Motor drive control device and control method thereof, and motor drive system

Abstract

The present invention provides a motor drive control device and a control method thereof, and a motor drive system, which can optimize the drive efficiency of each motor even when driving multiple motors at the same time. The motor drive control device (104) comprises: a receiving unit (12) which receives a target speed output to a motor that is a drive control target among multiple motors (102) from a superior device, and receives stability information indicating that the actual speed of the multiple motors has stabilized; an advance angle and duty ratio determination unit (15), a duty ratio setting unit (16), an advance angle control unit (17), and a power control unit (18) which, when receiving the stability information, adjusts a drive control signal (Sd) used to control the drive of the motor that is a drive control target so that the motor current is minimized at the target speed; and a motor drive unit (20) which drives the motor that is a drive control target based on the drive control signal (Sd).

Description

Technical Field

[0001] The invention relates to a motor drive control device, a motor drive system and a control method of the motor drive control device. Background Art

[0002] There is a motor drive system that controls a plurality of motor drive control devices by one control device and drives motors connected to the motor drive control devices. For example, there is a system that is used in an electrical equipment system and drives a plurality of fan motors respectively arranged in various parts of the electrical equipment by one control device to cool the electrical equipment (for example, Patent Document 1).

[0003] Patent document 1 describes a structure of an electric equipment system, which has multiple fan motor control units for controlling fan motors and a system control unit for controlling the electric equipment system, and controls multiple fan motors by performing data communication between the system control unit and the multiple fan motor control units.

[0004] (Prior art literature)

[0005] (Patent Document)

[0006] Patent document 1: JP2001-286187A. Summary of the invention

[0007] (Problems to be solved by the invention)

[0008] As a method for efficiently driving a motor used in a fan motor, there is a method of adjusting the advance angle value and the drive duty ratio of a drive control signal for driving the motor within a range that does not cause a large change in the rotation speed while measuring the motor current. According to this method, the motor current can be adjusted to be minimized at the same rotation speed.

[0009] However, when multiple fan motors are arranged in a closed space to cool electronic equipment, such as in a server device, each fan motor is affected by wind from other fan motors, and the load variation of the fan motor increases if affected by wind from other fan motors.

[0010] If the load changes greatly, based on the timing of measuring the motor current of each fan motor, there is a situation where even if it is determined that the combination of the advance angle value and the drive duty ratio that achieves the best efficiency is obtained at that timing, in fact, the measured motor current value is not appropriate. For example, when the motor current is measured at a timing when the load is heavier than usual, even if the combination of the advance angle value and the drive duty ratio that achieves the best efficiency at the time of measurement is used, the motor current will be higher than the combination of the advance angle value and the drive duty ratio measured at normal times. In this case, there is a possibility that the motor is not driven at the best efficiency.

[0011] The present invention is proposed in view of the above-mentioned existing problems, and an object of the present invention is to provide a motor drive control device, a motor drive system and a control method of the motor drive control device, which can optimize the driving efficiency of each motor even when driving multiple motors at the same time.

[0012] (Technical solutions to solve problems)

[0013] In order to solve the above-mentioned problems, a motor drive control device described in one embodiment comprises: a speed indication receiving unit, which receives a target speed output to a motor that is a drive control object among a plurality of specified motors from a superior device; a stability information receiving unit, which receives stability information indicating that the actual speeds of the plurality of specified motors have stabilized; a motor current adjustment unit, which, upon receiving the stability information, adjusts a drive control signal for controlling the drive of the motor that is the drive control object so that the motor current is minimized at the target speed; and a motor drive unit, which drives the motor that is the drive control object based on the drive control signal.

[0014] In the motor drive control device, the stability information may be transmitted from the host device to the motor drive control device as a current adjustment permission signal, and the current adjustment permission signal may permit adjustment of the drive control signal so that the current becomes minimum.

[0015] In the motor drive control device, the motor current adjustment unit may adjust the drive control signal so that the motor current becomes minimum within a predetermined time in response to receipt of the current adjustment permission signal.

[0016] In the motor drive control device, the motor current adjustment unit may end the adjustment of the drive control signal when receiving an adjustment end instruction from the host device requesting the end of the adjustment of the drive control signal.

[0017] Regarding the above-mentioned motor drive control device, it may be that the motor current adjustment unit has: an advance angle and duty cycle determination unit, which determines the prescribed advance angle value corresponding to the target speed and the duty cycle adjusted in a manner to achieve the target speed as a combination of the advance angle value and the duty cycle of the drive control signal until the stability information is received, and when the stability information is received, determines the combination of the advance angle value and the duty cycle of the drive control signal at which the motor current becomes minimum at the target speed; and a drive control signal generation unit, which generates the drive control signal based on the determined combination of the advance angle value and the duty cycle of the drive control signal.

