Motor control device, motor control method, and washing machine

Abstract

To control appropriate braking control on a permanent magnet synchronous motor.SOLUTION: A motor control device is provided with a phase current acquisition unit 22 that acquires phase currents Iu, Iv, Iw supplied to respective phases of the permanent magnet synchronous motor driven by a power converter, voltage command calculation units 24u, 24v, 24w that output voltage command values Vu*, Vv*, Vw* for decelerating the permanent magnet synchronous motor on the basis of the results of proportional and differential operations on the phase currents Iu, Iv, Iw, and a command signal generation unit that outputs a command signal that specifies the operation of the power converter on the basis of the voltage command values Vu*, Vv*, Vw*.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a motor control device, a motor control method, and a washing machine. [Background technology]

[0002] Since a permanent magnet synchronous motor needs to energize the stator coil according to the magnetic pole position in the rotor, a position detection sensor that detects the position information of the rotor may be provided. However, providing a position detection sensor increases the cost of the sensor and increases the risk of sensor failure. Therefore, many methods have been proposed for driving a permanent magnet synchronous motor by position sensorless control without using a position detection sensor. Furthermore, a brake may be applied to a permanent magnet synchronous motor as necessary. The following Patent Documents 1 and 2 describe techniques for performing brake control on a permanent magnet synchronous motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-84780 A [Patent Document 2] JP 2005-057880 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, there is a demand for more appropriate braking control for permanent magnet synchronous motors. The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a motor control device, a motor control method, and a washing machine that are capable of executing appropriate brake control for a permanent magnet synchronous motor. [Means for solving the problem]

[0005] In order to solve the above problems, the motor control device of the present invention is characterized by comprising: a phase current acquisition unit that acquires phase currents supplied to each phase of a permanent magnet synchronous motor driven by a power converter; a voltage command calculation unit that outputs a voltage command value for decelerating the permanent magnet synchronous motor based on a result of proportional and differential calculations performed on the phase currents; and a command signal generation unit that outputs a command signal for specifying the operation of the power converter based on the voltage command value. Effect of the Invention

[0006] According to the present invention, appropriate brake control can be executed for a permanent magnet synchronous motor. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram of a motor control device according to a first embodiment. [Diagram 2] FIG. 2 is a detailed block diagram of a power converter. [Diagram 3] FIG. 4 is an explanatory diagram of a short circuit brake mode. [Figure 4] FIG. 1 is an explanatory diagram of a single shunt current detection mode. [Diagram 5] FIG. 2 is a block diagram of a brake controller. [Figure 6] FIG. 4 is a simplified block diagram showing a transfer function in the first embodiment. [Figure 7] 4 is a flowchart of a stop processing routine executed in the controller. [Figure 8] FIG. 11 is a block diagram of a main part of a controller according to a second embodiment. [Figure 9] FIG. 13 is a block diagram of a voltage command calculation unit applied to a third embodiment. [Figure 10] This is the gain characteristic of the high-pass filter section. [Figure 11] FIG. 11 is a schematic cross-sectional view of a vertical washing machine according to a fourth embodiment. [Figure 12] FIG. 1 is a block diagram of a computer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Overview of the embodiment] For example, in a product such as a washing machine, for safety reasons, door locks and the like are released after the permanent magnet synchronous motor (motor) that rotates the washing tub is stopped. For this reason, it is desirable to stop the motor quickly. It is considered that the technology of Patent Document 1 mentioned above can be applied as a technology for stopping the motor, thereby controlling the q-axis current and generating a brake torque to stop the motor. This technology requires that the q-axis direction of the motor be known, and magnetic pole position information is required. During normal operation, in both systems, whether a system with a position sensor or a position sensorless control system, the magnetic pole position information is known, so the q-axis direction can be known and the q-axis current can be controlled to generate a brake torque.

