Motor drive control device and motor drive control method

Abstract

Motor drive control device (1), comprising a motor drive part (2) with a circuit for controlling a motor, and a control unit (3) which controls the operation of the circuit by outputting a control signal to the motor drive unit, where the control unit a speed measuring unit (32) that determines the actual speed of the motor, a mains voltage measuring unit (31) that detects a mains voltage, an electrical current measuring unit (31) that determines a quantity of the electric current flowing to the motor, a torque calculation unit (33) which calculates a quantity of a drive torque of the motor based on the determination result of the speed measuring unit, the determination result of the mains voltage measuring unit and the determination result of the electrical current measuring unit, a speed comparison unit (35) which compares a reference speed determined on the basis of the magnitude of the drive torque of the motor, calculated by the torque calculation unit, with the actual speed of the motor as determined by the speed measurement unit, and a lead value determination unit (38) which determines a lead value based on the comparison result of the speed comparison unit, wherein the control unit outputs a control signal based on the lead value determined by the lead value determination unit, wherein The reference speed is a speed that achieves an efficiency greater than or equal to a certain value, depending on the magnitude of the motor's drive torque.

Description

Technical area

[0001] The invention relates to a motor drive control device and a motor drive control method, in particular to a motor drive control device and a motor drive control method for performing advance adjustment. State of the art

[0002] Various methods for adjusting a phase angle of a motor have been proposed so far.

[0003] For example, JP 2008 - 99 511 A states that an increase / decrease of a load is estimated based on a calculated drive torque, and when the drive torque is decreased, a current advance value is reduced. Summary of the invention[Technical problem]

[0004] If an advance value is set using a speed as in JP 2008 - 99 511 A, when the load of a motor changes, the advance value is no longer optimal. Not only does the efficiency deteriorate and power consumption increase, but also the speed cannot be maintained under a heavy load, and the motor output drops. Another method is a method in which the advance value is set based on the magnitude of a calculated input torque, that is, the load size. In this case, the advance value changes when the electrical input changes due to a change in internal temperature, etc., but the speed is not stable, and fluctuations in the speed, etc., occur depending on the individual motor.In order to develop a high drive power and also to achieve a high motor efficiency, it is necessary to carry out an advance control by which the drive of the motor is adjusted to an appropriate state.

[0005] Further related techniques can be found in US 8 896 244 B2, which is directed to a motor control system for limiting regenerative current, and in US 6 803 739 B2, which describes a method and apparatus for controlling a synchronous motor.

[0006] The purpose of this invention is to provide a motor drive control apparatus and a motor drive control method by which a motor can be driven with high efficiency. Means of solving the task

[0007] The above object is achieved by a motor drive control device as defined by the appended independent claims 1 and 2, and a motor drive control method as defined by the appended independent claims 5 and 6. The respective dependent claims describe optional features and preferred embodiments.

[0008] To achieve the above purpose, according to one aspect of this invention, there is provided a motor drive control device comprising: a motor drive part having a circuit for driving a motor, and a control part that controls the operation of the circuit by outputting a control signal to the motor drive part, wherein the control part includes a speed measuring unit that detects an actual speed of the motor, a line voltage measuring unit that detects a line voltage, an electric current measuring unit that detects a magnitude of the electric current flowing to the motor, a torque calculating unit that calculates a magnitude of a drive torque of the motor based on the detection result of the speed measuring unit, the detection result of the line voltage measuring unit, and the detection result of the electric current measuring unit, a speed comparing unit that calculates a magnitude of the drive torque of the motor based on the magnitude of the drive torque of the motor,compares the reference speed calculated by the torque calculation unit with the actual speed of the motor determined by the speed measuring unit, and has an advance value determination unit that determines an advance value based on the comparison result of the speed comparison unit, wherein the control part outputs a control signal based on the advance value determined by the advance value determination unit, wherein the reference speed is a speed that achieves an efficiency greater than or equal to a certain value according to the size of the drive torque of the motor.

[0009] Preferably, the control part further comprises a storage unit, wherein a table in which the magnitude of the drive torque of the motor is associated with the reference speed is stored in advance in the storage unit, and the speed comparison unit determines the reference speed based on the magnitude of the drive torque of the motor calculated by the torque calculation unit and the table.