[0018] In order to solve the above-mentioned problems, a motor drive system described in one embodiment comprises: a plurality of specified motors; a motor drive control device described in any of the above items, each of which is arranged corresponding to the plurality of specified motors; and a superior device, which has a speed indicating unit, and the speed indicating unit outputs a target speed of the motor that is the drive control object of the motor drive control device to the motor drive control device.

[0019] Regarding the above-mentioned motor drive system, it may be that the superior device has: a stability judgment unit, which requests actual speed information from the motor drive control device of the specified multiple motors, and judges that the actual speeds of the specified multiple motors have stabilized when the actual speeds of the specified multiple motors obtained in response to the request are all included in the specified numerical range relative to the target speed of each motor; and a current adjustment permission unit, which, when the stability judgment unit judges that the actual speeds of the specified multiple motors have stabilized, sequentially generates current adjustment permission signals for the motor drive control devices of the specified multiple motors, and the current adjustment permission signal permits the drive control signal to be adjusted in a way that the current becomes minimum.

[0020] In order to solve the above-mentioned problems, a control method of a motor drive control device recorded in one embodiment is a control method of a motor drive control device recorded in any of the above-mentioned items, which includes: a speed indication receiving step, wherein a target speed output to a motor that is a drive control object among a specified plurality of motors is received from a superior device; a stability information receiving step, wherein stability information indicating that the actual speeds of the specified plurality of motors have stabilized is received; a motor current adjustment step, wherein, after the stability information receiving step, a drive control signal for controlling the drive of the motor that is the drive control object is adjusted in such a way that the motor current becomes minimum at the target speed; and a motor driving step, wherein the motor that is the drive control object is driven based on the drive control signal.

[0021] (Effects of the Invention)

[0022] According to the motor drive control device, the motor drive system, and the control method of the motor drive control device of the present invention, it is possible to optimize the driving efficiency of each of a plurality of motors driven simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic configuration diagram showing an example of the motor drive system 1 according to the embodiment.

[0024] Figure 2 1 is a schematic configuration diagram showing an example of a fan device 100 of the motor drive system 1 .

[0025] Figure 3 1 is a schematic configuration diagram showing an example of the control device 30 used in the motor drive system 1 .

[0026] Figure 4 This is a diagram for explaining an example of a communication sequence between the control device 30 and each of the fan devices 100a to 100d.

[0027] Figure 5 This is an example of a flowchart for explaining the operation of the current feedback control. DETAILED DESCRIPTION

[0028] Hereinafter, specific examples of the embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to the common components in each embodiment, and repeated descriptions are omitted.

[0029] (Implementation Method)

[0030] First, a motor drive control device, a motor drive system, and a control method of the motor drive control device according to the present embodiment will be described.

[0031] Figure 1 1 is a schematic configuration diagram showing an example of the motor drive system 1 according to the embodiment. Figure 1 A specific example of the motor drive system 1 shown is a server device that cools electronic equipment by arranging a plurality of fan motors in a closed space. Figure 1 As shown, the structure comprises: 4 fan devices 100a to 100d, which are arranged corresponding to the 4 cooling objects A, B, C, and D; a control device (an example of a superior device) 30, which outputs the target speed of the motor that becomes the drive control object to the 4 fan devices 100a to 100d (as a general term, also referred to as the fan device 100); and a communication line 5, which connects the 4 fan devices 100a to 100d with the control device 30.

[0032] In this embodiment, the motor drive system 1 includes an impeller 101 (see FIG. 1 ) for driving the fan device 100. Figure 2 ) is used as an example to explain the motor drive system 1, but it can also be a motor drive system 1 including motors for other purposes. Figure 1 The communication line 5 is shown as a wired one, but the communication between the four fan devices 100a to 100d and the control device 30 may also be wireless communication. Although the case where four fan devices 100 are connected to the control device 30 is described as an example, the number of fan devices 100 connected to the control device 30 is not limited to two or more.

[0033] Figure 2 1 is a schematic configuration diagram showing an example of a fan device 100 of the motor drive system 1. The fan device 100 includes an impeller 101, a motor 102, a position sensor 103, and a motor drive control device 104.

[0034] In the fan device 100, the impeller 101 is connected to the motor 102 and rotates together with the rotation of the rotor in the motor 102 (also referred to as "rotation of the motor 102"). The motor 102 is rotationally driven by the motor drive control device 104. As the motor 102, for example, a three-phase brushless motor can be used, but the type of motor is not limited to this, and the number of phases is not limited to three phases.

