Motor drive control device and fan unit

Abstract

To achieve motor output constant control by a simple configuration and calculation.SOLUTION: A motor drive control device 1 includes a control circuit 3 for outputting a drive control signal Sd for controlling drive of a motor 20 of a fan 22, and a motor drive circuit 2 for driving the motor 20 based on the drive control signal Sd. The control circuit 3 includes: a storage unit 31 that stores correspondence information 310_1 to 310_n indicating a relation between a value based on rotation speed of the motor 20 and torque when a motor output becomes constant at a predetermined value; a target torque determination unit 30 for determining a target torque Tg from the rotation speed by using the correspondence information 310 corresponding to a designated motor output; a target rotation speed determination unit 34 for determining target rotation speed EXC so that difference ΔT between the target torque Tg and a torque value Ts of the motor 20 becomes small; and a drive control signal generation unit 35 for generating the drive control signal Sd so that the rotation speed of the motor 20 approaches the target rotation speed EXC.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a motor drive control device and a fan unit.

Background Art

[0002] There is known a motor drive control device for driving a motor of a fan such as a ventilation fan or a dryer, which has a function of constant air volume control for controlling the motor so that the air volume of the fan remains constant even when the static pressure or the like changes. For example, Patent Document 1 discloses a technique for keeping the air volume of a fan constant by correcting the rotational speed of the motor using a predetermined air volume value and the torque value of the motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, power saving and cost reduction of fans such as ventilation fans and dryers have been desired. The inventor of the present application considered that in order to achieve power saving and cost reduction of the fan, it is essential to perform motor output constant control for controlling the motor output (work amount per unit time) of the motor to be constant. However, conventional motor output constant control techniques require a complex configuration and calculations, and in order to achieve power saving and cost reduction of the fan, it is necessary to realize motor output constant control with a simple configuration and calculations.

[0005] The present invention is for solving the above-described problems, and an object thereof is to realize motor output constant control with a simple configuration and calculations.

Means for Solving the Problems

[0006] A motor drive control device according to a typical embodiment of the present invention comprises a control circuit that outputs a drive control signal for controlling the drive of a motor, and a motor drive circuit that drives the motor based on the drive control signal output from the control circuit, wherein the control circuit includes a storage unit that stores correspondence information showing the relationship between a value based on the rotational speed of the motor and torque when the motor output of the motor becomes constant at a predetermined value, a target torque determination unit that determines a target torque value from a value based on the rotational speed of the motor using the correspondence information corresponding to a specified motor output, a torque acquisition unit that acquires the torque value of the motor, a target rotational speed determination unit that determines a target rotational speed of the motor which is the speed that minimizes the difference between the target torque value and the torque value acquired by the torque acquisition unit, and a drive control signal generation unit that generates the drive control signal based on the target rotational speed. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to achieve constant motor output control with a simple configuration and calculations. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the configuration of a fan unit equipped with a motor drive control device according to this embodiment. [Figure 2] This diagram shows the functional block configuration of the control circuit. [Figure 3] This diagram shows the relationship between the Hall period and the motor's q-axis current (torque). [Figure 4] This is a block diagram showing the internal configuration of the drive control signal generation unit. [Figure 5] This flowchart shows the processing flow for constant motor output control by the motor drive control device according to this embodiment. [Figure 6] This figure shows the characteristics of the motor when constant motor output control is performed using the motor drive control device according to this embodiment. [Modes for carrying out the invention]

[0009] 1. Overview of the Embodiment First, a general overview of a typical embodiment of the invention disclosed in this application will be provided. In the following description, as an example, reference numerals on the drawings corresponding to the components of the invention are indicated in parentheses.

[0010] [1] A motor drive control device (1) according to a typical embodiment of the present invention comprises a control circuit (3) that outputs a drive control signal (Sd) for controlling the drive of a motor (20), and a motor drive circuit (2) that drives the motor based on the drive control signal output from the control circuit, wherein the control circuit includes a storage unit (31) that stores correspondence information (310, 310_1 to 310_n) indicating the relationship between a value based on the rotational speed of the motor and torque when the motor output of the motor becomes constant at a predetermined value, a target torque determination unit (30) that determines a target torque value (Tg) from a value based on the rotational speed of the motor using the correspondence information corresponding to a specified motor output, a torque acquisition unit (32) that acquires the torque value (Ts) of the motor, a target rotational speed determination unit (34) that determines a target rotational speed (EXC) of the motor which is the speed that reduces the difference (ΔT) between the target torque value and the torque value acquired by the torque acquisition unit, and a drive control signal generation unit (35) that generates the drive control signal based on the target rotational speed.

[0011] [2] In the motor drive control device described in [1] above, the value based on the rotational speed of the motor may be the period (Hp) of a rotational position detection signal (Hu, Hv, Hw) whose voltage changes periodically according to the rotational position of the rotor of the motor.

[0012] [3] In the motor drive control device described in [1] above, the value based on the rotational speed of the motor may be the reciprocal of the rotational speed of the motor.

[0013] [4] In the motor drive control device described in any of [1] to [3] above, the torque acquisition unit may acquire the value of the q-axis current (Iq) corresponding to the torque of the motor as the torque value, and the target torque determination unit may determine the target value of the q-axis current (Iq_g) as the target torque value (Tg).

[0014] [5] In the motor drive control device described in [4] above, the motor has three-phase coils (Lu, Lv, Lw), the drive control signal generation unit calculates the q-axis current and the d-axis current corresponding to the magnetic flux of the motor based on the current (Si) flowing through the coils of each phase of the motor, determines the duty cycle so that the calculated q-axis current and the d-axis current match target current values ​​(Iq_req, Id_ref) corresponding to the target rotational speed, outputs a PWM signal having that duty cycle as the drive control signal, and the torque acquisition unit may acquire the q-axis current calculated by the drive control signal generation unit as the torque value.

[0015] [6] In the motor drive control device described in any of [1] to [5] above, the corresponding information includes a function (601 to 603) that represents the relationship between a value based on the rotational speed of the motor and torque, and the storage unit may store the function for each of the multiple command values ​​of the motor output that can be specified.

[0016] [7] A fan unit (100) according to a typical embodiment of the present invention is characterized by comprising a motor drive control device (1) as described in any of [1] to [5] above, a motor (20) driven by the motor drive control device, and an impeller (21) configured to be rotatable by the rotational force of the motor.