[0010] Preferably, the advance value determining unit determines, when it has been judged in the speed comparison unit that the actual speed of the engine is greater than the reference speed, as a new advance value a value at which a first determined value is subtracted from the current advance value, and when it has been judged in the speed comparison unit that the actual speed of the engine is less than the reference speed, as a new advance value a value at which a second determined value is added to the current advance value.

[0011] Preferably, the control signal includes an advance command value and a speed command value, wherein the speed command value is determined according to a rotational speed command.

[0012] According to another aspect of this invention, the motor drive control method is a motor drive control method by which the operation of a motor is controlled by means of a motor drive circuit, comprising: a speed detection step in which the actual speed of the motor is detected, a line voltage detection step in which the line voltage is detected, an electric current detection step in which the magnitude of the electric current flowing to the motor is detected, a torque calculation step in which the magnitude of the drive torque of the motor is calculated based on the detection result of the speed detection step, the detection result of the line voltage detection step, and the detection result of the electric current detection step, a speed comparison step,in which a reference speed determined based on the magnitude of the drive torque of the motor calculated by the torque calculation step is compared with the actual speed of the motor, a lead value determination step in which the lead value is determined based on the comparison result of the speed comparison step, and a control step in which the operation of the circuit is controlled based on the lead value determined by the lead value determination step, wherein the reference speed is a speed that achieves an efficiency greater than or equal to a certain value according to the magnitude of the drive torque of the motor. Effects of the invention

[0013] According to these of the invention, a motor drive control apparatus and a motor drive control method can be provided by which a motor can be driven with high efficiency. Brief description of the drawings [ Fig. 1] Fig. 1 is a block diagram schematically showing a circuit configuration of a motor drive control apparatus in one of the embodiments of the present invention. [ Fig. 2] Fig. 2 is a view showing a structure of a control part according to the present embodiment. [ Fig. 3] Fig. 3 is a flowchart showing the operation of the control part. [ Fig. 4] Fig. 4 is a view showing an example of reference speed information stored in a storage unit. [ Fig. 5] Fig. Figure 5 is a graph showing the relationship of rotational speed to a drive torque value at a given rotational speed command and the relationship of the efficiency of a motor to the drive torque value. Forms for carrying out the invention

[0014] The following explains an electronic device using a motor drive control device in one of the embodiments of the present invention.

[0015] Fig. 1 is a block diagram schematically showing a circuit configuration of a motor drive control device 1 in one of the embodiments of the present invention.

[0016] As in Fig. 1, the motor drive control device 1 is configured to drive a brushless motor 7 (hereinafter referred to simply as motor 7) using, for example, a 180-degree drive method with a leading control. In the present embodiment, the motor 7 is, for example, a 3-phase brushless motor. The motor drive control device 1 drives the motor 7 by supplying driving electric power to the motor 7. The 180-degree drive method is a method in which a driving pattern is generated based on the rotational speed and the driving is adapted to the rotational position at which the electric current flowing in coils of the motor 7 assumes a sine wave shape. Specifically, in the motor drive control device 1, the motor 7 is rotated, for example, by outputting a sine wave drive signal to the motor 7 and cyclically flowing a driving current into the coils of the motor 7.Motor 7 is not limited to the brushless motor, but can also be another motor. Furthermore, the driving method of motor 7 is not limited to the 180-degree control method, but can also be another driving method.

[0017] The motor drive control device 1 comprises a motor drive part 2, a control part 3, and a mains voltage monitoring part 4. For example, a specific mains voltage is supplied to the motor drive control device 1. The mains voltage is supplied to the motor drive part 2 and the control part 3, respectively. Fig. 1 are part of the entire motor drive control device 1, wherein the motor drive control device 1 may also include other components in addition to those shown in Fig. 1 shown components.

[0018] The motor drive control device 1 drives the motor 7 based on a rotation speed command sent from a host device 9. The host device 9 is, for example, an electronic device, etc., equipped with the motor 7 and the motor drive control device 1. The motor drive control device 1 may also be configured to drive the motor 7 at a specific speed as a rotation speed command, rather than based on a rotation speed command from another device. Furthermore, the motor drive control device 1 may also be configured to generate a rotation speed command of a speed corresponding to a signal sent from the host device 9, etc., and run following this rotation speed command.

[0019] In the present embodiment, the motor drive part 2 and the control part 3 are each an integrated circuit (IC) device in which circuits for implementing respective functions are integrated and packaged. The motor drive part 2 and the control part 3 can be packaged as an integrated circuit device, or an integrated circuit device can be constructed by packaging part of the motor drive control device 1 or the entire motor drive control device 1 together with other devices.

