JP3689327B2 - Motor control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor control device for controlling and driving a synchronous motor constituted by a rotor with a permanent magnet mounted without a position sensor, and more particularly to a configuration for switching the synchronous motor drive system in accordance with a disturbance. It is.
[0002]
[Prior art]
Conventionally, in a sensorless driving method in which a synchronous motor is controlled and driven without using a motor rotor position sensor, when energizing the motor coil, an energization stop period is provided for a certain period, and the motor coil is rotated by the motor during that period. Intermittent energization driving is performed in which the generated counter electromotive voltage is detected from the motor coil terminal and the energization timing to the motor is determined from the counter electromotive voltage. Among such energization drive systems, a so-called 120 degree energization drive system in which the energization angle is 120 degrees is particularly common.
[0003]
In contrast, a resistance is connected in parallel with the three-phase motor coil neutral point and the three-phase coil, and the motor starting voltage is detected by comparing the voltage between the neutral point and the resistance neutral point. Based on the phase difference between the motor drive voltage and the motor current, or the method of driving the motor by detecting the motor position by calculating the motor current at a high speed There is a so-called 180-degree energization drive, such as sine wave energization, in which the synchronous motor is driven without providing an energization stop period by a method of driving by determining the energization timing.
[0004]
In general, the 180-degree energization drive method has less torque fluctuation and rotation fluctuation due to the smoothness of the drive waveform than the 120-degree energization drive.
[0005]
[Problems to be solved by the invention]
By the way, in a synchronous motor having a permanent magnet rotor structure, so-called optimization of energization timing, in which the motor is energized at an accurate timing corresponding to the permanent magnet position, is an absolute condition for motor driving. Furthermore, in addition to the absolute conditions, in order to increase efficiency and stabilize rotation, it is necessary to set the energization timing to an optimum value determined for each rotation condition.
[0006]
In intermittent energization driving such as 120-degree energization driving, the back electromotive force related to the permanent magnet magnetic flux and the armature magnetic flux is directly detected, and the permanent magnet position, that is, the rotational position is actually detected. For this reason, it is possible to drive the motor at an accurate energization timing by removing noise and improving detection accuracy. That is, since the motor rotation position is directly detected, problems such as motor stop are less likely to occur even when a disturbance occurs.
[0007]
On the other hand, the 180 ° energization drive without position sensor has higher efficiency, lower noise, and lower vibration than the intermittent energization drive including 120 ° energization drive, but it is generally difficult to drive and control. There are challenges. This is because the motor rotational position is not directly detected or the detection accuracy of the energization timing is low, and problems such as motor stop are likely to occur due to disturbance.
[0008]
For example, in the 180-degree energization driving method in which the energization timing is determined by comparing the coil neutral point and the resistance neutral point, the energization timing of the drive voltage is controlled. However, the motor current is actually caused by the motor torque. In 180-degree energization driving without a pause period, a phase difference occurs between the driving voltage and the motor current due to the influence of the counter electromotive voltage of the permanent magnet and the coil inductance. When this is considered as the energization timing, the motor current becomes highly sensitive to the drive voltage. In the experiment, the result was obtained that the sensitivity was 2 to 3 times higher than in the intermittent energization drive depending on the rotation condition. For this reason, very strict energization timing detection is required. That is, the 180-degree energization drive requires 2-3 times higher accuracy than the intermittent energization drive.
[0009]
Also, in the 180-degree energization drive method that analyzes the motor current by high-speed computation and determines the energization timing, the energization timing detection resolution is higher than that of intermittent energization drive due to motor current detection error, computation error, computation delay, etc. The current situation is that the angle deteriorates by about 5 degrees.
[0010]
Further, in the method of performing energization driving at 180 degrees based on the phase difference between the motor drive voltage and the motor current, the energization is switched over time by so-called forced excitation, and the motor current phase difference, that is, the energization timing at this time is controlled. . However, the control error of the motor current phase difference becomes the error of the energization timing as it is. For this reason, the phase difference must be strictly controlled in order to maintain stable driving and motor rotation, and it is good when there is no disturbance, but control is particularly unstable when a disturbance occurs. There is a problem of becoming. Since the energization timing in the intermittent energization drive depends on the detected back electromotive voltage, an accurate energization timing can be realized at any time regardless of the control performance. Therefore, in the case of phase difference control, accurate and advanced control is required as compared with intermittent energization driving.
[0011]
As described above, since accurate and strict control is required in the 180-degree energization drive, if a disturbance request that reduces the control margin occurs, not only high-efficiency operation cannot be realized but also motor energization is not possible. The probability of occurrence of problems such as step-out and motor stop is very high compared to intermittent energization drive including 120 degree energization drive.
[0012]
The disturbance factor mentioned here is a change in the power supply voltage to the inverter that drives the apparatus or the synchronous motor, a change in the motor rotation speed, a change in the load torque, and the like. Since control is difficult compared to intermittent energization driving including high-frequency energization driving, the robustness against these disturbances also tends to be low.
[0013]
As described above, the 180-degree energization driving method is excellent in terms of efficiency, torque fluctuation, rotation unevenness, and noise, but has low control robustness. In the 180-degree conduction drive method, countermeasures against each disturbance factor have been made to improve the control performance itself, such as increasing the control gain, but avoid any disturbance that cannot be covered by these. There is no solution, and there is a problem that the motor stops.
[0014]
The “electric vehicle control device (Japanese Patent Laid-Open No. 10-341594)” discloses a configuration for switching between a 120-degree energization drive method and a 180-degree energization drive method (referred to as Document 1).
[0015]
However, the configuration shown in Document 1 is a configuration that uses rotation pulse generation means such as an encoder during 180-degree energization drive, and requires a position sensor that detects the motor position. Therefore, it cannot be applied to a configuration in which a motor is driven without a position sensor.
[0016]
Further, in Reference 1, when the output of the position sensor and the rotation pulse generating means cannot be obtained, switching to the 120-degree energization drive system, or 180-degree energization drive in the low speed region where the detection of the back electromotive voltage is difficult, In the region, the drive system is uniquely switched according to the 120-degree energization drive and the rotational speed. Therefore, it is impossible to cope with the occurrence of disturbances affecting the motor drive, and it is impossible to realize a motor drive with high efficiency, low noise, low vibration and high reliability.
[0017]
Therefore, the present invention has been made to solve such problems, and its purpose is to realize a highly efficient, low-noise, low-vibration and highly reliable motor drive in response to disturbance without a position sensor. An object of the present invention is to provide a motor control device that can perform the above-described operation.
[0018]
[Means for Solving the Problems]
  A motor control device according to the present invention is a motor control device that drives and controls a synchronous motor constituted by a rotor with a permanent magnet and a driving means for driving the synchronous motor without position sensors. 180 degree energization drive means for energizing drive and a synchronous motor, ThroughThe intermittent energization driving means for intermittent energization driving with an electrical angle of less than 180 degrees, the motor disturbance monitoring means for monitoring the disturbance of the synchronous motor or the driving means, and the driving method of the synchronous motor according to the output of the motor disturbance monitoring means. Drive type selection means for selecting whether to perform 180-degree energization drive or intermittent energization drive.Switching from 180-degree energization drive to intermittent energization drive has an energization pause period in which all energization to the coil terminals is turned off, and the motor rotation position is detected from the back electromotive voltage induced in the coil terminals during the energization pause period. The switching timing by the method selection means is calculated. In the switching from the intermittent energization drive to the 180-degree energization drive, the motor rotation position is detected based on the calculation of the sine wave phase with respect to the intermittent energization timing, and the switching timing by the drive method selection means is calculated.
[0019]
  Therefore, the 180-degree energization drive and the intermittent energization drive can be appropriately switched according to the disturbance. As a result, high-efficiency, low-noise, low-vibration motor drive is realized in steady state with little disturbance, and high-reliable motor drive does not cause problems such as motor stop in singular state where disturbance is detected. Can be realized.
  In addition, when switching from the 180-degree energization drive to the intermittent energization drive, a period for stopping energization of the synchronous motor is provided. Therefore, switching to intermittent energization driving can be performed reliably. When switching from intermittent energization drive to 180-degree energization drive, the energization phase of 180-degree energization drive is determined based on the energization timing immediately before switching. Therefore, since the drive system can be switched reliably, the drive switching reliability can be improved. Further, intermittent energization driving is a driving method in which energization switching is performed by detecting a counter electromotive voltage generated at the motor terminal of the synchronous motor. Thereby, it is possible to reliably detect the energization timing without being affected by disturbance. As a result, the reliability in driving the motor can be improved.
[0020]
Preferably, the energization angle of the intermittent energization drive means is 120 degrees. Therefore, it is easy to create a drive voltage waveform to be supplied to each phase and the detection interval of the counter electromotive voltage becomes long, so that the detection reliability is improved.
[0021]
Preferably, the driving means includes an inverter for driving the synchronous motor and an AC power supply unit for supplying an AC power supply voltage provided to the inverter, and the motor disturbance monitoring means is a DC power supply voltage or an AC in the inverter. The AC power supply voltage supplied by the power supply voltage supply means is monitored.
[0022]
Therefore, it is possible to determine that a fluctuation in the power supply voltage such as an instantaneous power failure occurs as a disturbance and switch to an appropriate driving method. As a result, it is possible to prevent problems such as motor stoppage caused by fluctuations in the power supply voltage and to realize highly reliable motor driving.
[0023]
Preferably, the motor disturbance monitoring means monitors the rotational speed of the synchronous motor. Therefore, it is possible to determine that the fluctuation of the motor rotation number is a disturbance and switch to an appropriate driving method. As a result, problems such as motor stop due to rotation speed change can be prevented, and highly reliable motor drive can be realized.
