Motor driving device, control method, and program

Abstract

The present invention suppresses a decrease in reliability caused by heat during operation of a dynamic brake. A motor drive device (1) is provided with a first control unit (11), a second control unit (12), and a dynamic brake (14). The first control unit (11) controls the first motor (2). The second control unit (12) controls the second motor (5). The second motor (5) cools at least one of the heat generation part (A1) and the heat dissipation part (B1). The dynamic brake (14) has resistors (14a-14c) connected between the terminals (P1-P3) of the first motor (2), and stops the first motor (2) by short-circuiting the terminals (P1-P3) and consuming the kinetic energy of the first motor (2) through the resistors (14a-14c). When the control of the first motor (2) is in a standby state, the second control unit (12) changes the rotational speed of the second motor (5) in accordance with the rotational speed of the first motor (2). The heat generating unit (A1) includes resistors (14a-14c).

Description

Technical Field

[0001] The present disclosure generally relates to a motor drive device, a control method, and a program. More specifically, the present disclosure relates to a motor drive device including a dynamic brake, a control method for the motor drive device, and a program. Background Art

[0002] Patent document 1 discloses a motor drive device for driving a motor installed in a working device. The motor drive device includes: a motor that drives a radiator for dissipating heat from a heat generating part of the motor drive device or a cooling fan for cooling the inside of the motor drive device; and a motor current detection unit that detects a current for controlling the motor. In addition, the motor drive device includes: an estimated heat generation calculation unit that calculates an estimated heat generation of the heat generating part or the inside of the motor drive device based on current information obtained from the motor current detection unit; and a motor power supply voltage adjustment unit that controls the rotation speed of the motor according to the estimated heat generation.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-88268 Summary of the invention

[0006] In addition, there is a motor drive device with a dynamic brake, which stops the motor by consuming the kinetic energy of the motor (first motor) through a resistor. In this motor drive device, when the drive control of the motor is in a standby state, in order to ensure the reliability of the entire device, the dynamic brake is activated to stop the motor. When the drive control is in a standby state, the motor sometimes rotates due to an external force, and the generated energy at this time is consumed by the resistor of the dynamic brake, so the resistor needs to be cooled. However, when the technology for controlling the rotation speed of the motor (second motor) disclosed in Patent Document 1 is applied to a motor drive device with a dynamic brake, when the motor is activated by an external force, the current used to control the motor detected by the motor current detection unit is zero, so the estimated heat generation is estimated to be small. As a result, the motor does not operate in the standby state, and the reliability of the motor drive device is sometimes reduced.

[0007] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a motor drive device, a control method, and a program capable of suppressing a reduction in reliability due to heat generated by the operation of a dynamic brake.

[0008] A motor drive device according to one embodiment of the present disclosure includes: a heating unit, a first control unit, a second control unit, and a dynamic brake. The heating unit generates heat due to the rotation of the first motor. The first control unit drives and controls the first motor. The second control unit drives and controls the second motor. The second motor cools the interior. The dynamic brake has a resistor electrically connected between the terminals of the first motor, which short-circuits the terminals and consumes the kinetic energy of the first motor through the resistor, thereby stopping the first motor. When the drive control of the first motor is in a standby state, the second control unit controls so that the rotation speed of the second motor is changed according to the rotation speed of the first motor. The heating unit includes the resistor.

[0009] A control method according to another embodiment of the present disclosure is a control method for a motor drive device. The control method includes a first control step, a second control step, and a stop control step. In the first control step, the first motor is drive-controlled. In the second control step, the second motor is drive-controlled. The second motor cools at least one of a heat generating portion and a heat dissipating portion for dissipating heat from the heat generating portion, wherein the heat generating portion generates heat due to the rotation of the first motor. In the stop control step, in a dynamic brake having a resistor electrically connected between terminals of the first motor, the terminals are short-circuited and the kinetic energy of the first motor is thermally consumed by the resistor, thereby stopping the first motor. In the second control step, when the drive control of the first motor is in a standby state, control is performed so that the rotation speed of the second motor is changed according to the rotation speed of the first motor. The heat generating portion includes the resistor.

[0010] A program according to another aspect of the present disclosure is a program for causing one or more processors to execute the above-mentioned control method.

[0011] According to the present disclosure, there is an advantage that a reduction in reliability due to heat generated by the operation of the dynamic brake can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a block diagram schematically showing the overall configuration of a motor control system including a motor drive device according to an embodiment.

[0013] Figure 2 This is a characteristic diagram for explaining the operation related to the drive control of the second motor (fan motor) in the motor drive device according to the embodiment.

[0014] Figure 3This is a characteristic diagram for explaining the operation related to the drive control of the second motor (fan motor) in the modified example of the motor drive device according to the embodiment. DETAILED DESCRIPTION

[0015] (summary)

[0016] Hereinafter, the motor drive device involved in the embodiment and the modified example will be described using the accompanying drawings. In addition, the following embodiment and the modified example are only one of the various embodiments of the present disclosure. In addition, the following embodiment and the modified example can be variously changed according to the design, etc. as long as the purpose of the present disclosure can be achieved. In addition, the structure of the modified example can also be appropriately combined.

[0017] The drawings described in the following embodiments and modifications are schematic drawings, and the sizes and thickness ratios of the components do not necessarily reflect the actual dimensional ratios. Figure 1 It is a schematic block diagram of the entire structure of a motor control system including a motor drive device 1 according to an embodiment. Figure 2 This is a characteristic diagram for explaining the operation related to the drive control of the second motor (fan motor) 5 in the motor drive device 1 .

[0018] like Figure 1 As shown, a motor drive device 1 according to one embodiment is a device configured to drive and control the motion (rotation motion) of a first motor 2 (servomotor). The first motor 2 (servomotor) is a rotary motor. The first motor 2 has, for example, a stator on which three-phase (U-phase, V-phase, W-phase) windings are wound.

[0019] like Figure 1 As shown, the motor drive device 1 includes a first control unit 11 , a second control unit 12 , and a dynamic brake 14 .

[0020] The first control unit 11 drives and controls the first motor 2. The second control unit 12 drives and controls the second motor 5. The second motor 5 is, for example, a fan motor (referred to as "fan motor" in the drawings) configured to cool the interior of the motor drive device 1 (inside the frame H1). In addition, the so-called fan motor refers to a motor having a fan. In particular, the second motor 5 cools at least one of the heat generating portion A1 that generates heat due to the rotation of the first motor 2 and the heat dissipating portion B1 that dissipates the heat of the heat generating portion A1.

[0021] The dynamic brake 14 includes resistors (e.g., a first resistor 14a, a second resistor 14b, and a third resistor 14c) electrically connected between terminals (e.g., a first terminal P1, a second terminal P2, and a third terminal P3 corresponding to three phases, respectively) of the first motor 2. The dynamic brake 14 short-circuits between the terminals (the first terminal P1 to the third terminal P3) of the first motor 2, and dissipates the kinetic energy of the first motor 2 by heat through the resistors (the first resistor 14a to the third resistor 14c), thereby stopping the first motor 2.

[0022] When the drive control of the first motor 2 is in the standby state, the second control unit 12 controls to change the rotation speed of the second motor 5 according to the rotation speed of the first motor 2. The heating unit A1 includes at least a resistor (a first resistor 14a to a third resistor 14c). In addition, regarding the rotation speed, when the rotating body rotates 360° around a certain axis every minute, the rotation speed is set to 1 [min -1 ].

[0023] In the following description, the three resistors (the first resistor 14a to the third resistor 14c) are sometimes abbreviated as resistors (14a to 14c), and the three terminals (the first terminal P1 to the third terminal P3) are sometimes abbreviated as terminals (P1 to P3). However, the description of resistors (14a to 14c) is not intended to limit the number of resistors to three. Similarly, the description of terminals (P1 to P3) is not intended to limit the number of terminals to three.

[0024] In the following description, the dynamic brake 14 may be abbreviated and referred to as DB14.

[0025] The heat generating unit A1 may include the processing unit 10 and the power conversion unit E1 accommodated in the housing H1 of the motor drive device 1 in addition to the resistors (14a to 14c) of DB14. The heat dissipating unit B1 may be a heat sink, for example, but the housing H1 itself may be included therein as a part of the heat dissipating unit B1.

