Drive control device

Abstract

To provide a joining structure of a power line bus bar and a stator coil capable of joining the power line bus bar and the stator coil while absorbing a physique difference for each motor with a simple configuration.SOLUTION: The drive control device includes a processor, and the processor switches a drive control method for the three phase motor from current advance angle control to current minimum control when a component temperature related to a component constituting the three phase motor becomes equal to or higher than a control switching threshold value lower than a cooling operation threshold value of the three phase motor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a drive control device. [Background technology]

[0002] In a drive system for a three-phase AC motor, the more the AC current is advanced, the more difficult it becomes to calculate the inverter modulation ratio. Therefore, a technique has been disclosed for controlling the current advance angle in accordance with the predicted modulation ratio. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-182669 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, when controlling the current advance angle, the same torque as before the advance angle is output, so the current needs to be increased, which increases the amount of heat generated by components such as the inverter element and the motor coil. For this reason, in the above-mentioned Patent Document 1, when the component temperature rises naturally and exceeds a threshold value, it becomes necessary to operate a cooling device, which not only consumes power but also imposes a limit on the motor's output, making it impossible to obtain the output required by the user.

[0005] The present disclosure has been made in view of the above, and aims to provide a drive control device that can delay the time until the motor starts cooling and the output is limited. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, the drive control device of the present disclosure is a drive control device for a three-phase motor, and is equipped with a processor, wherein when the component temperature of components constituting the three-phase motor reaches or exceeds a control switching threshold that is lower than the cooling operation threshold of the three-phase motor, the processor switches the drive control method for the three-phase motor from current advance control to current minimum control. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to delay the time until the motor starts to cool down and the output is limited. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the functional configuration of a drive system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating the relationship between the current advance angle and the torque command value of a three-phase motor according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram illustrating the relationship between the motor cooling operation threshold and time in the drive system according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a flowchart showing an outline of the processing executed by the drive control device 6 according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] A drive system including a drive control device according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical. Furthermore, the drawings referred to in the following description merely show a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present disclosure can be understood. In other words, the present disclosure is not limited to the shape, size, and positional relationship exemplified in each drawing.

[0010] [Functional configuration of the drive system] Fig. 1 is a schematic diagram showing the functional configuration of a drive system according to an embodiment of the present disclosure. The drive system 100 shown in Fig. 1 is mounted on a vehicle such as an HEV (Hybrid Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), an EV (Electric Vehicle), or an FCEV (Fuel Cell Electric Vehicle). The drive system 100 includes an ECU (Electronic Control Unit) 1, a temperature sensor 2, a DC power supply 3, a three-phase inverter 4, a three-phase motor 5, and a drive control device 6.

[0011] The ECU 1 is implemented using a processor having hardware such as an FPGA (Field-Programmable Gate Array) or a CPU (Central Processing Unit), and a memory serving as a temporary storage area used by the processor, storing software (programs) capable of executing applications (hereinafter simply referred to as "apps"). The ECU 1 outputs a torque command to the drive control device 6 in accordance with the opening of an accelerator pedal (not shown), for example.

[0012] The temperature sensor 2 is configured using a thermistor sensor, etc. The temperature sensor 2 detects the temperatures of the components that make up the three-phase motor 5 and the three-phase inverter, and outputs the component temperatures to the drive control device 6.

[0013] The DC power supply 3 is configured by a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The DC power supply 3 may be a battery having a liquid electrolyte between the positive and negative electrodes, or may be an all-solid-state battery having a solid electrolyte. The DC power supply 3 may be configured as a battery pack in which a plurality of unit cells (battery cells) such as lithium-ion batteries are electrically connected in series. The DC power supply 3 outputs a power supply current to a three-phase inverter 4.

[0014] The three-phase inverter 4 converts the DC current from the DC power supply 3 into AC power (motor current, inverter voltage) in accordance with a gate signal from the drive control device 6 to drive the three-phase motor 5.

[0015] The three-phase motor 5 is a drive motor that generates torque for driving the drive wheels of the vehicle. The three-phase motor 5 is a three-phase AC synchronous motor, and may be, for example, an interior permanent magnet (IPM) electric motor with a permanent magnet embedded in the rotor.

[0016] The drive control device 6 is realized using a processor having hardware such as an FPGA or a CPU, and a memory that is a temporary storage area used by the processor and stores software (programs) that can execute applications (hereinafter simply referred to as "apps"). The drive control device 6 includes a control method selection unit 7, a torque control unit 8, a current control unit 9, and a gate signal conversion unit 10.