[0009] Moreover, by applying the technology of the above-mentioned Patent Document 2, it is considered possible to estimate reactive power based on the phase current and rotational frequency command value of the motor and control the brake force. This technology assumes a brake operation during driving under V / f control, and requires motor rotational frequency command information. In a position sensorless control system, for example, a momentary power outage causes a reset operation in a controller such as a microcomputer. When the calculation information is reset in this way, magnetic pole position information, rotational frequency command information, etc. are lost, making appropriate brake control difficult. Therefore, the embodiment described below is intended to stop the motor for a short time even when the motor rotational speed and magnetic pole position information are unknown.

[0010] [First embodiment] Configuration of the First Embodiment FIG. 1 is a block diagram of a motor control device 100 according to the first embodiment. The motor control device 100 includes a controller 110 and a power converter 150. The controller 110 includes a brake controller 112 and a switching command generating unit 114 (command signal generating unit). The switching command generating unit 114 outputs a switching command signal CS (command signal) to the power converter 150. The brake controller 112 will be described later.

[0011] The power converter 150 generates a PWM (Pulse Width Modulation) voltage based on a switching command signal CS. This PWM voltage is applied to a motor 200 (permanent magnet synchronous motor) via wiring 20U, 20V, and 20W. The power converter 150 includes a current detection unit 158. The current detection unit 158 ​​detects a current Idc flowing through a bus of the power converter 150, and outputs the detection result. The motor control device 100 can be configured, for example, as a control board in which the power converter 150 and the controller 110 are integrated together.

[0012] When performing brake control on the motor 200, the brake controller 112 outputs voltage command values ​​Vu*, Vv*, and Vw* of U-phase, V-phase, and W-phase voltages to be applied to the motor 200 to the switching command generator 114. As a result, the switching command generator 114 outputs a switching command signal CS based on the voltage command values ​​Vu*, Vv*, and Vw*. The brake controller 112 performs proportional and differential calculations on the detection result of the current Idc detected by the current detector 158, and outputs the result as the voltage command values ​​Vu*, Vv*, and Vw*. In addition, the brake controller 112 determines whether the motor 200 has stopped based on the current Idc, and outputs the result as a stop determination signal JS. The stop determination signal JS is "0" while the motor 200 is rotating, and is "1" while the motor 200 is stopped. Here, "1" (stopped) does not necessarily mean that the motor 200 is completely stopped, but may also mean that the motor is rotating at a slow speed that can be considered stopped, depending on the application of the motor 200.

[0013] FIG. 2 is a detailed block diagram of power converter 150. Power converter 150 includes rectifier circuit 151, voltage sensor 154, inverter circuit 156, and the above-mentioned current detection unit 158. Rectifier circuit 151 includes diode bridge circuit 152 and smoothing capacitor 153. Thus, rectifier circuit 151 rectifies an AC voltage supplied from AC voltage source 220 (e.g., a commercial power source) into a DC voltage.

[0014] The voltage sensor 154 detects the terminal voltage of the capacitor 153, i.e., the DC voltage Vdc output by the rectifier circuit 151, and outputs the detection result. The inverter circuit 156 includes six switching elements S1 to S6 that perform PWM switching on the DC voltage Vdc, and six diodes D connected in reverse parallel to the switching elements S1 to S6. The switching elements S1 to S6 are, for example, IGBTs, and switch each switching element based on a switching command from the switching command generating unit 114 to apply a PWM voltage to the motor 200.

[0015] However, the switching elements S1 to S6 may be other semiconductor elements, etc. Combinations of switching elements S1 and S2, S3 and S4, and S5 and S6 control the energization of the U-phase, V-phase, and W-phase of the motor 200. Wires 1P and 1N are respectively wires on the positive potential side and the negative potential side of the DC voltage Vdc. The current detection unit 158 ​​includes a shunt resistor (not shown) inserted in the wire 1N, and detects the current Idc based on the voltage drop across the shunt resistor.

[0016] FIG. 3 is an explanatory diagram of the short circuit brake mode. In this embodiment, the short circuit brake mode is not necessarily executed, but the short circuit brake mode will be described for reference. In the short circuit brake mode, the switching elements S1, S3, and S5 in the inverter circuit 156 are turned off, and the switching elements S2, S4, and S6 are turned on. This causes the current of each phase of the motor 200 to circulate via the switching elements S2, S4, and S6, thereby allowing the motor 200 to decelerate and stop.