[0020] The motor drive part 2 includes an inverter circuit 21, a pre-driver (pre-driver circuit) 22, and a current detector circuit 23. The motor drive part 2 supplies electric drive power to the motor 7 based on a speed command value regarding the rotational speed of the motor 7 and an advance command value input from the control part 3.

[0021] The inverter circuit 21, together with the pre-driver 22, forms the motor drive part 2. The inverter circuit 21 outputs electric drive power to the motor 7 based on a drive signal output from the pre-driver 22 and drives the coils with which the motor 7 is equipped. That is, the inverter circuit 21 is a circuit for driving the motor 7. The inverter circuit 21 is constructed, for example, such that a pair of series circuits of two switching elements provided at both ends of a power supply voltage are arranged at respective phases (U-phase, V-phase, W-phase) of the coils. In the respective pairs of the two switching elements, the pole terminals of the respective phases of the motor 7 are connected to each other at the connection points of the switching elements.For each phase, changing the combination of switching on / off of the two switching elements changes whether or not current flows into the coil of that phase and the direction of that current.

[0022] The pre-driver 22 generates drive signals for driving the inverter circuit 21 based on the control of the control part 3 and outputs them to the inverter circuit 21. The pre-driver 22 generates drive signals based on a speed command value and an advance command value output from the control part 3. As drive signals, for example, six different signals are output, which correspond to the respective switching elements of the inverter circuit 21. By outputting these drive signals, the switching elements corresponding to the respective drive signals are turned on / off, a drive signal is output to the motor 7, and electric power is supplied to the respective phases of the motor 7.

[0023] In the present embodiment, rotation signals, which are sensor signals output from rotation position sensors 8 provided on the motor 7, are input to the pre-driver 22. The pre-driver 22 outputs a drive signal based on the rotation signal and the drive state of the motor 7.

[0024] The rotational position sensors 8 are, for example, Hall sensors (Hall elements, Hall ICs, etc.). For example, three Hall sensors are provided, corresponding to the respective phases of the coils of the motor 7. That is, the rotational position sensors 8 output rotation signals corresponding to the rotational position of the rotor of the motor 7. The pre-driver 22 outputs a drive signal corresponding to the rotational position of the rotor based on the rotation signal. The method for detecting the rotational position of the rotor of the motor 7 is not particularly limited; for example, instead of the rotational position sensors 8, a sensorless method that detects the position of the rotor using the back EMF may also be used.

[0025] The pre-driver 22 outputs a rotation output signal corresponding to the rotational speed of the motor 7 to the control part 3 in accordance with the input rotation signal. The rotation output signal is, for example, an FG signal.

[0026] A current detection circuit 23 detects the magnitude of the current flowing into the motor 7 (motor current value). The current detection circuit 23 includes, for example, a resistor to obtain a voltage value corresponding to the magnitude of the current flowing into the motor 7. That is, the motor current value is detected as a voltage value by the resistor provided between the switching elements of the inverter circuit 21 and a ground potential. In other words, the current detection circuit 23 functions as a sensor that detects the motor current value flowing into the coils of the motor 7. The motor current value detected by the current detection circuit 23 is output to the control part 3.

[0027] The control part 3 controls the operation of the motor drive part 2 by outputting a speed command value and an advance command value to the motor drive part 2. That is, the control part 3 controls the operation of the inverter circuit 21 by outputting control signals to the motor drive part 2.

[0028] A rotation speed command output from the host device 9 is input to the control part 3. The control part 3 outputs a speed command value to the pre-driver 22 of the motor drive part 2 based on the rotation speed command. The rotation speed command is, for example, a PWM signal. The control part 3 outputs a speed command value based on the input rotation speed command. That is, the speed command value is determined according to the rotation speed command. The form of the rotation speed command and the speed command value is not limited to this. Furthermore, the control part 3 can also be configured to output a speed command value by converting the input rotation speed command. Inputs from the host device 9 to the control part 3 include, for example, a start / stop signal, a brake signal, a rotation direction setting signal, etc.entered, but their representation is omitted.

