Motor control device and motor control method

Abstract

To control d-axis current even if the load or rotation speed of a motor changes without the need of current detection and without performing complex arithmetic processing.SOLUTION: A motor control device (10) comprises: a memory (14) that stores an advance map in which an advance map value and a load factor of a motor (30) are associated with each other in advance; an advance setting unit (13) that calculates the load factor of the motor (30) at motor application voltage applied to the motor (30), and sets the advance calculated on the basis of the motor application voltage and the advance map value obtained from the advance map by using the calculated load factor; and a PWM drive control unit (17) that controls the motor at the set advance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a motor control device and a motor control method. [Background technology]

[0002] By using vector control, brushless motors can adjust the current phase to the optimum even when the rotation speed or load changes, and can suppress the current with optimal motor characteristics to operate efficiently.

[0003] For example, Patent Document 1 describes a vector control device for a permanent magnet synchronous motor that controls the output voltage of a power converter that drives the permanent magnet synchronous motor based on a second d-axis current command value calculated from a first d-axis current command value, a second q-axis current command value calculated from a first q-axis current command value, a frequency command value, and a motor constant set value. This vector control device includes a motor constant identification calculation unit that identifies a motor constant of the permanent magnet synchronous motor connected to the power converter using the second d-axis current command value, the second q-axis current command value, a detected value of the output current of the power converter, and the motor constant set value, and drives and controls the permanent magnet motor using the motor constant identified by the motor constant identification calculation unit in vector control calculation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-049843 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned vector control requires a current detection unit that detects the current and a calculation unit that performs calculations such as coordinate conversion, and the cycle of the current control must be made faster especially when the current change is large, so a microcomputer with high processing power must be used. For this reason, when cost is important, the lead angle may be fixed in advance or set according to the rotation speed. In this case, in applications where the rotation speed or load fluctuates, the d-axis current may become excessive, resulting in reduced efficiency and reduced speed controllability.

[0006] An object of the present disclosure is to provide a motor control device and a motor control method that are capable of controlling the d-axis current without requiring current detection or complex arithmetic processing, even when the load or rotational speed of the motor changes. [Means for solving the problem]

[0007] A motor control device according to a first aspect of the present disclosure includes a memory unit that stores an lead-angle map that previously associates a motor lead-angle map value with a load factor, a calculation unit that calculates a load factor of the motor at a motor applied voltage that is a voltage applied to the motor, a setting unit that uses the calculated load factor to set a lead-angle calculated based on the lead-angle map value obtained from the lead-angle map and the motor applied voltage, and a drive control unit that controls the motor with the set lead-angle.

[0008] A motor control method according to a second aspect of the present disclosure is a motor control method using a motor control device having a memory unit that stores an lead-angle map that correlates in advance lead-angle map values ​​of the motor with load factors, wherein the motor control device calculates a load factor of the motor at a motor applied voltage that is an applied voltage to the motor, uses the calculated load factor to set a lead-angle calculated based on the lead-angle map value obtained from the lead-angle map and the motor applied voltage, and controls the motor using the set lead-angle. Effect of the Invention

[0009] The disclosed technique has the advantage that it is possible to control the d-axis current without the need for current detection and without complex arithmetic processing, even if the load or rotation speed of the motor changes. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an example of a configuration of a brushless motor system according to a first embodiment. [Diagram 2] 2 is a diagram showing a schematic diagram of the relationship between the d-axis and the q-axis of the brushless motor according to the embodiment. FIG. [Diagram 3] 5 is a graph showing an example of setting an advance angle map and advance angle map values ​​according to the embodiment; [Figure 4] Graph (A) shows an example of the relationship between the rotation speed and torque of a brushless motor and the relationship between the d-axis current and torque when the motor applied voltage Va=Vs, and graph (B) shows an example of the relationship between the rotation speed and torque of a brushless motor and the relationship between the d-axis current and torque when the motor applied voltage Va=Vs / 2. [Diagram 5] FIG. 2 is a block diagram showing a configuration of a motor control device according to a comparative example. [Figure 6] 5 is a flowchart showing an example of the flow of an advance angle control process by the motor control device according to the first embodiment. [Figure 7] Graph (A) shows another example of the setting of the advance angle map of the brushless motor when the motor applied voltage Va=Vs, and graph (B) shows another example of the relationship between the rotation speed and torque of the brushless motor when the motor applied voltage Va=Vs. [Figure 8] 4A and 4B are diagrams illustrating an example of an upper inverted position and a lower inverted position of a wiper arm provided on a windshield. [Figure 9] 6 is a graph showing simulation results of the wiper motor rotation speed, advance angle, q-axis current, and d-axis current at an upper reversing position and a lower reversing position of the wiper arm. [Figure 10] 10 is a flowchart showing an example of the flow of an advance angle control process by a motor control device according to a second embodiment. [Figure 11] 1A is a diagram showing an example of a correction value table correlating loads with advance angle correction values, FIG. 1B is a diagram showing an example of an advance angle map correlating advance angle map values ​​with rotation speeds, and FIG. 1C is a diagram showing an example of the correspondence relationship between rotation directions and loads. [Figure 12] 10 is a flowchart showing an example of the flow of an advance angle control process by a motor control device according to a third embodiment. [Figure 13] 10 is a flowchart showing an example of the flow of an advance angle control process by a motor control device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an example of an embodiment of the technology of the present disclosure will be described in detail with reference to the drawings.

[0012] [First embodiment] FIG. 1 is a block diagram showing an example of the configuration of a brushless motor system 100 according to the first embodiment.