[0017] FIG. 4 is an explanatory diagram of the one-shunt current detection mode. 4 shows, as an example, the state of the inverter circuit 156 when detecting the U-phase current Iu. When detecting the U-phase current Iu, the switching elements S1, S4, and S6 are turned on, and the switching elements S2, S3, and S5 are turned off. As a result, the current Idc becomes equal to the phase current Iu, and therefore the phase current Iu can be detected by detecting the current Idc.

[0018] Similarly, the V-phase current Iv can be detected by turning on switching elements S2, S3, and S6 and turning off the other elements. Similarly, the W-phase current Iw can be detected by turning on switching elements S2, S4, and S5 and turning off the other elements. Since the relationship "Iu+Iv+Iw=0" holds for the phase currents of motor 200, the currents for three phases can be calculated by executing at least two of these switching patterns.

[0019] FIG. 5 is a block diagram of the brake controller 112. The brake controller 112 includes a current restoration unit 22 (phase current acquisition unit) and voltage command calculation units 24u, 24v, and 24w. The current restoration unit 22 converts the current Idc detected by the current detection unit 158 ​​(see FIG. 2) into phase currents Iu, Iv, and Iw of the respective phases in accordance with a switching pattern based on a switching command signal CS.

[0020] As shown in Fig. 4, only one of the phase currents Iu, Iv, and Iw can be measured at a certain timing. Therefore, the current restoration unit 22 outputs continuous phase currents Iu, Iv, and Iw by interpolating the discrete phase currents Iu, Iv, and Iw. The voltage command calculation units 24u, 24v, and 24w perform proportional and differential calculations on the phase currents Iu, Iv, and Iw, respectively, and output the results as voltage command values ​​Vu*, Vv*, and Vw*. The transfer functions of the voltage command calculation units 24u, 24v, and 24w are all "Kp+sKd," where Kp is the proportional gain, Kd is the differential gain, and s is the parameter of the Laplace transform.

[0021] Next, the principle of decelerating and stopping the motor 200 by the brake controller 112 will be described. FIG. 6 is a simplified block diagram showing a transfer function in the first embodiment. That is, Fig. 6 shows the transfer functions of one phase of the motor 200 and one phase of the motor control device 100. Note that in the example of Fig. 6, a simplified block diagram of the U phase is shown. However, in Fig. 6, for the sake of simplicity, interference terms occurring in the power converter 150 and each phase of the motor 200 are ignored.

[0022] In Fig. 6, the induced voltage generated in the U-phase of motor 200 is designated as Emu. The impedance of the U-phase of motor 200 includes inductance Lu and resistance value Ru. When U-phase voltage Vu is output from power converter 150 (see Fig. 1), the result obtained by subtracting induced voltage Emu from this voltage Vu is called voltage Vmu. This voltage Vmu becomes the voltage applied to inductance Lu and resistance value Ru of the U-phase in motor 200. The transfer function with induced voltage Emu as input and phase current Iu as output can be expressed by the following [Equation 1].

[0023]

number

[0024] In the above-mentioned [Equation 1], if the proportional gain Kp and the differential gain Kd are both set to zero (i.e., the output voltage is set to zero), a phase current Iu flows, using the induced voltage Emu generated by the rotation of the motor 200 as an energy source. This phase current Iu, which flows using the induced voltage Emu as an energy source, becomes a brake current that decelerates and stops the motor 200. This state is the same as when the short-circuit brake mode shown in FIG. 3 is executed.

[0025] In [Equation 1], the factor "1 / (Ru-Kp)" corresponds to the proportional gain, and by increasing Kp, the motor resistance value Ru can be equivalently reduced. In other words, a larger current can be passed for the same induced voltage Emu, and the braking force can be increased. However, the variable range of the proportional gain Kp is restricted to be equal to or less than the resistance value Ru so that the sign of "1 / (Ru-Kp)" does not become negative. Also, in [Equation 1], the factor "1 / (1+s(Lu-Kd) / (Ru-Kp))" has the characteristics of a first-order lag filter, and increasing the proportional gain Kp reduces the time constant of the filter. Therefore, by using the differential gain Kd, the reduced responsiveness can be adjusted. However, the variable range of the differential gain Kd is restricted to be equal to or less than Lu.