[0026] In addition, when the drive control of the first motor 2 is in the standby state, the first motor 2 may rotate due to an external force. Since the power generation energy generated by the rotation of the first motor 2 is consumed by the resistor (14a to 14c) of DB14, it is necessary to cool the resistor (14a to 14c). The external force is of various types depending on the situation in which the first motor 2 is applied. For example, it is assumed that two first motors 2 are arranged at both ends of the starting point and the end point of the conveying device in order to drive a conveying device such as a conveyor belt. Usually, the belt of the conveying device is moved by the output shafts of each first motor 2 rotating in conjunction. However, for example, due to the occurrence of control abnormality, failure, etc. or a predetermined instruction such as a test action instruction, there is sometimes a situation where one of the first motors 2 is not driven (standby state), and only the other first motor 2 is driven to move the belt. In such a case, although the first motor 2 on one side is in the standby state, it is still rotated by the external force from the other first motor 2 via the belt.

[0027] According to the motor drive device 1 described above, when the drive control of the first motor 2 is in the standby state, the rotation speed of the second motor 5 is changed according to the rotation speed of the first motor 2. Therefore, even if the first motor 2 rotates due to an external force and the resistors (14a to 14c) of the DB14 generate heat, the possibility that the heat generating portion A1 or the heat dissipating portion B1 including the resistors (14a to 14c) can be appropriately cooled by the second motor 5 increases. As a result, the motor drive device 1 has an advantage of being able to suppress a reduction in reliability due to heat generated by the operation of the DB14.

[0028] In addition, a control method according to another embodiment is a control method for a motor drive device 1. The control method includes a first control step, a second control step, and a stop control step. In the first control step, the first motor 2 is drive-controlled. In the second control step, the second motor 5 is drive-controlled. The second motor 5 cools at least one of the heat generating portion A1 and the heat dissipating portion B1. In the stop control step, in the above-mentioned DB14, the terminals (P1 to P3) are short-circuited, and the kinetic energy of the first motor 2 is thermally consumed by the resistors (14a to 14c), so that the first motor 2 is stopped. In the second control step, when the drive control of the first motor 2 is in a standby state, the rotation speed of the second motor 5 is controlled to be changed according to the rotation speed of the first motor 2. The heat generating portion A1 includes resistors (14a to 14c). According to this structure, a control method for suppressing the reduction in reliability caused by the heat generated by the operation of DB14 can be provided. The control method is used in a computer system (motor drive device 1). That is, the control method can also be realized by a program. A program according to one embodiment is a program for causing one or more processors to execute the control method described above.

[0029] (Details)

[0030] Below, refer to Figure 1 An overall system (motor control system 100 ) including the motor drive device 1 according to the present embodiment and its peripheral configuration will be described in detail.

[0031] The motor control system 100 can be introduced into a facility such as a factory, for example. Figure 1 As shown, the peripheral structure of the motor control system 100 mentioned here includes a power supply S1 (for example, a commercial AC power supply), a first motor 2 (servo motor) and a rotation speed detection unit 3. In addition, the peripheral structure includes a user interface 6 (display monitor and operating device, etc.) for performing various setting inputs and monitoring of actions related to the motor drive device 1. In addition, the peripheral structure includes a host controller 7 that sends a control signal to the motor drive device 1. In addition, the peripheral structure can include an external server that can be connected to the motor drive device 1 and the host controller 7 by wired or wireless communication. The external server can also be set inside or outside the facility. At least a part of the peripheral structure can also be included in the structure of the motor drive device 1.

[0032] As described above, the first motor 2 is a rotary motor. The first motor 2 has an output shaft, and the output shaft is rotated according to the control of the motor drive device 1. The first motor 2 and the mechanical mechanism constitute a drive system. The mechanical mechanism is not particularly limited, and it is, for example, a ball screw mechanism, a gear mechanism, or a belt mechanism. The mechanical mechanism is connected to the output shaft of the first motor 2. The mechanical mechanism is applied with power from the first motor 2. For example, in the case where a plurality of first motors 2 are used in a conveying device such as a conveyor belt in a facility such as a factory, the output shaft of each first motor 2 rotates, and the belt rotates via the mechanical mechanism, so that a plurality of products or components loaded on the belt are automatically conveyed in sequence.

[0033] In addition, the first motor 2 is, for example, a three-phase brushless motor having a stator on which three-phase windings are wound. Specifically, the first motor 2 has a stator formed by windings of each phase, namely, a U-phase, a V-phase, and a W-phase, wound on a stator core, and a rotor having a permanent magnet. In addition, as Figure 1 As shown, the first motor 2 includes first to third terminals P1 to P3 corresponding to the three-phase input terminals, respectively. A driving voltage generated by the motor driving device 1 is applied to the first to third terminals P1 to P3, respectively, and a driving current flows, thereby rotating the rotor.

[0034] The rotation speed detection unit 3 is composed of an encoder or the like, and detects the rotation speed per unit time (in other words, the rotation speed) of the first motor 2 based on the rotation position of the first motor 2. The rotation speed detection unit 3 is electrically connected to the motor drive device 1. The rotation speed detection unit 3 outputs a detection signal (electrical signal) including a detection value to the motor drive device 1. The motor drive device 1 controls the operation of the first motor 2 based on the detection signal from the rotation speed detection unit 3 and the control signal from the host controller 7, so that the first motor 2 performs a given operation (for example, a transport operation).

[0035] The host controller 7 is constituted by, for example, a programmable logic controller, and controls the motor drive device 1 through action instructions, etc. The host controller 7 and the motor drive device 1 are connected to each other via a control bus, etc. so as to be able to communicate, and the action instructions from the host controller 7 are transmitted to the motor drive device 1, and the information from the motor drive device 1 is transmitted to the host controller 7.

[0036] Specifically, the upper controller 7 outputs a control signal to the motor drive device 1, thereby controlling the actions of the motor drive device 1 and the first motor 2. The control signal includes data for specifying the position and action of the movable part (load) in the mechanical mechanism. The motor drive device 1 determines the control value of the drive system (the first motor 2 and the mechanical mechanism) according to the control signal and the detection signal from the rotation speed detection unit 3. The control value includes, for example, the command value of the rotation speed of the first motor 2, the command value of the rotation angle, and the torque command value. The motor drive device 1 adjusts the power supplied to the first motor 2 based on the determined control value, thereby driving and controlling the first motor 2. In addition, the motor drive device 1 sends the control result of the first motor 2 to the upper controller 7.

[0037] like Figure 1 As shown, the motor drive device 1 includes a power conversion unit E1 , a processing unit 10 , a dynamic brake (DB) 14 , a pair of current detection units 15 a and 15 b , a second motor (fan motor) 5 , and a heat dissipation unit B1 . The motor drive device 1 further includes a housing H1 and a temperature detection unit 4 .

[0038] The power conversion unit E1 includes a rectifier 20 that rectifies AC power supplied from a power source S1 (for example, a commercial AC power source), and a smoothing capacitor 16 that smoothes power output from the rectifier 20 .

[0039] In addition, the power conversion unit E1 has an inverter unit 30. The inverter unit 30 is supplied with smoothed DC power smoothed by the smoothing capacitor 16. The inverter unit 30 has a plurality of semiconductor switching elements that perform switching operations. Specifically, the inverter unit 30 includes a high-speed power switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and a power conversion element such as a diode.

[0040] In the inverter unit 30, the plurality of semiconductor switching elements are PWM-controlled using a PWM (Pulse Width Modulation) signal output from the processing unit 10. As a result, the smoothed DC power is converted into three-phase AC power consisting of a U phase, a V phase, and a W phase. The inverter unit 30 drives the first motor 2 by supplying the converted three-phase AC power to the first motor 2.

[0041] The current of the U-phase AC component (U-phase current) is supplied from the first terminal P1 to the first motor 2 through the power line U1. The current of the V-phase AC component (V-phase current) is supplied from the second terminal P2 to the first motor 2 through the power line V1. The current of the W-phase AC component (W-phase current) is supplied from the third terminal P3 to the first motor 2 through the power line W1.

[0042] In addition, the power conversion unit E1 has a regeneration circuit 17 that consumes the regenerative power supplied from the first motor 2 via the inverter unit 30. The regeneration circuit 17 is provided at the front stage of the inverter unit 30. The regeneration circuit 17 includes a semiconductor switch element 17a, a diode 17b, and a regeneration resistor 17c. A series circuit of the semiconductor switch element 17a and the regeneration resistor 17c is connected in parallel to the smoothing capacitor 16. The diode 17b is connected in parallel to the regeneration resistor 17c. The semiconductor switch element 17a is turned on by the control of the processing unit 10, and a current flows through the regeneration resistor 17c, and the regeneration power is consumed by the regeneration resistor 17c.