[0013] 1, a brushless motor system 100 according to this embodiment includes a motor control device 10, an inverter 20, a brushless motor 30, and a temperature sensor 40. As an example, the brushless motor system 100 according to this embodiment is applied to driving a wiper device that wipes the windshield of a vehicle, but can also be applied to various auxiliary devices mounted on a vehicle. The brushless motor 30 is an example of a motor.

[0014] The motor control device 10 is a controller that is connected to an inverter 20 and controls the operation of a brushless motor 30 via the inverter 20, and is composed of, for example, a microcomputer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc.

[0015] The inverter 20 is disposed between the motor control device 10 and the brushless motor 30, and includes switching elements (not shown) that connect and disconnect an external power source (not shown) and an armature coil (not shown) of the brushless motor 30. The switching elements are, for example, configured of semiconductor elements such as FETs (Field Effect Transistors). More specifically, the inverter 20 includes three positive-side switching elements corresponding to the U, V, and W phases and connected to the positive pole of the external power source, and three negative-side switching elements corresponding to the U, V, and W phases and connected to the negative pole of the external power source. When the switching elements are connected (on) under the control of the motor control device 10, a current is supplied from the external power source to each armature coil, and when the switching elements are disconnected (off), no current is supplied from the external power source to each armature coil. The external power source is a battery, a capacitor, or the like mounted on the vehicle.

[0016] As an example of the brushless motor 30, a three-phase two-pole motor or a three-phase four-pole motor is used. The brushless motor 30 has a stator (not shown) and a rotor (not shown). The brushless motor 30 also has, for example, a cylindrical case (not shown) with a bottom, and the stator is fixed to the inner circumference of the case. The stator has three-phase armature coils, specifically, U-phase, V-phase, and W-phase. The rotor is provided inside the stator, and has a rotating shaft (not shown) and a permanent magnet (not shown) attached to the rotating shaft. A plurality of bearings (not shown) are provided inside the case, and the rotating shaft is rotatably supported by the plurality of bearings.

[0017] The temperature sensor 40 is a sensor that measures the temperature of the brushless motor 30, and may be a non-contact or contact sensor. Temperature information measured by the temperature sensor 40 is output to the motor control device 10.

[0018] The motor control device 10 according to this embodiment includes a position detection unit 11, a speed control unit 12, a lead angle setting unit 13, a memory 14, a lead angle correction unit 15, a three-phase conversion unit 16, and a PWM (Pulse Width Modulation) drive control unit 17.

[0019] The position detection unit 11 acquires rotational position signals (for example, every 60° electrical angle) of the brushless motor 30 from three Hall ICs (not shown) attached to the brushless motor 30. The position detection unit 11 calculates an electrical angle θ by interpolating and estimating positions between the rotational position signals based on the rotational position signals, and outputs the calculated electrical angle θ to the three-phase conversion unit 16. The position detection unit 11 also converts the rotational position signals into a current speed (actual rotational speed, hereinafter also referred to as “actual rotational speed”), and outputs the converted actual rotational speed ω to each of the speed control unit 12 and the lead angle setting unit 13.

[0020] The speed control unit 12 acquires a speed command including a target rotation speed from a higher-level device such as a PLC (Programmable Logic Controller). If the motor control device 10 has a program creation function, the motor control device 10 itself may function as a PLC. The speed control unit 12 also acquires an actual rotation speed ω from the position detection unit 11, calculates a motor applied voltage Va so that the difference between the target rotation speed included in the speed command and the actual rotation speed ω becomes small, and outputs the calculated motor applied voltage Va to each of the lead angle setting unit 13 and the three-phase conversion unit 16. The motor applied voltage Va is a voltage applied to the brushless motor 30.

[0021] A motor control program and necessary data for executing the lead angle control process according to this embodiment are stored in the memory 14. The memory 14 also stores in advance an lead angle map that correlates lead angle map values ​​of the brushless motor 30 with the load factor. The memory 14 is an example of a storage unit.

[0022] Lead angle setting unit 13 calculates the load factor of brushless motor 30 at motor applied voltage Va, which is the voltage applied to brushless motor 30. Lead angle setting unit 13 also derives lead angle map values ​​from a lead angle map in memory 14 using the calculated load factor, and calculates lead angle θ based on the derived lead angle map value and motor applied voltage Va. adv The lead angle setting unit 13 sets the lead angle θ adv to the three-phase conversion unit 16. The lead angle setting unit 13 is an example of a calculation unit and a setting unit.

[0023] The advance angle correction unit 15 adjusts the advance angle θ adv The temperature of the brushless motor 30 is acquired by the temperature sensor 40. Specifically, for example, the temperature of the brushless motor 30 and the advance angle θ adv It is conceivable to perform the correction using a data table in which the relationship between the advance angle correction unit 15 and the advance angle correction unit 16 is previously associated with each other.

[0024] Further, the advance angle correction unit 15 adjusts the advance angle θ adv The information acquired from the outside may be acquired as a LIN signal via a LIN (Local Interconnect Network). Specifically, for example, the LIN signal and the lead angle θ adv It is conceivable to correct this by using a data table in which the relationship between the

[0025] The three-phase conversion unit 16 receives the electrical angle θ from the position detection unit 11, the motor applied voltage Va from the speed control unit 12, and the lead angle θ from the lead angle setting unit 13. adv The electrical angle θ and the advance angle θ are obtained. adv Based on this, the motor application voltage Va is converted into three-phase motor application voltages Vu, Vv, and Vw, and the converted three-phase motor application voltages Vu, Vv, and Vw are output to the PWM drive control unit 17.

[0026] The PWM drive control unit 17 acquires the three-phase motor applied voltages Vu, Vv, and Vw from the three-phase conversion unit 16, generates a PWM signal from the acquired three-phase motor applied voltages Vu, Vv, and Vw, and outputs the generated PWM signal to the inverter 20. The PWM drive control unit 17 is an example of a drive control unit.

