Motor control device, motor drive control device, motor device, motor control program

Abstract

To reduce vibration caused by switching energization to a coil.SOLUTION: A drive control device 1 includes: a rotational speed calculation unit 42 that calculates a rotational speed of a motor 20 on the basis of a rotational position detection signal of the motor 20; an energization stop time calculation unit 43 that calculates an energization stop time for stopping energization to all phases of coils Lu, Lv, and Lw of the motor 20 on the basis of a target rotational speed Stg and the rotational speed of the motor 20; and an energization signal generation unit 44 that switches the energization to the coils Lu, Lv, and Lw of the motor 20, and generates an energization signal for controlling the energization of the coils Lu, Lv, and Lw of the motor 20 in order to stop the energization of all the coils Lu, Lv, and Lw of the motor 20 during the energization stop time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor control device, a motor drive control device, a motor device, and a motor control program. [Background technology]

[0002] In a typical motor, vibration occurs when the current to the coils is switched during operation. To reduce the vibration that occurs when the current to the coils is switched, a motor drive control device is known that performs overlapping current supply, in which current supply to one phase (coil) of the motor continues for a predetermined time before current supply to the other phase is terminated (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-184291 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional technology, the overlapping current is switched at regular intervals, which causes vibrations when the current is switched. Therefore, further improvements are needed to reduce vibrations caused by switching current to the coils in the motor.

[0005] The present invention addresses the above-mentioned problem as an example, and aims to provide a technique for reducing vibration caused by switching the power supply to a coil. [Means for solving the problem]

[0006] In order to achieve the above object, the motor control device of the present invention comprises: a rotational speed calculation unit that calculates the rotational speed of the motor based on a rotational position detection signal of the motor; a power stop time calculation unit that calculates a power stop time for stopping power to all coils of the motor based on the rotational speed of the motor; and a power signal generation unit that generates a power signal that controls power to each of the motor's coils in order to switch power to each of the motor's coils and stop power to all of the motor's coils during the power stop time. [Effects of the Invention]

[0007] According to the motor control device of the present invention, it is possible to reduce vibrations caused by switching the energization of the coil. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a schematic configuration of a motor device including a drive control device according to an embodiment of the present invention; [Figure 2] 4 is a timing chart showing Example 1 of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 3] 10 is a timing chart showing a second example of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 4] 10 is a timing chart showing a third example of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 5] 10 is a timing chart showing a fourth example of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 6] 10 is a timing chart showing a fifth example of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 7] 10 is a timing chart showing Example 6 of the waveform of a PWM signal in the drive control device according to the present embodiment. [Figure 8]4 is a flowchart for explaining a process for generating an energization signal in the drive control device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A motor control device, a motor drive control device, a motor device, and a motor control program according to embodiments of the present invention will be described below with reference to the drawings.

[0010] 1 is a block diagram showing a schematic configuration of a motor device 10 including a control unit 4 according to an embodiment of the present invention. As shown in FIG. 1, the motor device 10 includes a motor 20 and a drive control device 1.

[0011] The motor 20 is a three-phase brushless DC motor and includes a plurality of coils, i.e., coils Lu, Lv, and Lw for each phase, and a rotor (not shown). One ends of the coils Lu, Lv, and Lw are Y-connected. The other ends of the coils Lu, Lv, and Lw are connected to the U-phase output, V-phase output, and W-phase output, respectively, of an inverter circuit 2, which will be described later. The motor 20 is driven to rotate by the supply of three-phase AC from the inverter circuit 2. Note that the motor 20 is not limited to a three-phase brushless DC motor and may be, for example, a single-phase brushless DC motor.

[0012] The drive control device 1 is an example of a motor drive control device of the present invention. The drive control device 1 includes a control unit 4, a rotational position detection unit 5, and a drive circuit 6.

[0013] The rotational position detector 5 is, for example, a Hall element that outputs a signal according to the rotational position of the motor 20, specifically the position of the magnetic poles of the rotor. The rotational position detector 5 outputs a rotational position detection signal S1 according to the detected position of the magnetic poles of the rotor. The rotational position detection signal S1 is input to the controller 4.

[0014] The rotational position detector 5 is not limited to a Hall element, but may be, for example, a circuit for detecting a back electromotive force.