[0043] The current detection unit 15a is disposed on the power line U1 to detect a drive current (U-phase current) flowing for driving and controlling the first motor 2. The current detection unit 15a is disposed between the first resistor 14a of the DB 14 and a connection node N1 of the power line U1 and the inverter unit 30.

[0044] The current detection unit 15b is disposed on the power line W1 to detect a drive current (W-phase current) flowing to drive and control the first motor 2. The current detection unit 15b is disposed between the third resistor 14c of the DB 14, a connection node N3 of the power line W1, and the inverter unit 30.

[0045] As the current detection units 15a and 15b, for example, a shunt resistor is used when the motor current is a small current, but when the current is particularly large, the current is converted to a value of a few thousandths of a part by a CT (Current Transfer), and the output current from the CT is detected by the shunt resistor. The current detection signals output by the current detection units 15a and 15b are supplied to the processing unit 10.

[0046] The dynamic brake (DB) 14 includes three resistors (a first resistor 14 a , a second resistor 14 b , and a third resistor 14 c ) electrically connected between the first terminal P1 to the third terminal P3 of the first motor 2 , and two switches 14 d and 14 e .

[0047] The first resistor 14a and the switch 14d form a series circuit. The first resistor 14a has a first end electrically connected to the power supply line U1 via a connection node N1, and a second end electrically connected to a first end of the switch 14d.

[0048] The third resistor 14c and the switch 14e form a series circuit. The third resistor 14c has a first end electrically connected to the power supply line W1 via a connection node N3, and a second end electrically connected to a first end of the switch 14e.

[0049] In the second resistor 14b, a first end thereof is electrically connected to the power supply line V1 via a connection node N2, and a second end thereof is electrically connected to the second end of the switch 14d and the second end of the switch 14e via a connection node N4.

[0050] The switches 14d and 14e are composed of transistors, for example. The switches 14d and 14e receive drive control from the processing unit 10 and short-circuit / disconnect the windings of the first motor 2. For example, when the first motor 2 is rotating, the supply of drive current to the first motor 2 is stopped, and the switches 14d and 14e short-circuit the windings of the first motor 2, thereby enabling the rotation of the first motor 2 to be stopped urgently. That is, DB14 short-circuits the first terminal P1 to the third terminal P3 of the first motor 2, and consumes the kinetic energy (rotational energy) of the first motor 2 through the first resistor 14a to the third resistor 14c, thereby stopping the first motor 2.

[0051] In particular, when the drive control (operation state) of the first motor 2 is in the standby state (a state in which the drive current supplied to the first motor 2 is stopped), even if the first motor 2 is rotated by an external force, the processing unit 10 stops the rotation of the first motor 2 by operating the DB14.

[0052] The processing unit 10 includes a computer system having one or more processors and a memory. The processor of the computer system executes a program recorded in the memory of the computer system to realize at least a part of the function of the processing unit 10. The program can be recorded in the memory, provided through a telecommunication line such as the Internet, or recorded in a non-temporary recording medium such as a memory card.

[0053] like Figure 1 As shown, the processing unit 10 includes a first control unit 11 , a second control unit 12 , and a storage unit 13 .

[0054] The first control unit 11 is configured to drive and control the first motor 2. Specifically, the first control unit 11 receives control signals including information of motion instructions indicating position, speed, torque, etc. from the host controller 7. In addition, the first control unit 11 sends various information in the motor drive device 1 to the host controller 7. The first control unit 11 has a communication function for transmitting such information, and controls the rotation of the first motor 2 and performs motion control so that the first motor 2 performs a given motion.

[0055] As an example of a more specific process of the first control unit 11, the first control unit 11 performs the following control process based on feedback control. The first control unit 11 performs control calculations based on the action command indicating the position from the upper controller 7 and the rotation speed information (position information) from the rotation speed detection unit 3 to generate a speed command. Next, the first control unit 11 calculates the motor speed value corresponding to the actual speed of the first motor 2, and calculates the current command through speed control calculation based on the motor speed and the speed command. Next, the first control unit 11 calculates the voltage command of each phase through current control calculation based on the motor current detection value of the U phase and the motor current detection value of the W phase obtained through a pair of current detection units 15a and 15b, and the calculated current command. In addition, the first control unit 11 outputs the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value as voltage command values ​​representing the voltage commands of the U phase, the V phase, and the W phase. That is, the first control unit 11 performs torque calculation based on the action command from the upper controller 7, the rotation speed information (position information) of the first motor 2 and the current value of the current flowing through the winding of the first motor 2, and calculates the voltage command value (three-phase voltage command value) used to drive the first motor 2.

[0056] In addition, the first control unit 11 generates a PWM switching signal (PWM signal). The first control unit 11 generates the PWM signal of each phase by, for example, comparing the carrier signal of the triangular wave formed by the up / down counter with the voltage command value of each phase. The first control unit 11 supplies the generated PWM signal to the inverter unit 30 of the power conversion unit E1. That is, the first control unit 11 performs PWM modulation by comparing the voltage command value (three-phase voltage command value) with the triangular wave, and outputs the PWM signal (three-phase PWM switching signal).

[0057] The second control unit 12 is configured to drive and control the second motor 5. The second motor 5 is accommodated or held in the frame H1 of the motor drive device 1, and cools the inside of the frame H1. In particular, the second motor 5 cools at least one (for example, both) of the heat generating portion A1 generated by the rotation of the first motor 2 and the heat dissipating portion B1 that dissipates the heat of the heat generating portion A1. The second motor 5 is arranged opposite to at least one of the heat generating portion A1 and the heat dissipating portion B1, and the fan (blades) attached to the output shaft rotates by the rotation of the output shaft of the second motor 5, thereby cooling the heat generating portion A1 and the heat dissipating portion B1. The heat generating portion A1 includes at least the first resistor 14a to the third resistor 14c of DB14, and can also include the processing unit 10, the rectifier 20, and the inverter unit 30 (IGBT high-speed power switching element) accommodated in the frame H1 of the motor drive device 1. The heat dissipation unit B1 is a heat sink provided to dissipate heat from, for example, the processing unit 10 , the rectifier 20 , and the inverter unit 30 (IGBT high-speed power switching element), etc. The housing H1 itself may be included as a part of the heat dissipation unit B1 .

[0058] The second motor 5 is, for example, a brushless DC fan motor driven by a DC voltage, and the type of the second motor 5 is not particularly limited. The rotation speed of the second motor 5 can be changed under the control of the second control unit 12. That is, the second control unit 12 applies a drive voltage (DC voltage) corresponding to the target rotation speed of the second motor 5 to the second motor 5, so that a drive current flows through the second motor 5.

[0059] The second control unit 12 is electrically connected to the temperature detection unit 4 (temperature sensor) disposed in the housing H1, and receives a detection signal from the temperature detection unit 4. The second control unit 12 includes a temperature estimation unit 122 (see Figure 1 ), the temperature estimating unit 122 estimates the ambient temperature of the housing H1 based on the detection result of the temperature detecting unit 4.

[0060] The processing unit 10 monitors the ambient temperature obtained by the temperature estimation unit 122. When the ambient temperature exceeds a threshold value, the processing unit 10 notifies the outside of the temperature rise. The motor drive device 1 is assumed to be used in an ambient temperature range of 0°C to 55°C.

[0061] When the drive control of the first motor 2 is in the driving state (a state in which the first control unit 11 supplies a drive current to the first motor 2 ), the second control unit 12 drives and controls the second motor 5 at, for example, a predetermined rotation speed.

[0062] In addition, when the drive control of the first motor 2 is in a standby state (a state in which the first control unit 11 stops supplying the drive current to the first motor 2), the second control unit 12 performs control so as to change the rotation speed of the second motor 5 according to the rotation speed of the first motor 2. The "rotation speed of the first motor 2" mentioned here uses, for example, the rotation speed detected by the rotation speed detection unit 3. That is, the second control unit 12 changes the rotation speed of the second motor 5 according to the rotation speed of the first motor 2 detected by the rotation speed detection unit 3.