[0027] Next, the d-axis and q-axis of the brushless motor 30 will be specifically described with reference to FIG.

[0028] FIG. 2 is a diagram showing a schematic relationship between the d-axis and the q-axis of the brushless motor 30 according to this embodiment.

[0029] As shown in Fig. 2, the brushless motor 30 is virtually configured with a d-phase coil and a q-phase coil. The d-phase coil and the q-phase coil rotate together when the permanent magnet rotates. The d-axis is parallel to the magnetic flux of the magnet, and the q-axis is perpendicular to the d-axis. The d-axis current is a current component that generates a magnetic flux parallel to the magnetic flux of the magnet, and does not contribute to the magnet torque. The q-axis magnetic flux is a current component that generates a magnetic flux perpendicular to the magnetic flux of the magnet, and generates the magnet torque.

[0030] When a negative d-axis current is applied, the magnetic flux of the magnet is cancelled out, weakening the magnetic field. As a result, the current increases in the low load range, but the motor can rotate at high speed.

[0031] Fig. 3 is a graph showing an example of setting the advance angle map and advance angle map value according to this embodiment. In Fig. 3, the horizontal axis indicates the load factor [%], and the vertical axis indicates the advance angle map value [deg]. Note that the values ​​in the graph are only examples.

[0032] 3, as described above, associates advance angle map values ​​of brushless motor 30 with the load factor in advance, and is stored in memory 14. Here, load factor L is calculated, for example, using the following formula (1).

[0033] L = Vb / Va (1)

[0034] Here, Va indicates the motor applied voltage, which is determined by the speed control unit 12. Vb indicates the motor load voltage, which is the value obtained by subtracting the back electromotive force from the motor applied voltage Va. The motor load voltage Vb is calculated, for example, using the following formula (2).

[0035] Vb = Va-k × ω (2)

[0036] Here, k indicates the back electromotive force constant, and ω indicates the actual rotation speed.

[0037] 3, the advance angle map M1 is set so that, for example, when the motor applied voltage Va=Vs, the d-axis current Id of the brushless motor 30 becomes 0. Here, the advance angle θ adv and advance angle map value θ mp The relationship between is expressed by the following equation (3).

[0038] θ adv =θ mp ×V a / V s ···(3)

[0039] Here, Va indicates the voltage applied to the motor, and Vs indicates a reference voltage (for example, 13.5 V).

[0040] Here, as an example, a case where the motor applied voltage Va=Vs / 2 will be described. Using the above-mentioned formulas (1) and (2), the load factor L of the brushless motor 30 at Va=Vs / 2 is calculated. Next, the calculated load factor L is used to refer to the advance angle map M1 to obtain the advance angle map value θ mp Derive the lead angle map value θ mp and the motor applied voltage Va=Vs / 2 are substituted into the above equation (3), and the advance angle θ according to the motor applied voltage Va is calculated. adv Calculate.

[0041] Here, the advance angle map M1 is set so that when the load factor is in a range below a predetermined value, the angle is retarded, that is, a negative angle. Specifically, it is desirable that the load factor is in a negative range when the load factor is below the predetermined value. The "advance angle" according to this embodiment includes both a positive advance angle and a retard angle that is a negative advance angle.

[0042] Fig. 4(A) is a graph showing an example of the relationship between the rotation speed and torque of brushless motor 30 and the relationship between d-axis current Id and torque when motor applied voltage Va = Vs. Fig. 4(B) is a graph showing an example of the relationship between the rotation speed and torque of brushless motor 30 and the relationship between d-axis current Id and torque when motor applied voltage Va = Vs / 2.

[0043] In each of Figures 4(A) and 4(B), the horizontal axis of the upper graph indicates torque [N m], and the vertical axis indicates rotation speed [rpm]. Characteristic R1 shown in the upper graph indicates the case where the lead angle is 20°, characteristic R2 indicates the case where the lead angle is 10°, characteristic R3 indicates the case where the lead angle is 0°, and characteristic R4 indicates the case where Id = 0 in this embodiment. Moreover, the horizontal axis of the lower graph indicates torque [N m], and the vertical axis indicates d-axis current Id [A]. Characteristic I1 shown in the lower graph indicates the case where the lead angle is 20°, characteristic I2 indicates the case where the lead angle is 10°, characteristic I3 indicates the case where the lead angle is 0°, and characteristic I4 indicates the case where Id = 0 in this embodiment.

[0044] As shown in Figures 4(A) and 4(B), by adjusting the lead angle according to the voltage applied to the motor, the d-axis current Id becomes approximately 0 even if the voltage applied to the motor, the rotation speed, and the torque change. In other words, it is possible to perform control similar to Id = 0 control, which is a type of vector control.

[0045] In the above, the case of substantially sinusoidal wave energization using a waveform in which a sine wave and a third harmonic are superimposed has been shown, but the present invention can also be applied to various energization methods such as rectangular wave energization, trapezoidal wave energization, etc. In this case, although it is not possible to set Id=0 as in the case of sinusoidal wave energization, it is possible to set the lead angle that minimizes Id.

[0046] FIG. 5 is a block diagram showing a configuration of a motor control device 200 according to a comparative example.

[0047] As shown in FIG. 5, the motor control device 200 of the comparative example includes a speed control unit 201, a position detection unit 202, a current control unit 203, an inverse coordinate conversion unit 204, a three-phase conversion unit 205, a PWM drive control unit 206, a current detection unit 207, a two-phase conversion unit 208, and a coordinate conversion unit 209.