[0026] Operation of the First Embodiment FIG. 7 is a flowchart of a stop processing routine executed in the controller 110. This routine is executed when the controller 110 is reset due to, for example, a power outage. When the process proceeds to step S102 in this routine, the brake controller 112 sets the voltage command values ​​Vu*, Vv*, and Vw* to the same value. In other words, the switching state of the power converter 150 is made the same for all phases of the motor 200. For example, it is possible to set all of the voltage command values ​​Vu*, Vv*, and Vw* to "0". However, although the voltage command values ​​Vu*, Vv*, and Vw* are not limited to "0", it is preferable to avoid all of the switching elements S1 to S6 being in the off state at the same time.

[0027] Next, when the process proceeds to step S104 (phase current acquisition process), the brake controller 112 executes a current detection process to acquire phase currents Iu, Iv, and Iw. For example, the one-shunt current detection mode as shown in Fig. 4 may be executed for any two of the U phase, V phase, and W phase, and the current value of the remaining one phase may be detected by subtracting both of them from "0".

[0028] Next, when the process proceeds to step S106 (voltage command calculation process), the brake controller 112 calculates the voltage command values ​​Vu*, Vv*, and Vw*. That is, these voltage command values ​​are calculated by "Vu = (Kp + sKd) Iu", "Vv = (Kp + sKd) Iv", and "Vw = (Kp + sKd) Iw".

[0029] Next, when the process proceeds to step S108 (command signal generation process), the brake controller 112 executes a voltage output process. That is, the brake controller 112 outputs the calculated voltage command values ​​Vu*, Vv*, Vw* to the switching command generating unit 114. As a result, the switching command generating unit 114 outputs a switching command signal CS so that the power converter 150 outputs voltages according to these voltage command values ​​Vu*, Vv*, Vw*.

[0030] Next, when the process proceeds to step S110, the brake controller 112 determines whether a predetermined stop determination condition is satisfied. Here, the "stop determination condition" is that "all of the phase currents Iu, Iv, and Iw are less than a predetermined threshold value Ith." In other words, the stop determination condition is that "the motor 200 has completely stopped, or is rotating at a speed so slow that it may be considered to be stopped depending on the application."

[0031] If the determination in step S110 is "No", the process returns to step S104, and the operations of steps S104 to S108 are repeated. On the other hand, if the determination in step S110 is "Yes", the process proceeds to step S112. In step S112, the brake controller 112 stops the voltage output by the power converter 150. Next, when the process proceeds to step S114, the brake controller 112 outputs a stop determination signal to an external higher-level device (not shown). This ends the process of this routine.

[0032] As described above, according to this embodiment, the brake controller 112 calculates the voltage command values ​​Vu*, Vv*, Vw* by performing proportional and differential calculations on the detected phase currents Iu, Iv, Iw. The switching command generator 114 generates a switching command signal CS, which is a PWM signal, based on the calculated voltage command values ​​Vu*, Vv*, Vw*, and the power converter 150 applies a voltage to the motor 200 based on the switching command signal CS. This makes it possible to increase the brake current flowing through the motor 200 without using the magnetic pole position of the motor 200, and allows the motor 200 to decelerate and stop in a short time even when the magnetic pole position of the motor 200 is unknown.

[0033] [Second embodiment] Next, a description will be given of a motor control device according to a second embodiment. The hardware configuration of the motor control device according to the second embodiment is similar to that of the first embodiment (see FIG. 1). In the first embodiment and the present embodiment, the regenerative power generated during braking charges the capacitor 153, causing the DC voltage Vdc to rise. At that time, if the regenerative power is large, the DC voltage Vdc may become an overvoltage state. Therefore, in the present embodiment, the regenerative power is appropriately suppressed by adjusting the gain of the brake controller 112 according to the DC voltage Vdc.