[0015] The drive circuit 6 has an inverter circuit 2 and a pre-drive circuit 3 that drive the motor 20. The drive circuit 6 is supplied with power by a power supply voltage Vcc applied from a DC power supply Vd. A power supply current I flows from the DC power supply Vd to the inverter circuit 2. The drive circuit 6 receives power from the DC power supply Vd and, based on a conduction signal S4 (described later) output from the control unit 4, passes a drive current through the U-phase, V-phase, and W-phase coils Lu, Lv, and Lw of the motor 20 to rotate the rotor. The drive circuit 6 drives the motor 20, for example, with 120-degree conduction.

[0016] The inverter circuit 2 is connected to the pre-drive circuit 3 and the coils Lu, Lv, Lw of each phase of the motor 20. The inverter circuit 2 energizes the coils Lu, Lv, Lw of each phase of the motor 20 based on the drive signals Vuu to Vwl of the pre-drive circuit 3.

[0017] The inverter circuit 2 has a U-phase switching leg in which switching elements Q1 and Q2 are connected in series, a V-phase switching leg in which switching elements Q3 and Q4 are connected in series, and a W-phase switching leg in which switching elements Q5 and Q6 are connected in series. The switching elements Q1 to Q6 are, for example, field effect transistors (FETs). The switching elements Q1 to Q6 may also be, for example, insulated gate bipolar transistors (IGBTs). The inverter circuit 2 is connected to a DC power supply Vd and is further connected to a resistor R0.

[0018] The U-phase, V-phase, and W-phase switching legs each include switching elements Q1, Q3, and Q5 on the upper arm side and switching elements Q2, Q4, and Q6 on the lower arm side. The drain terminals of the switching elements Q1, Q3, and Q5 are each connected to the positive electrode of the DC power supply Vd. The source terminals of the switching elements Q1, Q3, and Q5 are each connected to the drain terminals of the switching elements Q2, Q4, and Q6, respectively, and AC signals of the U-phase, V-phase, and W-phase are output from the connection point. The source terminals of the switching elements Q2, Q4, and Q6 are each connected to ground (the negative electrode of the DC power supply Vd) via a resistor R0. The gate terminals of the switching elements Q1 to Q6 are each connected to the pre-drive circuit 3.

[0019] The inverter circuit 2 receives power from a DC power supply Vd, and when drive signals Vuu to Vwl are input from the pre-drive circuit 3, it passes three-phase AC current through the U-phase wiring, V-phase wiring, and W-phase wiring of the motor 20.

[0020] The pre-drive circuit 3 constitutes a motor drive unit in combination with the connected inverter circuit 2, and is connected to the control unit 4. The pre-drive circuit 3 includes, for example, six gate drive circuits, and generates drive signals Vuu to Vwl for driving the inverter circuit 2.

[0021] The control unit 4 is a program processing device (e.g., a computer such as a microcontroller or MCU (Micro Control Unit)) that has hardware elements such as a processor such as a CPU (Central Processing Unit), various memories such as ROM (Read Only Memory) and RAM (Random Access Memory), a timer, a counter, an A / D conversion circuit, an input / output I / F circuit, and a clock generation circuit, and the components are connected to each other via a bus or a dedicated line. The control unit 4 has a rewritable nonvolatile storage device such as a flash memory or an EEPROM (Electrically Erasable Programmable Read-Only Memory) as a memory.

[0022] The control unit 4 is an example of a motor control device of the present invention, and outputs a power supply signal S4 to the drive circuit 6. As shown in FIG. 1, the control unit 4 includes a rotation speed calculation unit 42, a power supply stop time calculation unit 43, and a power supply signal generation unit 44.

[0023] The control unit 4 uses the above functional units to PWM-control the drive circuit 6. These functional blocks are realized by the processor in the MCU described above, which executes various calculations in accordance with the motor control program stored in memory, and controls peripheral circuits such as timers and counters, A / D conversion circuits, and input / output I / F circuits.

[0024] The rotation speed calculation unit 42 calculates the rotation speed of the motor 20 based on the rotation position detection signal S1 of the motor 20 and generates a rotation speed signal S2 corresponding to the rotation speed of the motor 20.

[0025] The de-energization time calculation unit 43 acquires information on the target rotation speed Stg of the motor 20 from a drive command signal (e.g., a PWM (Pulse Width Modulation) signal) input from an external device, a memory, etc. Based on the target rotation speed Stg of the motor 20 and the rotation speed signal S2, the de-energization time calculation unit 43 calculates the time for energizing each of the coils Lu, Lv, and Lw of the motor 20 so that the motor 20 rotates at a desired rotation speed (number of rotations).