[0035] The position sensor 103 outputs a signal corresponding to the rotational position of the rotor in the motor 102 to the motor drive control device 104. In the present embodiment, the rotational position of the rotor is estimated in the motor drive control device 104 based on the output signal of the Hall element as the position sensor 103, and a rotational position signal of the rotor is generated. The position sensor 103 is not limited to the Hall element, and is not particularly limited as long as it is a sensor that can determine the rotational position of the rotor in the motor 102. In addition, a sensorless method without a position sensor may also be used.

[0036] The motor drive control device 104 applies a rectangular wave drive current (also referred to as "motor current") to the motor sub-coils of the three phases of the motor 102 based on the rotational position signal of the rotor, thereby rotating the motor 102. The motor drive control device 104 includes: a control circuit unit 10 that generates a drive control signal Sd for controlling the drive of the motor 102; a motor drive unit 20 that includes an inverter circuit 21 that applies a drive current to the motor 102 based on the drive control signal Sd; a current detection unit 25 that detects the drive current of the motor drive unit 20; and a position detection unit 26 that detects the rotational position of the rotor based on the output signal from the position sensor 103 and generates a rotational position signal.

[0037] For example, when the target speed is indicated by the superior device such as the controlled device 30, the control circuit unit 10 outputs a drive control signal Sd to the motor drive unit 20 to control the drive thereof, so that the rotation of the motor 102 reaches the target speed. In addition, if a notification request of the actual speed (also referred to as the current speed) is received from the superior device such as the control device 30, the actual speed of the motor 102 per unit time is notified to the control device 30. Furthermore, when the control circuit unit 10 receives stability information indicating that the actual speeds of the specified multiple motors have stabilized, the control circuit unit 10 drives the motor that is the object of the drive control in such a way that the motor current becomes the minimum at the indicated target speed. It should be noted that in the present embodiment, the control circuit unit 10 receives a current adjustment permission signal indicating permission for current adjustment from the control device 30 as stability information, specifically, as a result that the actual speeds of the specified multiple motors have stabilized.

[0038] The rotation position signal generated by the position detection unit 26 is input to the control circuit unit 10. The rotation speed measurement unit 19 of the control circuit unit 10 can measure the actual rotation speed of the motor 102 per unit time at present, i.e., the actual rotation speed, based on the rotation position of the rotor obtained from the rotation position signal generated by the position detection unit 26. The measured actual rotation speed is output to the communication processing unit 13 and the advance angle and duty ratio determination unit 15 through the rotation speed measurement unit 19 in the control circuit unit 10.

[0039] The motor driving unit 20 includes an inverter circuit 21 , and applies a driving current to the motor 102 via the inverter circuit 21 based on a driving control signal Sd output from the control circuit unit 10 .

[0040] The current detection unit 25 detects the drive current from the inverter circuit 21 as the motor current, and inputs the detected current into the advance angle and duty ratio determination unit 15 of the control circuit unit 10 .

[0041] The control circuit unit 10 includes hardware parts such as a processor such as a CPU, various memories such as ROM or RAM, a timer (counter), an A / D conversion circuit, an input / output I / F circuit, and a clock generation circuit, and is composed of a program processing device (for example, a microcontroller: MCU) in which each component is interconnected via a bus or a dedicated line.

[0042] The control circuit unit 10 performs various operations according to a program stored in a storage device such as a memory (not shown) through a processor and controls peripheral circuits such as an A / D conversion circuit and an input / output I / F circuit, thereby achieving Figure 2 The structure of each functional unit shown in FIG. Figure 2As shown, in the control circuit unit 10, as functional units, there are a sending unit 11, a receiving unit (an example of a speed indication receiving unit, an example of a stability information receiving unit) 12, a communication processing unit 13, an advance angle and duty cycle determination unit 15 (a part of a motor current adjustment unit), a duty cycle setting unit (a part of a motor current adjustment unit) 16, an advance angle control unit (a part of a motor current adjustment unit) 17, a power-on control unit (a part of a motor current adjustment unit, an example of a drive control signal generating unit) 18 and a speed measuring unit 19.

[0043] The transmission unit 11 transmits an arbitrary signal to a superior device such as the control device 30, and the receiving unit 12 receives an arbitrary signal from a superior device such as the control device 30. The transmission unit 11 and the receiving unit 12 are interfaces that are controlled by the communication processing unit 13 to perform transmission or reception of predetermined contents. The receiving unit 12 can function as a rotation speed indication receiving unit and a stability information receiving unit.