[0017] 2. Specific Examples of Embodiments Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are assigned to the common components in each embodiment, and repetitive descriptions are omitted. Also, note that the drawings are schematic, and it is necessary to be aware that the dimensional relationships of each element, the ratios of each element, etc. may differ from reality. There may also be parts where the dimensional relationships and ratios are different between the drawings.

[0018] ≪Embodiment≫

[0019] FIG. 1 is a diagram showing the configuration of a fan unit including a motor drive control device 1 according to this embodiment.

[0020] The fan unit 100 shown in FIG. 1 is a device that generates wind by rotating an impeller (fan). The fan unit 100 can be applied to, for example, a dryer or ventilation equipment (ventilation fan).

[0021] As shown in FIG. 1, the fan unit 100 includes a motor 20, an impeller 21, a rotation position detector 25 for detecting the rotation position of the motor 20, a rotation speed detector 26 for detecting the rotation speed of the motor 20, a current detector 27 for detecting the current flowing through the motor 20, and a motor drive control device 1 for driving the motor 20.

[0022] The motor 20 is, for example, a brushless motor. In this embodiment, the motor 20 is a brushless motor having three-phase coils. The motor drive control device 1 is a device for controlling the rotation of the motor 20. The motor drive control device 1 outputs a sine wave drive signal to the motor 20, for example, and periodically supplies a sine wave drive current to the three-phase coils Lu, Lv, Lw of the motor 20 to rotate the motor 20.

[0023] The impeller (bladed wheel) 21 is a component that generates airflow and is configured to rotate using the rotational force of the motor 20. For example, the rotation axis of the impeller 21 is coaxially connected to the output shaft of the motor 20. In this embodiment, for example, the impeller 21 and the motor 20 constitute a single fan 22.

[0024] The motor drive control device 1 includes a motor drive circuit 2 and a control circuit 3. Note that the components of the motor drive control device 1 shown in Figure 1 are only a part of the whole, and the motor drive control device 1 may have other components in addition to those shown in Figure 1.

[0025] The motor drive circuit 2 drives the motor 20 based on the drive control signal Sd output from the control circuit 3, which will be described later. The motor drive circuit 2 includes an inverter circuit 2a and a pre-drive circuit 2b.

[0026] The inverter circuit 2a outputs a drive signal to the motor 20 based on the output signal output from the pre-drive circuit 2b, and energizes the coils Lu, Lv, and Lw of the motor 20. The inverter circuit 2a is configured, for example, by arranging pairs of switch elements connected in series between the DC power supply Vcc and the ground potential, for each phase (U phase, V phase, W phase) of the coils Lu, Lv, and Lw. In each pair of switch elements, the terminals of each phase of the motor 20 are connected to the connection point between the switch elements.

[0027] The pre-drive circuit 2b generates an output signal to drive the inverter circuit 2a based on the drive control signal Sd from the control circuit 3, and outputs it to the inverter circuit 2a.

[0028] The drive control signal Sd is a signal for controlling the drive of the motor 20, and is, for example, a PWM (Pulse Width Modulation) signal. Specifically, the drive control signal Sd includes six types of PWM signals corresponding to each switch element of the inverter circuit 2a. More specifically, the drive control signal Sd is a signal that switches each switch element constituting the inverter circuit 2a on or off.

[0029] The pre-drive circuit 2b generates and outputs six types of drive signals Vuu, Vul, Vvu, Vvl, Vwu, and Vwl, which drive each switch element of the inverter circuit 2a, based on the drive control signal Sd. When these drive signals are input to the inverter circuit 2a, the switch elements corresponding to each drive signal that make up the inverter circuit 2a are turned on or off. By controlling the on / off state of each switch element of the inverter circuit 2a, the energizing patterns of the coils Lu, Lv, and Lw of the motor 20 are switched, and power is supplied to each phase of the motor 20.

[0030] The rotational position detectors 25u, 25v, and 25w generate signals corresponding to the rotational position of the rotor of the motor 20. The rotational position detectors 25u, 25v, and 25w are, for example, Hall elements. Hereinafter, the rotational position detectors 25u, 25v, and 25w will also be referred to as "Hall elements 25u, 25v, and 25w".

[0031] The three Hall elements 25u, 25v, and 25w are provided corresponding to each phase (U phase, V phase, and W phase) of the motor 20. The Hall elements 25u, 25v, and 25w are arranged around the rotor of the motor 20 at approximately equal intervals from each other (for example, at 120 degrees apart from adjacent elements).

[0032] The Hall elements 25u, 25v, and 25w each detect the magnetic poles of the rotor of the motor 20 and output Hall signals whose voltage changes periodically according to the rotational position of the rotor. Hereinafter, the Hall signals output from the Hall elements 25u, 25v, and 25w will also be referred to as "rotational position detection signals Hu, Hv, and Hw."

[0033] The rotational position detection signals Hu, Hv, and Hw are input to the control circuit 3. The control circuit 3 may also be configured to receive other signals corresponding to the rotational position of the motor 20's rotor as rotational position detection signals, instead of these Hall signals. For example, an encoder, resolver, or motor current detection circuit may be provided, and its detection signal may be input to the control circuit 3. In other words, the rotational position detectors 25u, 25v, and 25w are not limited to Hall elements.

[0034] The rotational speed detector 26 generates a rotational speed signal Sr corresponding to the rotation of the motor 20's rotor. The rotational speed detector 26 is, for example, an FG (Frequency Generator) pattern formed on the substrate (printed circuit board) on which the motor 20 is mounted. The FG pattern as the rotational speed detector 26 generates a signal (FG signal) with a period corresponding to the rotational speed of the motor 20. The FG signal output from the rotational speed detector 26 is input to the control circuit 3 as the rotational speed signal Sr.

[0035] In this embodiment, an FG pattern is used as the rotational speed detector 26, but it is not limited to this, and other rotational speed detectors such as encoders or resolvers may be used. Alternatively, the rotational speed detector 26 may derive the rotational speed based on the Hall signal (rotational position detection signals Hu, Hv, Hw) and input it to the control circuit 3 as a rotational speed signal Sr, or the control circuit 3 may calculate the rotational speed based on the Hall signal.

[0036] The current detector 27 generates a current detection signal Si corresponding to the current value of the current flowing on the DC side of the inverter circuit 2a that constitutes the motor drive circuit 2. The current detector 27 is, for example, a current detection element placed on the negative side (ground side) of the inverter circuit, and is, for example, a resistor (shunt resistor). The current detection element as the current detector 27 generates a voltage corresponding to the current flowing through it and outputs it as a current detection signal Si.