[0026] Furthermore, the de-energization time calculation unit 43 calculates a de-energization time for de-energizing the coils Lu, Lv, and Lw of all phases of the motor 20 based on the rotation speed signal S2 of the motor 20. The de-energization time calculation unit 43 calculates the de-energization time in accordance with the rotation speed signal S2 so as to shorten the de-energization time as the rotation speed increases, for example. By calculating the de-energization time in accordance with the rotation speed signal S2, the de-energization time calculation unit 43 adjusts the de-energization time so that the ratio of the de-energization time to one current period does not change depending on the rotation speed. The de-energization time calculation unit 43 generates a current command signal S3 that commands de-energization of the coils Lu, Lv, and Lw of all phases of the motor 20 based on the calculated de-energization time. The current command signal S3 also includes a signal commanding the supply of current to the coils Lu, Lv, and Lw of each phase of the motor 20.

[0027] The energization signal generation unit 44 generates an energization signal S4 that controls energization to each of the coils Lu, Lv, and Lw of the motor 20 in accordance with the energization command signal S3 in order to switch energization to the coils Lu, Lv, and Lw of each phase of the motor 20 and, during an energization stop time, stop energization to the coils Lu, Lv, and Lw of all phases of the motor 20. The generated energization signal S4 is output from the energization signal generation unit 44 to the pre-drive circuit 3.

[0028] Specifically, the energization signal generator 44 sets the energization signal S4 to perform the following energization switching. The energization signal generator 44 outputs the energization signal S4 to the pre-drive circuit 3 (part of the motor drive unit), which controls one of the coils Lu, Lv, and Lw of the motor 20 to alternately energize and deenergize. In this embodiment, a phenomenon that occurs once per rotation of the rotor of the motor 20 is defined as a first-order component, and a period corresponding to the number n of energization switching times per rotor rotation is defined as an nth-order component. Note that the energization signal generator 44 may perform overlapping energization in which, before energization of one of the coils Lu, Lv, and Lw of the motor 20 is terminated, i.e., while energization is being performed on one of the coils Lu, Lv, and Lw, energization of other coils Lu, Lv, and Lw of the motor 20 is continued for a predetermined time.

[0029] After the energization of any one of the coils Lu, Lv, and Lw of the motor 20 is terminated, the energization signal generation unit 44 stops energization of the other coils Lu, Lv, and Lw of the motor 20 other than the above-mentioned coils Lu, Lv, and Lw for a de-energization time. By stopping the energization of the other coils Lu, Lv, and Lw for the de-energization time in this manner, the energization signal generation unit 44 stops energization of all the coils Lu, Lv, and Lw, including the coils Lu, Lv, and Lw to which energization has been terminated. Specifically, the de-energization time may start when (simultaneously with) the energization of any one of the coils Lu, Lv, and Lw of the motor 20 is terminated, or may start a predetermined time after the energization is terminated.

[0030] For example, in the case of a 4-pole, 6-slot brushless motor, 12 energization switches occur per rotation. In motor 20, these energization switches resonate with the motor's natural value (natural frequency), resulting in large electromagnetic vibration components. The number of energization switches per rotation is calculated by multiplying half the number of poles by the number of energization switches per pole (e.g., six times for a three-phase motor).

[0031] The energization signal generating unit 44 outputs an energization signal S4 to the pre-drive circuit 3, which includes control to switch energization to the coils Lu, Lv, and Lw of the motor 20 as usual, and to stop energization to the coils Lu, Lv, and Lw other than the coils Lu, Lv, and Lw that are energized in the motor 20 for a de-energization time after energization to any of the coils Lu, Lv, and Lw has ended. As a result, the motor device 10 can suppress the electromagnetic vibration component by dispersing the n-th order component, which corresponds to the number of energization switching times n per rotor rotation and is a cause of the electromagnetic vibration component, into other order components.

[0032] Next, examples of waveforms of PWM signals in the drive control device 1 will be described with reference to timing charts. The timing charts shown below each show examples of waveforms of PWM signals output by the drive control device 1 to the motor 20 when the rotation speed of the motor 20 provided in the motor device 10 is constant.