[0034] FIG. 8 is a block diagram of a main part of a controller 110 in the second embodiment. The controller 110 in this embodiment includes a gain designation unit 116. The gain designation unit 116 calculates a differential gain Kd and a proportional gain Kp based on the DC voltage Vdc, and instructs the brake controller 112. The brake controller 112 calculates voltage command values ​​Vu*, Vv*, and Vw* using the designated differential gain Kd and proportional gain Kp.

[0035] Table 117 is stored in gain specification unit 116 and represents the relationship between DC voltage Vdc and proportional gain Kp. VdcMAX is the upper limit level of the DC voltage of the capacitor. That is, when the DC voltage Vdc is sufficiently lower than the upper limit level VdcMAX, gain specification unit 116 increases the proportional gain Kp to obtain a high braking force. As the DC voltage Vdc increases, the proportional gain Kp is decreased, and the proportional gain Kp is set to "0" at a value slightly lower than the upper limit level VdcMAX.

[0036] As described above, the proportional gain Kp needs to be set to a value smaller than the resistance value Ru of the motor 200. However, the resistance value Ru changes depending on the temperature condition of the motor 200, etc. Therefore, the maximum value of the proportional gain Kp is set to the resistance value R0 with a slight margin. In this way, by specifying the proportional gain Kp according to the DC voltage Vdc, it is possible to prevent the voltage of the capacitor from increasing suddenly and becoming an overvoltage. In addition, the gain specifying unit 116 calculates the differential gain Kd based on the simultaneous equations of [Equation 2] and [Equation 3]. In [Equation 2], Tb is the response time constant of the brake current.

[0037]

number

[0038]

number

[0039] The gain specifying unit 116 calculates the differential gain Kd based on [Equation 2] and [Equation 3], so that the same current response can be obtained even when the proportional gain Kp changes. As described above, according to this embodiment, the proportional gain Kp and the differential gain Kd in the brake controller 112 are set according to the DC voltage Vdc, so that the motor 200 can be decelerated in a short time while suppressing an increase in the DC voltage Vdc.

[0040] [Third embodiment] Next, a motor control device according to a third embodiment will be described. The hardware configuration of the motor control device according to the third embodiment is similar to that of the motor control device according to the first or second embodiment (see FIG. 1). The induced voltage Emu generated by the rotation of the motor 200 is an AC quantity, and ideally becomes "0" when the motor 200 is stopped. However, due to an offset error or the like generated in the current detection unit 158, there is a possibility that the current detection unit 158 ​​may erroneously detect the current Idc, which is a DC current that is not "0", when the motor 200 is stopped.

[0041] In the above-described first embodiment, there is a risk that the brake controller 112 continues to output the voltage command values ​​Vu*, Vv*, and Vw* due to this erroneously detected current Idc even when the motor 200 is stopped. Therefore, in this embodiment, the gain characteristic of the DC component of the current Idc in the brake controller 112 is set to 0 dB or less, thereby attenuating the DC component and preventing a detection error.

[0042] FIG. 9 is a block diagram of a voltage command calculation unit 26u applied to the third embodiment. In this embodiment, instead of the voltage command calculation unit 24u (see FIG. 5) in the first and second embodiments, a voltage command calculation unit 26u shown in FIG. 9 is applied. Also, in this embodiment, instead of the voltage command calculation units 24v and 24w in the first embodiment, voltage command calculation units 26v and 26w (not shown) configured similarly to the voltage command calculation unit 26u are applied.

[0043] 9, the voltage command calculation unit 26u includes a proportional / differential calculation unit 262 and a high-pass filter unit 264. The transfer function of the proportional / differential calculation unit 262 is "Kp+sKd", which is the same as the transfer function of the voltage command calculation units 24u, 24v, and 24w in the first embodiment. The output signal of the proportional / differential calculation unit 262 is called a proportional / differential signal. The transfer function of the high-pass filter unit 264 is "s / (1+Th·s)". Here, Th is the cutoff frequency and is a design value.

