Motor control device, and motor drive system, vacuum cleaner, and electric vehicle using the same

Abstract

To improve a degree of freedom in control of a motor by reducing an operation load of a motor control device.SOLUTION: The present invention relates to a motor control device to which current information flowing to a single-phase motor obtained by a current detection section is inputted and which outputs a drive signal to regulate a voltage for driving the single-phase motor to a single-phase power converter. The motor control device comprises: a filter to which the current information of the current detection section is inputted; an integrator which calculates a rotor position of the single-phase motor; and a single-phase AC voltage command creator. Based on a speed command value and the rotor position of the single-phase motor, the drive signal is adjusted in such a manner that a phase difference between the current of the single-phase motor and the voltage for driving the single-phase motor becomes a predetermined value.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a motor control device, and a motor drive system, an electric vacuum cleaner, and an electric vehicle that use the same. [Background technology]

[0002] Patent Document 1 discloses a motor drive device that controls the rotation speed of a single-phase motor in accordance with a physical quantity calculated by multiplying a sine wave based on a phase that is based on a change in polarity of an AC voltage by a current detected by a current detection unit, with the aim of obtaining a motor drive device that drives a single-phase motor by controlling active power and reactive power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 208785 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor drive device described in Patent Document 1, a PI controller 73 calculates active power, and a PI controller 74 calculates reactive power. Then, the calculated active power and reactive power are used to perform inverse PQ transformation, which increases the computational load and is therefore considered to leave room for improvement.

[0005] An object of the present disclosure is to reduce the computational load on a motor control device and increase the degree of freedom in motor control. [Means for solving the problem]

[0006] The motor control device disclosed herein receives information about the current flowing through a single-phase motor obtained by a current detection unit, and outputs a drive signal to a single-phase power converter to adjust the voltage for driving the single-phase motor.The motor control device includes a filter to which the current information from the current detection unit is input, an integrator that calculates the rotor position of the single-phase motor, and a single-phase AC voltage command generator, and adjusts the drive signal based on the speed command value and rotor position of the single-phase motor so that the phase difference between the current for the single-phase motor and the voltage for driving the single-phase motor becomes a predetermined value. Effect of the Invention

[0007] According to the present disclosure, it is possible to reduce the computational load on a motor control device and increase the degree of freedom in controlling a motor. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a motor drive system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic diagram showing the configuration of a single-phase motor 20 in FIG. [Diagram 3] 4 is a graph showing an example of waveforms of an induced voltage, a voltage of a single-phase motor, and a current of a single-phase motor relative to a rotor position. [Figure 4] 1 is a graph showing an induced voltage, a voltage of a single-phase motor, and a current of a single-phase motor as vector diagrams in a dq plane. [Diagram 5] FIG. 4 is a diagram illustrating an example of a configuration of a control unit. [Figure 6] FIG. 6 is a diagram showing the configuration of a simplified Fourier transformer 17 in FIG. 5. [Figure 7] 13 is a graph showing a case where a phase difference occurs on an axis of a control coordinate. [Figure 8] FIG. 13 is a configuration diagram showing an example of a control unit to which phase control is added. [Figure 9] FIG. 9 is a configuration diagram showing a modified example of the control unit 10 in FIG. [Figure 10] FIG. 2 is a configuration diagram showing a single-phase power converter 30. [Figure 11]1 is a graph showing a method of generating a drive signal using a standard triangular wave comparison method. [Figure 12] 1 is an external perspective view showing an example of a vacuum cleaner incorporating a motor control device according to the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, in which like reference numerals denote like elements and the same description will not be repeated.

[0010] The various components of the present disclosure do not necessarily have to be independent entities, and it is permitted that multiple components are formed as a single member, that one component is formed from multiple members, that one component is a part of another component, or that a part of one component overlaps with a part of another component, etc. EXAMPLES

[0011] <Outline of motor drive system configuration> FIG. 1 is a schematic diagram showing the configuration of a motor drive system according to an embodiment of the present invention.

[0012] The motor drive system 100 includes a control unit 10 (motor control device), a single-phase motor 20 (single-phase motor), a single-phase power converter 30 (single-phase inverter), and a current detection means 50 (also called a "current detection unit" or a "current sensor"). The single-phase power converter 30 is installed between the control unit 10 and the single-phase motor 20. The current detection means 50 is installed between the single-phase motor 20 and the single-phase power converter 30. Although not shown, a mechanism is mechanically or magnetically connected to the single-phase motor 20. The motor drive system 100 controls the rotation speed or torque of the single-phase motor 20 to a desired value.