[0033] FIG. 2 is a timing chart showing Example 1 of the waveforms of PWM signals in the drive control device 1. FIG. 2 shows drive waveforms of the overlapping energization method. In FIG. 2, waveform UH represents drive signal Vuu, waveform VH represents drive signal Vvu, and waveform WH represents drive signal Vwu. The waveforms UH, VH, and WH of these three drive signals alternately go to the H level. Furthermore, waveform UL represents drive signal Vul, waveform VL represents drive signal Vvl, and waveform WL represents drive signal Vwl. The waveforms UL, VL, and WL of these three drive signals alternately go to the H level.

[0034] Initially, the waveforms UH and VL are at H level, and a power supply current I flows from the DC power supply Vd to the ground via the switching element Q1, coils Lu and Lv, and switching element Q4.

[0035] Next, the waveform WL goes high, and power supply current I now flows from DC power supply Vd to ground via switching element Q1, coils Lu and Lw, and switching element Q6. Because the power supply current I flows in an overlapping manner through two systems, coils Lu and Lv and coils Lu and Lw, this is called the overlapping conduction method. After a period t1 has elapsed, the waveform VL goes low, and switching element Q4 turns off. This causes power supply current I to flow to ground only from DC power supply Vd via switching element Q1, coils Lu and Lw, and switching element Q6.

[0036] Next, waveform VH goes high, and power supply current I now flows from DC power supply Vd to ground via switching element Q3, coils Lv and Lw, and switching element Q6. That is, power supply current I flows in an overlapping manner through two systems: coils Lu and Lw and coils Lv and Lw. After a period t1 has elapsed, waveform UH goes low, and switching element Q1 turns off. As a result, power supply current I now flows to ground only from DC power supply Vd via switching element Q3, coils Lv and Lw, and switching element Q6.

[0037] Next, the waveform UL goes high, and power supply current I now flows from DC power supply Vd to ground via switching element Q3, coils Lv and Lu, and switching element Q2. That is, power supply current I flows in an overlapping manner through two systems: coils Lv and Lw and coils Lv and Lu. After a period t1 has elapsed, the waveform WL goes low, and switching element Q6 turns off. As a result, power supply current I now flows to ground only from DC power supply Vd via switching element Q3, coils Lv and Lu, and switching element Q2.

[0038] Next, waveform WH goes high, and power supply current I now flows from DC power supply Vd to ground via switching element Q5, coils Lw and Lu, and switching element Q2. That is, power supply current I flows in an overlapping manner through two systems: coils Lv and Lu and coils Lw and Lu. After a period t1 has elapsed, waveform VH goes low, and switching element Q3 turns off. As a result, power supply current I now flows to ground only from DC power supply Vd via switching element Q5, coils Lw and Lu, and switching element Q2.

[0039] Next, waveform VL goes high, and power supply current I now flows from DC power supply Vd to ground via switching element Q5, coils Lw and Lv, and switching element Q4. That is, power supply current I flows in an overlapping manner through two systems: coils Lw and Lu and coils Lw and Lv. After a period t1 has elapsed, waveform UL goes low, and switching element Q2 turns off. As a result, power supply current I flows from DC power supply Vd to ground only via switching element Q5, coils Lw and Lv, and switching element Q4. Similarly, switching elements Q1 to Q6 repeatedly turn on and off, causing motor 20 to rotate.

[0040] In Example 1 of the waveform of the PWM signal in the drive control device 1 shown in FIG. 2, after energization to any of the coils Lu, Lv, Lw of the motor 20 has ended, specifically, simultaneously with the end of energization, the energization signal generating unit 44 stops energization to all other coils Lu, Lv, Lw of the motor 20 that are energized other than the coils Lu, Lv, Lw, i.e., stops energization for each electrical angle, for predetermined energization stop times ts11, ts12.

[0041] 2, after the waveform VL indicating the energization of the coil Lv ends, the waveforms UH and WL indicating the energization of the other coils Lu and Lw in the motor 20 other than the coil Lv stop for a current-off time ts11. Similarly, after the waveform VH indicating the energization of the coil Lv ends, the waveforms UL and WH indicating the energization of the other coils Lu and Lw in the motor 20 other than the coil Lv stop for a current-off time ts12.