[0044] When the communication processing unit 13 receives an indication of the target speed of the motor to be driven and controlled from an upper device such as the control device 30, the target speed is notified to the advance angle and duty ratio determination unit 15. When the communication processing unit 13 receives a notification request of the speed from an upper device such as the control device 30, the communication processing unit 13 transmits information indicating the actual speed of the motor 102 received from the speed measurement unit 19, that is, actual speed information, to the notification request source via the transmission unit 11. Furthermore, when the communication processing unit 13 receives stability information indicating that the actual speeds of the specified plurality of motors have stabilized from an upper device such as the control device 30 via the reception unit 12, the communication processing unit 13 determines that current adjustment permission has been granted, and notifies the advance angle and duty ratio determination unit 15 that current adjustment permission has been granted (stability information has been received).

[0045] exist Figure 2 In the embodiment, the advance angle and duty ratio determination unit 15, the duty ratio setting unit 16, the advance angle control unit 17, and the energization control unit 18 function as a motor current adjustment unit. The motor current adjustment unit is a functional unit that adjusts the drive control signal Sd for controlling the drive of the motor that is the drive control object so that the motor current is minimized at the target speed when receiving the current adjustment permission signal as the stability information.

[0046] The advance angle and duty ratio determination unit 15 functions as an advance angle and duty ratio determination unit that determines a predetermined advance angle value corresponding to a target speed and a duty ratio adjusted to achieve the target speed as a combination of the advance angle value and the duty ratio of the drive control signal Sd until stable information is received, and determines a combination of the advance angle value and the duty ratio of the drive control signal Sd at which the motor current becomes minimum at the target speed when stable information is received.

[0047] The advance angle and duty ratio determination unit 15 outputs the advance angle value of the predetermined drive control signal Sd as the advance angle value of the drive control signal Sd corresponding to the target speed to the advance angle control unit 17 until the stable information is received, and outputs the arbitrary duty ratio to the duty ratio setting unit 16. The advance angle value of the drive control signal Sd predetermined as the advance angle value of the drive control signal Sd corresponding to the target speed can be determined as follows: a combination of the advance angle values ​​of the drive control signal Sd corresponding to the target speed is stored in a memory not shown, and is determined by referring to the memory. The arbitrary duty ratio is determined to be a value that makes the speed of the motor 102 fed back converge to the target speed. The actual speed of the motor 102 can use the speed obtained from the speed measurement unit 19.

[0048] Here, the adjustment of the advance angle value of the drive control signal Sd is described. Generally speaking, the faster the rotation speed of the motor, the more problematic the efficiency reduction caused by the phase delay of the coil current relative to the applied voltage becomes. The advance angle value of the drive control signal Sd in the present invention refers to the degree to which the rising edge timing of the pulse of the drive control signal Sd generated as a PWM signal, for example, is advanced compared to the timing that becomes the reference in order to achieve the advance angle control that advances the power-on timing of the drive current output in the inverter circuit 21 of the motor drive unit 20.

[0049] When receiving the stability information output from the control device 30 via the receiving unit 12 and the communication information unit 13, the advance angle and duty ratio determination unit 15 determines the combination of the advance angle value and the duty ratio of the drive control signal Sd at which the motor current becomes the minimum at the target speed based on the current (motor current) of the inverter circuit 21 detected by the current detection unit 25. The advance angle and duty ratio determination unit 15 changes the advance angle value and the duty ratio of the drive control signal Sd within the range in which the actual speed of the motor does not deviate from the target speed based on the motor current, and confirms that the motor current has become the minimum, and determines the combination of the advance angle value and the duty ratio of the drive control signal Sd at this time. In this specification, the method of determining the combination of the advance angle value and the duty ratio of the drive control signal Sd is referred to as "current feedback control". At this time, although the actual speed of the motor can be exactly consistent with the target speed, it only needs to be substantially the target speed and within a specified numerical range based on the target speed (plus or minus α% of the target speed, etc.).

[0050] When the current feedback control is completed, the advance angle and duty ratio determination unit 15 can notify the control device 30 of the completion via the communication processing unit 13 and the transmission unit 11 .

[0051] The advance angle and duty ratio determination unit 15 preferably performs current feedback control within a predetermined time in response to receipt of a current adjustment permission signal as stability information output from the control device 30. This allows current feedback control to be performed while the actual rotation speed of the other motors is reliably stable.

[0052] Preferably, the advance angle and duty ratio determination unit 15 terminates the execution of the current feedback control when an adjustment termination instruction requesting termination of the execution of the current feedback control is obtained from the control device 30. Based on this, when the actual rotation speed of the other motor becomes unstable, the control device 30 can grasp this situation and stop the current feedback control to prevent inappropriate adjustment.

[0053] The energization control unit 18 functions as a drive control signal generation unit that generates the drive control signal Sd based on a combination of the advance angle value and the duty ratio of the drive control signal Sd determined by the duty ratio setting unit 16 and the advance angle control unit 17 .