[0013] The single-phase power converter 30 has a DC voltage source such as a battery and a bridge circuit including switching elements, and outputs a voltage by switching the switching elements in response to an input drive signal. Assuming that the switching operation of the switching elements is ideally performed without delay, the voltage output from the single-phase power converter 30 is a pulsed voltage. Using the well-known concept of pulse width modulation, the pulsed voltage can be regarded as an AC voltage.

[0014] In pulse width modulation, it is common to make the cycle in which the switching element is turned on and off, that is, the switching frequency, sufficiently high relative to the frequency of the equivalent AC voltage (corresponding to the rotation frequency of the single-phase motor 20 in this case). However, it is also possible to consider the fundamental wave component of the pulsed voltage. For example, when the switching frequency is close to the rotation frequency of the single-phase motor 20, such as about 1 to 3 times, it can be considered that the fundamental wave component of the pulsed voltage is applied to the single-phase motor 20. Therefore, in this specification, the output voltage of the single-phase power converter 30 will be described as having an AC waveform.

[0015] Incidentally, instead of a DC voltage source, an AC power source may be converted into DC power by rectification or the like.

[0016] In the figure, a control unit 10 includes a single-phase AC voltage command generator 11, a filter 13, a PWM signal generator 14, an integrator 15, a proportional controller 16, and a table reference unit 70. The single-phase AC voltage command generator 11 includes a voltage command generator 12. Here, PWM is an abbreviation for Pulse Width Modulation.

[0017] The configuration of the control unit 10 will be described in detail later. The control unit 10 receives information on the current flowing through the single-phase motor 20 obtained by a current detection means 50, and outputs a drive signal for controlling the on / off of a switching element built into the single-phase power converter 30 from a PWM signal generator 14 based on a single-phase AC voltage command value output by a single-phase AC voltage command generator 11. In this figure, the speed command value (ω* ) are shown in the control unit 10, but may be obtained, for example, from a higher level control system or other control systems not shown.

[0018] FIG. 2 is a diagram illustrating a schematic structure of the single-phase motor 20 of FIG.

[0019] 2, the single-phase motor 20 includes a stator 21 and a rotor 22. The stator 21 has a plurality of stator poles 28 formed by windings 25 (coils) wound around a stator core 26 (stator core). The rotor 22 has a permanent magnet 27.

[0020] In this figure, an example is shown in which the number of magnetic poles (also called the number of slots) of stator 21 is 2, and the number of magnetic poles of rotor 22 is 2. The number of magnetic poles of stator 21 and rotor 22 can be freely selected, and the number of magnetic poles of stator 21 and rotor 22 may not be equal. Furthermore, the multiple windings may be connected in parallel or in series.

[0021] The stator magnetic poles 28 can generate magnetic poles as electromagnets by passing a current through the windings 25. Therefore, the polarity (north pole, south pole) can be changed depending on the direction of the current through the windings 25. In this specification, the rotation angle (rotational angle position) of the rotor 22 when the stator magnetic poles 28 become south poles when a positive direct current is passed through the windings 25 and the north pole of the permanent magnet 27 of the rotor 22 is attracted is defined as zero degrees (0 (deg)). Hereinafter, the rotational angle position of the rotor will be referred to as the rotor position θ d In the present specification, the direction in which the rotor 22 rotates counterclockwise is defined as the positive rotation. In addition, the direction of the N pole of the permanent magnet 27 of the rotor 22 is defined as the d-axis, and the direction 90 electrical degrees ahead of the d-axis in the direction of rotation is defined as the q-axis. The definition of the d-axis can also be said to be the rotation angle position at which the magnetic flux of the permanent magnet 27 interlinked with the reference winding 25 is maximized.

[0022] The d-axis can also be called the magnet flux axis, and the q-axis the winding flux axis. It is particularly important to appropriately control the current in the q-axis direction.

[0023] <How to drive a single-phase motor> When driving a single-phase motor 20 having a permanent magnet 27 in the rotor 22, the maximum torque can be obtained with the minimum current if the magnetic flux from the winding 25 is generated at a position 90 electrical degrees ahead of the magnetic flux from the permanent magnet 27 in the direction of rotation. Driving in this way not only makes it possible to reduce the size and weight of the single-phase motor 20, but also has the effect of making the single-phase power converter 30 smaller.