[0048] The motor control device 200 according to the comparative example is configured to perform vector control. As described above, the motor control device 200 performing vector control requires a current detection unit 207 that detects current, and an inverse coordinate conversion unit 204 and a coordinate conversion unit 209 that are calculation units that perform coordinate conversion calculations. In particular, when the current change is large, the cycle of current control must be made faster, and a microcomputer with high processing power must be adopted. For this reason, when cost is important, the lead angle may be fixed in advance or set according to the rotation speed. In this case, in applications where the rotation speed or load fluctuates, the d-axis current may become excessive, and efficiency and speed controllability may decrease.

[0049] In contrast, the motor control device 10 according to this embodiment stores an advance angle map M1 that associates advance angle map values ​​and load factors of the brushless motor 30. The motor control device 10 calculates the load factor L of the brushless motor 30 at the motor applied voltage Va, and uses the calculated load factor L to calculate the advance angle map value θ obtained from the advance angle map M1. mp and the advance angle θ calculated based on the motor applied voltage Va adv Set the lead angle θ adv The brushless motor 30 is controlled by the

[0050] As a result, even if the load or rotation speed of the brushless motor 30 changes, the d-axis current can be controlled without current detection or complex calculation processing.

[0051] When the rotation speed of the brushless motor 30 is equal to or lower than the threshold value, the lead angle setting unit 13 sets the lead angle θ adv Alternatively, the threshold value may be set to an appropriate value based on past knowledge or experimental results. For example, when detecting the electrical angle using a Hall IC, the estimation error of the electrical angle increases during startup when the rotation speed is low, so the advance angle θ that can reliably generate torque may be set to a fixed value. adv It is preferable to fix it at

[0052] In addition, the advance angle correction unit 15 adjusts the advance angle θ adv This makes it possible to suppress the influence of changes in characteristics due to the environmental temperature and heat generation of the motor.

[0053] Further, the lead angle correction unit 15 adjusts the lead angle θ based on information acquired from the outside (for example, a LIN signal). adv In this way, the advance angle θ adv can be corrected.

[0054] Next, the operation of the motor control device 10 according to the first embodiment will be described with reference to FIG.

[0055] FIG. 6 is a flowchart showing an example of the flow of advance angle control processing by the motor control device 10 according to the first embodiment.

[0056] First, when motor control device 10 is instructed to execute an advance angle control process, the motor control program is started and the following steps are executed.

[0057] 6, the position detection unit 11 acquires rotational position signals (for example, at every 60° electrical angle) of the brushless motor 30 from three Hall ICs (not shown) attached to the brushless motor 30. The position detection unit 11 calculates an electrical angle θ by interpolating and estimating positions between the rotational position signals based on the rotational position signals, and outputs the calculated electrical angle θ to the three-phase conversion unit 16. The position detection unit 11 also converts the rotational position signals into an actual rotational speed ω, and outputs the converted actual rotational speed ω to each of the speed control unit 12 and the lead angle setting unit 13.

[0058] In step S102, the speed control unit 12 acquires a speed command including a target rotation speed from a higher-level device such as a PLC, and acquires the actual rotation speed ω from the position detection unit 11. The speed control unit 12 calculates a motor applied voltage Va so that the difference between the target rotation speed included in the speed command and the actual rotation speed ω becomes small, and outputs the calculated motor applied voltage Va to each of the lead angle setting unit 13 and the three-phase conversion unit 16.

[0059] In step S103, the lead angle setting unit 13 estimates the load of the brushless motor 30. As a parameter corresponding to the load, for example, (motor applied voltage Va-back electromotive voltage) is estimated. Specifically, as one example, the motor load voltage Vb is calculated using the above-mentioned formula (2).

[0060] In step S104, the lead angle setting unit 13 calculates the load factor L from the motor applied voltage Va calculated in step S102 and the motor load voltage Vb calculated in step S103, for example, using the above-mentioned formula (1).

[0061] In step S105, the advance angle setting unit 13 refers to the advance angle map M1 stored in the memory 14 using the load factor L calculated in step S104 to set the advance angle map value θ mp Derive.

[0062] In step S106, the advance angle setting unit 13 sets the advance angle map value θ mpThe motor applied voltage Va calculated in step S102 is substituted into the above equation (3) to obtain the advance angle θ corresponding to the motor applied voltage Va. adv The lead angle setting unit 13 calculates the set lead angle θ adv is output to the three-phase conversion unit 16.

[0063] In step S107, the three-phase conversion unit 16 receives the electrical angle θ from the position detection unit 11, the motor applied voltage Va from the speed control unit 12, and the lead angle θ from the lead angle setting unit 13. adv The electrical angle θ and the advance angle θ are obtained. adv Based on this, motor application voltage Va is converted into three-phase motor application voltages Vu, Vv, and Vw, and the converted three-phase motor application voltages Vu, Vv, and Vw are output to PWM drive control unit 17. PWM drive control unit 17 controls the drive of brushless motor 30 based on motor application voltages Vu, Vv, and Vw, and then ends the advance angle control process according to this motor control program.

[0064] Fig. 7(A) is a graph showing another example of the setting of the advance angle map of brushless motor 30 when motor applied voltage Va = Vs, and Fig. 7(B) is a graph showing another example of the relationship between rotation speed and torque of brushless motor 30 when motor applied voltage Va = Vs.

[0065] In the advance angle map M3 shown in FIG. 7A, the advance angle is set to be large within a specific load factor range of the brushless motor 30.

[0066] Here, the advance angle map M3 shown in FIG. 7A is different from the advance angle map M1, which is set so that the d-axis current Id is 0, in that the advance angle map value θ mp is set large, and the negative d-axis current Id is used to weaken the field and increase the motor speed.

[0067] In other words, by setting a field-weakening region according to the operating range of the product, as in the characteristic R5 shown in Figure 7(B), the motor rotation speed can be increased within the operating range of the product to compensate for the characteristics of that operating range.