[0042] 2, after the waveform UH indicating the energization of coil Lu ends, the waveforms VH and WL indicating the energization of other coils Lv and Lw in motor 20 other than coil Lu stop for an energization stop time ts12. Similarly, after the waveform UL indicating the energization of coil Lu ends, the waveforms VL and WH indicating the energization of other coils Lv and Lw in motor 20 other than coil Lu stop for an energization stop time ts11.

[0043] In the PWM signal waveform example 1 shown in FIG. 2, the de-energization times ts11 and ts12 both start simultaneously with the end of energization to any of the coils Lu, Lv, and Lw of the motor 20, as described above, but have different lengths. In the PWM signal waveform example 1, the de-energization time ts11 is longer than the de-energization time ts12. The lengths of the de-energization times ts11 and ts12 are merely examples, and both times may be the same length, or three or more lengths may be set. Furthermore, the length of the de-energization time may vary depending on the rotation speed, etc. When the length of the de-energization time varies depending on the rotation speed, for example, the length of the de-energization time may be shortened as the rotation speed increases, thereby maintaining the ratio of the de-energization time to one current period.

[0044] Fig. 3 is a timing chart showing Example 2 of the waveform of the PWM signal in the drive control device 1. Fig. 3 shows drive waveforms of the overlapping energization method, as in Fig. 2. The waveforms UH, VH, and WH in Fig. 3 represent drive signals Vuu, Vvu, and Vwu, as in Fig. 2, and alternately go to the H level. Similarly to Fig. 2, the waveforms UL, VL, and WL represent drive signals Vul, Vvl, and Vwl, and alternately go to the H level.

[0045] 3, in the drive control device 1, similarly to the previously described PWM signal waveform example 1, the energization signal generating unit 44 stops energization of all other energized coils Lu, Lv, Lw of the motor 20 other than the coils Lu, Lv, Lw, i.e., stops energization for each electrical angle, for an energization stop time ts21 after energization of any of the coils Lu, Lv, Lw of the motor 20 has ended, specifically, simultaneously with the end of energization. The PWM signal waveform example 2 differs from the energization stop times ts11 and ts12 of the previously described example 1 in that the energization stop time ts21 is the same length in all waveforms.

[0046] Figure 4 is a timing chart showing Example 3 of the waveform of the PWM signal in the drive control device 1. Like Figures 2 and 3, Figure 4 shows drive waveforms of the overlapping energization method. Like Figures 2 and 3, waveforms UH, VH, and WH in Figure 4 represent drive signals Vuu, Vvu, and Vwu, which alternately go to the H level. Also, like Figures 2 and 3, waveforms UL, VL, and WL represent drive signals Vul, Vvl, and Vwl, which alternately go to the H level.

[0047] 4, in Example 3 of the PWM signal waveform in the drive control device 1, the energization signal generator 44 stops energization of the other energized coils Lu, Lv, Lw of the motor 20 for a predetermined de-energization time ts31 simultaneously with the end of energization of the high-side PWM signal to each phase of the coils Lu, Lv, Lw of the motor 20. In the drive control device 1, the energization that triggers setting the de-energization time is not limited to the example shown in FIGS. 2 and 3, in which energization is performed for all of the coils Lu, Lv, Lw of the motor 20. As shown in Example 3 of the PWM signal waveform, it may be performed for some of the phases of the coils Lu, Lv, Lw of the motor 20, for example, for the high-side PWM signal.

[0048] 4, after the waveform UH indicating energization of the PWM signal to the high side of coil Lu ends, the waveforms VH and WL indicating energization to the other coils Lv and Lw in the motor 20 that are energized other than coil Lu stop for the energization stop time ts31. Similarly, after the waveform VH indicating energization to the high side of coil Lv ends, the waveforms UL and WH indicating energization to the other coils Lu and Lw in the motor 20 that are energized other than coil Lv stop for the energization stop time ts31. Similarly, after the waveform WH indicating energization to the high side of coil Lw ends, the waveforms VL and UH indicating energization to the other coils Lu and Lv in the motor 20 that are energized other than coil Lw stop for the energization stop time ts31.

[0049] The length of the de-energization time ts31 is just an example, and two or more lengths may be set. The length of the de-energization time may also vary depending on the rotation speed, etc. The energization that triggers the setting of the de-energization time may be synchronized with the end of energization of the low-side PWM signal to each phase of the coils Lu, Lv, and Lw of the motor 20.