[0037] The control circuit 3 generates a drive control signal Sd to drive the motor 20 based on an output command signal Sf that specifies the magnitude of the motor output, and supplies it to the motor drive circuit 2. Specifically, the control circuit 3 monitors the rotational state of the motor 20 by obtaining information such as the rotational position and rotational speed of the motor 20's rotor based on rotational position detection signals Hu, Hv, Hw and rotational speed signal Sr, and controls the driving of the motor 20 by generating a drive control signal Sd so that the motor output of the motor 20 becomes the value specified by the output command signal Sf.

[0038] In this embodiment, the control circuit 3 is implemented by a program processing unit (e.g., a microcontroller) having a configuration in which a processor such as a CPU, various storage devices such as RAM and ROM, and peripheral circuits such as a counter (timer), A / D conversion circuit, D / A conversion circuit, clock generation circuit, and input / output I / F circuit are connected to each other via a bus or dedicated line.

[0039] The motor drive control device 1 may be configured such that at least a part of the control circuit 3 and at least a part of the motor drive circuit 2 are packaged as a single integrated circuit (IC), or the control circuit 3 and the motor drive circuit 2 may be configured such that they are each packaged as separate integrated circuit devices.

[0040] When the control circuit 3 controls the fan 22 based on the output command signal Sf, it performs constant motor output control by generating a drive control signal Sd so that the motor output of the motor 20 remains constant. The constant motor output control by the control circuit 3 will be described below.

[0041] Figure 2 shows the functional block configuration of the control circuit 3. As shown in Figure 2, the control circuit 3 includes a target torque determination unit 30, a memory unit 31, a torque acquisition unit 32, an error calculation unit 33, a target rotational speed determination unit 34, and a drive control signal generation unit 35 as functional blocks for achieving constant motor output control. These functional blocks are realized, for example, in a program processing unit as the control circuit 3, by a processor executing various calculation processes according to a program stored in memory, and controlling peripheral circuits such as counters and A / D conversion circuits. Note that some or all of the functional blocks constituting the control circuit 3 may be realized by dedicated hardware circuits.

[0042] The target torque determination unit 30 is a functional unit that determines the target torque value (hereinafter referred to as the "target torque value") of the motor 20 necessary for the motor output (work done per unit time) of the motor 20 to reach the value specified by the output command signal Sf. As will be described in detail later, the target torque determination unit 30 uses correspondence information 310, which shows the relationship between a value based on the motor's rotational speed and the torque, to calculate the target torque value Tg from the value based on the rotational speed.

[0043] The memory unit 31 is a functional unit that stores parameters and other information necessary for constant motor output control. For example, the memory unit 31 stores data such as correspondence information 310 and the initial value of the target rotation speed EXC set for each command value of the motor output.

[0044] Corresponding information 310, as described above, is data that shows the relationship between the value based on the rotational speed of the motor 20 and the torque when the motor output of the motor 20 is constant at a predetermined value.

[0045] Here, the value based on the rotational speed of the motor 20 is, for example, the period of the rotational position detection signals Hu, Hv, Hw, or the reciprocal of the rotational speed [rpm].

[0046] In this embodiment, as an example, the value based on the rotational speed of the motor 20 is assumed to be the period of one of the rotational position detection signals Hu, Hv, and Hw, and this period is referred to as the "Hall period Hp".

[0047] Generally, it is known that the torque of a motor is proportional to the current in the q-axis in a two-axis (q-axis, d-axis) rotating coordinate system in the vector control of the motor. Therefore, in this embodiment, as an example, the q-axis current Iq is used as a physical quantity to represent the torque of the motor.

[0048] In general, motor output, i.e., the amount of work P [W] per unit time, is expressed by the following equation (1). In equation (1), T is torque [N·m] and N is rotational speed [rpm].

[0049]

number

[0050] As mentioned above, in vector control of a motor, the q-axis current Iq and the motor torque T are proportional, so the following equation (2) holds true. α is a constant.

[0051]

number

[0052] Furthermore, since the motor's rotational speed N is inversely proportional to the Hall period Hp [s], the following equation (3) holds true. β is a constant.

[0053]

number

[0054] From equations (1) to (3) above, the following equation (4) holds for the q-axis current Iq.

[0055]

number

[0056] As can be seen from equation (4) above, when the motor output P is kept constant, the relationship between the q-axis current Iq (torque) and the Hall period Hp can be expressed as a linear equation.

[0057] Figure 3 shows the relationship between the Hall period and the motor's q-axis current (torque). In Figure 3, the horizontal axis represents the Hall period Hp, and the vertical axis represents the q-axis current Iq as the torque of the motor 20.

[0058] The graphs indicated by reference numerals 601 to 603 are Hall period-torque characteristics showing the relationship between the measured Hall period Hp and the measured q-axis current Iq (torque) of the motor 20 when the motor 20 is operated so that the motor output of the motor 20 is constant at a predetermined value. Specifically, reference numeral 601 shows the characteristics of the q-axis current Iq (torque) of the motor 20 with respect to the Hall period Hp when the motor output of the motor 20 is a first value (W1 = 5W (watts)). Reference numeral 602 shows the characteristics of the q-axis current Iq of the motor 20 with respect to the Hall period Hp when the motor output of the motor 20 is a second value (W2 = 10W). Reference numeral 603 shows the q-axis current of the motor 20 with respect to the Hall period Hp when the motor output of the motor 20 is a third value (W3 = 15W). IQ This represents the characteristics of the product.

[0059] As shown in Figure 3, it can be seen that the Hall period-torque characteristics of the motor based on the measured results can be approximated by a linear equation, as shown in equation (4) above. Therefore, by controlling the Hall period (rotational speed) and the q-axis current of the motor 20 to change according to characteristics 601 to 603 in accordance with the motor output required for the motor 20, it is possible to operate the motor 20 so that the motor output remains constant at the required value.

[0060] Therefore, the motor drive control device 1 according to this embodiment represents the relationship between the value based on the rotational speed of the motor 20 for each motor output (Hall period Hp) and the torque (q-axis current Iq). information 310 is stored in the memory unit 31 in advance, and the corresponding informationBy using 310 to adjust the rotational speed and torque of motor 20, the motor output of motor 20 is kept constant.