[0068] Next, with reference to Figs. 8 and 9, a simulation result in the case where the advance angle control process by the motor control device 10 according to this embodiment is applied to a wiper device will be described.

[0069] Fig. 8 is a diagram showing an example of an upper reversing position P1 and a lower reversing position P2 of the wiper arms 51, 52 provided on the windshield 50. Fig. 9 is a graph showing a simulation result of the wiper motor rotation speed, the advance angle, the q-axis current Iq, and the d-axis current Id at the upper reversing position P1 and the lower reversing position P2 of the wiper arms 51, 52.

[0070] Using the advance angle map M1 shown in FIG. 3 described above, a load change due to wind resistance was reproduced by simulation, and the effect of the advance angle control process according to this embodiment was confirmed.

[0071] As shown in Fig. 8, it is assumed that the brushless motor 30 according to this embodiment is directly or indirectly connected to drive the wiper arms 51, 52 of a wiper device. The wiper arms 51, 52 are provided on a windshield 50, and reciprocate between an upper reversing position P1 and a lower reversing position P2.

[0072] To ensure torque generation, the lead angle is fixed at 0° when the motor rotation speed is low. Since the q-axis current Iq is a value proportional to the torque generated by the motor, the load differs greatly between when the vehicle is stopped and when it is running at high speed, as shown in Fig. 9. However, it can be seen that the lead angle changes appropriately according to the load condition, and the d-axis current Id can be kept at almost 0 regardless of the load condition.

[0073] During forward movement, that is, movement from the lower reversal position P2 to the upper reversal position P1, regeneration occurs due to the influence of the wind, resulting in a retarded angle (i.e., a negative advance angle). On the other hand, during backward movement, that is, movement from the upper reversal position P1 to the lower reversal position P2, the load increases due to the influence of the wind, resulting in an increased advance angle.

[0074] As described above, according to this embodiment, even if the load or rotation speed of the motor changes, the d-axis current can be controlled without current detection or complex calculation processing.

[0075] [Second embodiment] In the above first embodiment, a form in which advance angle control processing is performed using an advance angle map that correlates advance angle map values ​​with a load factor has been described. In the second embodiment, a form in which advance angle control processing is performed using an advance angle map that correlates advance angle map values ​​with a rotation speed will be described.

[0076] The functional configuration of the motor control device 10A according to the second embodiment is similar to that of the motor control device 10 according to the first embodiment (see FIG. 1). A lead-angle map that associates lead-angle map values ​​of the brushless motor 30 with the rotation speed in advance is stored in the memory 14. The memory 14 is an example of a storage unit.

[0077] Lead-angle setting unit 13 is an example of an estimation unit, and estimates the load of brushless motor 30. Lead-angle setting unit 13 is an example of a calculation unit, and calculates a lead-angle correction value from the estimated load. Lead-angle setting unit 13 is an example of a setting unit, and sets a calculated lead-angle based on a lead-angle map value obtained from a lead-angle map in memory 14 using the actual rotation speed of brushless motor 30 and the calculated lead-angle correction value.

[0078] PWM drive control unit 17 is an example of a drive control unit, and controls brushless motor 30 with the lead angle set by lead angle setting unit 13 .

[0079] Next, the operation of the motor control device 10A according to the second embodiment will be described with reference to FIG.

[0080] FIG. 10 is a flowchart showing an example of the flow of advance angle control processing by the motor control device 10A according to the second embodiment.

[0081] First, when motor control device 10A is instructed to execute an advance angle control process, the motor control program is started and the following steps are executed.

[0082] 10, the position detection unit 11 acquires rotational position signals (for example, at every 60° electrical angle) of the brushless motor 30 from three Hall ICs (not shown) attached to the brushless motor 30. The position detection unit 11 calculates an electrical angle by interpolating and estimating positions between the rotational position signals based on the rotational position signals, and outputs the calculated electrical angle to the three-phase conversion unit 16. The position detection unit 11 also converts the rotational position signals into an actual rotational speed, and outputs the converted actual rotational speed to each of the speed control unit 12 and the lead angle setting unit 13.

[0083] At this time, the speed control unit 12 acquires a speed command including a target rotation speed from a higher-level device such as a PLC, and acquires the actual rotation speed from the position detection unit 11. The speed control unit 12 calculates a motor applied voltage so that the difference between the target rotation speed included in the speed command and the actual rotation speed becomes small, and outputs the calculated motor applied voltage to each of the lead angle setting unit 13 and the three-phase conversion unit 16.

[0084] In step S112, the lead angle setting unit 13 estimates the load of the brushless motor 30. As a parameter corresponding to the load, for example, (motor applied voltage-back electromotive voltage) is estimated. Specifically, as one example, the motor load voltage is calculated using the above-mentioned formula (2).

[0085] In step S113, lead-angle setting unit 13 calculates a lead-angle correction value from the load (for example, motor load voltage) estimated in step S112.

[0086] Fig. 11(A) is a diagram showing an example of a correction value table that associates loads with lead-angle correction values. This correction value table is stored in advance in memory 14. As an example, lead-angle setting unit 13 refers to the correction value table shown in Fig. 11(A) using an estimated load (for example, a motor load voltage) to calculate the lead-angle correction value.

[0087] In step S114, lead-angle setting unit 13 derives a lead-angle map value by referring to the lead-angle map stored in memory 14 using the actual rotation speed calculated in step S111.

[0088] Fig. 11(B) is a diagram showing an example of an advance-angle map that correlates advance-angle map values ​​with rotation speeds. This advance-angle map is stored in advance in memory 14. As an example, advance-angle setting unit 13 refers to the advance-angle map shown in Fig. 11(B) using the actual rotation speed to calculate the advance-angle map values.