Preferably, the motor disturbance monitoring means monitors the torque of the synchronous motor. Therefore, it is possible to determine that the fluctuation of the load torque is a disturbance and switch to an appropriate driving method. As a result, problems such as motor stop due to load torque fluctuations can be prevented, and highly reliable motor driving can be realized.
[0024]
Preferably, the motor disturbance monitoring means monitors the motor current of the synchronous motor. Therefore, it is possible to determine that the fluctuation of the motor current is a disturbance and switch to an appropriate driving method. As a result, problems such as motor stop due to fluctuations in motor current can be prevented, and highly reliable motor driving can be realized.
[0025]
Preferably, the motor disturbance monitoring unit monitors a phase difference between a driving voltage of a specific phase of the synchronous motor and a motor current of the synchronous motor. Therefore, it is possible to determine that the fluctuation of the phase difference between the drive voltage and the motor current is the occurrence of a disturbance and switch to an appropriate drive system. As a result, problems such as motor stop due to fluctuations in the phase difference can be prevented, and highly reliable motor driving can be realized.
[0026]
Preferably, the motor disturbance monitoring means monitors any one or more disturbances or disturbance signals among disturbances affecting the driving of the synchronous motor or disturbance signals changing in synchronization with the disturbances. Therefore, it is possible to detect the occurrence of a disturbance based on the disturbance affecting the driving of the synchronous motor or the fluctuation of the signal that changes due to the disturbance and switch to an appropriate driving method. As a result, it is possible to prevent a malfunction such as a motor stop accompanying fluctuations in various disturbances and to realize a highly reliable motor drive.
[0027]
Preferably, the motor disturbance monitoring unit detects whether the motor disturbance monitoring unit is in a steady state or a singular state, and the driving method selection unit performs 180-degree energization driving when the steady state is detected in the motor disturbance monitoring unit. When the singular state is detected, switching is performed so that intermittent energization driving is selected.
[0028]
Therefore, high-efficiency, low-noise, low-vibration and high-performance 180-degree conduction drive is selected in steady state with little disturbance, and intermittent conduction drive with low motor stoppage and high reliability is selected in singular state with large disturbance. can do. Thereby, high efficiency of motor drive, low vibration, low noise, and high reliability can be realized.
[0029]
Preferably, the motor disturbance monitoring unit detects whether the motor disturbance monitoring unit is in a steady state or a singular state, and the drive method selection unit selects 180-degree energization driving when the motor disturbance monitoring unit detects a steady state. When the singular state is detected, the intermittent energization drive is selected, and then the 180-degree energization drive is selected after a predetermined time has elapsed.
[0030]
Therefore, high-efficiency, low-noise, low-vibration and high-performance 180-degree conduction drive is selected in steady state with little disturbance, and intermittent conduction drive with low motor stoppage and high reliability is selected in singular state with large disturbance. Then, it can return to the 180-degree energization drive after a predetermined period when the disturbance is settled. Thereby, high efficiency of motor drive, low vibration, low noise, and high reliability can be realized.
[0031]
In particular, the singular state is a fluctuation in power supply voltage. Therefore, it is possible to switch to an appropriate driving system based on fluctuations in power supply voltage such as instantaneous power failure. As a result, it is possible to prevent problems such as motor stoppage caused by fluctuations in the power supply voltage and to realize highly reliable motor driving.
[0032]
In particular, the singular state is a change in the rotational speed of the synchronous motor or a change in the rotational speed. Therefore, it is possible to switch to an appropriate driving method based on the motor rotation speed. As a result, it is possible to prevent problems such as a motor stop associated with a change in the rotational speed, and to realize highly reliable motor driving.
[0033]
In particular, the singular state is a fluctuation in torque of the synchronous motor. Therefore, it is possible to switch to an appropriate driving method based on the fluctuation of the load torque. As a result, problems such as motor stop due to load torque fluctuations can be prevented, and highly reliable motor driving can be realized.
[0034]
In particular, the singular state is a fluctuation in the motor current of the synchronous motor. Therefore, it is possible to switch to an appropriate driving method based on the fluctuation of the motor current. As a result, problems such as motor stop due to fluctuations in motor current can be prevented, and highly reliable motor driving can be realized.
[0035]
In particular, the singular state is a fluctuation in the phase difference between the driving voltage of a specific phase of the synchronous motor and the motor current of the synchronous motor. Therefore, it is possible to switch to an appropriate driving method based on the fluctuation of the phase difference between the driving voltage and the motor current. As a result, problems such as motor stop due to fluctuations in the phase difference can be prevented, and highly reliable motor driving can be realized.
[0036]
In particular, the singular state is any one or more disturbances or disturbance signal fluctuations among disturbances affecting the motor drive of the synchronous motor or disturbance signals changing in synchronization with the disturbances. Therefore, it is possible to switch to an appropriate driving method based on a disturbance that affects the driving of the synchronous motor or a fluctuation of a signal that changes due to the disturbance. As a result, it is possible to prevent a malfunction such as a motor stop accompanying fluctuations in various disturbances and to realize a highly reliable motor drive.
[0037]
Preferably, the motor disturbance monitoring unit determines whether the state is a steady state or a singular state based on predetermined threshold data, and the predetermined threshold data is changed according to a rotation condition of the synchronous motor. Therefore, the threshold data can be switched depending on the rotation conditions such as the rotation speed and the steady load torque. Thereby, an accurate energization drive system can be selected.
[0039]
Preferably, when the synchronous motor is rotating at a low speed, when switching from the 180-degree energization drive to the intermittent energization drive, the rotational speed after the transition to the intermittent energization drive is the same as that at the 180-degree energization drive. Increase from the rotational speed. Accordingly, since the energization timing detection of the intermittent energization drive is ensured by increasing the rotation speed, the reliability of the motor drive can be improved.
[0042]
Preferably, the 180-degree energization drive is a drive that drives a motor by controlling current phase difference information that is a phase difference between a drive voltage applied to a motor terminal of a specific phase in a synchronous motor and a motor current flowing through the motor terminal. It is a method. Therefore, it is possible to drive by energization with a simple configuration and processing, and to realize cost reduction.
[0043]
Preferably, the current phase difference information includes a first motor current area that is an integrated value of the motor current during the first phase period based on the drive voltage phase in the synchronous motor, and a motor current during the second phase period. It is obtained by calculating the ratio with the second motor current area which is the integrated value of. Therefore, phase difference information can be detected with a simpler process and configuration than zero-cross detection. Malfunctions can be reduced against fluctuations in noise and motor current.
[0044]
In particular, the first motor current area is obtained by sampling the motor current during the first phase period a predetermined number of times and integrating the sampled current sampling data, and the second motor current area is determined by the second phase period. The motor current inside is sampled a predetermined number of times, and the sampled current sampling data is integrated.
[0045]
Therefore, the area of the motor current can be obtained, and the phase difference information can be obtained from the ratio. Further, in this area ratio detection, by using motor current sampling data obtained by a plurality of samplings, highly reliable phase difference detection can be realized by a simple process.
[0046]
Preferably, the motor disturbance monitoring means determines whether it is a steady state or a singular state based on the threshold data, and adds and subtracts a predetermined amount to the disturbance or disturbance signal input to the motor disturbance monitoring means. The resulting disturbance addition / subtraction is used as threshold data in the next disturbance or determination at the time of disturbance signal input. Therefore, it is possible to select an accurate energization driving method against sudden disturbance.
[0047]
Preferably, the motor disturbance monitoring unit determines whether the motor disturbance monitoring unit is in a steady state or a singular state based on the threshold value data, and determines whether the threshold value data is a disturbance or a disturbance signal input to the motor disturbance monitoring unit. Disturbance addition / subtraction obtained as a result of addition and subtraction of quantitative values and threshold data set from disturbances or steady values of disturbance signals are used. This makes it possible to select a more accurate energization drive method.
[0048]
Preferably, the motor disturbance monitoring unit determines whether the motor disturbance monitoring unit is in a steady state or a singular state, and synchronizes the determination timing of the steady state or the singular state in the motor disturbance monitoring unit with the motor rotation. Therefore, an accurate energization drive method can be selected even when periodic fluctuations occur during motor rotation.
[0049]
The disturbance or disturbance signal input to the motor disturbance monitoring means is a value obtained by averaging n rotations of the synchronous motor (where n is an integer of 1 or more). Therefore, an accurate energization drive method can be selected even when periodic fluctuations occur during motor rotation.
[0050]
Preferably, the motor disturbance monitoring means is turned off during acceleration / deceleration of the synchronous motor. Therefore, erroneous detection for energization drive method selection can be prevented, and an accurate energization drive method selection can be realized.
[0051]
As described above, according to the motor control device of the present invention, when motor driving is performed in 180-degree energization driving including sinusoidal energization with low noise, low vibration, and high efficiency, the superiority of 180-degree energization driving is achieved. The motor rotation can be maintained without switching to intermittent energization driving or stopping the motor rotation even when control and driving by 180-degree energization driving becomes impossible due to each disturbance. . Thereby, it becomes possible to improve the reliability of the entire apparatus including the motor.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a configuration according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol or symbol is attached | subjected to the same part in a figure, and the description is abbreviate | omitted.
[0053]
A motor control apparatus according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1 is a synchronous motor, 2 is an inverter circuit that drives the synchronous motor 1, and 3 is a converter circuit that converts an AC power source into direct current and supplies a direct current to the inverter circuit 2 (symbol AC- in the figure). DC), 4 is an AC power source, and 5 is a control microcomputer for driving and controlling the synchronous motor 1.