[0054] The duty ratio setting unit 16 and the advance angle control unit 17 notify the power-on control unit 18 of the advance angle value and duty ratio of the determined drive control signal Sd. The power-on control unit 18 generates a drive control signal Sd for controlling the drive of the inverter circuit 21 of the motor drive unit 20 based on the notified advance angle value and duty ratio. The power-on control unit 18 can obtain the generation timing of the drive control signal Sd based on the rotation position signal generated by the position detection unit 26. Based on the advance angle value of the determined drive control signal Sd, the power-on control unit 18 refers to the rotation position signal generated by the position detection unit 26, and controls and outputs the drive control signal Sd in such a way that the phase of the drive signal of the inverter circuit 21 becomes a prescribed advance angle value. Furthermore, based on the duty ratio of the drive control signal Sd, the power-on control unit 18 controls and outputs the duty ratio of the drive control signal Sd generated as a PWM signal, for example.

[0055] Figure 3 1 is a schematic structural diagram showing an example of a control device 30 used in the motor drive system 1. Figure 3 In the embodiment, the control device 30 includes a control unit 31 and a communication unit 32. The control unit 31 includes a processor such as a CPU, various memories such as ROM and RAM, a timer (counter), an A / D conversion circuit, an input / output I / F circuit, and a clock generation circuit, and is composed of a program processing device (for example, a microcontroller: MCU) in which each component is connected to each other via a bus or a dedicated line, and includes a rotation speed indicating unit 33, a stability determining unit 34, and a current adjustment permission unit 35 as functional units.

[0056] The communication unit 32 is a communication terminal connected to the communication line 5 or a wireless communication interface for performing wireless communication.

[0057] The speed indicating unit 33 outputs the target speed information to the four fan devices 100a to 100d of the control object. The stability determination unit 34 determines whether all the four fan devices 100a to 100d are rotating stably (stability operation). Specifically, the stability determination unit 34 requests the actual speed information of all the four fan devices 100a to 100d, and when the actual speeds of all the four motors obtained in response to the request are all included in the prescribed numerical range relative to the target speed of each motor, it is determined that the actual speeds of all the four motors are stable.

[0058] When the stability judgment unit 34 determines that the actual rotation speeds of all four motors have stabilized, the current adjustment permission unit 35 generates a current adjustment permission signal as stability information for all four fan devices 100a to 100d (motor drive control device 104 of motor 102) in sequence, and the current adjustment permission signal allows the drive control signal Sd to be controlled in a manner that the motor current becomes minimum. The current adjustment permission unit 35 specifies any one of the four fan devices 100a to 100d to transmit the stability information to the communication unit 32. However, the current adjustment permission unit 35 does not transmit the next stability information until it receives a completion notification from the fan device 100 that has notified the stability information via the communication unit 32. It is important here that the current adjustment permission is given to all four fan devices 100a to 100d in sequence. In other words, the current adjustment permission is not given to the four motors 102 at the same time. As a result, the drive control signal Sd can be adjusted in a manner that the motor current of each motor 102 of all four fan devices 100a to 100d becomes minimum without the influence of other motors 102.

[0059] If the actual rotation speed of the motor 102 in any fan device 100 that is not the current notification target becomes unstable during the period when the communication unit 32 has not received the completion notification since the last notification of the stability information, the current adjustment permission unit 35 can notify the fan device 100 that is the current notification target via the communication unit 32 of the adjustment completion instruction requesting the completion of the execution of the current feedback control. Based on this, when the actual rotation speed of other motors becomes unstable, the control device 30 can grasp this situation and stop the current feedback control without performing inappropriate adjustments.

[0060] Next, the operation of the motor drive system 1 will be described. Figure 4 1 is a diagram for explaining an example of a communication sequence between the control device 30 and each fan device 100 (fan devices 100a to 100d). Figure 4Before the timing shown, the target rotation speed is notified from the control device 30 to each fan device 100, and the duty ratio of the drive control signal Sd is adjusted in each fan device 100 so as to achieve the notified target rotation speed.

[0061] The control device 30 requests the first fan device 100a, the second fan device 100b, the third fan device 100c, and the fourth fan device 100d to notify the current rotation speed (actual rotation speed) (steps S101, S103, S105, S107). The first fan device 100a, the second fan device 100b, the third fan device 100c, and the fourth fan device 100d that receive the request obtain the current rotation speed of the motor 102 and return it to the control device 30 (steps S102, S104, S106, S108). In addition, the processing of steps S101 to S108 does not have to be limited to the order of the figure, and can also be performed simultaneously.

[0062] When the control device 30 can determine that the current rotation speeds of all the motors 102 are stable (step S109 ), the control device 30 transmits a current adjustment permission signal to the first fan device 100 a (step S110 ).