[0089] In step S115, lead-angle setting unit 13 sets the lead angle calculated based on the lead-angle map value derived in step S114 and the lead-angle correction value calculated in step S113. Lead-angle setting unit 13 outputs the set lead angle to three-phase conversion unit 16.

[0090] Fig. 11(C) is a diagram showing an example of the correspondence relationship between the rotation direction and the load. As an example, lead angle setting unit 13 calculates the lead angle by multiplying the lead angle map value by the lead angle correction value. The sign (+ / -) of the lead angle is determined from the correspondence relationship shown in Fig. 11(C).

[0091] In step S116, three-phase conversion unit 16 acquires the electrical angle from position detection unit 11, the motor applied voltage from speed control unit 12, and the lead angle from lead angle setting unit 13, converts the motor applied voltage into three-phase (u-phase, v-phase, w-phase) motor applied voltage based on the electrical angle and lead angle, and outputs the converted three-phase motor applied voltage to PWM drive control unit 17. PWM drive control unit 17 controls the drive of brushless motor 30 based on the three-phase motor applied voltage, and ends the lead angle control process according to this motor control program.

[0092] Thus, according to this embodiment, similar to the first embodiment described above, even if the load or rotation speed of the motor changes, the d-axis current can be controlled without current detection or complex calculation processing.

[0093] [Third embodiment] In the third embodiment, a form will be described in which advance angle control processing is performed using an advance angle map that correlates advance angle map values ​​with loads.

[0094] The functional configuration of the motor control device 10B according to the third embodiment is similar to that of the motor control device 10 according to the first embodiment (see FIG. 1). A lead-angle map that associates lead-angle map values ​​of the brushless motor 30 with the load is stored in advance in the memory 14. The memory 14 is an example of a storage unit.

[0095] Lead-angle setting unit 13 is an example of an estimation unit, and estimates the load of brushless motor 30. Lead-angle setting unit 13 is an example of a calculation unit, and calculates a lead-angle correction value from the actual rotation speed. Lead-angle setting unit 13 is an example of a setting unit, and sets a calculated lead-angle based on a lead-angle map value obtained from a lead-angle map in memory 14 and the calculated lead-angle correction value, using the load of brushless motor 30.

[0096] PWM drive control unit 17 is an example of a drive control unit, and controls brushless motor 30 with the lead angle set by lead angle setting unit 13 .

[0097] Next, the operation of the motor control device 10B according to the third embodiment will be described with reference to FIG.

[0098] FIG. 12 is a flowchart showing an example of the flow of advance angle control processing by the motor control device 10B according to the third embodiment.

[0099] First, when motor control device 10B is instructed to execute an advance angle control process, the motor control program is started and the following steps are executed.

[0100] 12, the position detection unit 11 acquires rotational position signals (for example, at every 60° electrical angle) of the brushless motor 30 from three Hall ICs (not shown) attached to the brushless motor 30. The position detection unit 11 calculates an electrical angle by estimating positions between the rotational position signals based on the rotational position signals through interpolation, and outputs the calculated electrical angle to the three-phase conversion unit 16. The position detection unit 11 also converts the rotational position signals into an actual rotational speed, and outputs the converted actual rotational speed to each of the speed control unit 12 and the lead angle setting unit 13.

[0101] At this time, the speed control unit 12 acquires a speed command including a target rotation speed from a higher-level device such as a PLC, and acquires the actual rotation speed from the position detection unit 11. The speed control unit 12 calculates a motor applied voltage so that the difference between the target rotation speed included in the speed command and the actual rotation speed becomes small, and outputs the calculated motor applied voltage to each of the lead angle setting unit 13 and the three-phase conversion unit 16.

[0102] In step S122, the lead angle setting unit 13 estimates the load of the brushless motor 30. As a parameter corresponding to the load, for example, (motor applied voltage-back electromotive voltage) is estimated. Specifically, as one example, the motor load voltage is calculated using the above-mentioned formula (2).

[0103] In step S123, lead-angle setting unit 13 calculates a lead-angle correction value from the actual rotation speed calculated in step S121. In this case, the correction value table shown in Fig. 11(A) described above may be used as a correction value table that associates the rotation speed with the lead-angle correction value. This correction value table is stored in advance in memory 14. As an example, lead-angle setting unit 13 refers to the correction value table using the calculated actual rotation speed to calculate the lead-angle correction value.

[0104] In step S124, lead-angle setting unit 13 uses the load estimated in step S122 to refer to the lead-angle map stored in memory 14 to derive an lead-angle map value. In this case, the lead-angle map shown in FIG. 11(B) described above may be an lead-angle map that associates the load with the lead-angle map value. This lead-angle map is stored in advance in memory 14. As an example, lead-angle setting unit 13 refers to the lead-angle map using the estimated load to calculate the lead-angle map value.

[0105] In step S125, lead-angle setting unit 13 sets the lead-angle calculated based on the lead-angle map value derived in step S124 and the lead-angle correction value calculated in step S123. Lead-angle setting unit 13 calculates the lead-angle by multiplying the lead-angle map value by the lead-angle correction value, for example. Lead-angle setting unit 13 outputs the set lead-angle to three-phase conversion unit 16.

[0106] In step S126, three-phase conversion unit 16 obtains the electrical angle from position detection unit 11, the motor applied voltage from speed control unit 12, and the lead angle from lead angle setting unit 13, converts the motor applied voltage into three-phase (u-phase, v-phase, w-phase) motor applied voltage based on the electrical angle and lead angle, and outputs the converted three-phase motor applied voltage to PWM drive control unit 17. PWM drive control unit 17 controls the drive of brushless motor 30 based on the three-phase motor applied voltage, and ends the lead angle control process according to this motor control program.