[0017] The control method selection unit 7 selects a control method for the three-phase motor 5 based on the component temperature input from the temperature sensor 2. Specifically, the control method selection unit 7 determines whether the component temperature input from the temperature sensor 2 is equal to or greater than the control switching threshold, and if the component temperature input from the temperature sensor 2 is equal to or greater than the control switching threshold, outputs a control flag to the torque control unit 8 to switch the drive control method for the three-phase motor 5 from current advance control to minimum current control. On the other hand, if the component temperature input from the temperature sensor 2 is not equal to or greater than the control switching threshold, the control method selection unit 7 outputs a control flag to the torque control unit 8 to change the drive control method for the three-phase motor 5 to current advance control.

[0018] The torque control unit 8 outputs a current command to the current control unit 9 for driving the three-phase motor 5 based on the torque command input from the ECU 1 and the control flag input from the control method selection unit 7.

[0019] The current control unit 9 outputs a three-phase voltage command for controlling the three-phase inverter 4 to the gate signal conversion unit 10 in accordance with the current command input from the torque control unit 8.

[0020] The gate signal conversion unit 10 outputs gate signals to the three-phase inverter 4 to drive and control the inverter elements that make up the three-phase inverter 4, in accordance with the three-phase voltage commands input from the current control unit 9.

[0021] [Example of control by the drive control device] Fig. 2 is a diagram showing the relationship between the current advance angle [deg] and the torque command value [Nm] of the three-phase motor 5. Each line in Fig. 2 indicates the effective current value of the three-phase motor 5 when the three-phase motor 5 is caused to output torque according to the torque command value. In Fig. 2, the horizontal axis indicates the current advance angle [deg], and the vertical axis indicates the torque command value [Nm] to the three-phase motor 5.

[0022] 2, when the component temperature input from the temperature sensor 2 is high, the control method selection unit 7 outputs a switching signal to the torque control unit 8 to switch to minimum current control, which reduces heat generation in the components that make up the three-phase inverter 4. Specifically, when the component temperature input from the temperature sensor 2 is high, the control method selection unit 7 outputs a switching signal to the torque control unit 8 to switch from the current advance control optimum line Lb to the current minimum control optimum line La.

[0023] Fig. 3 is a diagram showing the relationship between the motor cooling operation threshold and time. In Fig. 3, the horizontal axis represents component temperature [°C], and the horizontal axis represents time [seconds]. Also in Fig. 3, curve L10 represents the component temperature change when drive control of three-phase motor 5 is performed by drive control device 6, and curve L11 (dotted line) represents the component temperature change when conventional drive control of three-phase motor 5 is performed.

[0024] 3, the control method selection unit 7 switches the drive control method of the three-phase motor 5 from current quadrature control to current minimum control at the component temperature control switch threshold LT1, so the time until the component temperature reaches the motor cooling operation threshold LT2 can be delayed compared to curve L11. As a result, the drive control device 6 can delay the start of motor cooling of the three-phase motor 5 and also delay the time until output restriction occurs.

[0025] [Processing of the drive control device] Next, a description will be given of the processing executed by the drive control device 6. Fig. 4 is a flowchart showing an outline of the processing executed by the drive control device 6.

[0026] As shown in FIG. 4, first, the control method selection unit 7 determines whether the component temperature input from the temperature sensor 2 is higher than the control switching threshold LT1 (step S101). If the component temperature input from the temperature sensor 2 is higher than the control switching threshold LT1 (step S101: Yes), the control method selection unit 7 switches the drive control method of the three-phase motor 5 from current quadrature control to minimum current control (step S102). After step S102, the drive control device 6 ends this process. On the other hand, if the component temperature input from the temperature sensor 2 is not higher than the control switching threshold LT1 (step S101: No), the control method selection unit 7 changes the drive control method of the three-phase motor 5 to current quadrature control (step S103). After step S103, the drive control device 6 ends this process.

[0027] According to the embodiment described above, when the component temperature input from the temperature sensor 2 is higher than the control switching threshold LT1, the control method selection unit 7 switches the drive control method of the three-phase motor 5 from current right-angle control to current minimum control, thereby delaying the time until the cooling operation and output limitation of the three-phase motor 5 begin.

[0028] Furthermore, according to the embodiment, it is possible to suppress the temperature rise of the components that constitute the three-phase inverter 4 and the three-phase motor 5 without cooling the three-phase inverter 4 and the three-phase motor 5.

[0029] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0030] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0031] 1 ECU 2 Temperature Sensors 3 DC power supply 4-phase inverter 5 Three-phase motor 6 Drive control device 7 Control method selection section 8 Torque control section 9 Current control section 10 Gate signal conversion section 100 Drive System

Claims

[Claim 1] A drive control device for a three-phase motor, a processor; The processor: When the component temperature of the components constituting the three-phase motor becomes equal to or higher than a control switching threshold value that is lower than a cooling operation threshold value of the three-phase motor, a drive control method for the three-phase motor is switched from current advance control to current minimum control. Drive control device.

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