[0063] In particular, in this embodiment, the second control unit 12 calculates the heating value of the first resistor 14a to the third resistor 14c of the DB14 according to the rotation speed of the first motor 2, and changes the rotation speed of the second motor 5. That is, the second control unit 12 includes a heat estimation unit 121 (see Figure 1 ), the heat generation estimating unit 121 estimates the heat generation amount of the resistors ( 14 a to 14 c ) of the DB 14 based on the rotation speed of the first motor 2 .

[0064] The second control unit 12 changes the rotation speed of the second motor 5 according to the heat generation amount of the resistors ( 14 a to 14 c ) of the DB 14 estimated by the heat generation estimating unit 121 .

[0065] The second control unit 12 may directly use the rotation speed of the first motor 2 as a parameter for determining the rotation speed (target rotation speed) of the second motor 5, but the heat generation of the resistor (14a-14c) of DB14 changes according to its resistance value. Therefore, the second control unit 12 preferably has a heat generation estimation unit 121 that estimates the heat generation of the resistor (14a-14c) and uses the estimated heat generation as a parameter for determining the target rotation speed of the second motor 5. The heat generation estimation unit 121 may calculate (estimate) the heat generation of the resistor (14a-14c) of DB14 based on the rotation speed of the first motor 2 and the resistance value of the resistor (14a-14c) of DB14 using a given calculation formula stored in the storage unit 13. In addition, the second control unit 12 may calculate (determine) the target rotation speed of the second motor 5 based on the estimated heat generation using a given calculation formula stored in the storage unit 13. However, in the present embodiment, the target rotation speed of the second motor 5 is determined using reference information (correspondence table) described later.

[0066] The storage unit 13 is a non-volatile semiconductor memory such as a flash memory that can be electrically rewritten. The storage unit 13 may also be a memory of the processing unit 10. The storage unit 13 stores the following reference information: a correspondence relationship between a plurality of target rotational speeds for the second motor 5 and a plurality of rotational speeds (ranges) for the first motor 2 and a plurality of heating values ​​(ranges) of the resistors (14a to 14c) of the DB 14. Table 1 below shows an example of the reference information (correspondence table).

[0067] [Table 1]

[0068]

[0069] The second control unit 12 refers to reference information such as shown in Table 1 stored in the storage unit 13 , and determines the heating value of the resistors ( 14 a to 14 c ) and the target rotation speed of the second motor 5 based on the rotation speed of the first motor 2 detected by the rotation speed detection unit 3 .

[0070] That is, when the drive control of the first motor 2 is in the standby state, the second control unit 12 determines one target rotation speed from a plurality of target rotation speeds of reference information based on the heat generation of the resistors (14a to 14c) estimated by the heat generation estimating unit 121, and applies it to the rotation speed of the second motor 5.

[0071] The frame H1 is formed into a rectangular box shape, for example. The frame H1 accommodates at least the first control unit, the second control unit 12, and the DB14. In the present embodiment, the frame H1 accommodates the power conversion unit E1, the processing unit 10, the DB14, the pair of current detection units 15a, 15b, the heat dissipation unit B1, and the temperature detection unit 4, and accommodates or holds the second motor 5.

[0072] (Motor drive unit operation)

[0073] Below, refer to Figure 2 A series of steps of the control operation related to the second motor 5 in the motor drive device 1 will be described with reference to Table 1. The operation flow described below is only an example, and the order of the processing may be changed appropriately, and the processing may be added or omitted appropriately.

[0074] Figure 2 The horizontal axis is time, which shows the relationship between (A) power supply status, (B) motor drive device status, and (E) motor rotation speed [min -1 ] and (F) a characteristic diagram of time change related to the fan motor rotation speed (target rotation speed of the second motor 5).

[0075] exist Figure 2 At time point t1, the power supply S1 to the motor drive device 1 is switched from no supply to supply of the power supply S1 to the motor drive device 1. That is, at time point t1, the power supply of the motor drive device 1 is turned on. At time point t1, the drive control of the first motor 2 in the motor drive device 1 is in a standby state, and the standby state continues until time point t11. In the standby state, the motor drive device 1 operates DB14 to stop the rotating first motor 2, and the switches 14d and 14e short-circuit the windings of the first motor 2 (stop the execution of the control step). That is, in the standby state, when the first motor 2 rotates due to an external force, the first resistor 14a to the third resistor 14c generate heat.

[0076] exist Figure 2 In the embodiment, at a position slightly before the time point t2, the first motor 2 starts to rotate due to an external force, and as an example, the rotation speed of the first motor 2 increases at a fixed ratio. In response to the start of the rotation of the first motor 2, the kinetic energy of the first motor 2 starts to be consumed by the first resistor 14a to the third resistor 14c.

[0077] The motor drive device 1 refers to the reference information (see Table 1) to determine the target rotation speed of the second motor 5. As the detected rotation speed [min -1] is greater than 0 and less than 100 (marked as "0-100" in Table 1), and the estimated heating value [W·s] is less than 1 (marked as "1" in Table 1) until time point t2, based on the reference information, the target rotation speed of the second motor 5 is 0. That is, the motor drive device 1 maintains the second motor 5 stationary until time point t2.

[0078] At time point t2, the rotation speed of the first motor 2 is 100 or more and the estimated heating value is 1 or more, and the motor drive device 1 changes the target rotation speed of the second motor 5 to 1000 based on the reference information to drive the second motor 5. In other words, the motor drive device 1 drives and controls the second motor 5 (execution of the second control step).

[0079] In the time period from time point t2 to time point t3 when the rotation speed of the first motor 2 is greater than 100 and less than 1000 (marked as "100-1000" in Table 1) and the estimated heating value is greater than 1 and less than 10 (marked as "10" in Table 1), the target rotation speed of the second motor 5 is maintained at 1000.

[0080] At time t3 , the rotation speed of the first motor 2 is 1000 or more and the estimated heating value is 10 or more, and the motor drive device 1 changes the target rotation speed of the second motor 5 to 2000 based on the reference information.

[0081] In the time period from time point t3 to time point t4 when the rotation speed of the first motor 2 is greater than 1000 and less than 2000 (marked as "1000-2000" in Table 1) and the estimated heating value is greater than 10 and less than 20 (marked as "20" in Table 1), the target rotation speed of the second motor 5 is maintained at 2000.

[0082] At time t4 , the rotation speed of the first motor 2 is 2000 or more and the estimated heating value is 20 or more, and the motor drive device 1 changes the target rotation speed of the second motor 5 to 3000 based on the reference information.

[0083] In the time period from time point t4 to time point t5, when the rotation speed of the first motor 2 is 2000 or more and the estimated calorific value is 20 or more, the target rotation speed of the second motor 5 is maintained at 3000. In addition, at the midpoint between time points t4 and t5, the rotation speed of the first motor 2 reaches a peak, and thereafter, as an example, the rotation speed of the first motor 2 decreases at a fixed ratio. That is, through DB14, the first motor 2 starts to move toward a stopped state.

[0084] At time point t5, the rotation speed of the first motor 2 is lower than 2000 and the estimated heating value is lower than 20. However, the second control unit 12 of the present embodiment does not immediately change the target rotation speed of the second motor 5 to 2000 even if the rotation speed of the first motor 2 is lower than 2000 (threshold value). That is, when the drive control of the first motor 2 is in the standby state, even if the rotation speed of the first motor 2 is lower than a given threshold value (for example, 2000), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. After the fixed time T1 has passed, the second control unit 12 changes the rotation speed of the second motor 5 based on the reference information. The fixed time T1 is assumed to be, for example, several minutes to more than ten minutes, but is not particularly limited. In short, between time point t4 and time point t6, the target rotation speed of the second motor 5 is maintained at 3000.

[0085] At time point t6 , since the fixed time T1 has elapsed from time point t5 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 2000 based on the reference information.

[0086] At time t7, the rotation speed of the first motor 2 is lower than 1000 and the estimated heating value is lower than 10. However, the second control unit 12 of the present embodiment does not immediately change the target rotation speed of the second motor 5 to 1000 even if the rotation speed of the first motor 2 is lower than 1000 (threshold value). Here, when the drive control is in the standby state, even if the rotation speed of the first motor 2 is lower than a given threshold value (for example, 1000), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. In short, between time t6 and time t8, the target rotation speed of the second motor 5 is maintained at 2000.

[0087] At time point t8 , since the fixed time T1 has elapsed from time point t7 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 1000 based on the reference information.