[0029] A rotation output signal output from the pre-driver 22 is input to the control part 3. The control part 3 has a speed measuring unit 32 (in Fig. 2) which, as described later, detects the actual rotational speed of the motor 7 (also referred to as actual rotational speed) based on a rotational output signal. That is, the control part 3 detects the rotational speed of the motor 7 based on the output of the rotational position sensors 8 provided on the motor 7. Rotational signals output from the rotational position sensors 8, or an FG signal from an FG sensor provided on the motor 7, may also be input to the control part 3. In this case, it is also possible for the control part 3 to detect the rotational speed of the motor 7 based on the input signals.

[0030] The control part 3 outputs a signal representing the rotational speed of the motor 7 to the host device 9. Furthermore, it outputs a signal corresponding to the driving state of the motor 7 to the host device 9. Based on these signals, the host device 9 can output various commands related to driving the motor 7, such as a rotational speed command, etc., to the motor drive control device 1. These signals may also be output from the control part 3. For example, the rotation signals from the rotational position sensors 8 and the rotation output signal from the pre-driver 22 may also be directly input to the host device 9.

[0031] The grid voltage monitoring part 4 monitors the grid voltage supplied to the motor drive control device 1. The grid voltage monitoring part 4 outputs a voltage value of the grid voltage obtained by monitoring (grid voltage value) to the control part 3. The control part 3 (more specifically, an analog signal conversion unit 31 described later) determines the grid voltage supplied to the motor drive control device 1 based on the input grid voltage value. [Explanation regarding setting the lead command value]

[0032] In the present embodiment, the control part 3 functions as an advance value determining unit that determines an advance value and outputs a control signal including an advance command value based on the determined advance value. As explained below, the control part 3 executes a motor drive control method including: a speed detection step of detecting the actual speed of the motor 7; a power voltage detection step of detecting the power voltage; an electric current detection step of detecting the magnitude of the electric current flowing to the motor 7 (motor current value); and a torque calculation step of calculating the torque based on the detection result of the speed detection step.the determination result of the line voltage determination step and the determination result of the electric current determination step, the magnitude of the drive torque (drive torque value) of the motor 7 is calculated; a speed comparison step in which a reference speed determined based on the magnitude of the drive torque of the motor 7 calculated by the torque calculation step is compared with the actual speed of the motor 7; a lead value determination step in which the lead value is determined based on the comparison result of the speed comparison step; and a control step in which the operation of the inverter circuit 21 is controlled based on the lead value determined by the lead value determination step.

[0033] Fig. 2 is a view showing a structure of the control part 3 according to the present embodiment.

[0034] As in Fig. As shown in Fig. 2, the control part 3 includes an analog signal conversion unit 31 (example: a line voltage measuring unit, example: a current measuring unit), a speed measuring unit 32, a torque calculating unit 33, a storage unit 34, a speed comparing unit 35, an advance value determining unit 38, and an advance command value outputting unit 39. The control part 3 is, for example, a microcomputer. The control part 3 may be formed with a relatively simple structure and an inexpensive IC, rather than a microcomputer with a complicated structure. The components of the control part 3 are not limited to this. For example, the explanation of the components related to the output of the speed command value, etc., is omitted.

[0035] The analog signal conversion unit 31 functions as a grid voltage measurement unit that detects the grid voltage. That is, the analog signal conversion unit 31 performs A / D conversion of the grid voltage value input to the control section 3. Then, the detection information of the grid voltage value, converted into a digital signal, is output to the torque calculation unit 33.

[0036] Furthermore, the analog signal conversion unit 31 functions as a current measuring unit that detects the magnitude of the current flowing into the motor 7. That is, the analog signal conversion unit 31 performs A / D conversion of the motor current value input to the control section 3. Then, the detection information of the motor current value, converted into a digital signal, is output to the torque calculation unit 33.

[0037] The speed measuring unit 32 detects the actual speed of the motor 7. That is, the speed measuring unit 32 detects the speed of the motor 7 based on the rotation output signal output from the pre-driver 22 of the motor driving part 2, and outputs the detection result (actual speed) to the torque calculating unit 33 and the speed comparing unit 35.

[0038] The torque calculation unit 33 calculates the magnitude of the drive torque of the motor 7 (drive torque value) based on the actual speed, which is the detection result of the speed measurement unit 32, the grid voltage value, and the motor current value, which are the detection results of the analog signal conversion unit 31. The torque calculation unit 33 outputs the calculated drive torque value to the speed comparison unit 35.