[0063] When the first fan device 100a receives the current adjustment permission signal, it performs current feedback control (also referred to as "current FB control") (step S111). Figure 5 The current FB control will be described.

[0064] Figure 5 1 is an example of a flowchart for explaining the operation of current feedback control. The current FB control is performed by the advance angle and duty ratio determination unit 15 of the fan device 100. The advance angle and duty ratio determination unit 15 has, for example, an advance angle counter, which represents the degree of the advance angle value of the drive control signal Sd as a count value in units of any specified angle. The advance angle and duty ratio determination unit 15 sets the current rotation speed of the motor 102 as a variable A, the motor current as a variable B, the adjusted motor current as a variable C, the current duty ratio of the drive control signal Sd as a variable D, and the current value of the advance angle counter as a variable E and maintains it.

[0065] Although in this operation example, the case where the advance angle counter performs current feedback control in the range of "10" is described as an example, this range is not particularly limited. In addition, the advance angle counter is not limited to counting "1 degree" each time, and any advance angle value can be used. Although the duty cycle is also adjusted in units of "1", the value to be adjusted is not particularly limited. In addition, in the present invention, the value "1" represents the minimum value of the resolution.

[0066] The advance angle and duty ratio determination unit 15 clears the advance angle counter in advance (step S202). When receiving the current adjustment permission signal (stable information) (step S204), the advance angle and duty ratio determination unit 15 obtains the actual speed received from the speed measurement unit 19, and substitutes the obtained actual speed into the variable A as the current speed (step S206), substitutes the current received from the current detection unit 25 into the variable B (step S208), substitutes the finally determined duty ratio into the variable D (step S210), and substitutes the finally determined advance angle value into the variable E (step S212).

[0067] Next, the advance angle and duty ratio determination unit 15 confirms that the current advance angle counter value is less than "10" (step S214: "Yes"), advances the advance angle value by 1 degree, increments the advance angle counter by "1" (step S216), and decreases the duty ratio (Duty) by "1" (step S218).

[0068] At this time, the duty ratio setting unit 16 and the advance angle control unit 17 output the advance angle value and the duty ratio determined in step S216 and step S218 to the power-on control unit 18, and the power-on control unit 18 outputs the drive control signal Sd generated based on the input advance angle value and the duty ratio to the motor drive unit 20. The motor 102 driven by the motor drive unit 20 rotates based on the drive control signal Sd. The information of the current rotation speed of the motor 102 at this time can be obtained from the actual rotation speed input to the advance angle and duty ratio determination unit 15 via the position sensor 103, the position detection unit 26 and the rotation speed measurement unit 19. In addition, the motor current at this time is detected by the current detection unit 25 that detects the current of the inverter circuit 21, and is input to the advance angle and duty ratio determination unit 15.

[0069] After step S218, the advance angle and duty ratio determination unit 15 determines whether the current speed of the motor 102 obtained is a value within plus or minus 0.3% of the variable A substituted as the current speed of the motor 102 last time (step S220). If it is "no", it is determined whether the current speed of the motor 102 obtained is less than the value of the variable A (step S222). In the case that the current speed of the motor 102 obtained is greater than the value of the variable A (step S222: "No"), it returns to the duty ratio adjustment, i.e. step S218. In the case that the current speed of the motor 102 obtained is less than the value of the variable A (S222: "Yes"), it returns to step S214 of the confirmation of the advance angle counter.

[0070] When it is determined as "yes" in step S220, the advance angle and duty ratio determination unit 15 obtains the motor current and substitutes it into the variable C (step S224), and determines whether the variable B is greater than the variable C (step S226). When it is determined that the variable B is not greater than the variable C (step S226: "No"), it returns to step S214 again. When it is determined that the variable B is greater than the variable C (step S226: "Yes"), the variable C is substituted into the variable B (S228), and it returns to step S210 to update the variables D and E to new values. In this way, by maintaining the minimum motor current as the variable B, it is possible to update the combination of the advance angle value and the duty ratio of the drive control signal Sd when the motor current becomes smaller than this value.

[0071] When it is determined in step S214 that the advance angle counter is not less than 10 (step S214: No), the advance angle and duty ratio determination unit 15 pushes the advance angle value back by (10-E) degrees (step S230) to obtain the optimal advance angle value, and outputs the optimal advance angle value to the advance angle control unit 17. The advance angle and duty ratio determination unit 15 outputs the value of the variable D as the optimal duty ratio of the drive control signal Sd to the duty ratio setting unit 16 (step S232).

[0072] When the first fan device 100a is set so that the motor current becomes minimum at the target rotation speed according to the above current feedback control, the communication processing unit 13 notifies the control device 30 of the completion of the current adjustment (step S112).