[0054]
Further, in FIG. 1, 6 is a motor disturbance monitoring unit that receives a signal indicating disturbance from the synchronous motor 1 or the inverter circuit 2 and monitors the driving state, and 7 is a driving method based on the output of the motor disturbance monitoring unit 6. The drive system selection unit 8 determines the energization timing, the setting of the drive voltage (PWM duty) reference value, etc. in order to set the synchronous motor 1 to the intermittent energization drive with the energization stop period of less than 180 degrees. The intermittent energization drive unit 9 that controls the 180 degree energization drive unit that controls the setting of the energization timing and the setting of the drive voltage (PWM duty) reference value in order to drive the synchronous motor 1 by 180 degrees energization. The PWM duty reference value and the energization timing according to the selected drive method are sent to the PWM creation / each phase distribution unit 11 according to the selection result of the drive method selection unit 7. Switch to force, 11 is PWM created / phase distribution unit for creating a PWM signal for driving the motor driving device of the inverter circuit 2 for each drive element output.
[0055]
The power supply to the inverter circuit 2 may be a so-called PAM system that is a variable power supply system.
[0056]
The drive system selection unit 7 selects whether the synchronous motor 1 is intermittently energized or 180-degree energized according to the disturbance of the synchronous motor 1 or the inverter circuit 2 detected by the motor disturbance monitoring unit 6.
[0057]
A signal indicating a disturbance such as the synchronous motor 1 or the inverter circuit 2 input to the motor disturbance monitoring unit 6 affects a control variable in motor control / drive, that is, becomes a disturbance. These include, for example, a DC power supply voltage that is a power supply for each drive element of the inverter circuit 2, the rotational speed of the synchronous motor 1, the load torque generated in the synchronous motor 1, and the motor current and drive voltage of the motor coil that change accompanying these. And the phase difference between the motor current and the motor current.
[0058]
It is not necessary to directly detect these, other disturbance elements may be used, and accompanying disturbance information other than the information described above may be used. Usually, the disturbance information is often an important parameter indicating how much the steady-state value fluctuates, and it is desirable for the motor disturbance monitoring unit 6 to detect fluctuations in these values.
[0059]
The motor control apparatus according to the embodiment of the present invention is suitable for each type of disturbance, that is, has good control performance, in other words, driving that does not cause a problem such as stopping the motor against the disturbance. Select the method and drive the motor. This realizes an effective motor motion with high reliability.
[0060]
In order to improve efficiency, suppress torque fluctuation, vibration, and noise, it is desirable that the 180-degree energization drive is sine wave energization that can realize a smooth change in the drive waveform.
[0061]
Further, the drive waveform of intermittent energization drive may be any drive waveform as long as the energization angle is less than 180 degrees and an energization stop period is provided in the drive waveform and the counter electromotive voltage generated during that period can be detected. For example, 120-degree energization driving is complete two-phase energization, and rectangular wave energization is possible. Therefore, there is an advantage that a drive waveform supplied to each phase can be easily created.
[0062]
Here, the drive waveform of each phase will be described. FIG. 2 is a diagram illustrating a driving waveform of sinusoidal energization that is an example of 180-degree energization driving. FIG. 3 is a diagram illustrating a drive waveform of rectangular-wave 120-degree energization, which is an example of intermittent energization drive. FIG. 4 is a diagram illustrating a driving waveform of 150-degree energization driving, which is another example of intermittent energization driving. 2 to 4, a signal for driving the drive element of the inverter circuit 2 (PWM creation / output of each phase distribution unit 11) is shown as an analog value for each coil terminal. Note that the drive waveform during the actual energization period is a PWM waveform, and the PWM duty is changed during the energization period. In each figure, the horizontal axis corresponds to the coil energization electrical angle, and the vertical axis corresponds to the voltage. The coils of the motor to be driven are three phases of U phase, V phase, and W phase.
[0063]
As shown in FIG. 2, in the 180-degree energization drive method, each phase is energized in a sine waveform. For example, when a U-phase coil is used as a reference, the energization waveforms for the V-phase and W-phase are energized for the U-phase. It has a phase difference of 120 degrees or 240 degrees with the waveform.
[0064]
As shown in FIG. 3, in the 120-degree rectangular wave energization driving method, the rectangular wave energization is performed for the 120-degree period in each phase, and the remaining 60-degree period is the energization suspension period. For example, on the basis of the U-phase coil, the V-phase and W-phase have a phase difference of 120 degrees or 240 degrees with respect to the U-phase.
[0065]
As shown in FIG. 4, in the 150-degree rectangular wave energization driving method, the rectangular wave energization is performed for the 150-degree period for each phase, and the remaining 30-degree period is the energization suspension period.
[0066]
Here, the actual motor current waveform of the U-phase coil terminal when a disturbance occurs during the 180-degree energization drive will be described with reference to FIGS. In the experiments shown in FIGS. 5 and 6, a sine wave 180 ° energization drive was performed, the motor rotation speed was 3000 rpm, and the steady load torque was about 1.5 Nm.
[0067]
FIG. 5 shows a motor current waveform when a pulse for generating a torque fluctuation of about 0.5 Nm is given. As shown in FIG. 5, it can be seen that when torque fluctuation occurs, the amplitude of the motor current waveform increases, and the sine wave waveform is disturbed immediately after the fluctuation has subsided.
[0068]
FIG. 6 shows a motor current waveform when the DC power supply voltage of the inverter circuit 2 fluctuates. In the experiment shown in FIG. 6, the DC power supply voltage fluctuates by about 20V. As shown in FIG. 6, it can be seen that even if the DC power supply voltage changes, the motor current is disturbed in the same manner as when the load torque changes.
[0069]
This is because the energization timing changes instantaneously due to torque fluctuations, and driving at an accurate energization timing is not performed. In both the experiments of FIG. 5 and FIG. 6, the adverse effect due to the disturbance fluctuation is limited to the occurrence of a decrease in efficiency due to the fact that the control cannot catch up and the drive cannot be performed at an appropriate energization timing. However, if the amount of fluctuation of each disturbance becomes larger than this, or if the time until the end of the fluctuation becomes longer, the rotation of the motor cannot be continued and the motor stops.
[0070]
This is because each driving method of 180-degree energization driving has the characteristic that control robustness is low due to the difficulty of control as described above, and it is easily affected by disturbance.
[0071]
On the other hand, while being easily affected by disturbances, 180-degree drive, especially sine-wave 180-degree drive, has low motor noise and vibration due to the smooth drive waveform, and high efficiency due to high winding utilization. There is an advantage that is possible. For this reason, when the above disturbance does not exist, it is desirable to perform motor motion by 180 degree energization driving with high rotational performance.
[0072]
On the other hand, in intermittent energization driving such as 120-degree energization driving, a pause period during which no motor current is energized is provided, and a counter electromotive voltage that purely represents the motor rotation position is detected. For this reason, even if a disturbance such as torque fluctuation occurs, the rotational speed may fluctuate, but the energization timing hardly changes. Therefore, compared with the 180-degree energization drive, there is a low probability that a problem such as a motor stopping due to a disturbance or the like occurs, and the motor drive reliability is high.
[0073]
In view of this, the motor control device according to the embodiment of the present invention has a 180 degree conduction drive with high rotational performance in a steady state in which no disturbance is generated or there is little disturbance. In the state, a reliable intermittent energization drive is selected.
[0074]
Here, the processing contents of the motor disturbance monitoring unit 6 and the driving method selection unit 7 will be described with reference to the flowcharts of FIGS. These processes are performed every time the drive voltage (PWM duty) reference value is created or every PWM carrier cycle, and are usually started by an interrupt from the control microcomputer.
[0075]
First, a process when the current is 180-degree energization drive will be described. FIG. 7 shows the processing contents during 180-degree energization driving. First, in step S71, the disturbance signal is compared with threshold data indicating the allowable change amount.
[0076]
Here, the disturbance signal includes a signal indicating the load torque fluctuation and a signal indicating the power supply voltage. As a signal indicating the fluctuation of the load torque, a signal of the torque sensor, a signal indicating a fluctuation of the amplitude of the motor current, as shown in FIG. 5, a signal indicating the phase difference of the motor current with respect to the driving voltage, or accompanying a torque fluctuation It may be a fluctuation in the rotational speed generated. In addition, when rotational speed fluctuation information is input, it is possible to cope with motor energization failure during the forced acceleration / deceleration of the synchronous motor. Further, the signal indicating the power supply voltage may be a voltage value obtained by resistance-dividing the DC power supply, or a value indicating the AC power supply voltage.
[0077]
Further, such a disturbance signal is not limited to only one input, and the motor drive can be monitored more strictly by inputting a plurality of signals.
[0078]
In the threshold data, a value indicating a change amount is set such that the 180-degree energization drive does not cause a large efficiency drop or a motor stop does not occur due to disturbance. Taking the results of FIGS. 5 and 6 as an example, a value corresponding to 0.5 Nm capable of maintaining the motor rotation is set for the load torque fluctuation, and a value corresponding to 20 V is set for the DC power supply voltage fluctuation. .
[0079]
The threshold data may vary depending on the steady rotational speed and the steady load torque, and more effective energization drive selection can be performed if the value is switched according to each rotational condition. Further, threshold data may be used as a ratio of the fluctuation amount to the steady value, and the fluctuation amount may be compared with the threshold data.
[0080]
Note that the reliability of the comparison process in step S71 is further improved if it is detected that the comparison results are continuous a plurality of times in order to remove the influence of the detection noise.
[0081]
If the disturbance signal does not exceed the threshold data in step S71, the process proceeds to step S72. In step S72, a signal for continuing the 180-degree energization drive is output assuming that the 180-degree energization drive is possible with little disturbance.