[0039] The drive torque value is determined using the supplied electrical power value, which is determined from the grid voltage value and the motor current value, using the following formula. Where T is the drive torque value [mNm], ω is the angular velocity [rad / s], P is the input power [W], and η is the efficiency. T=P / ω×η

[0040] The storage unit 34 is, for example, a flash memory. The storage unit 34 stores the reference speed information. The reference speed information is preset information. The reference speed information is, for example, a lookup table in which the magnitude of the drive torque of the motor 7 is assigned to the corresponding reference speed.

[0041] The reference speed information can also be stored, for example, as a calculation formula for calculating the reference speed based on the drive torque value.

[0042] The speed comparison unit 35 reads the reference speed from the storage unit 34 based on the input drive torque value. That is, the speed comparison unit 35 reads the reference speed corresponding to the input drive torque value by referring to the reference speed information stored in the storage unit 34.

[0043] Furthermore, the speed comparison unit 35 compares the input actual speed with the reference speed read from the storage unit 34. That is, the speed comparison unit 35 compares the reference speed determined based on the magnitude of the drive torque of the motor 7 calculated by the torque calculation unit 33 with the actual speed of the motor 7 determined by the speed measuring unit 32. It then outputs the comparison result to the advance value determination unit 38.

[0044] The advance value determining unit 38 determines the advance value based on the comparison result of the speed comparing unit 35. The determined advance value is output to the advance command value output unit 39.

[0045] In the present embodiment, when the speed comparison unit 35 judges that the actual speed of the engine 7 is greater than the reference speed, the advance value determination unit 38 determines, as a new advance value, a value by which a first predetermined value is subtracted from the current advance value. On the other hand, when the speed comparison unit 35 judges that the actual speed of the engine 7 is less than the reference speed, the advance value determination unit 38 determines, as a new advance value, a value by which a second predetermined value is added to the current advance value.

[0046] The advance command value output unit 39 sets an advance command value based on the advance value determined by the advance value determination unit 38, and outputs the set advance command value to the motor drive part 2. The motor drive part 2 then outputs a drive signal advanced based on the advance command value to the motor 7.

[0047] A configuration is also possible in which the advance value determination unit 38 determines the amount by which the advance value is increased / decreased from the current advance value, and the advance command value output unit 39 outputs the determined value as the advance command value. In this case, the motor drive part 2 controls the motor 7 by increasing / decreasing the advance amount based on the advance command value.

[0048] Fig. 3 is a flowchart showing the operation of the control part 3.

[0049] Fig. 3 only illustrates the processing flow relating to the setting of the advance command value, which is carried out in the control part 3. The control part 3 carries out the setting of the advance command value (calculation of the advance value) as follows by means of the respective units described above: the analog signal conversion unit 31, the speed measuring unit 32, the torque calculation unit 33, the storage unit 34, the speed comparison unit 35, the advance value determination unit 38, and the advance command value output unit 39. Fig. 3 is always repeatedly performed during operation of the motor drive control device 1.

[0050] In step S11, the control section 3 detects and acquires various information used to set the advance command value. That is, the analog signal conversion unit 31 detects the grid voltage value and the motor current value (grid voltage detection step, current detection step). Furthermore, the speed measurement unit 32 detects the actual speed (speed detection step).

[0051] In step S12, the torque calculation unit 33 determines the electric motor drive power based on the grid voltage value and the motor current value.

[0052] In step S13, the torque calculation unit 33 determines the drive torque value of the motor 7 based on the motor electric drive power and the actual speed (torque calculation step).

[0053] In step S14, the speed comparison unit 35 determines the reference speed based on the drive torque value based on the reference speed information stored in the storage unit 34.

[0054] In steps S15 and S16, the speed comparison unit 35 compares the reference speed with the actual speed (speed comparison step). That is, in step S15, the speed comparison unit 35 judges whether the actual speed is greater than the reference speed. If the actual speed is greater than the reference speed, step S17 follows (step S15: YES); otherwise, step S16 follows (step S15: NO).

[0055] In step S16, the speed comparison unit 35 judges whether the actual speed is lower than the reference speed. If the actual speed is lower than the reference speed, step S18 follows (step S16: YES); otherwise, step S19 follows (step S16: NO).

[0056] In step S17 and step S18, the advance value determining unit 38 calculates the advance value based on the comparison result of the reference rotational speed with the actual rotational speed (advance value determining step).