[0073] When the control device 30 receives a response indicating that the current adjustment is completed from the first fan device 100a, it sends a current adjustment permission signal to the second fan device 100b (step S113). The second fan device 100b also executes the same operation as above. Figure 5 Similarly, current feedback control is performed (step S114), and a response that current regulation is completed is notified to control device 30 (step S115).

[0074] When the control device 30 receives a response indicating that the current adjustment is completed from the second fan device 100b, it sends a current adjustment permission signal to the third fan device 100c (step S116). The third fan device 100c also executes the same operation as above. Figure 5 Similarly, current feedback control is performed (step S117), and a response that current regulation is completed is notified to control device 30 (step S118).

[0075] When the control device 30 receives a response indicating that the current adjustment is completed from the third fan device 100c, it sends a current adjustment permission signal to the fourth fan device 100d (step S119). Figure 5Similarly, the current feedback control is performed (step S120), and the response that the current adjustment is completed is notified to the control device 30 (step S121).

[0076] Thus, in addition to the initial transmission, the transmission of the current adjustment permission signal must be conditional on the response that the current adjustment is completed being notified. Thus, according to the motor drive system 1 of the present embodiment, the current feedback control is not executed simultaneously in the plurality of fan devices 100a to 100d, and thus can be executed without being affected by the load changes caused by the changes in the rotation of other motors. That is, according to the motor drive system 1 of the present embodiment, the current feedback control can be executed without being affected by the load changes caused by the changes in the rotation of other motors, and the drive control signal Sd used to control the drive of the motor that is the object of drive control can be adjusted to minimize the motor current. As a result, the drive efficiency of each of the plurality of motors driven simultaneously can be optimized.

[0077] (Variation of the embodiment)

[0078] In the above embodiment, the stability information from the control device 30 specifies one of the plurality of fan devices 100a to 100d and is notified, and the current feedback control is executed using the fact that only the specified fan device 100 receives the stability information as a trigger condition. However, the control device 30 may not specify one of the plurality of fan devices 100a to 100d and notify the stability information, and each fan device 100 may spontaneously declare the execution of the current feedback control. In this case, the communication processing unit 13 of the fan device 100 declares the execution of the current feedback control, and the current adjustment permission unit 35 of the control device 30 notifies the other fan devices 100 of the prohibition of the execution of the current feedback control upon receiving the declaration, or the communication processing unit 13 of the fan device 100 receives the declaration of the execution of the current feedback control from the other fan devices 100, and does not actively declare the execution of the current feedback control until the completion of the current feedback control is received.

[0079] In the above embodiments, using Figure 2 The motor drive control device composed of Figure 5 A specific example of a control method for a motor drive control device is described. However, the configuration of the motor drive control device and the control method of the motor drive control device are not particularly limited to the described example. Figure 2In the motor drive control device 104, the actual rotation speed of the motor 102 is measured in the rotation speed measuring unit 19 based on the rotation position signal from the position detecting unit 26. Instead of the rotation speed measuring unit 19, a configuration for measuring the rotation speed of the motor 102 based on the rotation position signal from the position detecting unit 26 may be provided. In this case, the communication processing unit 13 and the advance angle and duty ratio determining unit 15 may convert the rotation speed of the motor 102 into the actual rotation speed of the motor 102 and perform various processes.

[0080] in addition, Figure 3 The structure of the control device 30, Figure 4 The timing of is also an example, and is not limited to this. For example, in the control device 30, the stability judgment unit 34 judges the stable operation based on the speed information of the motor 102 received from each fan device 100, but it can also be included in the judgment material of the stable operation by setting a structure to obtain information other than the actual speed such as temperature and air volume, and input it to the stability judgment unit. In addition, for example, the stability judgment unit 34 judges the stable operation based on the situation that the actual speed of all fan devices 100 has stabilized, but it can also judge the stable operation based on the situation that the fan device other than any one fan device 100 has stabilized, and notify the current adjustment permission unit 35 of this situation. When the current adjustment permission unit 35 receives a notification indicating that the fan device other than any one fan device 100 has stabilized, it can notify the stability information of the specified arbitrary one fan device 100. Furthermore, the stability judgment unit 34 can still judge the stable operation of each fan device 100 after the judgment of the stable operation is once made. This is because it is considered that even if it becomes a stable operation once, it may become unstable.

[0081] The communication method between the control device and each motor drive control device is not limited. In the above embodiment, an example of serial communication is recorded, but for example, parallel communication may also be used. In addition, when the communication line 5 between the control device and each motor drive control device is wired, it can be either unidirectional communication based on one communication line or bidirectional communication based on one communication line. In addition, in the case of bidirectional communication, it is not limited to single-line communication, and two-line communication with a transmitting and receiving line may also be used.