[0061] Specifically, the memory unit 31 stores functions corresponding to command values ​​for multiple motor outputs that can be specified for the motor 20. information Store it as 310. For example, in motor 20, if the motor output level can be switched between n (where n is an integer greater than or equal to 2) levels, a function representing the relationship between the Hall period Hp and the q-axis current Iq is assigned to each of the n command values ​​for the motor output. information The values ​​310_1 to 310_n are stored in the memory unit 31.

[0062] For example, as shown in Figure 3, the Hall period and the q-axis current (torque) of the motor 20 are measured in advance by experimentation or simulation so that the motor output of the motor 20 remains constant at a predetermined value. Next, an approximate function (e.g., a linear function) showing the relationship between the Hall period and the q-axis current is calculated for each motor output by performing regression analysis using the measured values ​​of the Hall period and the q-axis current. Then, for example, information representing these approximate functions (e.g., the coefficients of the linear function) is stored in the memory unit 31 of the motor drive control device 1 as corresponding information 310_1 to 310_n. Hereinafter, corresponding information 310_1 to 310_n will also be referred to as "functions 310_1 to 310_n".

[0063] For example, consider a case where the fan unit 100 is applied to a hair dryer, and the motor output of the hair dryer (motor 20) can be set to three levels (n=3): "low (5W)", "medium (10W)", and "high (15W)". In this case, the coefficients of the approximation function representing the relationship between the measured Hall period and the measured q-axis current when the motor output is kept constant at "low (5W)" are stored in the storage unit 31 as corresponding information 310_1. Similarly, the coefficients of the approximation function representing the relationship between the measured Hall period and the measured q-axis current when the motor output is kept constant at "medium (10W)" are stored as corresponding information 310_2, and the coefficients of the approximation function representing the relationship between the measured Hall period and the measured q-axis current when the motor output is kept constant at "high (15W)" are stored in the storage unit 31 as corresponding information 310_3.

[0064] The target torque determination unit 30 calculates the target torque value Tg based on the output command signal Sf, a value based on the rotational speed of the motor 20, and functions 310_1 to 310_n stored in the storage unit 31. Specifically, as shown in Figure 2, the target torque determination unit 30 includes an output command acquisition unit 36, a function selection unit 37, and a target torque calculation unit 38.

[0065] The output command acquisition unit 36 ​​is a functional unit that acquires a command value for motor output from an output command signal Sf input from an external source. For example, when a user specifies a desired output by operating the operation input unit of the fan 22, the operation input unit generates an output command signal Sf indicating the specified output and inputs it to the output command acquisition unit 36.

[0066] The output command acquisition unit 36 ​​acquires the command value of the motor output from the input output command signal Sf. For example, consider the case where the motor output of the hair dryer (motor 20) can be set to three levels: "weak," "medium," and "strong," as described above, and the output command signal Sf is a 2-bit digital signal. In this case, the output command acquisition unit 36 ​​determines whether the command value of the motor output is "weak," "medium," "strong," or "stop operation" based on the 2-bit logical value of the output command signal Sf. For example, the output command acquisition unit 36 ​​determines that if the output command signal Sf is "00," it is a stop command for the hair dryer (motor 20); if the output command signal Sf is "01," it is determined that the command value of the hair dryer's motor output is "weak"; if the output command signal Sf is "10," it is determined that the command value of the hair dryer's motor output is "medium"; and if the output command signal Sf is "11," it is determined that the command value of the hair dryer's motor output is "strong."

[0067] The function selection unit 37 selects one of the functions 310_1 to 310_n based on the motor output command value obtained by the output command acquisition unit 36. The function selection unit 37 selects a function 310_1 to 310_n corresponding to the motor output of the motor 20 specified by the motor output command value obtained by the output command acquisition unit 36 ​​and reads it from the storage unit 31.

[0068] The target torque calculation unit 38 uses the function 310 selected by the function selection unit 37 to calculate the target torque value Tg from a value based on the rotational speed of the motor 20.

[0069] First, the target torque calculation unit 38 calculates a value based on the rotational speed of the motor 20. For example, the target torque calculation unit 38 calculates the Hall period Hp as a value based on the rotational speed, based on the rotational position detection signals Hu, Hv, and Hw. Specifically, the target torque calculation unit 38 calculates the period of one of the rotational position detection signals Hu, Hv, and Hw, and sets it as the Hall period Hp.

[0070] The method for calculating the Hall period Hp is not limited to the method described above. For example, the target torque calculation unit 38 may calculate the average value of the periods of the three rotational position detection signals Hu, Hv, and Hw and use that as the Hall period Hp, or it may synthesize the three rotational position detection signals Hu, Hv, and Hw using a known method to generate a three-phase combined signal, and then calculate the Hall period Hp based on the period of the three-phase combined signal.

[0071] Next, the target torque calculation unit 38 calculates the target torque value Tg of the motor 20 based on the calculated Hall period Hp and the function 310 selected by the function selection unit 37. For example, the target torque calculation unit 38 calculates the target value Iq_g of the q-axis current by substituting the value of the Hall period Hp calculated based on the rotational position detection signals Hu, Hv, and Hw into the variable (Hall period) in the function 310, and outputs the calculated target value Iq_g of the q-axis current as the target torque value Tg.

[0072] The torque acquisition unit 32 is a functional unit that acquires the measured torque of the motor 20. For example, the torque acquisition unit 32 acquires the q-axis current Iq calculated in the vector control calculation process performed in the drive control signal generation unit 35, which will be described later. The torque acquisition unit 32 calculates the torque value Ts based on the q-axis current Iq calculated in the drive control signal generation unit 35. For example, the torque acquisition unit 32 outputs the q-axis current Iq calculated in the drive control signal generation unit 35 as the torque value Ts.

[0073] The method for calculating the torque value Ts by the torque acquisition unit 32 is not limited to the method described above. For example, the torque acquisition unit 32 may calculate the average value of the q-axis current Iq for each predetermined period and output that value as the torque value Ts, or it may output a value obtained by multiplying the q-axis current Iq or the average value of the q-axis current Iq for each predetermined period by a predetermined coefficient as the torque value Ts. When the torque acquisition unit 32 converts the q-axis current Iq to torque, for example, the target torque calculation unit 38 may calculate the torque value Ts by multiplying the target value Iq_g of the q-axis current calculated using the correspondence information 310 by a predetermined coefficient, or the correspondence information 310 may be a function that shows the relationship between the value obtained by converting the q-axis current to torque and the Hall period Hp.