[0057] In step S17, the advance value determination unit 38 determines the advance value as a value resulting from subtracting one unit from the previous value. For example, the advance value is reduced by one degree. Step S16 then follows.

[0058] In step S18, the advance value determination unit 38 determines the advance value as a value resulting from adding one unit to the previous value. For example, the advance value is increased by one degree. Step S19 then follows.

[0059] In step S17 and step S18, the amount by which the advance value is increased / decreased should be set appropriately.

[0060] In step S19, the advance command value output unit 39 updates the advance command value. That is, the advance command value output unit 39 sets the advance value increased / decreased by the advance value determination unit 38 as the new advance command value. Then, by outputting the adjusted advance command value to the motor drive part 2, the operation of the inverter circuit 21 is controlled (control step).

[0061] The order in which the processing of step S15 and the accompanying processing of step S17, as well as the processing of step S16 and the accompanying processing of step S18, are performed is not limited to this order. The respective processing may also be performed in a different order or in parallel.

[0062] Fig. 4 is a view showing an example of the reference speed information stored in the storage unit 34.

[0063] As in Fig. As shown in Figure 4, the reference speed information is information in which the drive torque value of the motor 7 is associated with the reference speed corresponding thereto, and these are set according to the rotation speed command. The number of combinations of the drive torque value and the reference speed is not limited to that shown in the figure, but can also be set in more detail.

[0064] The reference speed describes a speed that achieves an efficiency greater than or equal to a specific value, depending on the magnitude of the drive torque of motor 7. The reference speed is a quantification for deriving the combination of the speed and the drive torque value based on information obtained in advance by evaluating the torque characteristics of motor 7, and a target value determined for each different drive torque value.More specifically, the reference speed corresponding to a certain drive torque value is the speed when the motor 7 rotates with a maximum efficiency to generate this drive torque value, but this is not limited to this, and instead of the speed at which the maximum efficiency is achieved, it may also be the speed at which an efficiency greater than or equal to a certain efficiency is achieved.

[0065] Fig. 5 is a graph showing the relationship of rotational speed to a drive torque value at a certain rotational speed command and the relationship of the efficiency of the motor 7 to the drive torque value.

[0066] In Fig. 5, a graph showing the relationship of efficiency to drive torque value and a graph showing the relationship of speed to drive torque value are shown respectively in the case where the motor 7 is driven at three kinds of fixed advance values ​​(15 degrees, 20 degrees and 30 degrees) and in the case where advance control is performed based on rotational speed as in the present embodiment.

[0067] As in Fig.As shown in Figure 5, at all drive torque values, the efficiency becomes higher when the speed-based advance control is performed in the present embodiment than when the motor 7 is driven at a constant advance value. Regarding changes in the speed versus changes in the drive torque value, the fluctuations become smaller when the speed-based advance control is performed in the present embodiment than when the motor 7 is driven at a constant advance value.

[0068] As explained above, in the present embodiment, as described above, the reference speed is used to judge whether to increase or decrease the advance value in comparison with the actual speed. The control part 3 calculates the drive torque value of the driven motor 7, derives the stored optimal speed from the drive torque value obtained by the calculation, and compares it with the actual speed. Control is performed such that when the actual speed is lower, the advance value is increased, and when the actual speed is higher, the advance value is reduced. By repeatedly performing this control, the advance value of the motor 7 is adjusted, and the motor 7 enters a state where it is driven at a speed close to the reference speed at a certain drive torque value.That is, the motor 7 enters a state where it is driven at high efficiency. In other words, the control part 3 performs advance control such that, by utilizing the characteristic in which the speed and drive torque value of the motor 7 driven according to the advance value change, the motor 7 is driven at a speed and drive torque value with high efficiency. As a result, the motor 7 can be driven at high efficiency over a wide range of drive torque values. Within the wide range of drive torque values, the fuel consumption of the motor 7 can be kept low.

[0069] The object rotated by motor 7 (e.g., if motor 7 is a fan motor, its impeller) is used under various load conditions, in which case, advance control is required to adjust the drive of motor 7 to an appropriate state according to the load and speed. If the advance value is inappropriate, the efficiency of motor 7 deteriorates, which not only increases consumption but also makes it impossible to achieve high drive output (driving a heavy load at high speed). As described above, the speed at which higher efficiency is achieved is not constant but changes with the size of the load.In the present embodiment, by controlling the advance value with the reference speed at which a higher efficiency is obtained as the target value, an object to be rotated can be operated with a high efficiency.