[0088] At time point t9, the rotation speed of the first motor 2 is lower than 100 and the estimated heating value is lower than 1. However, the second control unit 12 of the present embodiment does not immediately change the target rotation speed of the second motor 5 to 0 even if the rotation speed of the first motor 2 is lower than 100 (threshold value). Here, when the drive control is in the standby state, even if the rotation speed of the first motor 2 is lower than a given threshold value (for example, 100), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. In short, between time point t8 and time point t10, the target rotation speed of the second motor 5 is maintained at 1000.

[0089] At time point t10 , since the fixed time T1 has elapsed from time point t9 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 0 based on the reference information.

[0090] In the above example, three given thresholds are set (2000, 1000, 100), but the number of given thresholds is not particularly limited, and may be only one, for example.

[0091] In addition, the three fixed times T1 corresponding to the three given thresholds are set to be the same length, but may be different from each other. When the three fixed times T1 are all different, for example, the three fixed times T1 may be set to be shorter as the rotation speed of the first motor 2 decreases, such as 10 minutes, 5 minutes, and 1 minute, or conversely, the three fixed times T1 may be set to be longer as the rotation speed of the first motor 2 decreases, such as 1 minute, 5 minutes, and 10 minutes.

[0092] Thereafter, at time t11, the motor drive device 1 switches the drive control of the first motor 2 from the standby state to the drive state. That is, the motor drive device 1 drives and controls the first motor 2 (execution of the first control step).

[0093] According to the switching of the operation state, the second control unit 12 sets the target rotation speed of the second motor 5 to 3000 and drives the second motor 5. In other words, when the drive control of the first motor 2 changes from the standby state to the drive state, the second control unit 12 drives the second motor 5 at a given rotation speed (in Figure 2 The second control unit 12 preferably changes the target rotation speed of the second motor 5 in the standby state within a range below the given rotation speed (3000) in the driving state. In addition, there is a slight time lag from the time point t11 ​​when the standby state is switched to the driving state to the increase in the rotation speed of the first motor 2.

[0094] exist Figure 2 In the example shown, the motor drive device 1 maintains the rotation speed of the first motor 2 at a fixed value of 2000 or more for a predetermined period, and then performs control to reduce the rotation speed of the first motor 2 toward the end of the drive control (time point t12 ).

[0095] At time t12, the motor drive device 1 switches the drive control of the first motor 2 from the drive state to the standby state. The motor drive device 1 controls the first motor 2 so that the rotation speed of the first motor 2 reaches 0 slightly before time t12 when the first motor 2 is switched to the standby state.

[0096] Here, the second control unit 12 of the present embodiment does not immediately change the target rotation speed of the second motor 5 to 0 even if the rotation speed of the first motor 2 is 0 and the drive control of the first motor 2 is switched from the drive state to the standby state. That is, the second control unit 12 performs control so that the target rotation speed of the second motor 5 is switched to 0 at a given rotation speed (in the case of the first motor 2) even if the drive control of the first motor 2 is switched from the drive state to the standby state. Figure 2 3000 in the example) maintains the rotation speed of the second motor 5 for a specified time T2. After the specified time T2 has passed, the second control unit 12 controls so that the rotation speed of the second motor 5 is changed according to the rotation speed of the first motor 2. The specified time T2 is, for example, conceived to be several minutes to more than ten minutes, but is not particularly limited. The length of the specified time T2 can be the same as or different from the fixed time T1. In short, between time point t11 ​​and time point t13, the target rotation speed of the second motor 5 is maintained at 3000.

[0097] At time point t13 , the predetermined time T2 has elapsed from time point t12 , and therefore the motor drive device 1 changes the target rotation speed of the second motor 5 to 0 based on the reference information.

[0098] Thereafter, when the first motor 2 is rotated again by the external force, the rotation speed of the second motor 5 is changed as shown from the time point t1 to the time point t11.

[0099] [advantage]

[0100] Thus, according to the motor drive device 1 involved in this embodiment, when the drive control of the first motor 2 is in the standby state, the rotation speed of the second motor 5 is changed according to the rotation speed of the first motor 2. Therefore, even if the first motor 2 rotates due to an external force, the first resistor 14a to the third resistor 14c of the DB14 generate heat, and the possibility that the heat generating portion A1 and the heat dissipating portion B1 are properly cooled by the second motor 5 increases. Therefore, it is possible to suppress the reduction in reliability of the motor drive device 1 due to the heat generated by the operation of the DB14.

[0101] In addition, compared with the case where the second motor 5 is always driven and controlled at a fixed rotation speed during the period when the drive control of the first motor 2 is in the standby state, it is easy to reduce useless power consumption in the second motor 5, and it will also contribute to extending the life of the second motor 5. In addition, compared with the case where the second motor 5 is always driven and controlled at a fixed rotation speed during the period when the drive control of the first motor 2 is in the standby state, the noise of the second motor 5 can be reduced.

[0102] Furthermore, in the present embodiment, since the rotation speed of the second motor 5 is changed according to the heat generation amount of the first resistor 14 a to the third resistor 14 c of the DB 14 , it is possible to realize the drive control of the second motor 5 with higher reliability.

[0103] Furthermore, in the present embodiment, since one target rotation speed determined from a plurality of target rotation speeds of the reference information is applied to the target rotation speed of the second motor 5 , it is possible to realize drive control of the second motor 5 with higher reliability.

[0104] In addition, in the present embodiment, a fixed time T1 is set. Therefore, the possibility that the heat generating portion A1 and the heat dissipating portion B1 of the resistor (14a to 14c) including DB14 are sufficiently cooled by the second motor 5 increases. In addition, when the first motor 2 rotates at a rotation speed near a given threshold, the rotation speed of the second motor 5 can be suppressed from being frequently switched due to noise or the like.

[0105] In addition, in this embodiment, a predetermined time T2 is set. Therefore, after the heat generating part A1 and the heat dissipating part B1 in the driving state are cooled more fully, the control method related to the rotation speed of the second motor 5 is switched. That is, the second control unit 12 has a first control mode and a second control mode as control methods (control modes). The first control mode controls the rotation speed of the second motor 5 at a given rotation speed (in the driving state). Figure 2 The second control mode controls the rotation speed of the second motor 5 based on the reference information in the standby state. In the present embodiment, after the predetermined time T2 has passed, the control mode is switched from the first control mode to the second control mode. Therefore, the reliability of the motor drive device 1 is further improved.

[0106] (Variant 1)

[0107] Hereinafter, the motor drive device 1 according to the modification (modification 1) will be described in detail. In addition, in the following, for the components of the motor drive device 1 according to modification 1, the components that are substantially the same as those of the motor drive device 1 according to the above-mentioned embodiment are sometimes given the same reference numerals, and their descriptions are appropriately omitted.

[0108] The motor drive device 1 according to the first modification is different from the motor drive device 1 according to the above embodiment in the control of the rotation speed of the second motor 5 in the second control unit when the drive control of the first motor 2 is in the standby state.

[0109] Specifically, when the drive control of the first motor 2 is in the standby state, the second control unit 12 of the modification 1 changes the rotation speed of the second motor 5 based on the heat generation of the resistor (14a to 14c) estimated by the heat generation estimation unit 121 and the detection result of the temperature detection unit 4. That is, in the modification 1, the second control unit 12 uses not only the estimated heat generation but also the detection result of the temperature detection unit 4 as a parameter for determining the target rotation speed of the second motor 5.

[0110] The detection result (detection value) of the temperature detection unit 4 can be used as a parameter as it is. In the first modification, the temperature estimation unit 122 (see Figure 1 ) The ambient temperature of the frame H1 is estimated based on the detection value of the temperature detection unit 4, and the ambient temperature of the frame H1 is used as a parameter for determining the target rotation speed of the second motor 5. That is, when the drive control of the first motor 2 is in the standby state, the second control unit 12 changes the rotation speed of the second motor 5 based on the heat generation of the resistor (14a~14c) estimated by the heat estimation unit 121 and the ambient temperature estimated by the temperature estimation unit 122.

[0111] The heating value of the resistors (14a-14c) may be calculated based on the rotation speed of the first motor 2 and the resistance value of the resistors (14a-14c) using a given calculation formula. In addition, the target rotation speed of the second motor 5 may be calculated based on the heating value of the resistors (14a-14c) and the ambient temperature using a given calculation formula. However, in the first modification, the target rotation speed of the second motor 5 is determined using the reference information (correspondence table) described later, as in the above-mentioned embodiment.