[0044] FIG. 10 shows the gain characteristic of the voltage command calculation unit. The horizontal axis of Fig. 10 represents the frequency components of the proportional / differential signals, and the vertical axis represents the gain. G26 represents the gain characteristic in the voltage command calculation units 26u, 26v, and 26w of this embodiment, and G24 represents the gain characteristic in the voltage command calculation units 24u, 24v, and 24w of the first and second embodiments. As shown in the figure, according to the gain characteristic G26, the gain in the low frequency region included in the proportional / differential signal is 0 dB or less. As a result, according to this embodiment, even if a detection error of the current Idc occurs due to an offset error in the current detection unit 158 ​​or the like, appropriate voltage command values ​​Vu*, Vv*, and Vw* can be output, and the motor 200 can be decelerated and stopped in a short time.

[0045] [Fourth embodiment] 11 is a schematic cross-sectional view of a vertical washing machine 300 according to the fourth embodiment. In the following description, the same reference numerals are used to designate parts corresponding to those in the other embodiments described above, and the description thereof may be omitted. In Fig. 11, a vertical washing machine 300 (washing machine) includes a housing 6 and an outer lid 5 attached to the housing 6. The vertical washing machine 300 also includes a water tub 7, a washing tub 3, a motor 200, and a motor control device 100 inside the housing 6 and the outer lid 5. The motor control device 100 is any one of the motor control devices according to the first to third embodiments described above. A door lock unit 11 locks the outer lid 5 in a closed state.

[0046] In the washing process, laundry is put into the washing tub 3, washing water is stored in the water tub 7 from the water supply device 8, and the laundry is washed by rotating only the agitating blade 4 connected to the motor 200. In the spin-drying process, the clutch 9 connected to the motor 200 is switched, and both the washing tub 3 and the agitating blade 4 are rotated to spin the laundry by centrifugal force.

[0047] As described above, the stop determination signal JS is "0" while the motor 200 is rotating, and is "1" while the motor is stopped. Here, "1" (stopped) does not necessarily mean that the motor 200 is completely stopped, but may also mean that the motor is moving at a low speed that is safe for the user to touch the washing tub 3. When the stop determination signal JS becomes "1", the door lock unit 11 releases the locked state of the outer lid 5, allowing the outer lid 5 to be opened or closed.

[0048] [Computer Configuration] FIG. 12 is a block diagram of a computer 980 . The controller 110 in each of the first to fourth embodiments includes one or more computers 980 shown in FIG. 12. In FIG. 12, the computer 980 includes a CPU (Central Processing Unit) 981, a storage unit 982, a communication I / F (Interface) 983, an input / output I / F 984, and a DSP (Digital Signal Processor) 985. Here, the storage unit 982 includes a RAM 982a and a ROM 982b. The communication I / F 983 is connected to a communication circuit 986. The input / output I / F 984 is connected to an input / output device 987. The ROM 982b stores control programs and various data executed by the CPU 981 and the DSP 985. The CPU 981 and the DSP 985 execute these control programs to realize various functions. The inside of the controller 110 shown in FIG. 1 is shown as a block diagram of functions realized by the control programs and the like.

[0049] [Variations] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. The above-mentioned embodiment is exemplified to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. In addition, the control lines and information lines shown in the figure show those that are considered necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In reality, it may be considered that almost all the configurations are connected to each other. Possible modifications of the above-mentioned embodiment are, for example, as follows.

[0050] (1) In each of the above embodiments, the inverter circuit 156 PWM-modulates the DC voltage Vdc. However, the modulation method of the inverter circuit 156 is not limited to PWM modulation and may be, for example, step wave modulation.

[0051] (2) In each of the above embodiments, the current detection unit 158 ​​is inserted into the wiring 1N (see FIG. 2), and one-shunt current detection is performed in step S104 (see FIG. 7). However, instead of this method, a detection unit similar to the current detection unit 158 ​​may be inserted into at least two phases of the wirings 20U, 20V, and 20W (see FIG. 2). This makes it possible to constantly detect continuous phase currents Iu, Iv, and Iw, so that step S104 in FIG. 7 can be omitted.