[0070] If the advance value is calculated solely based on the driving state of the motor 7, such as a method in which the advance value is directly adjusted based on the magnitude of a calculated driving torque, that is, the magnitude of the load, the advance value will change even for a motor 7 of the same type when the input electric power changes due to a change in the internal temperature. This poses a problem that, as a result, the rotational speed of the motor 7 is unstable or fluctuations in the rotational speed, etc., occur in each body of the motor 7. In particular, interference is likely to occur in 180-degree driving because the rotational speed that changes due to the advance value is large.In contrast, in the present embodiment, the advance value is set based on the reference speed information as the target value, so that the speed of the motor 7 can be stabilized, and further fluctuations of each body of the motor 7 can be reduced.

[0071] The control part 3 stores reference speed information in advance, corresponding to a rotation speed command, in which the magnitude of the drive torque is associated with the optimum speed corresponding thereto, and performs control based thereon to rotate at the reference speed. As a result, the motor 7 can be driven in a state of high efficiency for a wide load condition. Furthermore, since such control for adjusting the lead is always performed, the motor 7 can be driven following this state even during load fluctuations, and a state of high efficiency can be maintained. Since the lead control is performed based on the reference speed information, the lead control can be performed easily and accurately.

[0072] The adjustment of the advance command value can be performed without using a special circuit, using only a simple, inexpensive microcomputer constituting the control part 3. Consequently, the manufacturing cost of the motor drive control device 1 can be kept low. [Miscellaneous]

[0073] The motor drive control device is not limited to the circuit configuration shown in the above-described embodiment. Various circuit configurations configured to meet the purpose of the present invention can be adopted.

[0074] For example, it may also be a configuration in which the control part outputs a drive signal directly to the inverter circuit without a pre-driver. In this case, the control part should be configured such that a drive signal is output to the inverter circuit based on the advance value determined by the advance value determination unit, thereby controlling the operation of the inverter circuit.

[0075] The motor driven by the motor drive control device of the present embodiment is not limited to a three-phase brushless motor, but may also be a brushless motor with a different number of phases. Furthermore, the type of motor is not particularly limited.

[0076] The method for detecting the speed of the motor is not particularly limited, and various methods can be used, such as a method using Hall sensors, a method of reading an FG signal from the pre-driver, a method of monitoring the back EMF, etc.

[0077] The motor drive method is not limited to a normal sine wave drive, but can also be a rectangular wave drive method, a trapezoidal wave drive method, a specially modulated sine wave drive method, etc.

[0078] The motor current value is not limited to the motor current flowing through the coils of a motor. For example, the control unit can also determine the magnitude of an input current as the motor current value.

[0079] The flowchart described above shows an example to explain the operation, but is not limited to this. The steps shown in the respective flowchart figures are concrete examples, and are not limited to this flow. For example, the order of the respective steps can be changed, other processing can be inserted between the respective steps, or the processing can be performed in parallel.

[0080] Part or all of the processing in the above-described embodiment can also be performed using software or hardware circuitry. For example, the control part is not limited to a microcomputer. The internal structure of the control part can be at least partially processed by software. List of reference symbols 1 Motor drive control device 2 Motor drive part 3 Control part 4 Mains voltage monitoring part 7 Engine 8 Rotation position sensor 21 Inverter circuit 22 pre-drivers 23 Current detector circuit 31 Analog signal conversion unit (example of a mains voltage measuring unit, example of a current measuring unit) 32 speed measuring unit 33 Torque calculation unit 34 storage unit 35 Speed ​​comparison unit 38 Advance value determination unit 39 Lead command value output unit