[0082]
If the disturbance signal exceeds the threshold data, the process proceeds to step S73. In step S73, assuming that the disturbance is large and the 180-degree energization drive is impossible, a process (switching) for shifting to intermittent energization drive described later is performed. The process ends here.
[0083]
The contents of the above process will be described with reference to FIG. In FIG. 19, the phase difference information of the motor current with respect to the drive voltage is used as the disturbance signal. This is because when the motor drive is controlled by the phase difference, the phase difference information can be used as a disturbance signal, which is an efficient method.
[0084]
FIG. 19 shows the power supply voltage waveform when the power supply voltage fluctuates, the motor current waveform, the phase difference information of the motor current with respect to the drive voltage as a disturbance signal, the output of the motor disturbance monitoring unit 6, and the selection state of the drive method selection unit 7. Is shown.
[0085]
The phase difference information fluctuates due to the occurrence of disturbance. When the phase difference information exceeds the set threshold data, the motor disturbance monitoring unit 6 changes the output. In response to the change in the output of the motor disturbance monitoring unit 6, the drive method selection unit 7 outputs a signal for selecting a drive method.
[0086]
The simplest configuration of the motor disturbance monitoring unit 6 is based on a comparator that compares a disturbance signal having a function of holding an output value for a certain period of time and threshold data, and further performs averaging of the comparison results. High accuracy can be achieved by incorporating the above. In addition, what is necessary is just to perform a process with the same structure also about the return from the intermittent energization drive mentioned later to 180 degree energization drive.
[0087]
Next, the processing situation when the current is intermittent energization drive will be described. FIG. 8 shows the processing contents during intermittent energization driving. In step S81, it is determined whether or not the disturbance signal has become smaller than the value represented by the threshold data. The disturbance signal and the threshold data are as described above.
[0088]
If the disturbance signal does not fall within the threshold data, the process proceeds to step S82. In step S82, it is determined that the disturbance is in a large state, and a signal for continuing the intermittent energization drive is output.
[0089]
If the disturbance signal falls within the threshold data, the process proceeds to step S83. In step S83, it is determined that the disturbance is in a small state, and processing (switching) for returning to 180-degree energization driving, which will be described later, is performed. The process ends here.
[0090]
Here, another setting method of threshold data and the flow of processing by the setting method will be described. When the phase difference of the motor current with respect to the power supply voltage and the driving voltage is used as the disturbance signal, the value of the disturbance signal may change each time depending on the rotation speed of the synchronous motor 1 and the load torque. This can be considered, for example, when a disturbance signal is not provided with a DC component cutoff filter.
[0091]
Accordingly, when threshold data is set based on a steady value as shown in FIG. 19, there is a disadvantage that an accurate disturbance cannot be detected if the disturbance signal and the steady value are deviated.
[0092]
For example, in the example shown in FIG. 20, a large disturbance signal fluctuation occurs at point a, but no disturbance is detected. Further, at point b, it is erroneously detected that a disturbance has occurred even though the disturbance is small.
[0093]
Therefore, as shown in FIG. 21, for each input of a disturbance signal, a predetermined amount is added to or subtracted from the input to calculate a disturbance adjustment value, and the disturbance adjustment value is used as threshold data at the next disturbance signal input. use. As a result, accurate disturbance detection and accurate energization drive method selection can be realized.
[0094]
The flow of processing based on the disturbance adjustment value will be described with reference to FIG. It is assumed that the current is 180-degree energization drive. Referring to FIG. 22, in step S221, disturbance signal Sd is compared with threshold value data + Sr, -Sr. If the disturbance signal Sd exceeds the threshold data as a result of the comparison processing, intermittent energization driving is selected in step S73, and the processing of FIG. 10 is performed.
[0095]
On the other hand, if the disturbance signal Sd is within the threshold data, the process proceeds to step S72, and the 180 ° energization drive is continued. Then, the process proceeds from step S72 or S73 to step S222, and a disturbance addition / subtraction value obtained by adding / subtracting the predetermined value Sv to / from the disturbance signal Sd is calculated, and this is set as new threshold data + Sr, -Sr.
[0096]
FIG. 22 shows the flow of processing when the current is 180-degree energization driving, but it goes without saying that similar processing may be performed even with intermittent energization driving. The predetermined value Sv may be set, for example, by experimentally obtaining a value that does not stop the synchronous motor 1 due to disturbance in 180-degree energization drive.
[0097]
It is more effective if the method of using the disturbance addition / subtraction value as threshold data and the method of using threshold data set from steady values as shown in FIG. 19 are used in combination.
[0098]
For example, if the disturbance signal seems to deviate from the steady value, a method of obtaining threshold data from the disturbance adjustment value as described with reference to FIG. 22 is effective. On the other hand, if it is found that the deviation of the disturbance signal from the steady value is small, the calculation of the disturbance addition / subtraction value can be omitted by using the threshold data set from the steady value, so that the processing can be simplified. The deviation between the disturbance signal and the steady value may be, for example, a comparison between a value obtained by capturing the disturbance signal a predetermined number of times and averaging it.
[0099]
Alternatively, when monitoring disturbances using multiple disturbance signals, you can select which threshold data to use depending on the nature of the disturbance signal, such as little deviation from the steady value. Efficient and effective processing can be realized.
[0100]
An example of other processing during intermittent energization driving will be described with reference to FIG. The process shown in FIG. 9 includes the process of step S91 instead of step S81 shown in FIG. In step S91, it is detected whether or not a predetermined time has elapsed since the generation of the disturbance signal. When a predetermined time has elapsed since the generation of the disturbance signal, the process proceeds to step S83 to perform processing (switching) for returning to the 180-degree energization drive. If the predetermined period has not elapsed since the generation of the disturbance signal, the process proceeds to step S82 to select (continue) intermittent energization drive.
[0101]
In general, a disturbance occurs instantaneously, such as an instantaneous power failure or load switching, and then often returns or maintains a new value. That is, when the instantaneous fluctuation is settled, the steady state is restored thereafter. Therefore, for example, after a certain period of time such as 2 seconds has elapsed, processing may be performed so as to return to 180-degree energization driving.
[0102]
In this way, by monitoring the load torque, rotation speed, power supply voltage, or signals associated therewith, and comparing the amount of change of these signals with an allowable value, an appropriate drive system, that is, in a steady state with little disturbance. The 180-degree energization drive is processed so that intermittent energization drive is selected in a singular state with many disturbances. As a result, it is possible to realize a motor motion with high efficiency, low noise, low vibration and high reliability.
[0103]
Next, the transition process step S73 to intermittent energization drive and the return process step S83 to 180 degree energization drive will be described. FIG. 10 shows the processing in step S73 for shifting from the 180-degree energization drive shown in FIG. 7 to the intermittent energization drive. In step S101, energization to all coil terminals of the synchronous motor is turned off. This is because in the 180-degree energization drive, there is no pause period, so an accurate counter electromotive voltage cannot be detected from the coil terminals. However, by turning off all the coil terminals, a pure counter electromotive voltage is detected and an accurate motor rotation is detected. This is to detect the position.
[0104]
In step S102, the counter electromotive voltage is detected, and the input of the counter electromotive voltage pulse is detected. The detection of the counter electromotive voltage is repeated until a pulse is input.
[0105]
In addition, in order to eliminate the influence of the coil terminal voltage due to the 180-degree energization drive and perform accurate rotational position detection, the pulse input is detected about twice, and the second detection is made accurate pulse detection. Can be increased. Although the accuracy increases as the number of detections is increased, the motor energization is turned off during this period. For this reason, there is a concern that the motor will stop if the number of detections is increased too much. Experimentally, detection about twice was optimal.
[0106]
If a back electromotive voltage pulse is detected, the process proceeds to step S103. In step S103, in accordance with the back electromotive voltage pulse, intermittent energization drive that switches the energization phase with a waveform as shown in FIG. 3 or FIG. 4 is selected, and the synchronous motor is driven. The process ends here.
[0107]
When the energization timing is advanced / delayed from the counter electromotive voltage pulse for the purpose of improving efficiency or the like, the above process may be performed using the adjusted counter electromotive voltage pulse.
[0108]
Note that the drive voltage (PWM duty) reference value at the time of transition may be set in consideration of the value at the 180-degree energization drive.
[0109]
At low speeds, the back electromotive voltage generated in proportion to the rotational speed is low, and it is considered that the transition cannot be made accurately. However, this problem can be avoided by setting the drive voltage (PWM duty) reference value to a high value and driving at a high speed immediately after the transition to the intermittent energization drive. Alternatively, in the extremely low speed range, the transition to the intermittent energization drive becomes very difficult, and therefore it is necessary to prohibit the transition depending on the synchronous motor.
[0110]
According to the experiment, the rotational speed that required high-speed rotation immediately after the transition was 500 to 1000 rpm, and the extremely low speed that makes the transition difficult was 500 rpm or less. Note that the rotation speed depends on the back electromotive force amplitude, S / N, and the like, and is preferably set in consideration of these.
[0111]
The result of experiment on the transition from the 180-degree energization drive to the intermittent energization drive will be described using the motor current waveform shown in FIG. In this experiment, the rotation speed was 3000 rpm and the load torque was 1.5 Nm. Various waveforms are shown when transitioning to intermittent energization driving in accordance with the occurrence of fluctuations in the power supply voltage of the inverter circuit 2 that is a disturbance. Note that the 120-degree energization drive is used as the intermittent energization drive.
[0112]
As shown in FIG. 11, at the time of transition, it can be seen that the energization of all the coil terminals is turned off, and the transition to the intermittent energization drive is surely made. Thus, by providing a period in which energization of all the coil terminals is suspended, it is possible to accurately detect the back electromotive voltage, and the transition process to the intermittent energization drive can be reliably performed, and the reliability can be improved.