[0112] The storage unit 13 of the modification example 1 stores the following reference information: a correspondence relationship between a plurality of target rotational speeds for the second motor 5 and a plurality of rotational speeds (ranges) for the first motor 2, a plurality of heating values ​​(ranges) for the resistors (14a to 14c), and a plurality of ambient temperatures (ranges). Table 2 below shows an example of the reference information (correspondence table) of the modification example 1.

[0113] [Table 2]

[0114]

[0115] The second control unit 12 refers to reference information such as that shown in Table 2 stored in the storage unit 13 to determine a target rotation speed of the second motor 5 .

[0116] Below, refer to Figure 3A series of steps of the control operation related to the second motor 5 in the motor drive device 1 of Modification 1 will be described with reference to Table 2. The operation flow described below is only an example, and the order of the processing may be changed appropriately, and the processing may be added or omitted appropriately.

[0117] Figure 3 The horizontal axis is time, and the graph shows the relationship between (A) power supply status, (B) motor drive device status, (C) ambient temperature estimation range, (D) estimated ambient temperature, and (E) motor rotation speed [min -1 ] and (F) a characteristic diagram showing the time variation of the rotation speed of the second motor (target).

[0118] exist Figure 3 At time point t21, the power supply S1 to the motor drive device 1 is switched from no supply to supply of the power supply S1 to the motor drive device 1. That is, at time point t21, the power supply of the motor drive device 1 is turned on. At time point t21, the drive control of the first motor 2 in the motor drive device 1 is in a standby state, and the standby state continues until time point t31. In the standby state, the motor drive device 1 activates DB14, and the switches 14d and 14e short-circuit the windings of the first motor 2. That is, in the standby state, when the first motor 2 rotates due to an external force, the first resistor 14a to the third resistor 14c generate heat.

[0119] In variation 1, if Figure 3 As shown, the section indicated as “estimation” in the (C) ambient temperature estimation section is set as a section in which the motor drive device 1 estimates the ambient temperature. In addition, the section indicated as “non-estimation” in the (C) ambient temperature estimation section is set as a section in which the motor drive device 1 does not estimate the ambient temperature.

[0120] For example, in Figure 3 In FIG. 1 , time t21 to time t31 are set as the "estimated" period, and the estimated ambient temperature is 25°C.

[0121] exist Figure 3 In the embodiment, at a position slightly before time point t22, the first motor 2 starts to rotate due to an external force, and as an example, the rotation speed of the first motor 2 increases at a fixed ratio. In response to the start of rotation of the first motor 2, the kinetic energy of the first motor 2 starts to be consumed by heat of the first resistor 14a to the third resistor 14c.

[0122] The motor drive device 1 refers to the reference information (see Table 2) to determine the target rotation speed of the second motor 5. As the rotation speed [min -1] is greater than 0 and less than 100 (marked as "0-100" in Table 2), the estimated calorific value [W·s] is less than 1 (marked as "1" in Table 2), and the estimated ambient temperature is 25°C, and the target rotation speed of the second motor 5 is 0 based on the reference information until the time point t22. That is, the motor drive device 1 maintains the second motor 5 stationary until the time point t22.

[0123] As can be seen from Table 2, the reference information of Modification 1 is divided into a range where the estimated ambient temperature is 0°C or higher and lower than 30°C (marked as "0-30" in Table 2) and a range where the estimated ambient temperature is 30°C or higher and lower than 60°C (marked as "30-60" in Table 2) for each estimated heating value range (each motor rotation speed range). The target rotation speed of the second motor 5 is set in accordance with each estimated ambient temperature range.

[0124] At time t22 , the rotation speed of the first motor 2 is 100 or more and the estimated heating value is 1 or more (the estimated ambient temperature is 25° C.). The motor drive device 1 changes the target rotation speed of the second motor 5 to 500 based on the reference information and controls the drive of the second motor 5 .

[0125] In the time period from time point t22 to time point t23 when the rotation speed of the first motor 2 is greater than 100 and less than 1000 (marked as "100-1000" in Table 2) and the estimated heating value is greater than 1 and less than 10 (marked as "10" in Table 2), the target rotation speed of the second motor 5 is maintained at 500.

[0126] At time t23 , the rotation speed of the first motor 2 is 1000 or more and the estimated heating value is 10 or more (the estimated ambient temperature is 25° C.), and the motor drive device 1 changes the target rotation speed of the second motor 5 to 1000 based on the reference information.

[0127] In the time period from time point t23 to time point t24 when the rotation speed of the first motor 2 is greater than 1000 and less than 2000 (marked as "1000-2000" in Table 2) and the estimated heating value is greater than 10 and less than 20 (marked as "20" in Table 2), the target rotation speed of the second motor 5 is maintained at 1000.

[0128] At time t24 , the rotation speed of the first motor 2 is 2000 or more and the estimated heating value is 20 or more (the estimated ambient temperature is 25° C.), and the motor drive device 1 changes the target rotation speed of the second motor 5 to 2000 based on the reference information.

[0129] In the time period from time point t24 to time point t25, when the rotation speed of the first motor 2 is 2000 or more and the estimated calorific value is 20 or more, the target rotation speed of the second motor 5 is maintained at 2000. In addition, at the middle point between time points t24 and t25, the rotation speed of the first motor 2 reaches a peak, and thereafter, as an example, the rotation speed of the first motor 2 decreases at a fixed ratio. That is, through DB14, the first motor 2 starts to move toward a stopped state.

[0130] At time point t25, the rotation speed of the first motor 2 is lower than 2000 and the estimated heating value is lower than 20 (the estimated ambient temperature is 25°C). However, even if the rotation speed of the first motor 2 is lower than 2000 (threshold), the second control unit 12 does not immediately change the target rotation speed of the second motor 5 to 1000. That is, as described in the above embodiment, when the drive control is in the standby state, even if the rotation speed of the first motor 2 is lower than the given threshold (2000), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. After the fixed time T1 has passed, the second control unit 12 changes the rotation speed of the second motor 5 based on the reference information. In short, between time point t24 and time point t26, the target rotation speed of the second motor 5 is maintained at 2000.

[0131] At time point t26 , since the fixed time T1 has elapsed from time point t25 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 1000 based on the reference information.

[0132] At time t27, the rotation speed of the first motor 2 is lower than 1000 and the estimated heating value is lower than 10 (the estimated ambient temperature is 25°C). However, even if the rotation speed of the first motor 2 is lower than 1000 (threshold), the second control unit 12 does not immediately change the target rotation speed of the second motor 5 to 500. Here, when the drive control is in the standby state, even if the rotation speed of the first motor 2 is lower than the given threshold (1000), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. In short, between time t26 and time t28, the target rotation speed of the second motor 5 is maintained at 1000.

[0133] At time point t28 , since the fixed time T1 has elapsed from time point t27 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 500 based on the reference information.

[0134] At time point t29, the rotation speed of the first motor 2 is lower than 100 and the estimated heat generation is lower than 1 (the estimated ambient temperature is 25°C). However, even if the rotation speed of the first motor 2 is lower than 100 (threshold), the second control unit 12 does not immediately change the target rotation speed of the second motor 5 to 0. Here, when the drive control is in the standby state, even if the rotation speed of the first motor 2 is lower than the given threshold (100), the second control unit 12 maintains the rotation speed of the second motor 5 for a fixed time T1. In short, between time point t28 and time point t30, the target rotation speed of the second motor 5 is maintained at 500.

[0135] At time point t30 , since the fixed time T1 has elapsed from time point t29 , the motor drive device 1 changes the target rotation speed of the second motor 5 to 0 based on the reference information.

[0136] Then, at time point t31, the motor drive device 1 switches the drive control of the first motor 2 from the standby state to the drive state. According to the switching of the operation state, the second control unit 12 sets the target rotation speed of the second motor 5 to 3000 and drives the second motor 5. In addition, there is a slight time lag from the time point t31 when the operation state is switched to the increase of the rotation speed of the first motor 2.

[0137] The motor drive device 1 maintains the rotation speed of the first motor 2 at a fixed value of 2000 or more for a predetermined period, and then decreases the rotation speed of the first motor 2 toward the end of the drive control (time point t32 ).

[0138] At time t32, the motor drive device 1 switches the drive control of the first motor 2 from the drive state to the standby state. The motor drive device 1 controls the first motor 2 so that the rotation speed of the first motor 2 reaches 0 slightly before time t32 when the first motor 2 is switched to the standby state.