Claims

[1] Motor drive control device (1) comprising a motor drive part (2) with a circuit for controlling a motor, and a control part (3) which controls the operation of the circuit by outputting a control signal to the motor drive part, where the control part a speed measuring unit (32) which determines an actual speed of the engine, a mains voltage measuring unit (31) which detects a mains voltage, an electric current measuring unit (31) which determines a value of the electric current flowing to the motor, a torque calculation unit (33) which calculates a value of a drive torque of the motor based on the detection result of the speed measuring unit, the detection result of the mains voltage measuring unit and the detection result of the electric current measuring unit, a speed comparison unit (35) which compares a reference speed determined based on the magnitude of the drive torque of the motor calculated by the torque calculation unit with the actual speed of the motor determined by the speed measuring unit, and an advance value determination unit (38) which determines an advance value based on the comparison result of the speed comparison unit, wherein the control part outputs a control signal based on the advance value determined by the advance value determining unit, wherein the reference speed is a speed that achieves an efficiency greater than or equal to a certain value depending on the size of the motor's drive torque. [2] Motor drive control device (1) comprising a motor drive part (2) with a circuit for controlling a motor, and a control part (3) which controls the operation of the circuit by outputting a control signal to the motor drive part, where the control part a speed measuring unit (32) which determines an actual speed of the engine, a mains voltage measuring unit (31) which detects a mains voltage, an electric current measuring unit (31) which determines a value of the electric current flowing to the motor, a torque calculation unit (33) which calculates a value of a drive torque of the motor based on the detection result of the speed measuring unit, the detection result of the mains voltage measuring unit and the detection result of the electric current measuring unit, a speed comparison unit (35) which compares a reference speed determined based on the magnitude of the drive torque of the motor calculated by the torque calculation unit with the actual speed of the motor determined by the speed measuring unit, and an advance value determination unit (38) which determines an advance value based on the comparison result of the speed comparison unit, wherein the control part outputs a control signal based on the advance value determined by the advance value determining unit, wherein the advance value determination unit, if the speed comparison unit judges that the actual speed of the motor is greater than the reference speed, determines as a new advance value a value at which a first determined value is subtracted from the current advance value, and If the speed comparison unit judges that the actual speed of the motor is lower than the reference speed, the new advance value is determined to be a value in which a second determined value is added to the current advance value. [3] Motor drive control device (1) according to claim 1 or 2, wherein the control part further comprises a storage unit (34), a table in which the magnitude of the drive torque of the motor is associated with the reference speed is stored in advance in the storage unit, and the speed comparison unit determines the reference speed based on the magnitude of the drive torque of the motor calculated by the torque calculation unit and the table. [4] A motor drive control device according to any one of claims 1 to 3, wherein the control signal includes an advance command value and a speed command value, and the speed command value is determined according to a rotation speed command. [5] A motor drive control method by which the operation of a motor is controlled by means of a motor drive circuit, comprising: a speed detection step (S11), in which the actual speed of the motor is determined, a mains voltage detection step (S11), in which the mains voltage is detected, an electric current detection step (S11) in which the magnitude of the electric current flowing to the motor is determined, a torque calculation step (S12, S13) in which the magnitude of the drive torque of the motor is calculated based on the determination result of the speed determination step, the determination result of the line voltage determination step and the determination result of the electric current determination step, a speed comparison step (S14, S15, S16) in which a reference speed determined based on the magnitude of the motor drive torque calculated by the torque calculation step is compared with the actual speed of the motor, a step for determining the advance value (S17, S18) in which the advance value is determined based on the comparison result of the speed comparison step, and a control step (S19) in which the operation of the circuit is controlled based on the advance value determined by the advance value determination step, wherein the reference speed is a speed that achieves an efficiency greater than or equal to a certain value depending on the size of the motor's drive torque. [6] A motor drive control method by which the operation of a motor is controlled by means of a motor drive circuit, comprising: a speed detection step (S11), in which the actual speed of the motor is determined, a mains voltage detection step (S11), in which the mains voltage is detected, an electric current detection step (S11) in which the magnitude of the electric current flowing to the motor is determined, a torque calculation step (S12, S13) in which the magnitude of the drive torque of the motor is calculated based on the determination result of the speed determination step, the determination result of the line voltage determination step and the determination result of the electric current determination step, a speed comparison step (S14, S15, S16) in which a reference speed determined based on the magnitude of the motor drive torque calculated by the torque calculation step is compared with the actual speed of the motor, a step for determining the advance value (S17, S18) in which the advance value is determined based on the comparison result of the speed comparison step, and a control step (S19) in which the operation of the circuit is controlled based on the advance value determined by the advance value determination step, wherein the step of determining the advance value comprises a step (S17) of determining, as a new advance value, a value at which a first determined value is subtracted from the current advance value when the speed comparison step determines that the actual speed of the motor is greater than the reference speed, and the step of determining the advance value comprises a step (S18) of determining, as a new advance value, a value at which a second determined value is added to the current advance value when the step of comparing the speed determines that the actual speed of the motor is less than the reference speed.

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