[0113]
Next, the processing in step S83 for returning from the intermittent energization drive to the 180-degree energization drive in FIGS. 8 and 9 will be described with reference to FIG. In step S121, the current energization phase is calculated from the energization timing. For example, in the case of 120-degree energization driving, when energization is started from the U-phase coil terminal to the V-phase coil terminal, it is obtained by calculating how many times the sine wave waveform corresponds to the sine wave phase. Can do.
[0114]
In step S122, sine wave data is set with the calculated phase. In step S123, the power supply to all the coil terminals is turned off once. This is to completely remove the influence of intermittent energization drive when switching energization at the time of return.
[0115]
In step S124, the 180-degree energization drive is selected and the return process is terminated. The drive voltage (PWM duty) reference value at the time of return may be set in consideration of the value at the time of intermittent energization drive.
[0116]
An experimental result obtained by experimenting the transition from the intermittent energization drive to the 180-degree energization drive will be described with reference to FIG. In this experiment, the rotation speed was 3000 rpm and the load torque was 1.5 Nm. For intermittent energization drive, 120-degree energization drive is used. FIG. 13 shows a motor current waveform when the disturbance is reduced or a predetermined time has elapsed and the motor is returned to the 180-degree energization drive.
[0117]
As shown in FIG. 13, it can be seen that the phase information is taken over at the time of return, and the drive is reliably returned to the 180-degree energization drive with an accurate phase.
[0118]
Thus, by calculating the phase information of the intermittent energization drive and referring to this when setting the energization phase of the 180-degree energization drive, the reliability of the motor drive operation can be improved.
[0119]
By the way, the comparison between the disturbance signal and the threshold data in the motor disturbance monitoring unit 6 (that is, disturbance detection) is performed for each PWM carrier period as described above, so that immediate disturbance detection is realized. However, when a disturbance such as a load torque fluctuation synchronized with the motor rotation occurs, more accurate detection can be performed by detecting the disturbance synchronized with the motor rotation.
[0120]
Taking an air conditioner compressor drive motor as an example, it is known that a load torque fluctuation in synchronization with one rotation of the motor is very large in a single rotary compressor or the like.
[0121]
These load torque fluctuations occur constantly during motor rotation, and often do not stop the motor drive. If these load torque fluctuations are regarded as disturbances, they will affect the processing for the original disturbances. As a result, unnecessary energization drive method switching occurs.
[0122]
FIG. 23 shows the relationship between the disturbance signal that varies in synchronization with the motor rotation and the threshold data set based on the steady value. In the case shown in FIG. 23, the disturbance signal changes in the threshold data due to the load torque fluctuation, and the accuracy of the disturbance detection is lowered. Therefore, this load torque fluctuation must be taken into account when creating threshold data, and extra processing is required.
[0123]
In addition, in the case of such a load torque fluctuation, the part where the load torque fluctuates is often synchronized with the motor rotation, and it is rare that the disturbance must be detected every PWM carrier cycle. For example, in the case shown in FIG. 23, a point P (fluctuation peak point) at which the load torque fluctuation reaches a peak is a place where the load torque fluctuation is remarkably generated. Therefore, the disturbance is detected at the fluctuation peak point P. This enables efficient disturbance detection.
[0124]
The following motor control device focuses on these and performs disturbance detection in synchronization with the rotation of the motor. An example of a motor control device that detects disturbance in synchronization with motor rotation will be described with reference to FIG. The motor control device shown in FIG. 24 includes a motor disturbance monitoring unit 61 instead of the motor disturbance monitoring unit 6.
[0125]
The motor disturbance monitoring unit 61 receives motor rotation information including a signal indicating a specific position of motor rotation. The motor disturbance monitoring unit 61 detects disturbance according to the motor rotation information. Thereby, accurate disturbance detection is realized.
[0126]
Preferably, if the information corresponding to the location indicating the fluctuation peak point P in FIG. 23 is input as the motor rotation information, the accuracy of disturbance detection can be improved. Alternatively, a disturbance signal can be taken for one rotation of the synchronous motor 1 based on the motor rotation information, the peak point of the disturbance signal can be detected, and the disturbance can be detected accurately at the same peak point.
[0127]
As the motor rotation information, a sensor signal output from a sensor attached to the rotating shaft of the synchronous motor 1 may be used, or new information can be obtained by using information used for motor driving such as motor current and motor driving voltage. There is no need to add a circuit, and an increase in cost can be prevented.
[0128]
For the above-described load torque fluctuation synchronized with the motor rotation, it is effective to use the configuration shown in FIG. Another example of the motor control device that detects disturbance in synchronization with the motor rotation will be described with reference to FIG. The motor control device shown in FIG. 25 includes a motor disturbance monitoring unit 61, and a disturbance averaging unit 12 that receives a disturbance signal and motor rotation information as input.
[0129]
The disturbance averaging unit 12 averages disturbance signals for n rotations (n is an integer of 1 or more) of the synchronous motor 1. The disturbance averaging unit 12 averages the disturbance signal in synchronization with the rotation of the motor, and inputs the averaged value to the motor disturbance monitoring unit 61 to perform the same disturbance detection processing as described above.
[0130]
By averaging the disturbance signal, fluctuations during rotation of the motor 1 can be removed. Thereby, accurate disturbance detection can be realized as in the case described above.
[0131]
Although the disturbance detection by the motor disturbance monitoring units 6 and 61 described above is always performed while the motor is rotating, it may be desirable not to detect the disturbance depending on the state of motor operation.
[0132]
Here, a disturbance detection situation when a motor current is used as a disturbance signal will be described with reference to FIG. FIG. 26 shows the relationship between threshold data set based on steady values and motor current (disturbance signal). In the figure, during the period T1, the motor rotation is accelerating, and during the period T2, the motor rotation is decelerating. There are places where the disturbance signal fluctuates. This is where the motor rotation is increased (ie, accelerated) or lowered (ie, decelerated).
[0133]
Normally, it is known that the motor current changes when the motor rotation is accelerated or decelerated. When accelerating, more motor current is required than in the steady state in order to overcome the motor inertia that tries to continue the rotation at the current rotation speed and increase the rotation. On the other hand, at the time of deceleration, the motor tries to continue the rotation at the current rotation speed, and therefore the motor current is decreased from the normal time to decrease the rotation speed.
[0134]
Therefore, if the motor rotation is accelerated or decelerated, the motor current fluctuates as shown in FIG. 26 and erroneous detection of disturbance detection occurs.
[0135]
Needless to say, threshold value data may be newly set during motor rotation acceleration / deceleration. However, disturbance signal fluctuations during motor rotation acceleration / deceleration are closely related to the characteristics of the control system, and it is difficult to set accurate threshold data.
[0136]
Therefore, the following motor control device pays attention to these, and turns off the disturbance detection process during acceleration / deceleration of motor rotation. An example of a motor control device that turns off disturbance detection processing during acceleration / deceleration of motor rotation will be described with reference to FIG. The motor control device shown in FIG. 27 includes a motor disturbance monitoring unit 62 instead of the motor disturbance monitoring unit 6.
[0137]
A motor rotation speed command is input to the motor disturbance monitoring unit 62. The motor disturbance monitoring unit 62 determines that acceleration / deceleration of the motor rotation is occurring when there is a change in the motor rotation speed command, and turns off the disturbance detection process.
[0138]
For the motor rotation speed command, target rotation speed information used in motor driving may be used. Thereby, accurate disturbance detection can be realized.
[0139]
Next, a typical configuration of motor drive by the intermittent energization drive unit 8 will be described with reference to FIG. In FIG. 14, 141 is a magnetic pole position detection unit that filters the signal of the motor coil terminal and compares the reference voltage to detect the rotational position of the synchronous motor 1, and 142 stores target rotational speed information of the synchronous motor 1. A target speed information storage unit 143 is an adder that calculates an error between the period information of the magnetic pole position detection unit 141 and the target period information of the target speed information storage unit 142, and 144 amplifies the error output from the adder 143. It is a speed control gain unit.
[0140]
The output of the speed control gain unit 144 is input to the PWM creation / each phase distribution unit 11 as the PWM duty reference value, and the position signal of the magnetic pole position detection unit 141 is input as the energization timing. The inverter circuit 2 receives a drive signal from the PWM creation / phase distribution unit 11. Based on this, the synchronous motor 1 is driven.
[0141]
In the case of 120-degree energization drive, each motor coil terminal has a pause period as shown in FIG. 3, and a back electromotive force is generated during the pause period by the movement and rotation of the permanent magnet of the motor rotor. The counter electromotive voltage waveform appearing during the pause period is shifted depending on the energization timing. Therefore, it is possible to detect the magnetic pole position of the motor rotor which is the motor rotation position from the motor coil terminal.
[0142]
As filtering in the magnetic pole position detection unit 141, it is simple and reliable to use a low-pass filter with a first-order lag and as a voltage comparison to compare with the intermediate potential of the motor coil terminal. When energization is performed in the advance phase or the delay phase, the magnetic pole position detection signal pulses are counted by a timer or the like to obtain a desired energization timing and output it as a position signal. Since the magnetic pole position detection unit 141 requires complicated processing such as filtering and voltage conversion, the magnetic pole position detection unit 141 may be configured by an external circuit without being performed in the control microcomputer 5.
[0143]
The magnetic pole position detection unit 141 is not limited to the above-described configuration, and compares the motor coil terminal signal with the reference voltage as it is without filtering, and removes the PWM component and noise component to detect the motor rotation position. It may be configured.