[0024] <Purpose of this disclosure> There is a method called vector control as a method for controlling the current and voltage in the d-axis and q-axis directions. This method is very useful and is widely used, especially as a drive method for three-phase motors. Vector control requires using coordinate transformation to convert three-phase AC values ​​into values ​​in the d-axis and q-axis directions for control, and then performing coordinate transformation again to return to three-phase AC values. It is also common to control the current separately in the d-axis and q-axis directions. Also, the calculation of vector control is performed based on the switching frequency. Therefore, when rotating a motor at high speed, the calculation time (calculation load) of vector control and current control becomes an obstacle.

[0025] Therefore, an object of the present disclosure is to provide a motor control device suitable for reducing the calculation load. Another object is to easily obtain the q-axis current. Another object of the present disclosure is to realize a control configuration according to the rotor position without using a position sensor.

[0026] <Vector representation of voltage and current of single-phase motor 20> According to the above definition, the magnetic flux Φ interlinked with the winding 25 is m can be expressed as the following equation (1).

[0027]

number

[0028] In the formula, Φ max is the magnetic flux Φ m is the amplitude of

[0029] Also, the magnetic flux Φ m The induced voltage e0 generated in winding 25 by this leads the magnetic flux by 90° in phase, and can be expressed as in the following equation (2).

[0030]

number

[0031] In the formula, E0 is the amplitude of the induced voltage.

[0032] FIG. 3 is a graph showing an example of the waveforms of the induced voltage, the voltage of a single-phase motor, and the current of a single-phase motor with respect to the rotor position. In the figure, the dashed line indicates the induced voltage e0, and the solid line indicates the motor voltage v m , the dashed line indicates the motor current i m The voltage amplitude of a single-phase motor is V m , the amplitude of the current in a single-phase motor is I m It is.

[0033] In this figure, when the induced voltage e0 is used as the reference, the voltage v of the single-phase motor m and current i m The phase shifts are a voltage phase δ and a current phase φ, respectively.

[0034] Therefore, the voltage v of a single-phase motor m and current i m can be expressed by the following equations (3) and (4), respectively.

[0035]

number

[0036]

number

[0037] FIG. 4 is a graph showing the induced voltage, the voltage of the single-phase motor, and the current of the single-phase motor as a vector diagram in the dq plane.

[0038] In this figure, the d-axis can be considered to correspond to a cosine wave, and the q-axis to a negative sine wave. In other words, the above equations (3) and (4) include a negative sine wave (-sin).

[0039] The amplitude E0 of the induced voltage is expressed as a coordinate on the q-axis. The rotation speed of the dc-axis is ω1, the resistance of the winding 25 (Figure 2) is R, and the inductance of the winding 25 is L.

[0040] Single-phase motor voltage v m and current i m is expressed as a vector with a voltage phase δ and a current phase φ.

[0041] As shown in Figure 4, the motor voltage v m is the d-axis voltage V d and the q-axis voltage V q and can be expressed by the following formula (5).

[0042]

number

[0043] In the example of Figure 4, V d Since is a negative value, for example, V d If you want to consider V as a magnitude, you need to multiply it by -1 later. d and V q By calculating the magnitude of each of the above, multiplying them by a cosine wave and a sine wave, and then combining them, a single-phase AC voltage with any amplitude and phase can be generated.

[0044] <Overall configuration of the control unit> FIG. 5 is a configuration diagram illustrating an example of the control unit.

[0045] The control unit 10a shown in this figure is most effective in reducing the calculation load and is suitable for cases such as when the load torque of the single-phase motor 20 (FIG. 1) is small, when the induced voltage is relatively large and the motor current is small, and so on.

[0046] 5, control unit 10a includes a single-phase AC voltage command generator 11, a PWM signal generator 14, an integrator 15, and a simplified Fourier transformer 17. Single-phase AC voltage command generator 11 includes a voltage command generator 12 and a subtractor 191. Voltage command generator 12 includes an adder 90 and a multiplier 92. Simple Fourier transformer 17 includes a filter 13a.