[0052] (3) In each of the above embodiments, the motor 200 is a three-phase permanent magnet synchronous motor. However, the motor 200 may be a multi-phase motor having three or more phases.

[0053] (4) In the third embodiment, the high-pass filter unit 264 is provided in the voltage command calculation units 26u, 26v, and 26w. However, instead of the high-pass filter unit 264, for example, a band-pass filter unit (not shown) that passes only a frequency band that satisfies the operating range of the motor 200 may be provided. By doing so, it is possible to prevent the gain characteristics of high-frequency components from becoming excessive.

[0054] (5) In the fourth embodiment, an example in which the present invention is applied to a vertical washing machine has been described. However, the present invention may also be applied to a drum type washing machine or a washer-dryer.

[0055] (6) Since the hardware of the controller 110 in the above embodiment can be realized by a general-purpose computer, the processes corresponding to the above-mentioned block diagrams and flowcharts, as well as programs for executing the various processes described above, may be stored on a storage medium (a computer-readable storage medium on which a program is recorded) or distributed via a transmission path.

[0056] (7) In the above-described embodiments, the processes corresponding to the block diagrams and flowcharts, as well as the various other processes described above, have been described as software-based processes using a program. However, some or all of them may be replaced with hardware-based processes using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), etc.

[0057] [Effects of the embodiment] As described above, according to each of the embodiments, the motor control device 100 includes a phase current acquisition unit (22) that acquires phase currents Iu, Iv, Iw supplied to each phase of the permanent magnet synchronous motor (200) driven by the power converter 150, voltage command calculation units 24u, 24v, 24w, 26u, 26v, 26w that output voltage command values ​​Vu*, Vv*, Vw* for decelerating the permanent magnet synchronous motor (200) based on a result of proportional and differential calculations performed on the phase currents Iu, Iv, Iw, and a command signal generation unit (114) that outputs a command signal (CS) that specifies the operation of the power converter 150 based on the voltage command values ​​Vu*, Vv*, Vw*.

[0058] This makes it possible to execute appropriate brake control on the permanent magnet synchronous motor (200). That is, voltage command calculation units 24u, 24v, 24w, 26u, 26v, 26w calculate voltage command values ​​Vu*, Vv*, Vw* based on the results of proportional and differential calculations performed on phase currents Iu, Iv, Iw. This makes it possible to increase the brake current flowing through the permanent magnet synchronous motor (200) without using the magnetic pole position of the permanent magnet synchronous motor (200), and to decelerate and stop the permanent magnet synchronous motor (200) in a short time even when the magnetic pole position is unknown.

[0059] Moreover, as in the second embodiment, the power converter 150 receives a DC voltage Vdc, which is the terminal voltage of the capacitor 153, from a rectifier circuit 151 including a capacitor 153, and it is more preferable that the power converter 150 further includes a gain specification unit 116 that changes a proportional gain Kp and a differential gain Kd used in the proportional and differential calculations according to the DC voltage Vdc.

[0060] In this manner, by changing the proportional gain Kp and the differential gain Kd in response to the DC voltage Vdc, the permanent magnet synchronous motor (200) can be decelerated in a short time while suppressing an increase in the DC voltage Vdc.

[0061] Furthermore, as in the third embodiment, it is more preferable that the voltage command calculation units 26u, 26v, 26w include a proportional / differential calculation unit 262 that performs proportional / differential calculations on the phase currents Iu, Iv, Iw, and a high-pass filter unit 264 that performs high-pass filtering on the output of the proportional / differential calculation unit 262. As a result, even if a detection error occurs in the phase currents Iu, Iv, Iw, appropriate voltage command values ​​Vu*, Vv*, Vw* can be output, and the permanent magnet synchronous motor (200) can be decelerated and stopped in a short time.

[0062] Moreover, as in the modified example, it is more preferable that the voltage command calculation units 26u, 26v, 26w include a proportional / differential calculation unit 262 that performs proportional / differential calculations on the phase currents Iu, Iv, Iw, and a band-pass filter unit that passes the drive frequency band of the permanent magnet synchronous motor (200) to the output of the proportional / differential calculation unit 262. By applying the band-pass filter unit, it is possible to prevent the gain characteristics of high frequency components from becoming excessive.