[0139] The second control unit 12 does not immediately change the target rotation speed of the second motor 5 to 0 even if the rotation speed of the first motor 2 is 0 and the drive control of the first motor 2 is switched from the drive state to the standby state. That is, the second control unit 12 controls so that the rotation speed of the second motor 5 is maintained at a given rotation speed (3000) for a predetermined time T2 even if the drive control is switched from the drive state to the standby state. After the predetermined time T2 has passed, the second control unit 12 controls so that the rotation speed of the second motor 5 is changed according to the rotation speed of the first motor 2. In short, between time point t31 and time point t33, the target rotation speed of the second motor 5 is maintained at 3000.

[0140] In Modification 1, the period between time t31 and time t33 is set as a "non-estimation" period, and the estimated ambient temperature during this period is unknown. That is, the predetermined time T2 is also set as a "non-estimation" period.

[0141] At time point t33 , the predetermined time T2 has elapsed from time point t32 , and therefore the motor drive device 1 changes the target rotation speed of the second motor 5 to 0 (the estimated ambient temperature is 25° C.) based on the reference information.

[0142] Thereafter, when the first motor 2 is rotated again by the external force, the rotation speed of the second motor 5 is changed as shown from the time point t21 to the time point t31.

[0143] Modification 1 can also suppress reliability degradation caused by heat generated by the operation of DB 14. In particular, since the rotation speed of the second motor 5 is changed using the estimated ambient temperature of the housing H1, drive control of the second motor 5 can be achieved with higher reliability.

[0144] (Other variations)

[0145] The same functions as those of the motor drive device 1 according to the above-described embodiment and Modification 1 can also be realized by a control method, a computer program, or a non-transitory recording medium having the computer program recorded thereon.

[0146] The motor drive device 1 (especially the processing unit 10) in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. The function of the motor drive device 1 (especially the processing unit 10) in the present disclosure is realized by executing the program recorded in the memory of the computer system by the processor. The program can be pre-recorded in the memory of the computer system, provided through an electrical communication line, or recorded in a non-temporary recording medium such as a memory card, an optical disk, a hard disk drive, etc. that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI mentioned here are called differently according to the degree of integration, including integrated circuits called system LSI, VLSI (Very Large Scale Integration) or ULSI (Ultra Large Scale Integration). Furthermore, a programmable FPGA (Field-Programmable Gate Array) after the manufacture of the LSI, or a logic device that can reconstruct the bonding relationship within the LSI or the circuit division within the LSI, can also be used as a processor. Multiple electronic circuits can be concentrated in one chip or dispersed in multiple chips. Multiple chips can be concentrated in one device or dispersed in multiple devices. The computer system described here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0147] In addition, the structure in which the plurality of functions of the motor drive device 1 are concentrated in one housing (frame H1 ) as in the above-mentioned embodiment and modification 1 is not necessarily a structure. For example, the components of the motor drive device 1 may be dispersed in a plurality of housings.

[0148] On the contrary, multiple functions of the motor drive device 1 may be integrated in one housing as in the above-mentioned embodiment and modification 1. Furthermore, at least a part of the functions of the motor drive device 1, for example, a part of the functions of the motor drive device 1 may be implemented by cloud computing or the like.

[0149] The structure of DB14 described in the above embodiment (see Figure 1) is just an example, and the type, number, wiring connection relationship, etc. of the resistors (14a-14c) of DB14 and the type, number, and wiring connection relationship of the switches (14d, 14e) are not particularly limited. In short, as long as the component includes a structural element (resistor, etc.) that generates heat due to the operation of DB14 and requires cooling of the second motor 5 in order to maintain the stability of the motor drive device 1, the structure is not limited. For example, the resistors (14a-14c) may also include variable resistors.

[0150] In the above-mentioned embodiment and modification 1, Figure 2 as well as Figure 3 As shown, when the drive control of the first motor 2 is in the driving state, the second motor 5 is controlled to maintain a fixed rotation speed. However, the motor drive device 1 can also be controlled so that even in the driving state, the target rotation speed of the second motor 5 is changed according to, for example, the rotation speed of the first motor 2.

[0151] (Summarize)

[0152] According to the above-described embodiments and the like, the following aspects are disclosed.

[0153] The motor drive device (1) involved in the first embodiment includes: a heating unit (A1), a first control unit (11), a second control unit (12) and a dynamic brake (14) inside. The heating unit (A1) generates heat due to the rotation of the first motor (2). The first control unit (11) drives and controls the first motor (2). The second control unit (12) drives and controls the second motor (5). The second motor (5) cools the inside. The dynamic brake (14) has resistors (14a to 14c) electrically connected between the terminals (P1 to P3) of the first motor (2). The dynamic brake (14) short-circuits the terminals (P1 to P3) and uses the resistors (14a to 14c) to dissipate the kinetic energy of the first motor (2) by heat, thereby stopping the first motor (2). When the drive control of the first motor (2) is in a standby state, the second control unit (12) controls so as to change the rotation speed of the second motor (5) according to the rotation speed of the first motor (2). The heating unit (A1) includes resistors (14a to 14c).

[0154] According to the above-mentioned method, when the drive control of the first motor (2) is in a standby state, the rotation speed of the second motor (5) is changed according to the rotation speed of the first motor (2). Therefore, even if the first motor (2) rotates due to an external force and the resistors (14a to 14c) generate heat, the possibility that the heat generating portion (A1) including the resistors (14a to 14c) will be properly cooled by the second motor (5) is increased. As a result, the motor drive device (1) has the advantage of being able to suppress the reduction in reliability caused by the heat generated by the operation of the dynamic brake (14).

[0155] Regarding the motor drive device (1) involved in the second embodiment, in the first embodiment, the second control unit (12) has: a heat generation estimating unit (121) that estimates the heat generation of the resistors (14a-14c) based on the rotation speed of the first motor (2). The second control unit (12) changes the rotation speed of the second motor (5) according to the heat generation of the resistors (14a-14c) estimated by the heat generation estimating unit (121).

[0156] According to the above aspect, since the rotation speed of the second motor (5) is changed according to the heat generated by the resistors (14a to 14c), it is possible to realize drive control of the second motor (5) with higher reliability.

[0157] The motor drive device (1) according to the third aspect is further provided with a storage unit (13) in the second aspect. The storage unit (13) stores reference information indicating a correspondence between a plurality of target rotational speeds of the second motor (5) and a plurality of rotational speeds of the first motor (2) and a plurality of heat amounts of the resistors (14a to 14c). When the drive control of the first motor (2) is in a standby state, the second control unit (12) determines a target rotational speed from the plurality of target rotational speeds of the reference information based on the heat amount of the resistors (14a to 14c) estimated by the heat estimation unit (121), and applies the target rotational speed to the rotational speed of the second motor (5).

[0158] According to the above aspect, since one target rotational speed determined from a plurality of target rotational speeds of the reference information is applied to the rotational speed of the second motor (5), it is possible to realize drive control of the second motor (5) with higher reliability.

[0159] Regarding the motor drive device (1) involved in the fourth aspect, in the third aspect, when the drive control of the first motor (2) is in a standby state, even if the rotation speed of the first motor (2) is lower than a given threshold value, the second control unit (12) maintains the rotation speed of the second motor (5) for a fixed time (T1). After the fixed time (T1) has passed, the second control unit (12) changes the rotation speed of the second motor (5) based on the reference information.

[0160] According to the above-mentioned method, the possibility of the heat generating portion (A1) or the heat dissipating portion (B1) including the resistor (14a-14c) being sufficiently cooled by the second motor (5) is increased. In addition, when the first motor (2) rotates at a rotation speed near a given threshold value, the rotation speed of the second motor (5) can be suppressed from being frequently switched due to noise or the like.

[0161] The motor drive device (1) involved in the fifth embodiment further includes a frame (H1) and a temperature detection unit (4) in any of the second to fourth embodiments. The frame (H1) at least accommodates the first control unit, the second control unit (12) and the dynamic brake (14). The temperature detection unit (4) is arranged in the frame (H1). When the drive control of the first motor (2) is in a standby state, the second control unit (12) changes the rotation speed of the second motor (5) based on the heat generation of the resistor (14a~14c) estimated by the heat estimation unit (121) and the detection result of the temperature detection unit (4).

[0162] According to the above aspect, since the rotation speed of the second motor (5) is changed according to the heat generation of the resistors (14a-14c) and the detection result of the temperature detection unit (4), it is possible to realize the drive control of the second motor (5) with higher reliability.