[0107] Thus, according to this embodiment, similar to the first embodiment described above, even if the load or rotation speed of the motor changes, the d-axis current can be controlled without current detection or complex calculation processing.

[0108] [Fourth embodiment] In the fourth embodiment, an embodiment will be described in which advance angle control processing is performed using a first advance angle map that correlates advance angle map values ​​with rotation speeds, and a second advance angle map that correlates advance angle map values ​​with loads.

[0109] The functional configuration of the motor control device 10C according to the fourth embodiment is similar to that of the motor control device 10 according to the first embodiment (see FIG. 1). A first advance angle map correlating the advance angle map values ​​of the brushless motor 30 with the rotation speed, and a second advance angle map correlating the advance angle map values ​​with the load are stored in advance in the memory 14 of the motor control device 10C according to the fourth embodiment. The memory 14 is an example of a first storage unit and a second storage unit.

[0110] Lead-angle setting unit 13 is an example of an estimation unit, and estimates the load of brushless motor 30. Lead-angle setting unit 13 is an example of a setting unit, and sets a lead-angle calculated using a first lead-angle map value obtained from a first lead-angle map in memory 14 using the actual rotation speed of brushless motor 30, and a second lead-angle map value obtained from a second lead-angle map in memory 14 using the estimated load.

[0111] PWM drive control unit 17 is an example of a drive control unit, and controls brushless motor 30 with the lead angle set by lead angle setting unit 13 .

[0112] Next, the operation of the motor control device 10C according to the fourth embodiment will be described with reference to FIG.

[0113] FIG. 13 is a flowchart showing an example of the flow of advance angle control processing by the motor control device 10C according to the fourth embodiment.

[0114] First, when the motor control device 10C is instructed to execute the advance angle control process, the motor control program is started and the following steps are executed.

[0115] 13, the position detection unit 11 acquires rotational position signals (for example, at every 60° electrical angle) of the brushless motor 30 from three Hall ICs (not shown) attached to the brushless motor 30. The position detection unit 11 calculates an electrical angle by interpolating and estimating positions between the rotational position signals based on the rotational position signals, and outputs the calculated electrical angle to the three-phase conversion unit 16. The position detection unit 11 also converts the rotational position signals into an actual rotational speed, and outputs the converted actual rotational speed to each of the speed control unit 12 and the lead angle setting unit 13.

[0116] At this time, the speed control unit 12 acquires a speed command including a target rotation speed from a higher-level device such as a PLC, and acquires the actual rotation speed from the position detection unit 11. The speed control unit 12 calculates a motor applied voltage so that the difference between the target rotation speed included in the speed command and the actual rotation speed becomes small, and outputs the calculated motor applied voltage to each of the lead angle setting unit 13 and the three-phase conversion unit 16.

[0117] In step S132, the lead angle setting unit 13 estimates the load of the brushless motor 30. As a parameter corresponding to the load, for example, (motor applied voltage-back electromotive voltage) is estimated. Specifically, as one example, the motor load voltage is calculated using the above-mentioned formula (2).

[0118] In step S133, lead-angle setting unit 13 uses the actual rotation speed calculated in step S131 to refer to the first lead-angle map stored in memory 14 to derive a first lead-angle map value. In this case, lead-angle setting unit 13, as one example, uses the actual rotation speed to refer to the first lead-angle map shown in Fig. 11(B) described above to calculate the first lead-angle map value.

[0119] In step S134, lead-angle setting unit 13 uses the load estimated in step S132 to refer to the second lead-angle map stored in memory 14 to derive a second lead-angle map value. In this case, the first lead-angle map shown in Fig. 11(B) described above can be used as the second lead-angle map that associates the load with the lead-angle map value. As an example, lead-angle setting unit 13 uses the estimated load to refer to the second lead-angle map to calculate the second lead-angle map value.

[0120] In step S135, lead-angle setting unit 13 sets the lead angle calculated using the first lead-angle map value derived in step S133 and the second lead-angle map value derived in step S134. As an example, lead-angle setting unit 13 calculates the lead angle by multiplying the first lead-angle map value by the second lead-angle map value. Lead-angle setting unit 13 outputs the set lead angle to three-phase conversion unit 16.

[0121] In step S136, three-phase conversion unit 16 obtains the electrical angle from position detection unit 11, the motor applied voltage from speed control unit 12, and the lead angle from lead angle setting unit 13, converts the motor applied voltage into three-phase (u-phase, v-phase, w-phase) motor applied voltage based on the electrical angle and lead angle, and outputs the converted three-phase motor applied voltage to PWM drive control unit 17. PWM drive control unit 17 controls the drive of brushless motor 30 based on the three-phase motor applied voltage, and ends the lead angle control process according to this motor control program.

[0122] Thus, according to this embodiment, similar to the first embodiment described above, even if the load or rotation speed of the motor changes, the d-axis current can be controlled without current detection or complex calculation processing.

[0123] The following supplementary notes are further disclosed regarding the above embodiment.