[0047] The voltage command generator 12 generates a speed command value (ω * ), the output value of the filter 13a, and the output value from the integrator 15 are used as inputs to calculate V d and V q It outputs a voltage command value equivalent to K in Fig. 5. e means the induced voltage constant, and is related to the induced voltage e0, whose magnitude is determined in proportion to the rotation speed. The amplitude of the induced voltage E0 and the induced voltage constant K e The relationship between them can be expressed by the following equation (6).

[0048]

number

[0049] In FIG. 5, R denotes the resistance of the winding 25, and L denotes the inductance of the winding 25. The calculation of the voltage command generator 12 shown in the figure is to convert the output value of the filter 13a into I q * Then, V q and V d can be expressed by the following equations (7) and (8).

[0050]

number

[0051]

number

[0052] That is, V q The voltage equivalent to the speed command value (ω * ) with the induced voltage constant K e The result of multiplying this by the winding resistance R and the output value of the filter 13a is I q * The result of multiplying and is added by adder 90. d The voltage equivalent to is calculated by dividing the winding inductance L and the output value of the filter 13a by I q * The result of multiplication is multiplied by multiplier 92 to obtain the speed command value (ω * ) is obtained by multiplying

[0053] Incidentally, the configuration of the voltage command generator 12 shown in FIG. 5 is just an example, and the voltage command generator 12 may be configured in other forms.

[0054] In the control unit 10a shown in FIG. d is the speed command value (ω * ) by integrator 15. As described above, the d-axis can be considered as a cosine wave and the q-axis can be considered as a negative sine wave, so the above formula (7) is multiplied by a negative sine wave, and the above formula (8) is multiplied by a cosine wave, and then the difference between these values ​​is calculated by subtractor 191. The reason for using a multiplier is that the V calculated by the above formula (8) is d This is because is used as the magnitude in the calculation.

[0055] The control unit 10a detects the current value (i m ) is entered.

[0056] The motor current i shown in Fig. 3 m Although the waveform example in shows only the fundamental wave component that does not include higher harmonics, it may contain second or higher harmonics depending on the structure of the single-phase motor 20, i.e., the magnetic circuit. In this specification, attention is focused on the fundamental wave component in order to control the rotation speed or torque of the single-phase motor 20 to a desired value.

[0057] Therefore, we will use the simple idea of ​​Fourier transform.

[0058] In FIG. 5, a simplified Fourier transformer 17 including a filter 13a is used.

[0059] Motor current i m can be expressed by the above formula (4), but if the voltage applied to the single-phase motor 20, the rotation speed, the load torque, etc. change, the current phase φ changes. Even in a state where such changes occur, in order to easily obtain the q-axis current, which is the object of the present disclosure, V q The motor current i is multiplied by the voltage equivalent to the negative sine wave m The result of this multiplication is used to extract the DC component by the filter 13a. q By multiplying the voltage equivalent to the negative sine wave, we can obtain a sine wave of the same frequency and phase as the amplitude of the negative sine wave.

[0060] The voltage applied to the single-phase motor 20 (the voltage v m ) has a different phase from the q-axis, as can be seen from the vector diagram in Figure 4, and the voltage phase δ changes depending on the state of the motor, such as the rotation speed and load torque. In this way, even when the phases of the motor voltage and motor current change depending on the driving state, it is possible to easily determine the q-axis component of the motor current, that is, the current that is in phase with the induced voltage.

[0061] The simplified Fourier transformer 17 shown in FIG. 5 can change the amplitude of a sine wave or cosine wave that has the same frequency and phase as the reference waveform that can be extracted, by changing the AC waveform that is input as the reference waveform.

[0062] In other words, since the control unit 10a is configured to perform feedback control using the phase instead of the magnitude of the current, the number of variables to be integrated is reduced to one, making it possible to reduce the computation load.

[0063] <Simple Fourier transformer 17> FIG. 6 is a diagram showing the configuration of the simplified Fourier transformer 17 in FIG.

[0064] In this figure, a reference waveform and an input waveform are input to a multiplier of a simplified Fourier transformer 17, and an amplitude is output.

[0065] The input reference waveform is a sine wave or a cosine wave. From any input AC waveform, a sine wave or cosine wave with the same frequency and phase as the reference waveform is output.

[0066] <Example of phase control configuration> The above description shows a configuration example suitable for a case where the load torque of the single-phase motor 20 is small. In other words, there is no deviation between the d-axis and q-axis directions of the single-phase motor 20 and the dc-axis and qc-axis directions assumed in the control. Here, the dc-axis and qc-axis refer to the coordinates assumed in the control, i.e., the control coordinates.