[0163] Regarding the motor drive device (1) involved in the sixth aspect, in the fifth aspect, the second control unit (12) has: a temperature estimating unit (122) that estimates the ambient temperature of the frame (H1) based on the detection result of the temperature detecting unit (4). When the drive control of the first motor (2) is in a standby state, the second control unit (12) changes the rotation speed of the second motor (5) based on the heat generation amount of the resistors (14a to 14c) estimated by the heat generation estimating unit (121) and the ambient temperature estimated by the temperature estimating unit (122).

[0164] According to the above aspect, since the rotation speed of the second motor (5) is changed using the estimated ambient temperature of the housing (H1), it is possible to realize drive control of the second motor (5) with higher reliability.

[0165] Regarding the motor drive device (1) involved in the seventh aspect, in any one of the first to sixth aspects, when the drive control of the first motor (2) changes from the standby state to the drive state, the second control unit (12) controls the second motor (5) at a given rotation speed. The second control unit (12) controls so that even if the drive control of the first motor (2) changes from the drive state to the standby state, the rotation speed of the second motor (5) is maintained at the given rotation speed for a predetermined time (T2). After the predetermined time (T2) has passed, the second control unit (12) controls so that the rotation speed of the second motor (5) is changed according to the rotation speed of the first motor (2).

[0166] According to the above aspect, since the control method related to the rotation speed of the second motor (5) is switched after the heat of the heat generating portion (A1) in the driven state is further sufficiently cooled, the reliability of the motor driving device (1) is further improved.

[0167] Regarding the motor drive device (1) involved in the eighth aspect, in the first aspect, the motor drive device (1) further includes: a heat dissipation portion (B1) for dissipating heat from the heat generating portion (A1) and dissipating heat from at least one of the heat generating portion (A1) and the heat dissipation portion (B1).

[0168] According to the above aspect, the possibility of the heat dissipation portion (B1) being appropriately cooled by the second motor (5) increases. As a result, the motor drive device (1) has the advantage of being able to suppress a reduction in reliability due to heat generated by the operation of the dynamic brake (14).

[0169] The control method involved in the ninth aspect is a control method for a motor drive device (1). The control method includes a first control step, a second control step, and a stop control step. In the first control step, the first motor (2) is drive-controlled. In the second control step, the second motor (5) is drive-controlled. The second motor (5) cools at least one of a heat generating portion (A1) and a heat dissipating portion (B1) for dissipating heat from the heat generating portion (A1), and the heat generating portion (A1) generates heat due to the rotation of the first motor (2). In the stop control step, in a dynamic brake (14) having a resistor (14a-14c) electrically connected between terminals (P1-P3) of the first motor (2), a short circuit is made between the terminals (P1-P3). In the stop control step, the kinetic energy of the first motor (2) is thermally consumed by the resistor (14a-14c) through the short circuit, thereby stopping the first motor (2). In the second control step, when the drive control of the first motor (2) is in a standby state, control is performed so that the rotation speed of the second motor (5) is changed according to the rotation speed of the first motor (2). The heating unit (A1) includes resistors (14a to 14c).

[0170] According to the above aspect, a control method can be provided which can suppress a reduction in reliability due to heat generated by the operation of a dynamic brake (14).

[0171] The program according to the tenth aspect is a program for causing one or more processors to execute the above-mentioned control method.

[0172] According to the above aspect, it is possible to provide a function of suppressing a decrease in reliability due to heat generated by the operation of the dynamic brake (14).

[0173] The structures according to the second to seventh aspects are not essential structures in the motor drive device (1) and can be omitted as appropriate.

[0174] Industrial Applicability

[0175] According to the motor drive device, control method, and program of the present disclosure, it is possible to suppress a decrease in reliability due to heat generated by the operation of the dynamic brake. As such, the motor drive device, control method, and program of the present disclosure are industrially useful.

[0176] Explanation of symbols

[0177] 1 Motor drive unit

[0178] 11. Control Unit 1

[0179] 12 Second Control Unit

[0180] 121 Fever Estimation Department

[0181] 122 Temperature estimation unit

[0182] 14 Dynamic brake

[0183] 14a 1st resistor (resistor)

[0184] 14b Second resistor (resistor)

[0185] 14c 3rd resistor (resistor)

[0186] 2. 1st motor

[0187] 4 Temperature detection unit

[0188] 5. Second Motor

[0189] A1 Heating part

[0190] B1 Heat dissipation unit

[0191] H1 frame

[0192] P1 1st terminal (terminal)

[0193] P2 2nd terminal (terminal)

[0194] P3 3rd terminal (terminal)

[0195] T1 fixed time

[0196] T2 stipulated time.

Claims

1. A motor drive device, internally provided with: A heat generating portion that generates heat due to the rotation of the first motor; a first control unit for driving and controlling the first motor; a second control unit that drives and controls a second motor that cools the interior; and a dynamic brake having a resistor electrically connected between terminals of the first motor, which short-circuits between the terminals and thermally consumes the kinetic energy of the first motor through the resistor, thereby stopping the first motor; When the drive control of the first motor is in a standby state, the second control unit controls so as to change the rotation speed of the second motor according to the rotation speed of the first motor. The heat generating portion includes the resistor.

2. The motor drive device according to claim 1, wherein: The second control unit includes a heat generation estimating unit that estimates the heat generation amount of the resistor based on the rotation speed of the first motor. The second control unit changes the rotation speed of the second motor according to the heat generation amount of the resistor estimated by the heat generation estimating unit.

3. The motor drive device according to claim 2, wherein: The motor drive device further includes: a storage unit storing reference information indicating a correspondence relationship between a plurality of target rotational speeds for the second motor and a plurality of rotational speeds for the first motor and a plurality of heat amounts for the resistor; When the drive control of the first motor is in the standby state, the second control unit determines one target rotation speed from the plurality of target rotation speeds of the reference information based on the heating value of the resistor estimated by the heat estimating unit, and applies the target rotation speed to the rotation speed of the second motor.

4. The motor drive device according to claim 3, wherein: When the drive control of the first motor is in the standby state, even if the rotation speed of the first motor is lower than a given threshold, the second control unit maintains the rotation speed of the second motor for a fixed time, and changes the rotation speed of the second motor based on the reference information after the fixed time has passed.

5. The motor drive device according to claim 2, wherein: The motor drive device further comprises: a frame body that accommodates at least the first control unit, the second control unit, and the dynamic brake; and The temperature detection unit is arranged in the frame. When the drive control of the first motor is in the standby state, the second control unit changes the rotation speed of the second motor based on the heat generation amount of the resistor estimated by the heat generation estimating unit and the detection result of the temperature detecting unit.

6. The motor drive device according to claim 5, wherein: The second control unit includes a temperature estimating unit that estimates the ambient temperature of the frame based on the detection result of the temperature detecting unit. When the drive control of the first motor is in the standby state, the second control unit changes the rotation speed of the second motor according to the heating value of the resistor estimated by the heat estimation unit and the ambient temperature estimated by the temperature estimation unit.

7. The motor drive device according to claim 1, wherein: When the driving control of the first motor changes from the standby state to the driving state, the second control unit controls the second motor at a given rotation speed. The second control unit controls so that even if the drive control of the first motor changes from the driving state to the standby state, the rotation speed of the second motor is maintained at the given rotation speed for a specified time. After the specified time has passed, the second control unit controls so that the rotation speed of the second motor is changed according to the rotation speed of the first motor.

8. The motor drive device according to claim 1, wherein: The motor drive device further comprises: a heat dissipation unit for dissipating heat from the heat generating unit. The second motor dissipates heat from at least one of the heat generating portion and the heat dissipating portion.

9. A control method is a control method for a motor drive device, the control method comprising: A first control step of driving and controlling the first motor; a second control step of driving and controlling a second motor for cooling at least one of a heat generating portion and a heat dissipating portion for dissipating heat from the heat generating portion, the heat generating portion generating heat due to the rotation of the first motor; and a stop control step of short-circuiting the terminals in a dynamic brake having a resistor electrically connected between terminals of the first motor to thermally consume the kinetic energy of the first motor through the resistor, thereby stopping the first motor; In the second control step, when the drive control of the first motor is in a standby state, control is performed so that the rotation speed of the second motor is changed according to the rotation speed of the first motor. The heat generating portion includes the resistor. 10 . A program for causing one or more processors to execute the control method according to claim 8 .

Images