[0144]
By using such an intermittent energization drive unit 8, the motor rotation position can be reliably detected from the back electromotive voltage generated at the motor coil terminal, so that highly reliable motor driving can be realized.
[0145]
Next, the motor drive configuration by the 180-degree energization drive unit 9 will be described with reference to FIG. As described above, 180-degree energization drive includes a motor current calculation and a neutral point, but a so-called phase difference based on the phase difference between the drive voltage and the motor current shown in FIG. The control has the advantage that the configuration and processing are simple and the cost can be reduced.
[0146]
By the way, in the phase difference control, a method of detecting a zero cross of a motor current that is easy to process is common. However, according to the method described with reference to FIG. Can be realized.
[0147]
In FIG. 15, 151 is a current sensor that detects a motor current flowing in a specific phase (U phase in the figure) among the motor coil terminals U phase, V phase, and W phase, and 152 is detected. The motor current detection amplifier unit outputs the motor current signal by amplifying and offsetting the motor current by a predetermined amount. The current sensor 151 and the motor current detection amplifier unit 152 are simpler and more practical when configured with an external circuit than when configured within the control microcomputer 5. Reference numeral 153 denotes a phase difference detection unit that takes in a motor current signal by performing analog / digital conversion at a predetermined timing, calculates and outputs phase difference information, and 154 stores target phase difference information (target phase difference information). The target phase difference information storage unit.
[0148]
The phase difference detection unit 153 samples and integrates the motor current a plurality of times every two motor drive voltage phase periods, and calculates the motor current signal area in each phase period. Then, the area ratio of these motor current signal areas is calculated and output as phase difference information.
[0149]
Since the highest-efficiency energization timing varies depending on the rotation conditions and motor current distortion, it is preferable that the target phase difference information is configured to be set as needed depending on the rotation conditions and the like.
[0150]
155 shown in FIG. 15 is an adder that calculates error data between the target phase difference information and the phase difference information output from the phase difference detector 153, and 156 is an error data calculated by the adder 155. A PI calculation unit that calculates proportional error data and accumulated error data and outputs a duty reference value. By using the PI control, the residual error of the phase difference can be controlled to zero.
[0151]
Further, in FIG. 15, reference numeral 157 denotes a rotational speed setting unit for setting a rotational speed command for the synchronous motor, 158 denotes a sine wave data table composed of a predetermined number of data, and 159 denotes a sine wave data creation unit. The sine wave data creation unit 159 reads out sine wave data corresponding to each phase of the motor coil terminal U-phase, V-phase, and W-phase from the sine wave data table 158 according to the rotational speed command and the passage of time, and the U-phase sine wave Outputs U-phase motor drive voltage phase information from the data.
[0152]
As an example of the current sensor 151, a so-called current sensor configured by a coil element and a Hall element may be used, or a current transformer or the like may be used. In the embodiment of the present invention, the motor current is detected for one specific phase (U phase) of the plurality of phases. However, the present invention is not limited to this, and the motor current of each phase is detected. May be. In this case, it is possible to realize motor driving with higher accuracy.
[0153]
The sine wave data may be created by calculation instead of being created based on the sine wave data table 158 stored in advance.
[0154]
FIG. 15 shows a configuration in the case of sine wave energization drive as 180 degree energization drive. According to the sine wave energization drive, a smooth motor current can be supplied by using a sine wave waveform, and therefore vibration and noise can be reduced. However, the drive waveform is not limited to a sine waveform, and driving with higher efficiency can be achieved by using drive waveform energization that can obtain a motor current that matches the magnetic flux distribution of the motor rotor.
[0155]
As described above, the phase difference detection unit 153 calculates the area ratio of the two motor current signal areas detected in the two motor drive potential phase periods, and outputs the result as phase difference information. PI calculation is performed on the error amount between the phase difference information output from the phase difference detection unit 153 and the target phase difference information. The PWM creation / each phase distribution unit 11 calculates the output duty each time from the duty reference value that is the output of the PI calculation unit 156 and sine wave data that is separately obtained from the rotation speed command. The synchronous motor 1 is driven by controlling the motor coil via the inverter circuit 2 with the value calculated in this way.
[0156]
That is, the configuration shown in FIG. 15 determines the magnitude of the drive voltage (duty width of the PWM duty) by the phase difference control feedback for controlling the motor current phase difference constant with respect to the motor drive voltage (output duty). In order to rotate the synchronous motor 1 at a desired rotational speed, the rotational speed is determined by sine wave data output at a desired frequency. As a result, the motor can be driven and controlled with a desired phase difference and a desired rotational speed.
[0157]
The start-up is performed by forcible excitation in which each phase is forcibly energized to give a rotating magnetic field, and control may be performed by the above method during normal driving. Further, the phase difference may be controlled as described above.
[0158]
Here, the fact that the synchronous motor 1 can be driven and controlled by the above-described phase difference control will be described based on an experimental result with an IPM (Interior Permanent Magnet) motor.
[0159]
In the case of a so-called IPM motor having a shape in which a permanent magnet is packed in a rotor, a reductance using a so-called magnet torque generated along with a magnetic flux and a coil current and a change in the inductance of the motor coil depending on the rotor shape. Use torque. The relative position between the rotor and the stator where the sum of the magnet torque and the reductance torque is maximum varies depending on the rotation conditions. In order to drive the IPM motor with high efficiency, it is necessary to optimize the energization timing for detecting the relative position between the rotor and the stator and energizing the motor coil with the optimum positional relationship. In the case of a synchronous motor, even if it is simply driven without considering efficiency, if the energization timing is not set to a value within a certain range, brake torque may be generated and the motor may stop. For example, in intermittent energization driving, a counter electromotive voltage is used to detect the relative position between the rotor and the stator.
[0160]
An experimental result in an experiment in which the synchronous motor is driven based on the phase difference control according to the embodiment of the present invention will be described with reference to FIG. The vertical axis in FIG. 16 corresponds to the phase difference information, and the horizontal axis corresponds to the relative position between the rotor and the stator measured by the encoder indicating the motor rotation position. The rotation conditions of this experiment were a rotation speed of 1000 rpm and a load torque of 15 kgf · cm.
[0161]
The phase difference control according to the embodiment of the present invention does not directly detect the relative position between the rotor and the stator. However, as shown in FIG. 16, it can be seen that the relationship between the phase difference information and the relative position between the rotor and the stator is substantially proportional. Therefore, by controlling the phase difference information to a predetermined value, the relative position between the rotor and the stator can be indirectly controlled. By optimizing the target phase difference information, the highest efficiency can be obtained. It can be seen that the motor can be driven at the obtained energization timing.
[0162]
The result of measuring the relationship between the drive voltage (PWM duty reference value) and the phase difference information under the same experimental conditions as in FIG. 16 will be described with reference to FIG. In FIG. 17, the vertical axis corresponds to the phase difference information, and the horizontal axis corresponds to the motor drive voltage (duty reference value). As shown in FIG. 17, it can be seen that the phase difference information and the motor drive voltage are in a substantially proportional relationship. Therefore, it can be seen that the phase difference information can be controlled by increasing or decreasing the drive voltage (PWM duty reference value).
[0163]
That is, when the drive voltage (duty reference value) is increased or decreased at a constant rotation speed, the current / voltage phase difference (phase difference information) changes, and the drive voltage (phase difference information is determined by the configuration of the embodiment of the present invention). It can be seen that a phase difference control feedback loop for increasing or decreasing (duty reference value) is effective.
[0164]
From the above experimental results, it can be seen that the actual motor current is not a pure sine wave, but the phase difference control is possible even though the distortion component is superimposed. Further, it can be seen that the detection accuracy of the phase difference information based on the motor current signal area ratio in the two phase periods is sufficient. Further, it goes without saying that the above problem is solved and the detection accuracy is improved as compared with a phase difference detection method in which one point having a motor current such as zero cross is detected.
[0165]
Although each characteristic of these experimental results seems to be almost proportional, strictly speaking, the data is not on a complete straight line. This is considered to be due to the distortion of the motor current in addition to the measurement error. For this reason, the control system gain of the phase difference control system changes depending on the value of the phase difference, but it is sufficient to set the gain as the control system in anticipation of this non-linearity. If changed, a more accurate control system can be configured.
[0166]
In addition, the slope of each characteristic may change depending on the rotation condition, but it is sufficient to configure the control system in anticipation of the amount of change in the control system gain due to the rotation condition. If the gain of the control system is changed according to the rotation condition, In addition, a highly accurate control system can be configured.
[0167]
In this experiment, an inverting amplifier was used as the motor current detection amplifier unit 152.
[0168]
Next, a method for setting the rotational speed in the phase difference control using the sine wave data table and the PWM output will be described.
[0169]
The phase difference control method according to the embodiment of the present invention is different from the method of detecting the back electromotive voltage pulse and controlling the speed, and the motor rotation speed is the frequency of the sine wave voltage (PWM) energized to the motor coil. This is the so-called forced excitation drive determined by
[0170]
The sine wave data table 158 stores a data string in which a sine wave waveform is output when D / A is output continuously. For example, if one period is composed of 360 pieces of sine wave data, each sine wave data has a value corresponding to an electrical angle every one degree. Hereinafter, regarding the sine wave data table, 360 sine wave data are stored for one cycle, the PWM carrier frequency is 3 kHz, and the synchronous motor 1 rotates once in two sine wave cycles for one phase. Shall.
[0171]
In the case of 180-degree sine wave energization, the motor drive voltage (output duty) needs to be a sine wave waveform, and therefore it is necessary to update the sine wave data for each PWM carrier cycle. In addition, 360 × 2 = 720 updates are required for one rotation of the synchronous motor.