[0074] The error calculation unit 33 is a functional unit that calculates the difference between the target torque value Tg determined by the target torque determination unit 30 and the torque value Ts, which is a measured value of the motor 20's torque acquired by the torque acquisition unit 32. The error calculation unit 33 outputs the difference between the target torque value Tg and the torque value Ts as the torque error ΔT.

[0075] The target rotational speed determination unit 34 is a functional unit that determines the target rotational speed EXC of the motor 20 so that the difference between the target torque value Tg and the torque value Ts is small. As shown in Figure 2, the target rotational speed determination unit 34 has a PI control calculation unit 40 and a target rotational speed calculation unit 41. The PI control calculation unit 40 calculates a control amount so that the torque error ΔT becomes zero through PI control calculation. That is, the target rotational speed calculation unit 41 determines the target rotational speed EXC of the motor 20, which is the speed that reduces the difference between the target torque value Tg and the torque value Ts acquired by the torque acquisition unit 32. For example, the target rotational speed calculation unit 41 calculates the target rotational speed EXC by multiplying the control amount calculated by the PI control calculation unit 40 by a predetermined conversion coefficient.

[0076] For example, in a fan, generally, increasing the motor's rotational speed increases air resistance and thus increases the load (torque), while decreasing the motor's rotational speed reduces air resistance and thus decreases the load. In other words, in a fan, the torque error ΔT can be controlled to zero by controlling the motor's rotational speed. In this case, if the output signal of the PI control calculation unit 40 is a 10-bit digital value, that output signal becomes a manipulated variable signal represented by 0 to 1023. Therefore, the target rotational speed determination unit 34 converts the manipulated variable output from the PI control calculation unit 40 into a target rotational speed EXC by multiplying the output signal (digital value) of the PI control calculation unit 40 by a predetermined conversion coefficient.

[0077] The target rotational speed determination unit 34 may calculate the target rotational speed EXC from the output signal of the PI control calculation unit 40 by performing Q-formatting (fixed-point) and upper and lower limit saturation processing, rather than multiplying the output signal of the PI control calculation unit 40 by a predetermined conversion coefficient.

[0078] If the target rotational speed determination unit 34 and the drive control signal generation unit 35 are implemented using different integrated circuit devices (ICs), the target rotational speed determination unit 34 may, for example, generate a periodic signal having a frequency corresponding to the target rotational speed EXC. In this case, the periodic signal is output from an external terminal of the integrated circuit device in which the target rotational speed determination unit 34 is formed and input to an external terminal of the integrated circuit device in which the drive control signal generation unit 35 is formed. The drive control signal generation unit 35 obtains information on the target rotational speed EXC by analyzing the frequency of the input periodic signal.

[0079] The drive control signal generation unit 35 is a functional unit that generates a drive control signal Sd so that the rotational speed of the motor 20 approaches the target rotational speed EXC. The drive control signal generation unit 35 generates the drive control signal Sd as a PWM signal, for example, by so-called vector control calculation. The method of generating the drive control signal Sd by the drive control signal generation unit 35 is not limited to the vector control calculation described above, but may also be a calculation based on known motor drive control techniques such as vf control or advance angle control. However, in this embodiment, the drive control signal generation unit 35 will be described as generating the drive control signal Sd by vector control calculation.

[0080] The drive control signal generation unit 35 calculates a q-axis current Iq corresponding to the torque of the motor 20 and a d-axis current Id corresponding to the magnetic flux of the motor 20 based on the current flowing through the coils of each phase of the motor 20 as a vector control calculation. It then determines the duty cycle so that the calculated q-axis current Iq and d-axis current Id match the target current values ​​Iq_ref and Id_ref corresponding to the target rotational speed EXC, and outputs a PWM signal with that duty cycle as the drive control signal Sd.

[0081] In this embodiment, the case in which the drive control signal generation unit 35 performs vector control calculations using the rotational position detection signals Hu, Hv, and Hw output from the Hall element is described, but the invention is not limited to this, and the drive control signal generation unit 35 may also perform so-called sensorless vector control calculations that do not use the rotational position detection signals Hu, Hv, and Hw.

[0082] Figure 4 is a block diagram showing the internal configuration of the drive control signal generation unit 35. The drive control signal generation unit 35 includes, as functional blocks for functioning as a vector control unit, a current measurement unit 50, a Clark conversion unit 51, a Park conversion unit 52, a rotation information generation unit 56, a rotation speed PI control unit 60, a flux weakening PI control unit 61, a torque PI control unit 62, a flux PI control unit 63, an inverse Park conversion unit 64, an inverse Clark conversion unit 65, and a PWM signal generation unit 66. These functional blocks are realized in the program processing unit that constitutes the control circuit 3, by the processor executing various arithmetic operations according to a program stored in memory and controlling peripheral circuits such as counters and A / D conversion circuits. Some or all of these functional blocks may be realized by dedicated hardware circuits.

[0083] The current measurement unit 50 acquires the current detection signal Si output from the current detector 27 and generates measured values ​​of the phase currents Iu, Iv, and Iw of each phase of the motor 20 based on the acquired current detection signal Si. The Clarke transform unit 51 calculates the currents Iα and Iβ in a two-phase Cartesian coordinate (fixed coordinate) system (α,β) by performing a Clarke transform on the measured values ​​of the phase currents Iu, Iv, and Iw generated by the current measurement unit 50. The Parke transform unit 52 performs a Parke transform on the currents Iα and Iβ using the electrical angle θ (sinθ and cosθ) calculated by the electrical angle calculation unit 54, thereby calculating the currents Iα and Iβ in a two-phase fixed coordinate system. from Calculate the q-axis current Iq and d-axis current Id of the rotating coordinate system.

[0084] Here, the q-axis current Iq is the current corresponding to the torque of the motor 20 (torque current), and the d-axis current Id is the excitation current of the motor 20.

[0085] The rotation information generation unit 56 is a functional unit that generates information (rotation information) regarding the rotational state of the motor 20. The rotation information generation unit 56 calculates the rotation angle θ, sinθ, cosθ of the rotor of the motor 20, and the rotational speed (actual rotational speed) of the motor 20 as rotation information for the motor 20.