[0050] Fig. 5 is a timing chart showing Example 4 of the waveform of a PWM signal in the drive control device 1. Fig. 5 shows drive waveforms of the overlapping energization method, similar to Figs. 2 to 4. The waveforms UH, VH, and WH in Fig. 5 represent drive signals Vuu, Vvu, and Vwu, respectively, similar to Figs. 2 to 4, and alternately go to the H level. Similarly to Figs. 2 to 4, the waveforms UL, VL, and WL represent drive signals Vul, Vvl, and Vwl, respectively, and alternately go to the H level.

[0051] 5, in Example 4 of the PWM signal waveforms in the drive control device 1, similar to Example 2 of the PWM signal waveforms described above, after the energization of any one of the coils Lu, Lv, Lw of the motor 20 is terminated, the energization signal generating unit 44 terminates the energization of all other energized coils Lu, Lv, Lw of the motor 20 other than the coil Lu, Lv, Lw, i.e., the energization of each electrical angle. Example 4 of the PWM signal waveforms differs from Example 2 described above in that the start timing of the energization stop time ts41 in all waveforms is a predetermined interval tw4 after the end of energization of any one of the coils Lu, Lv, Lw of the motor 20, which is the same as the start timing of the energization stop time ts21 (simultaneous with the end of energization).

[0052] In the drive control device 1, the start timing of the de-energization time generated by the energization signal generation unit 44 may be simultaneous with the end of energization to any of the coils Lu, Lv, Lw of the motor 20 as in Examples 1 to 3, or may start after a predetermined interval tw4 has elapsed as in Example 4. Furthermore, in the drive control device 1, the length of the interval tw4 from the end of energization to the coils Lu, Lv, Lw to the start of the de-energization time is not particularly limited.

[0053] Fig. 6 is a timing chart showing Example 5 of the waveform of a PWM signal in the drive control device 1. Fig. 6 shows drive waveforms of the overlapping energization method, similar to Figs. 2 to 5. The waveforms UH, VH, and WH in Fig. 6 represent drive signals Vuu, Vvu, and Vwu, respectively, similar to Figs. 2 to 5, and alternate between H levels. Similarly to Figs. 2 to 5, the waveforms UL, VL, and WL represent drive signals Vul, Vvl, and Vwl, respectively, and alternate between H levels.

[0054] In PWM signal waveform example 5 of the drive control device 1 shown in FIG. 6 , the energization signal generator 44, similar to the previously described PWM signal waveform example 2, stops energizing any of the coils Lu, Lv, and Lw of the motor 20 after the energization of the coils Lu, Lv, and Lw is stopped. This stops energization of all other energized coils Lu, Lv, and Lw of the motor 20, i.e., for each electrical angle. PWM signal waveform example 5 differs from previously described example 2 in that, in all waveforms, the energization time of any of the coils Lu, Lv, and Lw of the motor 20, specifically, overlapping energization time t2, is shortened to start an energization stop time ts51. In PWM signal waveform example 5, overlapping energization time t2 is shorter than overlapping energization time t1 in previously described PWM signal waveform example 2 and the like.

[0055] Fig. 7 is a timing chart showing Example 6 of the waveform of a PWM signal in the drive control device 1. Fig. 7 shows drive waveforms of the overlapping energization method, similar to Figs. 2 to 6. The waveforms UH, VH, and WH in Fig. 7 represent drive signals Vuu, Vvu, and Vwu, respectively, similar to Figs. 2 to 6, and alternate between H levels. Similarly to Figs. 2 to 6, the waveforms UL, VL, and WL represent drive signals Vul, Vvl, and Vwl, respectively, and alternate between H levels.

[0056] In Example 6 of the PWM signal waveforms in the drive control device 1 shown in FIG. 7 , the energization signal generator 44, after terminating energization of one of the coils Lu, Lv, and Lw of the motor 20, stops energization of all other energized coils Lu, Lv, and Lw of the motor 20, i.e., stops energization for each electrical angle, as in Example 5 of the PWM signal waveforms described above. Example 6 of the PWM signal waveforms differs from Example 5 described above in that, among the energization of one of the coils Lu, Lv, and Lw of the motor 20, the energization time is shortened to start an energization stop time ts61 for only the waveforms UL, VL, and WL indicating low-side energization. In Example 6 of the PWM signal waveforms, the overlap energization time t3 for the waveforms UL, VL, and WL indicating low-side energization is shorter than the overlap energization time t1 for the waveforms UH, VH, and WH indicating high-side energization.

