaptation map values can be reduced.

[0043] (Third Embodiment) A motor regenerative control program according to an aspect of the present invention will be described. This motor regenerative control program causes a positive-direction energization current to flow from the battery 11 to the motor 12 (see FIG. 5), generates a positive torque in the motor 12, and then causes a negative-direction energization current to flow from the battery 11 through the inverter circuit 13 to the motor 12 (see FIG. 5), thereby realizing a regenerative control in which a regenerative current flows from the motor 12 to the battery 11 to charge the battery 11.

[0044] This program is a motor regenerative control program that realizes the following functions (a) to (f). Although the program realizes the following functions by a microcomputer, other devices may be used as long as they can realize the following functions.

[0045] ・Function (a): A function to set a target regenerative current value based on the state of the battery 11. The target regenerative current value is set based on the state of the battery 11, or based on the state of the battery 11 and the state of the motor 12. ・Function (b): A function to measure the regenerative current while supplying regenerative current to the battery 11 by supplying a negative current to the motor 12 to bring it closer to the target regenerative current value set in function (a). ・Function (c): A function to perform feedback control by supplying a negative current to the motor 12 to bridge the difference between the regenerative current value measured in function (b) and the target regenerative current value. ・Function (d): A function to determine whether the measured regenerative current value is increasing or decreasing. Specifically, this function measures the regenerative current while supplying current to the motor 12 under feedback control in function (c), and determines whether the measured regenerative current value is increasing or decreasing. ・Function (e): A function to maintain feedback control if it is determined that the measured regenerative current value is increasing. In detail, Function (c) is a function that measures the regenerative current while supplying current to the motor 12 under feedback control, and maintains the feedback control if it is determined that the measured regenerative current value is increasing. Function (f): If it is determined that the measured regenerative current value is decreasing because it has not reached the target regenerative current value, this function detects the maximum regenerative current value based on the history of the measured regenerative current value and controls the current supplied to the motor 12 by adjusting it to target the maximum regenerative current value. In detail, Function (c) is a function that measures the regenerative current while supplying current to the motor 12 under feedback control, and if it is determined that the measured regenerative current value is decreasing because it has not reached the target regenerative current value, this function detects the maximum regenerative current value based on the history of the measured regenerative current value and controls the current supplied to the motor 12 by adjusting it to target the maximum regenerative current value. In other words, if it is determined that the regenerative current value is decreasing, this function controls the motor current in the positive direction to maximize the regenerative current value.

[0046] In this embodiment, the same effects as in the first embodiment can be obtained.

[0047] Furthermore, various embodiments of the present invention can also be implemented by appropriately combining the first, second, and third embodiments described above.

[0048] 11 Battery 12 Motor 13 Inverter circuit 14 Inverter drive control unit 15 Motor current supply command unit 16 Power supply current measurement unit

Claims

1. In a regenerative control method in which a positive torque is generated in a motor by flowing a positive current from the battery to the motor, and then a regenerative current is flowed from the motor to the battery by flowing a negative current to the motor to charge the battery, a target regenerative current value is set based on the state of the battery, the regenerative current is measured while a regenerative current is flowing to the battery by flowing a negative current to the motor to approach the target regenerative current value, feedback control is performed to flow a negative current to the motor to bridge the difference between the measured regenerative current value and the target regenerative current value, it is determined whether the measured regenerative current value is increasing or decreasing, and if it is determined that the measured regenerative current value is increasing, the feedback control is maintained. A motor regeneration control method characterized in that, if it is determined that the measured regenerative current value has not reached the target regenerative current value and the measured regenerative current value has decreased, the maximum value of the regenerative current is detected based on the history of the measured regenerative current value, and the current supplied to the motor is adjusted and controlled with the maximum value of the regenerative current as the target.

2. The motor regeneration control method according to claim 1, characterized in that the regenerative current is measured continuously or intermittently.

3. A motor regeneration control method according to claim 1 or 2, characterized in that when determining whether the measured regenerative current value has increased or decreased, the measured regenerative current value is compared with a previously measured regenerative current value, and if it has increased by a predetermined value or more, it is determined that the measured regenerative current value has increased, and if it has decreased by a predetermined value or more, it is determined that the measured regenerative current value has decreased.

4. A motor regenerative control method according to claim 1 or 2, characterized in that the feedback control is PI control.

5. The motor regeneration control method according to claim 1 or 2, characterized in that the motor regeneration control method is a control method that does not use a compatible map value.

6. A motor control circuit that generates positive torque in a motor by supplying a positive current from a battery to the motor through an inverter circuit, and then charges the battery by supplying a negative current from the battery to the motor through the inverter circuit, thereby supplying a regenerative current from the motor to the battery, comprising: an inverter drive control unit that drives and controls the inverter circuit; a power supply current measurement unit that sets a target regenerative current value based on the state of the battery and supplies a negative current to the motor to approach the target regenerative current value, thereby supplying the regenerative current while supplying it to the battery; a motor current supply command unit that determines a current supply command value for supplying a negative current to the motor to bridge the difference between the regenerative current value measured by the power supply current measurement unit and the target regenerative current value, and inputs the current supply command value to the inverter drive control unit; and a determination unit that determines whether the regenerative current value measured by the power supply current measurement unit is increasing or decreasing. If the determination unit determines that the regenerative current value measured by the power supply current measurement unit is increasing, the motor energizing current command unit continues to control the motor to supply a negative current to bridge the gap between the regenerative current value measured by the power supply current measurement unit and the target regenerative current value. If the determination unit determines that the regenerative current value measured by the power supply current measurement unit is decreasing and has not reached the target regenerative current value, the power supply current measurement unit detects the maximum regenerative current value based on the history of the measured regenerative current value, the motor energizing current command unit determines an energizing current command value that adjusts the energizing current supplied to the motor to target the maximum regenerative current value, and inputs the energizing current command value to the inverter drive control unit.

7. In a program that implements regenerative control in which a positive torque is generated in the motor by flowing a positive current from the battery to the motor, and then a regenerative current is flowed from the motor to the battery by flowing a negative current to the motor to charge the battery, the program includes: a function to set a target regenerative current value based on the state of the battery (a); a function to measure the regenerative current while flowing a regenerative current to the battery by flowing a negative current to the motor to approach the target regenerative current value (b); a function to perform feedback control by flowing a negative current to the motor to bridge the difference between the measured regenerative current value and the target regenerative current value (c); a function to determine whether the measured regenerative current value is increasing or decreasing (d); and a function to maintain the feedback control if it is determined that the measured regenerative current value is increasing (e). A motor regenerative control program characterized by having the following function (f): If the measured regenerative current value is determined to be decreasing without reaching the target regenerative current value, the program detects the maximum regenerative current value based on the history of the measured regenerative current value and controls the current supplied to the motor by adjusting it to target the maximum regenerative current value.

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