[0067] When rotor 22 of single-phase motor 20 has permanent magnets 27 as shown in Fig. 2, it is classified as a permanent magnet synchronous motor. In such a case, rotor 22 basically rotates in synchronization with the magnetic poles of stator magnetic poles 28. However, when the load torque of single-phase motor 20 is large, a difference (phase difference) occurs between the angles of both shafts.

[0068] FIG. 7 is a graph showing a case where a phase difference occurs on the axes of the control coordinate system.

[0069] In this figure, when the d-axis based on the magnetic flux of the permanent magnet 27 of the rotor 22 is used as a reference, the phase difference between the d-axis and the dc-axis (so-called virtual d-axis) which is the axis of the control coordinate system is the axis error Δθ.

[0070] The rotation speed of the dc axis is ω1, while the rotation speed of the d axis is ω r It is.

[0071] Estimated q-axis current (I qc ) is expressed as a vector on the qc axis with respect to the axis error Δθ. qcThe q-axis and d-axis components of I q , I d It is.

[0072] In a single-phase motor 20 having a permanent magnet 27 in the rotor 22, when the AC voltage applied to the single-phase motor 20 is equal to or greater than a predetermined value, the single-phase motor 20 can be driven with an axis error Δθ occurring so that the torque generated by the single-phase motor 20 and the load torque of the motor are balanced. Therefore, there is no problem in adopting this type of drive. However, when it is desired to obtain the effect of reducing the current flowing through the single-phase motor 20, a configuration for controlling the axis error Δθ is added.

[0073] FIG. 8 is a configuration diagram showing an example of a control unit to which phase control is added.

[0074] In this figure, the control unit 10 has two simple Fourier transformers 17a and 17b. The reference waveforms input to the simple Fourier transformers 17a and 17b are V q The same negative sine wave multiplied by the voltage equivalent to V d By using the same cosine wave multiplied by the voltage corresponding to and, the current corresponding to the q axis and the current corresponding to the d axis can be detected.

[0075] The outputs of the respective simplified Fourier transformers 17a and 17b are input to an arctangent calculator 86, and a current phase φ c Here, the current phase φ c Although an arctangent calculator 86 is used to obtain the arctangent, other means may be used.

[0076] In this figure, a table reference unit 70 is used as a configuration for calculating a target value of the calculated current phase. The table reference unit 70 uses the q-axis current estimation value (I qc ) based on the target value of the current phase (φ * ) to output.

[0077] Current phase target value φ * and the obtained current phase φ cThe difference between the current phase φ and the frequency of the AC voltage or the equivalent AC voltage output by the single-phase power converter 30 is calculated by the proportional controller 16 using the difference. c is the target value of the current phase φ * 7, the dc axis assumed in the control is ahead of the d axis based on the magnetic flux of the permanent magnet 27 of the rotor 22. Therefore, the output of the proportional controller 16 (negative in this case) is set to the speed command value (ω * ) and reduce the rotation speed ω1 of the dc axis by that amount, the axis error Δθ will be reduced. As a result, the current phase φ c is the current phase target value φ * It is possible to make it operate in accordance with the above.

[0078] In summary, the speed command value (ω * ) and rotor position θ d Based on this, the drive signal is adjusted so that the phase difference between the current of the single-phase motor 20 and the voltage for driving the single-phase motor 20 becomes a predetermined value.

[0079] FIG. 9 is a configuration diagram showing a modification of the control unit 10 in FIG.

[0080] In FIG. 9, the table reference unit 70a calculates the q-axis current estimate (I qc ) and the speed command value (ω * ) and the target value of the current phase (φ * This modification is particularly suitable when the difference in inductance between the d-axis and the q-axis is large.

[0081] <Single-phase power converter 30 (single-phase inverter)> FIG. 10 is a configuration diagram showing a single-phase power converter 30. As shown in FIG.

[0082] The single-phase power converter 30 mainly includes an inverter 131, a DC voltage source 130, and a gate driver circuit 133. The inverter 131 includes switching elements 132a, 132b, 132c, and 132d (e.g., semiconductor switching elements such as IGBT, MOS-FET, GaN, and SiC). These switching elements 132a, 132b, 132c, and 132d are connected in series with the switching elements 132a and 132b and the switching elements 132c and 132d, respectively, to form two pairs of upper and lower arms. This is a so-called H-bridge circuit.