[0057] FIG. 8 is a flowchart for explaining the energization signal generation process in the drive control device 1.

[0058] In the control unit 4, the de-energization time calculation unit 43 acquires information on the target rotation speed Stg of the motor 20 from a drive command signal (for example, a PWM (Pulse Width Modulation) signal) input from an external device, a memory, etc. (step S101).

[0059] The de-energization time calculation unit 43 acquires the rotation speed signal S2 that is generated by the rotation speed calculation unit 42 and corresponds to the rotation speed of the motor 20 (step S102).

[0060] The de-energization time calculation unit 43 calculates a de-energization time for stopping the energization of the coils Lu, Lv, Lw of all phases of the motor 20 based on the rotation speed signal S2 of the motor 20 (step S103). The de-energization time calculation unit 43 generates a current command signal S3 that commands the stopping of the energization of the coils Lu, Lv, Lw of all phases of the motor 20 in accordance with the calculated de-energization time.

[0061] The energization signal generating unit 44 generates an energization signal S4 for controlling energization to each phase of the motor 20 in response to the energization command signal S3 in order to switch energization to the coils Lu, Lv, Lw of each phase of the motor 20 and stop energization to the coils Lu, Lv, Lw of all phases of the motor 20 during the energization stop time (step S104). The generated energization signal S4 is output from the energization signal generating unit 44 to the pre-drive circuit 3.

[0062] [Effects of the embodiment] As described above, in the motor device 10, the control unit 4 of the drive control device 1 includes a rotational speed calculation unit 42 that calculates the rotational speed of the motor 20 based on the rotational position detection signal of the motor 20, a current stop time calculation unit 43 that calculates a current stop time for stopping current to all phases of the coils Lu, Lv, and Lw of the motor 20 based on the target rotational speed Stg of the motor 20 and the rotational speed, and a current signal generation unit 44 that generates a current signal to control current to the coils Lu, Lv, and Lw of the motor 20 in order to switch current to the coils Lu, Lv, and Lw of the motor 20 and to stop current to all coils Lu, Lv, and Lw of the motor 20 during the current stop time.

[0063] Specifically, as shown in Figures 2 to 7, after the current supply to one of the phases of the motor 20 is terminated, the current supply to the other coils Lu, Lv, and Lw of the motor 20 that are currently energized is stopped for a current stop time, thereby stopping the current supply to all phases of the motor 20.

[0064] The drive control device 1, which includes a control unit 4 having a de-energization time calculation unit 43 and a power signal generation unit 44, sets a de-energization time for the other energized coils Lu, Lv, and Lw after terminating the energization of one of the coils Lu, Lv, and Lw of the motor 20, as shown in FIGS. 2 to 8 . By setting the de-energization time when switching energization to the coils Lu, Lv, and Lw of the motor 20 in the motor device 10, the drive control device 1 can distribute the timing of the de-energization state of the coils Lu, Lv, and Lw. Furthermore, by dispersing the timing of the de-energization state of the coils Lu, Lv, and Lw, the drive control device 1 can distribute the timing of vibrations that occur when switching energization of the coils Lu, Lv, and Lw for each of the coils Lu, Lv, and Lw. In other words, by dispersing the timing of vibrations that occur when switching energization of the coils Lu, Lv, and Lw, the drive control device 1 can reduce overlapping of vibrations that occur when switching energization of the coils Lu, Lv, and Lw.

[0065] Therefore, the drive control device 1 can reduce vibrations in the motor 20 caused by switching the energization of the coils Lu, Lv, and Lw.

[0066] In the drive control device 1, the de-energization time may be calculated so that it becomes shorter as the rotation speed increases. In this way, the drive control device 1 can shorten the de-energization time as the rotation speed increases, unlike when the de-energization time is constant regardless of the rotation speed. In other words, by calculating the de-energization time according to the rotation speed, the de-energization time can be adjusted so that the ratio of the de-energization time to one current period does not change according to the rotation speed.

[0067] 5, the de-energization time may start a predetermined time tw4 after the end of energization to any of the coils Lu, Lv, Lw of the motor 20. In this way, the drive control device 1 can distribute the timing of switching when energizing the coils Lu, Lv, Lw of the motor 20 in the motor device 10, thereby reducing vibrations in the motor 20 caused by switching energization to the coils Lu, Lv, Lw.