[0086] The rotation information generation unit 56 includes, for example, a rotation position detection signal acquisition unit 53, an electrical angle calculation unit 54, and a rotation speed signal acquisition unit 55. The rotation position detection signal acquisition unit 53 acquires rotation position detection signals (Hall signals) Hu, Hv, and Hw output from rotation position detectors 25u, 25v, and 25w. The electrical angle calculation unit 54 calculates the rotation angle θ of the rotor of the motor 20, as well as sinθ and cosθ, based on the three rotation position detection signals Hu, Hv, and Hw acquired by the rotation position detection signal acquisition unit 53 using a known calculation method. The rotation speed signal acquisition unit 55 acquires the rotation speed signal (FG signal) Sr output from the rotation speed detector 26 and acquires a measured value of the rotation speed of the motor 20 based on the acquired rotation speed signal Sr.

[0087] Furthermore, if the drive control signal generation unit 35 performs the sensorless vector control described above, the rotation information generation unit 56 may calculate the rotor rotation angle θ, sinθ, cosθ, and rotation speed (ω) by known sensorless vector control calculations.

[0088] The rotational speed PI control unit 60 performs PI control calculations based on the target rotational speed EXC of the motor 20 output from the target rotational speed determination unit 34 and the measured value of the rotational speed of the motor 20 acquired by the rotational speed signal acquisition unit 55. The rotational speed PI control unit 60 calculates the difference between the target rotational speed EXC and the measured value of the rotational speed of the motor 20, and calculates a control amount through PI control calculations to minimize that difference.

[0089] The flux weakening PI control unit 61 calculates the target value of the torque current, which is the q-axis current target value Iq_ref, and the target value of the excitation current, which is the d-axis current target value Id_ref, respectively, based on the voltage command values ​​Vq and Vd described later and the control amount calculated by the rotation speed PI control unit 60, using a known calculation method.

[0090] The torque PI control unit 62 performs PI control calculations based on the q-axis current target value Iq_ref calculated by the flux weakening PI control unit 61 and the q-axis current Iq calculated by the park converter unit 52. The torque PI control unit 62 calculates the difference between the q-axis current target value Iq_ref and the q-axis current Iq, and calculates a voltage command value Vq as a control amount to reduce that difference through PI control calculations. The flux PI control unit 63 calculates the difference between the d-axis current target value Id_ref and the d-axis current Id, and calculates a voltage command value Vd as a control amount to reduce that difference through PI control calculations.

[0091] The inverse Park transformer 64 calculates the voltages Vα and Vβ of the two-phase fixed coordinates from the rotating coordinates by performing an inverse Park transform on the voltage command values ​​Vq and Vd using the electrical angles θ (sinθ and cosθ) calculated by the electrical angle calculationer 54. The inverse Clark transformer 65 calculates the phase voltages Vu, Vv, and Vw of the three phases by performing an inverse Clark transform on the voltages Vα and Vβ of the two-phase fixed coordinates.

[0092] The PWM signal generation unit 66 calculates the duty cycles (set values ​​for the duty cycle of each phase) Udu, Vdu, and Wdu for generating a three-phase PWM signal using a known calculation method, based on the phase voltages Vu, Vv, and Vw of each phase calculated by the inverse Clarke transform unit 65. The PWM signal generation unit 66 generates a three-phase PWM signal having the calculated duty cycles of each phase and outputs it as a drive control signal Sd.

[0093] Next, the processing flow of constant motor output control by the motor drive control device 1 according to this embodiment will be described.

[0094] Figure 5 is a flowchart showing the processing flow of constant motor output control by the motor drive control device 1 according to this embodiment.

[0095] For example, consider a case where the fan 22 (e.g., a hair dryer) is stopped, and the user operates the fan 22's control input to instruct it to operate at a predetermined output. In this case, the fan 22's control input input inputs an output command signal Sf, which includes a command value for the motor output, to the motor drive control device 1 in response to the user's operation (step S1).

[0096] When the motor drive control device 1 receives the output command signal Sf, it starts controlling the motor 20 (step S2). Specifically, in the motor drive control device 1, for example, the target torque determination unit 30 reads the initial value of the target rotational speed EXC corresponding to the command value of the motor output specified by the output command signal Sf from the storage unit 31 and sets it in the target rotational speed determination unit 34. The target rotational speed determination unit 34 then inputs the set initial value of the target rotational speed EXC to the drive control signal generation unit 35. Based on the initial value of the target rotational speed EXC input from the target rotational speed determination unit 34, the drive control signal generation unit 35 performs the vector control calculation described above to generate a drive control signal Sd and inputs it to the motor drive circuit 2. As a result, the motor 20 starts to rotate.

[0097] Next, the target torque determination unit 30 selects a function 310 corresponding to the motor output command value specified in step S1 (step S3). Specifically, as described above, the function selection unit 37 reads the function 310 corresponding to the motor output command value specified by the output command signal Sf from the storage unit 31 and provides it to the target torque calculation unit 38.

[0098] The target torque calculation unit 38 acquires the Hall period Hp (step S4). For example, as described above, the target torque calculation unit 38 acquires the period of at least one of the rotational position detection signals Hu, Hv, and Hw as the Hall period Hp.

[0099] Next, the target torque calculation unit 38 calculates the target torque value Tg (target value Iq_g of the q-axis current) from the Hall period Hp calculated in step S4 using the function 310 read in step S3 by the method described above (step S5).

[0100] Furthermore, in the motor drive control device 1, the torque acquisition unit 32 calculates the torque of the motor 20 (step S6). Specifically, as described above, the torque acquisition unit 32 acquires the q-axis current Iq calculated by the vector control calculation performed by the drive control signal generation unit 35, and calculates the torque value Ts (measured torque value) of the motor 20 based on the q-axis current Iq.

[0101] Next, in the motor drive control device 1, the error calculation unit 33 performs step S 5 Step S7 calculates the torque error ΔT, which is the difference between the target torque value Tg (target value of q-axis current Iq_g) calculated in step S6 and the torque value Ts (q-axis current Iq) calculated in step S6.

[0102] Next, in the motor drive control device 1, the target rotational speed determination unit 34 calculates the target rotational speed EXC from the torque error ΔT calculated in step S7 using the method described above (step S8). As a result, the value of the target rotational speed EXC is updated based on the torque error ΔT that reflects the actual driving state of the motor 20.