[0082] Description of symbols

[0083] 1 Motor drive system, 5 Communication line, 30 Control device (an example of a superior device), 31 Control unit, 32 Communication unit, 33 Rotation speed indication unit, 34 Stability determination unit, 35 Current adjustment permission unit, 10 Control circuit unit, 11 Transmitter, 12 Receiving unit (an example of a rotation speed indication receiving unit, an example of a stability information receiving unit), 13 Communication processing unit, 15 Advance angle and duty ratio determination unit (a part of a motor current adjustment unit), 16 Duty ratio setting unit (a part of a motor current adjustment unit), 17 Advance angle control unit (a part of a motor current adjustment unit), 18 Energization control unit (a part of a motor current adjustment unit, an example of a drive control signal generation unit), 19 Rotation speed measurement unit, 20 Motor drive unit, 21 Inverter circuit, 25 Current detection unit, 26 Position detection unit, 100 Fan device, 101 Impeller, 102 Motor, 103 Position sensor, 104 Motor drive control device.

Claims

1. A motor drive control device, characterized in that: have: a rotation speed instruction receiving unit that receives, from a higher-level device, a target rotation speed to be output to a motor to be driven and controlled among a plurality of predetermined motors; a stabilization information receiving unit for receiving stabilization information indicating that the actual rotation speeds of the plurality of motors have stabilized; a motor current adjustment unit that, upon receiving the stability information, adjusts a drive control signal for controlling the drive of the motor that is the drive control object so that the motor current becomes minimum at the target rotation speed; a motor driving unit that drives the motor to be the drive control object based on the drive control signal; as well as a sending unit that sends a completion notification to the upper device when the motor current adjustment unit that has received the stability information completes the adjustment of the drive control signal, The stability information is a current adjustment permission signal, and the current adjustment permission signal permits the drive control signal to be adjusted so that the motor current of the motor that is the drive control object becomes the minimum, and when the actual rotation speeds of the specified multiple motors are all stabilized, the stability information is sent from the superior device to the multiple motors in sequence, and at the same time, the stability information is not sent from the superior device to the next motor until a completion notification of the adjustment of the drive control signal is received from the sending unit of the motor drive control device corresponding to the motor that received the stability information.

2. The motor drive control device according to claim 1, wherein: The motor current adjustment unit adjusts the drive control signal within a predetermined time in response to receipt of the current adjustment permission signal so that the motor current becomes minimum.

3. The motor drive control device according to claim 1, wherein: The motor current adjustment unit ends the adjustment of the drive control signal when receiving an adjustment end instruction requesting the end of the adjustment of the drive control signal from the host device.

4. The motor drive control device according to claim 1, wherein: The motor current adjustment unit comprises: an advance angle and duty ratio determination unit that determines a predetermined advance angle value corresponding to the target speed and a duty ratio adjusted to achieve the target speed as a combination of the advance angle value and the duty ratio of the drive control signal until the stabilization information is received, and determines a combination of the advance angle value and the duty ratio of the drive control signal that minimizes the motor current at the target speed when the stabilization information is received; as well as A drive control signal generating unit generates the drive control signal based on the determined combination of the advance angle value and the duty ratio of the drive control signal.

5. A motor drive system, characterized in that: have: Multiple motors specified; A motor drive control device according to any one of claims 1 to 4, which is respectively arranged corresponding to the plurality of specified motors; as well as The host device includes a rotation speed instruction unit that outputs a target rotation speed of the motor to be driven and controlled by the motor drive control device to the motor drive control device.

6. The motor drive system according to claim 5, wherein: The superior device has: a stability determination unit that requests actual speed information from the motor drive control device of the plurality of motors, and determines that the actual speeds of the plurality of motors are stable when all the actual speeds of the plurality of motors acquired in response to the request are within a predetermined numerical range relative to the target speed of each motor; as well as A current adjustment permission unit, which generates current adjustment permission signals for the motor drive control devices of the specified multiple motors in sequence when the stability judgment unit determines that the actual rotation speeds of the specified multiple motors have stabilized, and the current adjustment permission signals permit the drive control signals to be adjusted so that the motor current is minimized.

7. A control method for a motor drive control device, which is the control method for a motor drive control device according to any one of claims 1 to 4, the control method being characterized by comprising: a rotation speed instruction receiving step, in which a target rotation speed output to a motor to be driven and controlled among a plurality of predetermined motors is received from a superior device; a stabilization information receiving step, wherein stabilization information indicating that the actual rotation speeds of the plurality of motors are stabilized is received; a motor current adjustment step, wherein, after the stabilization information receiving step, a drive control signal for controlling the drive of the motor to be the drive control object is adjusted so that the motor current becomes minimum at the target rotation speed; and A motor driving step of driving the motor to be the drive control target based on the drive control signal.

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