[0068] Furthermore, the energization signal generating unit 44 may perform overlapping energization, in which energization of coils other than the coils Lu, Lv, and Lw of the motor 20 continues for a predetermined time before terminating energization of any of the coils Lu, Lv, and Lw of the motor 20. Overlapped energization is a technique for reducing vibrations that occur when energization to a coil is switched, and therefore, by combining overlapping energization with a de-energization time, it is possible to reduce vibrations in the motor 20 that occur when energization to the coils Lu, Lv, and Lw is switched.

[0069] In addition, those skilled in the art can appropriately modify the present invention in accordance with conventionally known knowledge. As long as such modifications still comprise the structure of the present invention, they are of course included in the scope of the present invention.

[0070] For example, in the embodiment, an example has been described in which the drive control device 1 performs overlapping energization in which power supply current I flows in an overlapping manner through two systems of coils Lu, Lv, and Lw of the motor 20, and after energization of one of the coils Lu, Lv, and Lw of the motor 20 is terminated, a de-energization time for the other energized coils Lu, Lv, and Lw is set. However, the process in the drive control device 1 of setting a de-energization time for the other energized coils Lu, Lv, and Lw after energization of one of the coils Lu, Lv, and Lw of the motor 20 is terminated can be applied even when overlapping energization is not performed.

[0071] For example, in the embodiment, the drive control device 1 is described as being applied to drive control of a 4-pole, 6-slot brushless motor 20. However, the drive control device 1 does not limit the number of poles, slots, or phases of the motor 20. [Explanation of symbols]

[0072] 1: drive control device, 2: inverter circuit, 3: pre-drive circuit, 4: control unit, 5: rotation position detection unit, 6: drive circuit, 10: motor device, 20: motor, 42: rotation speed calculation unit, 43: power supply stop time calculation unit, 44: power supply signal generation unit, I: power supply current, Lu, Lv, Lw: coil, Q1:, Q2, Q3, Q4, Q5, Q6: switching elements, R0: resistance element, S1: rotation position detection signal, S2: rotation Speed ​​signal, S3: energization command signal, S4: energization signal, Stg: target rotation speed, UH, UL, VH, VL, WH, WL: waveform, Vcc: power supply voltage, Vd: DC power supply, Vul, Vuu, Vvl, Vvu, Vwl, Vwu: drive signal, n: energization switching count, t1, t2, t3: overlap energization period, ts11, ts12, ts21, ts31, ts4, ts51, ts61: energization stop time, tw4: interval

Claims

1. a rotation speed calculation unit that calculates the rotation speed of the motor based on a rotation position detection signal of the motor; a de-energization time calculation unit that calculates a de-energization time for de-energizing all coils of the motor based on the rotational speed of the motor; an energization signal generating unit that generates an energization signal that controls energization to each of the coils of the motor in order to switch energization to each of the coils of the motor and stop energization to all of the coils of the motor during the energization stop time; Equipped with The motor control device, wherein the energization signal generating unit performs overlapping energization by continuing energization of the other coils of the motor for a predetermined time before energization of one of the coils of the motor is terminated.

2. the energization signal generating unit stops energization of the other coils of the motor that are being energized for the energization stop time after the energization of any one of the coils of the motor is stopped; The motor control device according to claim 1 .

3. The de-energization time is calculated to be shorter as the rotation speed increases.

3. The motor control device according to claim 1 or 2.

4. The de-energization time period starts after a predetermined time has elapsed since the end of energization of any one of the coils of the motor.

3. The motor control device according to claim 1 or 2.

5. The motor control device according to claim 1 ; a drive circuit that drives the motor based on the energization signal; A motor drive control device comprising:

6. the motor is a brushless type having a plurality of the coils, The motor drive control device according to claim 5 , A motor device comprising:

7. calculating a rotation speed of the motor based on a rotation position detection signal of the motor; calculating a de-energization time for de-energizing all coils of the motor based on the rotational speed of the motor; generating an energization signal for controlling energization of each of the coils of the motor in order to switch energization of each of the coils of the motor and to stop energization of all of the coils of the motor during the de-energization period; on the computer, A motor control program, wherein the step of generating the energization signal performs overlapping energization in which, before energization of one of the coils of the motor is terminated, energization of the other coils of the motor is continued for a predetermined time.

Images