[0124] (Appendix 1) a storage unit that stores an advance angle map in which an advance angle map value of the motor is related to a load factor; A calculation unit that calculates a load factor of the motor at a motor applied voltage that is a voltage applied to the motor; a setting unit that sets a lead angle calculated based on a lead angle map value obtained from the lead angle map and the motor applied voltage using the calculated load factor; a drive control unit that controls the motor with the set advance angle; A motor control device comprising: (Appendix 2) The advance angle map is set so that the d-axis current of the motor is 0. 2. A motor control device as described in claim 1. (Appendix 3) the advance angle map is set so that the advance angle is larger in a specific load factor range than the advance angle map set so that the d-axis current of the motor is 0; 3. The motor control device according to claim 2. (Appendix 4) the advance map is set so that the advance angle is retarded when the load factor is in a range less than a predetermined value; The motor control device according to any one of Supplementary Note 1 to Supplementary Note 3. (Appendix 5) The range less than the predetermined value is a negative range of the load ratio. 5. The motor control device according to claim 4. (Appendix 6) the setting unit switches to a mode in which the advance angle is fixed when the rotation speed of the motor is equal to or lower than a threshold value. The motor control device according to any one of Supplementary Note 1 to Supplementary Note 5. (Appendix 7) The motor further includes a correction unit that corrects the advance angle in accordance with the temperature of the motor. The motor control device according to any one of claims 1 to 6. (Appendix 8) The device further includes a correction unit that corrects the advance angle based on information obtained from an external source. The motor control device according to any one of Supplementary Note 1 to Supplementary Note 7. (Appendix 9) a storage unit that stores an advance angle map in which an advance angle map value of the motor is related to a rotation speed; an estimation unit that estimates a load on the motor; a calculation unit that calculates an advance correction value from the estimated load; a setting unit that sets a calculated lead angle based on a lead angle map value obtained from the lead angle map using an actual rotation speed of the motor and the calculated lead angle correction value; a drive control unit that controls the motor with the set advance angle; A motor control device comprising: (Appendix 10) a storage unit that stores an advance angle map in which an advance angle map value of the motor is related to a load; an estimation unit that estimates a load on the motor; a calculation unit that calculates an advance angle correction value from an actual rotation speed of the motor; a setting unit that sets a calculated advance angle based on an advance angle map value obtained from the advance angle map using the estimated load and the calculated advance angle correction value; a drive control unit that controls the motor with the set advance angle; A motor control device comprising: (Appendix 11) a first storage unit that stores a first advance angle map in which an advance angle map value of the motor and a rotation speed are related in advance; a second storage unit that stores a second advance angle map in which an advance angle map value of the motor is related to a load; an estimation unit that estimates a load on the motor; a setting unit that sets an advance angle calculated using a first advance angle map value obtained from the first advance angle map using an actual rotation speed of the motor and a second advance angle map value obtained from the second advance angle map using the estimated load; a drive control unit that controls the motor with the set advance angle; A motor control device comprising: (Appendix 12) A motor control method using a motor control device having a storage unit that stores an advance angle map in which an advance angle map value of a motor is related to a load factor, the method comprising: The motor control device, Calculating a load factor of the motor at a motor applied voltage, which is an applied voltage to the motor; using the calculated load factor to set a lead angle calculated based on a lead angle map value obtained from the lead angle map and the motor applied voltage; Controlling the motor with the set lead angle. Motor control methods. [Explanation of symbols]

[0125] 10, 10A, 10B, 10C motor control device, 11 position detection unit, 12 speed control unit, 13 lead angle setting unit, 14 memory, 15 lead angle correction unit, 16 three-phase conversion unit, 17 PWM drive control unit, 20 inverter, 30 brushless motor, 40 temperature sensor, 100 brushless motor system

Claims

1. a storage unit (14) for storing an advance angle map in which an advance angle map value of the motor (30) is related to a load factor; a calculation unit (13) that calculates a load factor of the motor, which is a value obtained by dividing a motor load voltage calculated by subtracting a back electromotive voltage of the motor from a motor applied voltage, which is a voltage applied to the motor, by the motor applied voltage; a setting unit (13) that sets a calculated lead angle based on a lead angle map value obtained from the lead angle map and the motor applied voltage using the calculated load factor; a drive control unit (17) for controlling the motor by outputting a three-phase voltage of the advance angle set by the setting unit; A motor control device (10) comprising:

2. The advance angle map is set so that the d-axis current of the motor becomes 0. The motor control device according to claim 1 .

3. the advance angle map is set so that the advance angle is larger in a specific load factor range than the advance angle map set so that the d-axis current of the motor is 0; The motor control device according to claim 2 .

4. the advance map is set so that the advance angle is retarded when the load factor is in a range less than a predetermined value; The motor control device according to claim 1 .

5. The range less than the predetermined value is a negative range of the load ratio. The motor control device according to claim 4.

6. the setting unit switches to a mode in which the advance angle is fixed when the rotation speed of the motor is equal to or lower than a threshold value. The motor control device according to claim 1 .

7. The motor further includes a correction unit (15) that corrects the advance angle in accordance with the temperature of the motor. The motor control device according to claim 1 .

8. The device further includes a correction unit (15) that corrects the advance angle based on information obtained from an external source. The motor control device according to claim 1 .

9. A memory unit (14) that stores an advance angle map that correlates an advance angle map value of a motor (30) with an actual rotation speed of the motor; A calculation unit (13) that calculates a motor load voltage by subtracting a back electromotive voltage of the motor from a motor applied voltage that is a voltage applied to the motor; a setting unit (13) that sets a lead angle calculated based on a lead angle correction value calculated from the motor load voltage, a lead angle map value obtained from the lead angle map using an actual rotation speed of the motor, and a voltage applied to the motor; a drive control unit (17) for controlling the motor by outputting a three-phase voltage of the advance angle set by the setting unit; A motor control device (10A) comprising:

10. A motor control method using a motor control device (10) having a storage unit (14) that stores an advance angle map in which an advance angle map value of the motor is previously associated with a load factor, the method comprising: The motor control device, a motor load voltage calculated by subtracting a back electromotive force of the motor from a motor applied voltage, which is a voltage applied to the motor, is divided by the motor applied voltage to calculate a load factor of the motor; setting a lead angle calculated based on a lead angle map value obtained from the lead angle map using the calculated load factor and the motor applied voltage; The motor is controlled by outputting a three-phase voltage having the set lead angle. Motor control methods.

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