[0103] Next, in the motor drive control device 1, the drive control signal generation unit 35 determines the duty cycle of the PWM signal as the drive control signal Sd based on the target rotational speed EXC updated in step S8, generates a drive control signal Sd having the determined duty cycle, and provides it to the motor drive circuit 2 (step S9). This adjusts the rotational speed of motor 20 to the target rotational speed EXC and the torque of motor 20 to the target torque value Tg. In other words, the Hall period Hp corresponding to the rotation of motor 20 and the torque of motor 20 are controlled to conform to the Hall period-torque characteristic shown in Figure 3, so that motor 20 (fan 22) operates so that the motor output of motor 20 remains constant at the value specified in step S1.

[0104] Subsequently, the motor drive control device 1 determines whether the specified value of the motor output has been changed (step S10). If the command value of the motor output has been changed by the new output command signal Sf (step S10: Yes), the motor drive control device 1 proceeds to step S3 and executes the above-described process (S3~S9) to read the function 310 corresponding to the new command value of the motor output, update the target torque value Tg (target value of q-axis current Iq_g), and generate a drive control signal Sd based on the recalculated target rotational speed EXC to control the rotation of the motor 20. As a result, the fan 22 operates at a newly specified constant motor output.

[0105] On the other hand, if the command value for the motor output has not been changed (step S10: No), the motor drive control device 1 determines whether or not the operation of the fan 22 has been instructed to stop (step S11). If the operation of the fan 22 has not been instructed to stop by the output command signal Sf (step S11: No), the motor drive control device 1 proceeds to step S5 and executes the above-described process (S6~S9) to generate a drive control signal Sd so that the fan 22 continues to operate at the motor output specified in step S1.

[0106] On the other hand, if the operation of the fan 22 is instructed to stop (step S11: Yes), the motor drive control device 1 stops the rotation of the motor 20 with a drive control signal Sd. For example, the target torque determination unit 30 (e.g., the output command acquisition unit 36) instructs the target rotation speed determination unit 34 (e.g., the target rotation speed calculation unit 41) to set the target rotation speed EXC to zero. As a result, the rotation of the motor 20 stops, and the fan 22 stops.

[0107] Figure 6 shows the characteristics of the motor 20 when the motor output is controlled to a constant level by the motor drive control device 1.

[0108] In Figure 6, the horizontal axis represents the torque [mN·m] of motor 20, the left side of the vertical axis represents the rotational speed [rpm] of motor 20, and the right side of the vertical axis represents the motor output [W]. Reference numeral 701 indicates the change in motor output with respect to torque (measured value) when the motor output is kept constant at 5W, and reference numeral 801 indicates the change in rotational speed with respect to torque (measured value) when the motor output is kept constant at 5W. Reference numeral 702 indicates the change in motor output with respect to torque (measured value) when the motor output is kept constant at 10W, and reference numeral 802 indicates the change in rotational speed with respect to torque (measured value) when the motor output is kept constant at 10W. Reference numeral 703 indicates the change in motor output with respect to torque (measured value) when the motor output is kept constant at 15W, and reference numeral 803 indicates the change in rotational speed with respect to torque (measured value) when the motor output is kept constant at 15W.

[0109] As shown in Figure 6, with the motor drive control device 1 according to this embodiment, the motor output becomes constant because the rotational speed (Hall period Hp) is controlled in accordance with the change in torque of the motor 20.

[0110] As described above, the motor drive control device 1 according to this embodiment stores in the storage unit 31 in advance correspondence information (Hall period-torque characteristics) 310_1 to 310_n that shows the relationship between a value based on the rotational speed of the motor 20 (for example, the Hall period Hp) when the motor output of the motor 20 is constant at a predetermined value and the torque. The motor drive control device 1 uses the correspondence information 310 corresponding to the command value of the specified motor output to calculate a target torque value Tg from a value based on the rotational speed of the motor 20. The motor drive control device 1 determines the target rotational speed EXC of the motor so that the difference between the calculated target torque value and the measured torque value of the motor 20 is small, and generates a drive control signal Sd based on the target rotational speed EXC to drive the motor 20.

[0111] According to this, the motor drive control device 1 determines the target rotational speed EXC of the motor 20 according to the relationship between the value based on the rotational speed of the motor 20 at a specified motor output value and the torque, so that the motor 20 can be rotated so that the motor output remains constant.

[0112] Furthermore, the motor drive control device 1 stores in the storage unit 31, as correspondence information 310, the relationship between the value based on the rotational speed of the motor 20 at a predetermined motor output and the torque. Since the target torque value is calculated from the value based on the rotational speed using this correspondence information 310, complex calculations are not required to calculate the target torque value. This reduces the processing load on the microcontroller and other components that make up the control circuit 3.

[0113] Therefore, according to the motor drive control device 1 of this embodiment, it is possible to control the motor output to be constant with a simple configuration and calculations. In other words, it is possible to achieve constant motor output control using a less expensive microcontroller rather than an expensive microcontroller capable of performing complex calculations at high speed.

[0114] Furthermore, in the motor drive control device 1, the corresponding information 310 includes a function that represents the relationship between a value based on the rotational speed of the motor 20 and the torque, and the storage unit 31 stores functions 310_1 to 310_n for each of the multiple motor output command values ​​that can be specified for the fan 22.

[0115] According to this, even if multiple motor outputs are selectable in the fan 22, it becomes easy to control the motor 20 so that the motor output remains constant at a specified value by appropriately selecting the value-torque characteristic function 310_1~310_n based on the rotational speed according to the specified motor output.

[0116] Furthermore, in the motor drive control device 1, the value based on the rotational speed of the motor 20 is the period (Hall period Hp) of the rotational position detection signals Hu, Hv, and Hw, whose voltage changes periodically according to the rotational position of the rotor of the motor 20.

[0117] According to this, calculating the target torque value Tg becomes even easier, as shown below. If the rotational speed of the motor 20 is used as the value based on its rotational speed, the torque (target torque value) and the rotational speed are inversely proportional. This necessitates "division" to calculate the target torque value from the rotational speed, increasing the processing load on the microcontroller in the control circuit 3. In contrast, if the Hall period Hp is used as the value based on the rotational speed of the motor 20, the torque (target torque value) and the Hall period Hp are proportional (see equation (4)). Therefore, the control circuit 3 only needs to "multiply" to calculate the target torque value from the Hall period Hp. This reduces the processing load on the control circuit 3, making it possible to use a less expensive microcontroller in the control circuit 3.