[0172]
Here, if the reference data in the sine wave data table is updated one by one for each PWM carrier period, the PWM carrier period is 1/3000 = 0.333 msec, so that 720 × 0.333 = 0 for one rotation. .24 sec is required, and the rotation speed is about 250 rpm. That is, the motor rotation speed is determined by the PWM carrier frequency and the reference data update interval of the sine wave data table, excluding the motor structure. For example, if the number of coil phases is three, the data of each phase may be referred to sine wave data shifted by 120 degrees in electrical angle. Note that sine wave data may be generated by performing sine wave calculation each time.
[0173]
The obtained sine wave data for each phase is multiplied by the duty reference value calculated by the phase difference control. A PWM generator such as a so-called PWM waveform generator receives the multiplied value and outputs a PWM waveform. The PWM waveform generator creates a triangular wave with, for example, a PWM carrier period, compares the peak value of this triangular wave with the multiplied value, and outputs high / low based on the comparison result.
[0174]
This PWM waveform generator is often prepared by a dedicated IC or provided as a function of a control microcomputer. By using these, a PWM waveform corresponding to each drive element can be easily obtained. .
[0175]
Next, processing and configuration from detection of phase difference information to calculation of a duty reference value will be described.
[0176]
FIG. 18 is a diagram for describing detection of phase difference information. The U-phase motor current has a substantially sinusoidal waveform centered on zero level. The motor current is amplified and set by the motor current detection amplifier 152 to create a motor current signal. This is performed to adjust the motor current to a convertible voltage range (for example, 0 V to +5 V) of an A / D converter (not shown).
[0177]
Also, the U-phase motor drive voltage phase information is created from the U-phase sine wave data by the sine wave data creation unit 159. Note that the motor drive voltage phase information does not actually need to be a sine wave waveform, and only the phase information needs to be known.
[0178]
A motor current signal and motor drive voltage phase information as shown in FIG. 18 are input to the phase difference detection unit 153. In the phase difference detection unit 153, n times per phase period (twice in the case of FIG. 18) at a predetermined sampling phase (sampling timing) in a predetermined phase period determined in advance from the motor drive voltage phase information, Sample the motor current signal.
[0179]
For example, in the phase period θ0, the motor current signals (I0, I1) are sampled at the sampling timings s0, s1. In the phase period θ1, the motor current signals (I2, I3) are sampled at the sampling timings s2, s3. In the phase period θ2, the motor current signals (I4, I5) are sampled at the sampling timings s4, s5. In the phase period θ3, the motor current signals (I6, I7) are sampled at the sampling timings s6, s7.
[0180]
For example, if the predetermined phase periods determined in advance are θ0 and θ1, the sampled current sampling data is integrated in each of the phase periods θ0 and θ1, and motor current signal areas Is0 and Is1 are calculated (Is0 = I0 + I1). , Is1 = I2 + I3).
[0181]
Then, calculate the ratio of each motor current signal area Is0, Is1. This is referred to as phase difference information. The processing can be simplified by making the interval between the sampling timings s0 to s3 constant.
[0182]
If the predetermined phase periods determined in advance are θ2 and θ3, the sampled current sampling data is integrated in each of the phase periods θ2 and θ3 to calculate motor current signal areas Is2 and Is3 (Is2 = I4 + I5, Is3 = I6 + I7). Then, the ratio of the motor current signal areas Is2 and Is3 is calculated.
[0183]
As shown in FIG. 18, it is more advantageous for setting the target value that the phase period is centered on the drive voltage electrical angle of 90 degrees and / or its inversion of 270 degrees. It should be noted that the phase difference information is more reliable when averaged multiple times.
[0184]
As described above, by adopting a configuration in which the phase difference between the motor drive voltage and the motor current is detected as the drive method of the 180-degree energization drive, the processing and the circuit can be easily realized. Further, by obtaining the area of the motor current and obtaining the phase difference information based on the ratio, highly reliable phase difference detection can be realized. Further, in this area ratio detection, by using motor current sampling data obtained by a plurality of samplings, highly reliable phase difference detection can be realized by a simple process.
[0185]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.
[0186]
【The invention's effect】
As described above, according to the motor control device of the present invention, the 180-degree energization drive and the intermittent energization drive can be appropriately switched by disturbance. As a result, high-efficiency, low-noise, low-vibration motor driving can be realized in the steady state, and high-reliability motor driving can be realized in the singular state without causing problems such as motor stoppage.
[0187]
According to the motor control device of the present invention, the energization angle of the intermittent energization drive means is set to 120 degrees energization drive. This makes it easy to create a drive voltage waveform to be supplied to each phase. In addition, since the detection interval of the back electromotive voltage becomes longer, the detection reliability is improved.
[0188]
Further, according to the motor control apparatus of the present invention, the fluctuation of the power supply voltage including the instantaneous power failure is monitored, and the fluctuation is determined to be the occurrence of the disturbance, and the driving method is switched to an appropriate driving method. As a result, problems such as motor stop caused by power supply voltage fluctuation can be prevented, and highly reliable motor driving can be realized.
[0189]
Further, according to the motor control device of the present invention, the fluctuation of the motor rotation number is monitored, and the fluctuation is judged as the occurrence of disturbance, and the driving method is switched to an appropriate driving method. As a result, it is possible to prevent a problem such as a motor stop accompanying a change or fluctuation in the rotational speed, and to realize a highly reliable motor drive.
[0190]
Further, according to the motor control device of the present invention, the fluctuation of the load torque is monitored, and the fluctuation is determined to be a disturbance occurrence, and the driving method is switched to an appropriate driving method. As a result, problems such as motor stop due to load torque fluctuation can be prevented, and highly reliable motor driving can be realized.
[0191]
In addition, according to the motor control device of the present invention, the fluctuation of the motor current is monitored, and the fluctuation is judged to be a disturbance occurrence and switched to an appropriate driving method. As a result, problems such as motor stop due to fluctuations in motor current can be prevented, and highly reliable motor driving can be realized.
[0192]
Further, according to the motor control device of the present invention, the fluctuation of the phase difference between the driving voltage and the motor current is monitored, and this fluctuation is judged as the occurrence of disturbance, and is switched to an appropriate driving method. As a result, problems such as motor stop due to fluctuations in the phase difference can be prevented, and highly reliable motor driving can be realized.
[0193]
Further, according to the motor control device of the present invention, the disturbance that affects the driving of the synchronous motor or the fluctuation of the signal that changes due to the disturbance is monitored, and the fluctuation is judged as the occurrence of the disturbance, and the appropriate driving is performed. You can switch to the method. As a result, it is possible to prevent a malfunction such as a motor stop accompanying fluctuations in various disturbances and to realize a highly reliable motor drive.
[0194]
Further, according to the motor control device of the present invention, 180 degree conduction drive with high efficiency, low noise, low vibration, and high driving performance is performed in a steady state with little disturbance, and the motor is stopped in a singular state with large disturbance. By selecting a small and highly reliable intermittent energization drive, high motor drive efficiency, low vibration, low noise, and high reliability can be realized.
[0195]
Further, according to the motor control device of the present invention, it is possible to switch the drive system accurately regardless of the rotation condition of the motor, and to improve the reliability of drive switching.
[0196]
In addition, according to the motor control device of the present invention, the driving method can be switched reliably, so that the reliability of driving switching can be improved.
[0197]
In addition, according to the motor control device of the present invention, it is possible to reliably detect the energization timing of the intermittent energization drive that can detect the back electromotive voltage. For this reason, the reliability of motor drive can be improved.
[0198]
Further, according to the motor control device of the present invention, it is possible to detect phase difference information with a simpler process and configuration than zero cross detection. Malfunctions can be reduced against fluctuations in noise and motor current. Further, by obtaining the area of the motor current and obtaining the phase difference information based on the ratio, highly reliable phase difference detection can be realized. In particular, in this area ratio detection, highly reliable phase difference detection can be realized with simple processing by using motor current sampling data obtained by a plurality of samplings.
[0199]
Further, according to the motor control device of the present invention, disturbance addition / subtraction obtained as a result of adding and subtracting a predetermined amount to the disturbance or disturbance signal input to the motor disturbance monitoring means is performed in the determination at the next disturbance or disturbance signal input. Can be used as threshold data. Therefore, when the disturbance signal deviates from the steady value, it is possible to realize a more accurate disturbance detection than the threshold data based on the steady value. Thereby, motor driving with high reliability can be realized.
[0200]
Further, according to the motor control device of the present invention, the determination timing of the steady state or the singular state in the motor disturbance monitoring means can be synchronized with the motor rotation. Therefore, accurate disturbance detection can be realized even when the disturbance fluctuation during one rotation of the motor is large. Thereby, motor driving with high reliability can be realized.
[0201]
Furthermore, according to the motor control device of the present invention, it is possible to prevent erroneous detection of disturbance detection by turning off disturbance detection during motor acceleration / deceleration, thereby realizing accurate disturbance detection. Thereby, motor driving with high reliability can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a motor control device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a driving waveform of sinusoidal energization that is an example of 180-degree energization driving.
FIG. 3 is a diagram illustrating a drive waveform of rectangular wave 120-degree energization, which is an example of intermittent energization drive.
FIG. 4 is a diagram illustrating a driving waveform of 150-degree energization driving, which is another example of intermittent energization driving.
FIG. 5 is a diagram showing a motor current waveform when a pulse for generating torque fluctuation is given.
FIG. 6 is a diagram showing a motor current waveform with respect to fluctuations in the DC power supply voltage of the inverter circuit 2;
FIG. 7 is a flowchart showing a processing flow of a motor disturbance monitoring unit 6 and a driving method selection unit 7 during intermittent energization driving.