[0063] Moreover, the power converter 150 switches the DC voltage Vdc and applies it to the permanent magnet synchronous motor (200), and more preferably further has a function of making the switching state of the power converter 150 the same for all phases of the permanent magnet synchronous motor (200) before the phase current acquisition unit (22) acquires the phase currents Iu, Iv, Iw. This makes it possible to decelerate the permanent magnet synchronous motor (200) before the phase current acquisition unit (22) acquires the phase currents Iu, Iv, Iw.

[0064] Moreover, it is more preferable that the motor control device 100 operates the voltage command calculation units 24u, 24v, 24w, 26u, 26v, and 26w and the command signal generation unit (114) when the motor control device 100 is reset. This makes it possible to stop the permanent magnet synchronous motor (200) when, for example, an instantaneous power outage occurs and the motor control device 100 is reset. [Explanation of symbols]

[0065] 3 Washing tub 4 Stirring blade 22 Current restoration unit (phase current acquisition unit) 24u, 24v, 24w, 26u, 26v, 26w Voltage command calculation unit 100 Motor control device 114 Switching command generating unit (command signal generating unit) 116 Gain specification section 150 Power Converter 151 Rectifier circuit 153 Capacitor 200 Motor (permanent magnet synchronous motor) 262 Proportional and differential calculation section 264 High-pass filter section 300 Vertical washing machine (washing machine) CS Switching command signal (command signal) S104 step (phase current acquisition process) S106 Step (Voltage command calculation process) S108 Step (command signal generation process) Iu phase current Kd Differential Gain Kp Proportional Gain Vdc DC voltage Iu,Iv,Iw Phase current Vu*, Vv*, Vw* Voltage command value

Claims

1. a phase current acquisition unit that acquires a phase current supplied to each phase of a permanent magnet synchronous motor driven by a power converter; a voltage command calculation unit that outputs a voltage command value for decelerating the permanent magnet synchronous motor based on a result of performing proportional and differential calculations on the phase current; a command signal generating unit that outputs a command signal for specifying an operation of the power converter based on the voltage command value. A motor control device comprising:

2. the power converter receives a DC voltage, which is a terminal voltage of a capacitor, from a rectifier circuit including a capacitor; The control circuit further includes a gain specifying unit that changes a proportional gain and a differential gain used in the proportional and differential calculations in accordance with the DC voltage.

2. The motor control device according to claim 1 .

3. The voltage command calculation unit a proportional / differential calculation unit that performs the proportional / differential calculation on the phase current; a high-pass filter unit that performs high-pass filtering on the output of the proportional / differential calculation unit; 2. The motor control device according to claim 1 .

4. The voltage command calculation unit a proportional / differential calculation unit that performs the proportional / differential calculation on the phase current; a bandpass filter unit that passes a drive frequency band of the permanent magnet synchronous motor with respect to an output of the proportional / differential calculation unit.

2. The motor control device according to claim 1 .

5. The power converter switches a DC voltage and applies it to the permanent magnet synchronous motor, The power converter may further include a function of making the switching states of the power converter for all phases of the permanent magnet synchronous motor the same before the phase current acquisition unit acquires the phase current.

2. The motor control device according to claim 1 .

6. The motor control device operates the voltage command calculation unit and the command signal generation unit when the motor control device is reset.

2. The motor control device according to claim 1 .

7. a phase current acquisition step of acquiring a phase current supplied to each phase of a permanent magnet synchronous motor driven by a power converter; a voltage command calculation step of outputting a voltage command value for decelerating the permanent magnet synchronous motor based on a result of performing proportional and differential calculations on the phase current; a command signal generating step of outputting a command signal for specifying an operation of the power converter based on the voltage command value. A motor control method comprising:

8. A motor control device according to any one of claims 1 to 6, The permanent magnet synchronous motor; A washing tub into which laundry is put; and an agitating blade for agitating the laundry. The permanent magnet synchronous motor rotates the washing tub or the agitating blade. A washing machine characterized by:

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