[0083] 1, switching operation is performed in response to pulse-like drive signals 134a, 134b, 134c, and 134d output by a gate driver circuit 133. By switching the DC voltage source 130 to output a voltage, a single-phase AC voltage of any frequency can be applied to the single-phase motor 20. This allows variable speed driving, position control driving, and torque control driving of the single-phase motor 20.

[0084] Furthermore, if a shunt resistor 135 is added to the DC side of the single-phase power converter 30 as shown in FIG. 10, it can be used as an overcurrent protection circuit for protecting the switching elements 132a, 132b, 132c, and 132d when an excessive current flows, or as a single shunt current detection method described later.

[0085] FIG. 11 is a graph showing a method for generating a drive signal using a standard triangular wave comparison method.

[0086] In this figure, an AC voltage command value and a triangular wave carrier signal for generating a drive signal are shown. The two are compared, and depending on which is larger, a drive signal Gp for the upper arm and a drive signal Gn for the lower arm are generated as shown in the figure.

[0087] Because there is a risk of the switching elements of the upper and lower arms shorting out due to delays in the gate driver circuit 133 or the switching elements themselves, a dead time (several microseconds to a dozen microseconds) during which both the upper and lower arms are switched off is actually added to the final drive signal. However, the dead time has no effect on the purpose and effects of the present disclosure, so an ideal drive signal is shown in this specification. Of course, a configuration in which the dead time is added may also be used.

[0088] <Current detection means 50> A current detection means 50 such as a CT (current transformer) can be provided on the lower arm of the inverter 131. This allows the current i flowing through the winding 25 of the single-phase motor 20 to be detected. m can be detected.

[0089] As the current detection means 50, for example, a phase shunt current method can be adopted in which, instead of a CT, a shunt resistor is added to the lower arm of the single-phase power converter 30 and the current flowing in a phase of the single-phase power converter 30 is detected from the current flowing in the shunt resistor.

[0090] Instead of or in addition to the current detection means 50, a single shunt current detection method may be adopted in which the current on the AC side of the single-phase power converter 30 is detected from the DC current flowing through a shunt resistor 135 added to the DC side of the single-phase power converter 30. The single shunt current detection method utilizes the fact that the current flowing through the shunt resistor 135 changes over time depending on the energization state of the switching element 122 that constitutes the single-phase power converter 30.

[0091] FIG. 12 is an external perspective view showing an example of a vacuum cleaner incorporating a motor control device according to the present disclosure.

[0092] As shown in the figure, the electric vacuum cleaner 200 is configured in a stick shape by combining a vacuum cleaner main body 202 provided with a hand-operated switch 207 etc., an extension tube 205, and a suction body 206. The electric vacuum cleaner 200 also includes a rechargeable battery 224 (secondary battery) which is the power source for driving the vacuum cleaner main body 202 and the suction body 206.

[0093] Cleaner body 202 includes electric blower 201 that generates suction force, dust collection section 222 that collects dust collected by the suction force of electric blower 201, and the like. Cleaner body 202 also includes a control device for rechargeable battery 224 built-in.

[0094] One end of the extension pipe 205 is connected to a connection port 223 of the vacuum cleaner body 202 so as to communicate with the dust collecting section 222 of the vacuum cleaner body 202. The other end of the extension pipe 205 is connected to the suction body 206. The extension pipe 205 has a ventilation passage (not shown) formed therein, and is provided with wiring (not shown) that electrically connects the rechargeable battery 224 and a brush motor (not shown) of the suction body 206.

[0095] When the hand-operated switch 207 is operated, a main body control device (not shown) including a motor control device controls the operation and stop of the electric blower 201, switching of the suction power, and the operation and stop of the electric motor (not shown) provided in the suction mouth body 206. The main body control device is provided in the vacuum cleaner body 202.

[0096] The vacuum cleaner is not limited to the stick type vacuum cleaner shown in the figure, but may be a rechargeable (cordless) vacuum cleaner such as a handheld vacuum cleaner, a canister vacuum cleaner (cylinder type vacuum cleaner), or a robot vacuum cleaner. The present invention may also be applied to a corded vacuum cleaner having a similar configuration.