[0118] Furthermore, the motor drive control device 1 obtains the q-axis current Iq, which is calculated by so-called vector control calculation, as the torque value Ts of the motor 20, and calculates the target value Iq_g of the q-axis current as the target torque value Tg.

[0119] According to this, the torque acquisition unit 32 does not need to perform complex calculations to calculate the torque value Ts of the motor 20, making it possible to achieve constant motor output control with a simpler and less expensive configuration. For example, consider the case where the drive control signal generation unit (vector control unit) 35 in the motor drive control device 1 is implemented by an existing integrated circuit (IC) for vector control calculations, and the target torque determination unit 30, storage unit 31, torque acquisition unit 32, and target rotational speed determination unit 34 in the motor drive control device 1 are implemented by an integrated circuit different from the above-mentioned integrated circuit for vector control calculations.

[0120] In this case, the integrated circuit device for realizing the target torque determination unit 30, the storage unit 31, the torque acquisition unit 32, and the target rotational speed determination unit 34 does not need to perform complex calculations such as vector control to calculate the torque value Ts. Therefore, an inexpensive microcontroller with limited functionality can be used in this integrated circuit device.

[0121] <<Extension of the Embodiment>> Although the present inventors have described the invention in detail based on embodiments, it goes without saying that the present invention is not limited thereto and can be modified in various ways without departing from its essence.

[0122] For example, in the above embodiment, if the drive control signal generation unit 35 calculates the rotational speed by sensorless vector control calculation, the target torque calculation unit 38 may use the reciprocal of the rotational speed calculated by the drive control signal generation unit 35 as the Hall period Hp and calculate the target torque value Tg using the method described above.

[0123] Furthermore, the method for detecting the motor's rotational speed is not particularly limited. For example, when the motor 20 is driven by sensorless drive control without using a Hall element, the motor drive control device 1 (control circuit 30) may detect the rotational speed using the back electromotive force of the motor 20. In this case, the target torque calculation unit 38 may, for example, use the reciprocal of the detected rotational speed as the Hall period Hp and calculate the target torque value Tg using the method described above.

[0124] Furthermore, the control circuit 3 is not limited to the circuit configuration shown above. Various circuit configurations can be applied to the control circuit 3 to suit the purpose of the present invention.

[0125] The flowchart described above is just an example and is not limited to this flowchart. For example, other processes may be inserted between each step, or the processes may be parallelized.

[0126] The number of phases of the motor driven by the motor drive control device 1 of the above embodiment is not limited to 3 phases. Also, the number of Hall elements is not limited to 3. [Explanation of Symbols]

[0127] 1…Motor drive control device, 2…Motor drive circuit, 2a…Inverter circuit, 2b…Pre-drive circuit, 3…Control circuit, 20…Motor, 21…Impeller, 22…Fan, 25, 25u, 25v, 25w…Rotation position detector (Hall element), 26…Rotation speed detector, 27…Current detector, 30…Target torque determination unit, 31…Memory unit, 32…Torque acquisition unit, 33…Error calculation unit, 34…Target rotation speed determination unit, 35…Drive control signal generation unit (vector control unit), 36…Output command acquisition unit, 37…Function selection unit, 38…Target torque calculation unit, 40…PI control calculation unit, 41…Target rotation speed calculation unit, 50…Current measurement unit, 51…Clark conversion unit, 52…Park conversion unit, 53…Rotation position detection signal acquisition unit, 54…Electrical angle calculation unit, 55…Rotation speed signal acquisition unit, 56…Rotation information generation unit, 60…Rotation speed PI control unit, 61… weaker 62...Magnetic flux PI control unit, 63...Magnetic flux PI control unit, 64...Reverse Park conversion unit, 65...Reverse Clark conversion unit, 66...PWM signal generation unit, 100...Fan unit, 310, 310_1~310_n...Corresponding information (function), EXC...Target rotational speed, Id...d-axis current, Id_ref...d-axis current target value, Iq...q-axis current, Iq_ref...q-axis current target value, Iq_g...q-axis current of Sd…Drive control signal, Sf…Output command signal, Si…Current detection signal, Sr…Rotation speed signal (FG signal), Tg…Target torque value, Ts…Torque value, ΔT…Torque error.

Claims

1. A control circuit that outputs a drive control signal to control the motor's drive, The motor drive circuit drives the motor based on the drive control signal output from the control circuit, The aforementioned control circuit is A storage unit that stores correspondence information showing the relationship between a value based on the rotational speed of the motor and the torque when the motor output of the motor becomes constant at a predetermined value, A target torque determination unit that determines a target torque value from a value based on the rotational speed of the motor using the corresponding information corresponding to the specified motor output, A torque acquisition unit that acquires the torque value of the motor, A target rotational speed determination unit determines the target rotational speed of the motor, which is the speed at which the difference between the target torque value and the torque value obtained by the torque acquisition unit is reduced. Includes a drive control signal generation unit that generates the drive control signal based on the target rotational speed. Motor drive control device.

2. In the motor drive control device according to claim 1, The value based on the rotational speed of the motor is the period of the rotational position detection signal, the voltage of which changes periodically according to the rotational position of the motor's rotor. Motor drive control device.

3. In the motor drive control device according to claim 1, The value based on the rotational speed of the motor is the reciprocal of the rotational speed of the motor. Motor drive control device.

4. In the motor drive control device according to any one of claims 1 to 3, The torque acquisition unit acquires the value of the q-axis current corresponding to the torque of the motor as the torque value, The target torque determination unit determines the target value of the q-axis current as the target torque value. Motor drive control device.

5. In the motor drive control device according to claim 4, The motor has three-phase coils, The drive control signal generation unit calculates the q-axis current and the d-axis current corresponding to the magnetic flux of the motor based on the current flowing through the coils of each phase of the motor, determines the duty cycle so that the calculated q-axis current and d-axis current match the target current value corresponding to the target rotational speed, and outputs a PWM signal having that duty cycle as the drive control signal. The torque acquisition unit acquires the q-axis current calculated by the drive control signal generation unit as the torque value. Motor drive control device.

6. In the motor drive control device according to claim 1, The aforementioned correspondence information includes a function that represents the relationship between a value based on the rotational speed of the motor and torque, The storage unit stores the function for each of the multiple command values ​​of the motor output that can be specified. Motor drive control device.

7. A motor drive control device according to any one of claims 1 to 3, The motor driven by the motor drive control device, The system comprises an impeller configured to be rotatable by the rotational force of the motor. Fan unit.

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