FIG. 8 is a flowchart showing a processing flow of a motor disturbance monitoring unit 6 and a driving method selection unit 7 during intermittent energization driving.
FIG. 9 is a flowchart showing a processing flow of a motor disturbance monitoring unit 6 and a driving method selection unit 7 during intermittent energization driving.
FIG. 10 is a flowchart showing a flow of processing for shifting from 180 degree energization driving to intermittent energization driving.
FIG. 11 is a diagram showing an experimental result of an experiment of a transition from a 180-degree energization drive to an intermittent energization drive.
FIG. 12 is a flowchart for explaining a flow of processing for returning from intermittent energization driving to 180-degree energization driving.
FIG. 13 is a diagram showing an experimental result of an experiment of transition from intermittent energization driving to 180-degree energization driving.
FIG. 14 is a diagram for explaining an example of a specific configuration of the intermittent energization drive unit 8;
FIG. 15 is a diagram for explaining an example of a specific configuration of the 180-degree energization drive unit 9;
FIG. 16 is a diagram showing experimental results obtained in an experiment of driving a synchronous motor based on phase difference control.
FIG. 17 is a diagram illustrating an experimental result of an experiment in which a relationship between a drive voltage (PWM duty reference value) and phase difference information is measured.
FIG. 18 is a diagram for explaining detection of phase difference information.
FIG. 19 is a diagram for explaining the output of the motor disturbance monitoring unit 6 and the output of the drive method selection unit 7 when the power supply voltage fluctuates.
FIG. 20 is a diagram illustrating a relationship between a disturbance signal and threshold data set based on a steady value when the disturbance signal fluctuates.
FIG. 21 is a diagram illustrating a relationship between a disturbance signal and a disturbance adjustment value (threshold data) when the disturbance signal fluctuates.
FIG. 22 is a flowchart for explaining the flow of a disturbance detection process based on a disturbance adjustment value.
FIG. 23 is a diagram showing a relationship between a disturbance signal having a fluctuation synchronized with motor rotation and threshold data set based on a steady value.
FIG. 24 is a diagram illustrating a configuration example of a motor control device that performs disturbance detection in synchronization with motor rotation according to an embodiment of the present invention.
FIG. 25 is a diagram illustrating another configuration example of the motor control device that performs disturbance detection in synchronization with the motor rotation according to the embodiment of the present invention.
FIG. 26 is a diagram showing a relationship between threshold data set based on a steady value and a motor current (disturbance signal).
FIG. 27 is a diagram illustrating a configuration example of a motor control device that turns off disturbance detection during acceleration / deceleration of motor rotation according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Synchronous motor, 2 Inverter circuit, 3 Converter circuit, 4 AC power supply, 5 Control microcomputer, 6, 61, 62 Motor disturbance monitoring part, 7 Drive system selection part, 8 Intermittent conduction drive part, 9 180 degree conduction drive part, 10 Switch, 11 PWM creation / each phase distribution unit, 12 disturbance averaging unit, 141 magnetic pole position detection unit, 142 target speed information storage unit, 143 adder, 144 speed control gain unit, 151 current sensor, 152 motor current detection amplifier unit, 153 phase difference detection unit, 154 target phase difference information storage unit, 157 rotation speed setting unit, 158 sine wave data table, 159 sine wave data creation unit.

Claims (26)

In a motor control device that drives and controls a synchronous motor constituted by a rotor mounted with a permanent magnet and a driving means for driving the synchronous motor, without a position sensor,
180 degree energization driving means for energizing the synchronous motor 180 degrees;
The synchronous motor, the intermittent conduction drive means for intermittently energizing the drive below conductible angle 180 degrees,
Motor disturbance monitoring means for monitoring disturbance of the synchronous motor or the driving means;
Drive system selection means for selecting whether to drive the synchronous motor according to the output of the motor disturbance monitoring means as the 180-degree energization drive or the intermittent energization drive ;
The switching from the 180-degree energization drive to the intermittent energization drive includes an energization pause period in which all energization to the coil terminals is turned off, and the motor rotation position is determined from the back electromotive voltage induced in the coil terminals during the energization pause period. Is detected and the switching timing by the driving method selection means is calculated,
Switching from the intermittent energization drive to the 180-degree energization drive is a motor control device in which the switching timing by the drive method selection unit is calculated based on calculation of a sine wave phase with respect to the intermittent energization timing .   The motor control device according to claim 1, wherein an energization angle of the intermittent energization drive unit is 120 degrees. The driving means includes
An inverter for driving the synchronous motor;
The provided et the the inverter includes an AC power supply unit for supplying an AC power supply voltage,
The motor disturbance monitoring means is
The motor control device according to claim 1 or 2, wherein a DC power supply voltage in the inverter or an AC power supply voltage supplied by the AC power supply means is monitored. The motor disturbance monitoring means is
The motor control device according to claim 1, wherein the number of rotations of the synchronous motor is monitored. The motor disturbance monitoring means is
The motor control device according to claim 1, wherein torque of the synchronous motor is monitored. The motor disturbance monitoring means is
The motor control device according to claim 1, wherein the motor current of the synchronous motor is monitored. The motor disturbance monitoring means is
The motor control device according to claim 1, wherein a phase difference between a driving voltage of a specific phase of the synchronous motor and a motor current of the synchronous motor is monitored. The motor disturbance monitoring means is
The disturbance or the disturbance signal, which is any one or more of disturbances affecting driving of the synchronous motor or disturbance signals changing in synchronization with the disturbances, is monitored. 2. The motor control device according to 2. The motor disturbance monitoring means is
Detect whether it is steady or singular,
The driving method selection means includes
When the steady state is detected in the motor disturbance monitoring means, the 180-degree energization drive is switched, and when the singular state is detected, the intermittent energization drive is selected. The motor control device according to claim 1. The motor disturbance monitoring means is
Detect whether it is steady or singular,
The driving method selection means includes
In the motor disturbance monitoring means, when the steady state is detected, the 180-degree energization drive is selected, and when the singular state is detected, the intermittent energization drive is selected, and after the elapse of a predetermined time, the 180-degree energization drive is selected. 9. The motor control device according to claim 1, wherein energization driving is selected. The singular state is
The motor control device according to claim 9, wherein the motor control device is a fluctuation of a power supply voltage. The singular state is
11. The motor control device according to claim 9, wherein the motor control device is a change in the rotation speed of the synchronous motor or a change in the rotation speed. The singular state is
The motor control device according to claim 9, wherein the motor control device is a fluctuation in torque of the synchronous motor. The singular state is
The motor control device according to claim 9, wherein the motor control device is a fluctuation of a motor current of the synchronous motor. The singular state is
11. The motor control device according to claim 9, wherein the motor control device is a variation in a phase difference between a driving voltage of a specific phase of the synchronous motor and a motor current of the synchronous motor. The singular state is
The disturbance according to claim 9 or 10, wherein the disturbance is one or more disturbances or disturbance signal fluctuations among disturbances affecting the motor driving of the synchronous motor or disturbance signals changing in synchronization with the disturbances. The motor control apparatus described. The motor disturbance monitoring means is
Determine whether the steady state or the singular state based on predetermined threshold data,
The predetermined threshold data is
The motor control device according to claim 9, wherein the motor control device is changed according to a rotation condition of the synchronous motor. When the synchronous motor rotates at a low speed, when switching from the 180-degree energization drive to the intermittent energization drive, the rotational speed after the transition to the intermittent energization drive is set to the 180-degree energization drive. wherein the raised Rukoto than the rotational speed of the time, the motor control device according to any one of claims 1 to 17. The 180-degree energization drive is a drive that drives a motor by controlling current phase difference information that is a phase difference between a drive voltage applied to a motor terminal of a specific phase in the synchronous motor and a motor current flowing through the motor terminal. wherein the method der Rukoto, motor control device according to any one of claims 1 to 18. The current phase difference information is
The first motor current area, which is an integrated value of the motor current during the first phase period with reference to the drive voltage phase in the synchronous motor, and the second integrated value of the motor current during the second phase period. wherein the obtained Rukoto by calculating the ratio of the motor current area, the motor control device according to claim 19. The first motor current area is obtained by sampling the motor current during the first phase period a predetermined number of times and integrating the sampled current sampling data, and the second motor current area is the motor current during the second phase period predetermined number of times of sampling, and wherein Rukoto determined by integrating the current sampling data the sampled motor control device according to claim 20. The motor disturbance monitoring means is
Determine whether it is steady or singular based on threshold data,
That you use the motor disturbance monitoring means adding and subtracting the resulting disturbance adding or subtracting a predetermined amount to the input disturbance or a disturbance signal, as the threshold data in the determination of the next disturbance or when a disturbance signal input wherein the motor control device according to any one of claims 1 to 16. The motor disturbance monitoring means is
Determine whether it is steady or singular based on threshold data,
As the threshold data, a threshold value set based on disturbance addition / subtraction obtained as a result of adding and subtracting a predetermined amount to the disturbance or disturbance signal input to the motor disturbance monitoring means and a steady value of the disturbance or disturbance signal. characterized that you use the value data, the motor control device according to any one of claims 1 to 16. The motor disturbance monitoring means is
Determine whether it is steady or singular,
Determining timing of a steady state or specific condition in the motor disturbance monitoring means and Rukoto in synchronism with motor rotation, the motor control device according to any one of claims 1 to 16. Disturbance or a disturbance signal input to said motor disturbance monitoring means, n rotations of the synchronous motor (the n is an integer of 1 or more), characterized in averaged value and to Rukoto and claims 1 16 The motor control apparatus in any one of. The motor control device according to claim 1, wherein the motor disturbance monitoring unit is turned off during acceleration / deceleration of the synchronous motor .

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