[0097] In the above description, the motor control device according to the present disclosure is applied to a rechargeable vacuum cleaner, but the motor control device according to the present disclosure is not limited to the above description, and may have other configurations as long as the characteristics described in this specification are not impaired. For example, the motor control device according to the present disclosure can be applied to a rechargeable personal computer (PC), a mobile terminal such as a smartphone, a home router, an electric vehicle that controls a motor without using an external data center (server), etc.

[0098] The motor control device according to the present disclosure can reduce the computational load when controlling a motor, and eliminates the need to keep the rotation speed of the motor low immediately after startup, thus increasing the degree of freedom in motor control and improving the user experience.

[0099] Preferred embodiments of the present disclosure will be summarized below.

[0100] The motor control device further includes a table look-up unit and a proportional controller, wherein the filter calculates the current phase from the current information, the table look-up unit obtains a target value for the current phase using the current phase calculated by the filter, and the proportional controller calculates a manipulation amount for the voltage frequency from the difference between the target value for the current phase and the current phase.

[0101] The motor control device adjusts the amplitude of the voltage according to a value obtained by multiplying the current of the single-phase motor by the negative sine value of the rotor position and inputting the multiplied value to a filter, or a DC component.

[0102] The motor control device adjusts the amplitude of the voltage in accordance with the current of the single-phase motor when the phase difference is at a predetermined value.

[0103] The motor drive system includes a motor control device, a single-phase motor, a single-phase power converter, and a current detection unit.

[0104] The motor drive system can be applied to electric vacuum cleaners, electric vehicles, and the like.

[0105] The present disclosure is not limited to the above-described embodiment, and includes various modified examples. For example, the above-described embodiment has been described in detail to clearly explain the present disclosure, and the present disclosure is not necessarily limited to those including all of the described configurations.

[0106] In addition, the above-mentioned configurations, functions, processing units, processing procedures, etc. may be realized in part or in whole by hardware, for example, by designing them as integrated circuits, etc. In addition, the above-mentioned configurations and functions, etc. may be realized in software, by a processor interpreting and executing a program that realizes each function. [Explanation of symbols]

[0107] 10: control unit, 11: single-phase AC voltage command generator, 12: voltage command generator, 13: filter, 14: PWM signal generator, 15: integrator, 16: proportional controller, 17: simple Fourier transformer, 20: single-phase motor, 21: stator, 22: rotor, 25: winding, 26: stator core, 27: permanent magnet, 28: stator pole, 30: single-phase power converter, 50: current detection means, 70: table reference unit, 100: motor drive system.

Claims

1. A motor control device that receives information about a current flowing through a single-phase motor obtained by a current detection unit, and outputs a drive signal to a single-phase power converter to adjust a voltage for driving the single-phase motor, a filter to which the current information of the current detection unit is input; an integrator for calculating a rotor position of the single-phase motor; A single-phase AC voltage command generator; adjusting the drive signal based on a speed command value of the single-phase motor and the rotor position so that a phase difference between a current of the single-phase motor and the voltage for driving the single-phase motor becomes a predetermined value; A table reference portion; A proportional controller, The filter calculates a current phase from the current information, the table reference unit determines a target value of the current phase by using the current phase calculated by the filter; The proportional controller calculates a manipulated variable for a frequency of the voltage from a difference between the target value of the current phase and the current phase.

2. A motor control device that receives current information flowing through a single-phase motor obtained by a current detection unit, and outputs a drive signal for adjusting a voltage for driving the single-phase motor to a single-phase power converter, a filter to which the current information of the current detection unit is input; an integrator for calculating a rotor position of the single-phase motor; A single-phase AC voltage command generator; adjusting the drive signal based on a speed command value of the single-phase motor and the rotor position so that a phase difference between a current of the single-phase motor and the voltage for driving the single-phase motor becomes a predetermined value; a motor control device that adjusts the amplitude of the voltage according to a value obtained by multiplying the current of the single-phase motor by a negative sine value of the rotor position and inputting the multiplied value to the filter or a DC component.

3. 3. The motor control device according to claim 1, further comprising: a control circuit for controlling a current of the single-phase motor and a control circuit for controlling a current of the single-phase motor;

4. A motor control device according to claim 1 or 2, The single-phase motor; The single-phase power converter; A motor drive system comprising the current detection unit.

5. A vacuum cleaner comprising the motor drive system according to claim 4.

6. An electric vehicle comprising the motor drive system according to claim 4.

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